CA1220152A - Process for production of light hydrocarbons by treatment of heavy hydrocarbons with water - Google Patents
Process for production of light hydrocarbons by treatment of heavy hydrocarbons with waterInfo
- Publication number
- CA1220152A CA1220152A CA000442994A CA442994A CA1220152A CA 1220152 A CA1220152 A CA 1220152A CA 000442994 A CA000442994 A CA 000442994A CA 442994 A CA442994 A CA 442994A CA 1220152 A CA1220152 A CA 1220152A
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- CA
- Canada
- Prior art keywords
- zone
- water
- heavy
- light
- phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G21/00—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
- C10G21/06—Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents characterised by the solvent used
- C10G21/08—Inorganic compounds only
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G31/00—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for
- C10G31/08—Refining of hydrocarbon oils, in the absence of hydrogen, by methods not otherwise provided for by treating with water
Abstract
ABSTRACT
PROCESS FOR PRODUCTION OF LIGHT HYDROCARBONS BY
TREATMENT OF HEAVY HYDROCARBONS WITH WATER
A process for converting heavy hydrocarbons into light hydrocarbons which comprises contacting, in a first zone, a heavy hydrocarbon having an API gravity at 25°C of less than about 20, such as Boscan heavy crude oil and tar sand bitumen, with a liquid comprising water, in the absence of externally added catalyst and hydrogen, while maintaining the first zone at a tempera-ture between about 380° and about 480°C and at a pres-sure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 atm), for a time sufficient to produce a uniform reac-tion mixture; forwarding the uniform reaction mixture to a second zone wherein the temperature and pressure con-ditions of the first zone are maintained for a time suf-ficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water, withdrawing the residue and said phase from the second zone; and recovering a light hydrocarbon product having an API gravity at 25°C of greater than about 20 and substantially free of vanadium and nickel values, i.e., less than 50 ppm, preferably less than 30 ppm, a gaseous product, and a residue is disclosed.
PROCESS FOR PRODUCTION OF LIGHT HYDROCARBONS BY
TREATMENT OF HEAVY HYDROCARBONS WITH WATER
A process for converting heavy hydrocarbons into light hydrocarbons which comprises contacting, in a first zone, a heavy hydrocarbon having an API gravity at 25°C of less than about 20, such as Boscan heavy crude oil and tar sand bitumen, with a liquid comprising water, in the absence of externally added catalyst and hydrogen, while maintaining the first zone at a tempera-ture between about 380° and about 480°C and at a pres-sure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 atm), for a time sufficient to produce a uniform reac-tion mixture; forwarding the uniform reaction mixture to a second zone wherein the temperature and pressure con-ditions of the first zone are maintained for a time suf-ficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water, withdrawing the residue and said phase from the second zone; and recovering a light hydrocarbon product having an API gravity at 25°C of greater than about 20 and substantially free of vanadium and nickel values, i.e., less than 50 ppm, preferably less than 30 ppm, a gaseous product, and a residue is disclosed.
Description
~, ~L
~ESCRIPTION
PROCESS FOR PRODUCTION OF LIGHT HYDROCARBONS BY
TREATMENT OF HEAVY HYDROCARBONS WITH WATER
BACKGROUND OF THE INVENTION
The present invention relates to a process for treating heavy hydrocarbons with water to form ligllt hydrocarbons, a gaseous product and a residue. More particularly, the present invention is directed to a process for treating heavy hydrocarbons containing organometallics, for example vanadium and nickel, organosulfur and organonitrogen compounds, and asphalt-enes with water at elevated temperatures and pressures, in the absence of externally added catalyst and hydro-yen, for a time sufficient to form a light hydrocarbon product, substantially free of vanadium and nickel, a gaseous product and a residue.
There exist enormous quantities of heavy hydrocar-bons such as heavy petroleum crude oils and tar sand bitumen (the heavy hydrocarbons extracted from tar sands), as well as residual heavy hydrocarbon fractions obtained from heavy hydrocarbon crudes such as atmos-pheric tower bottoms products, vacuum tower bottoms products, crude oil residuum and heavy vacuum gas oils. These heavy crude and residual hydrocarbon streams contain large amounts of organometallic com-pounds, especially those containing nickel and vanadium, !~
,i ,~1" ~
~;~2~
organosulfur and organonitrogen compounds, and asphalt-enes (high molecular weight polycyclic, pentane insolu-ble materials). In addition, these heavy crude and residual hydrocarbons are viscous and as such require a greater degree of processing to convert them into liquid materials that can be transported easily.
A number of alternate physical and chemical routes have been and are still being developed for converting heavy hydrocarbon materials into lighter liquid and gas-eous fuels. Among the approaches are physical separa-tion processes such as vacuum distillationl steam dis-tillation, and solvent deasphalting, various thermal conversion processes such as visbreaking, delayed cok-ing, fluid coking and coke gasification, catalytic pro-cesses such as hydrotreating, hydrorefining and hydro-cracking, as well as multistage catalytic and non-catalytic processes. Each of these approaches has one or more drawbacks. In physical separation processes such as vacuum distillation, steam distillation and sol-vent deasphalting, a liquid hydrocarbon fraction isrecovered in low yield but the asphaltene and resinous materials are not converted into product and must be disposed of separately. The various thermal conversion processes such as visbreaking, delayed coking, fluid coking and coke gasification require high temperatures above 500C and yenerate a low quality by-product coke. In coke gasification, treatment of heavy hydro-carbons with steam and oxygen at high temperatures is necessary to produce a product gas, which must be uti-lized locally, and a limited yield of lighter liquid hydrocarbon product. Recently, a thermal conversion i process called the Eureka process was disclosed in Chemical Engineering Progress, Februar~ L, ~ages 37-44 and in U.S. Patent 4,242,196. The Eureka process converts petroleum residues, such as mixtures of vacuum residues from Khafij crude oil, or Iranian heavy crude oil, into a low sulfur petroleum oil and petroleum pitch by preheating the mixture of vacuum residues to about ~2;2~15~
450 to 520C, feeding the preheated mixture to a frac-tionator and then to a charge heater at 500C before stripping the thermally cracked low molecular weight hydrocarbons with superheated steam in a delayed coker reactor at 420-430C under atmospheric pressure~ Cata-lytic hydrogenation processes such as hydrotreating, hydrorefining, and hydrocracking may be used for con-verting heavy hydrocarbon feedstocks into a good quality material in high yield. However the hydrogenation cata-lyst employed in each of these processes is rapidly poi-soned by the exceedingly large amounts of organometallic compounds and asphaltenic material in the heavy hydro-carbon feedstocks. The high levels of organometallic compounds in the feedstocks interfere considerably with the activity of the catalyst with respect to destructive removal of nitrogen and sulfur and oxygenated compounds such that the consumption of more than 3 kilograms of catalyst per 1000 kilograms of oil processed is normally required.
The prior art has also converted organic heavy hydrocarbons and other organic liquids to fuels by reac-tion with water. U.S. Patent No. 4,113,446 (Modell et al.) discloses that liquid or solid organic materials can be converted into high BTU gas, with little or no formation of undesirable char or coke, when organic material is reacted with water at a temperature at or above the critical temperature of water and at or above the critical pressure of water to achieve the critical density of water. While U.S. Patent 4,113,446 discloses that the process may be conducted either in the presence or absence of a catalyst, only gas and no liquid hydro-carbon Eractions are recovered. International Publica-tion No. WO 81/00855 discloses that organic solid or liquid material is admixed with water (in the region of the critical density of water, i.e., densities of water from 0.2 to 0.7 gms/cm3) at pressures from 200-2500 atoms-_4~ 52 pheres and at temperatures from 374C to at least about450C to restructure the organic mat~rials to form use-ful volatile organic liquids.
U.S. Patent No. 3,983,027 tMcCollum et al.) dis-closes a process for cracking, desulf~rizing anddemetallizing heavy hydrocarbon feed~tocks such as vacuum gas oil, tar sand oils and at~ospheric residual oils to produce gases, liquids (heavy ends and light ends), and a solid residue by contacting the heavy hydrocarbons with a dense-water containing fluid at a temperature in the range of 349C to 400C (660-752F) and at a pressure in the range of 2S~0 psig to 4400 psig in the absence of an externally supplied catalyst and hydrogen or other reducing gas. The density of water in the dense-water containing fluid was at least about 0.1 g/mL, and sufficient water was present to serve as an effective solvent for recovered liquids and gases. How-ever, in the examples which disclose a process for removal of vanadium and nickel, straight tar sands hav-ing no more than 256 ppm of vanadium and nickel weretreated with water at 400C and 4100-4350 psig for at least one hour. To produce a hydrocarbon product having an API density of 21 and low (10 ppml nickel and vana-dium content, the presence of alundum balls in the reac-tion zone at 400C and 4100 psig and extremely low flowrates (1 mL of tar sands and oil per ~our) were required. In another example run under identical condi-tions except that the flow rate was 2 mL/hour, the hydrocarbon product had an API density of 17.8 and an unacceptably higher (77 ppm) nickel and vanadium con-tent.
U.S. Patent No. 2,135,332 (Gary~ discloses a pro-cess for the cracking of relatively heavy oil, such as reduced crude, other heavy oils of residual nature or a heavy gas oil consisting principally of constituents boiling above 700F to produce gases, liquids (lower boiling hydrocarbons of the gasoline range) and a solid or liquid residue including coke by admixing the heavy -5~ 2 oil with a diluent such as steam, low boiling hydrocar-bon gases or fixed gases at temperatures in the range of 650-975F (343-524C) and at pressures as low as 300 lbs/sq in, preferably in the neiyhborhood of 2,000-3,000 lbs/sq in. Gary discloses the admixture is treated in three coils in a furnace; the admixture is preheated to a temperature just below the cracking temperature, such as 650-700F (343-371C), followed by passing the pre-heated mixture to a zone wherein it i5 rapidly heated to a temperature in excess of 900F (>482C) followed by heating in another portion of the furnace at a tempera-ture below the cracking temperature wherein the desired conversion is carried to completion. The converted products from the furnace are passed through a pressure 15 letdown valve and forwarded thence to an evaporator where vapors separate from a residue which may be solid coke or liquid. In the evaporator the residue is sepa-rated from the vapors and the vapors are forwarded to a fractionation zone to separate out the higher boiling 20 components and recover liquid boiling in the gasoline range. Further, Gary discloses that coke is formed within the heating coil by conversion of heavy asphaltenes and viscous materials due to the higher tem-perature and prolonged heating within the heating zone, 25 but that less coking difficulties are encountered within the heating coil when operating under his high tempera-ture (>480C) and high pressure (2000-3000 psi) condi-tions than are encountered under low temperature, low pressure conditions. However, Gary does not suggest a 30 method of converting heavy oil containing high metal values, e.g., nickel and vanadium, into a light hydro-carbon oil substantially free of such metal values. e In addition, there are various catalytic processes for treating heavy hydrocarbons with water with specific 35 externally supplied catalyst systems and externally sup-plied hydrogen at specified temperatures above the cri-tical temperature of water and at specified pressures, from below to above the critical pressure of water.
-6-- 122~15~ `
SUMMARY OF THE INVENTION
It has been discovered that heavy hydrocarbons feedstocks containing vanadium and nickel values, may be converted into light hydrocarbon products substantially free of vanadium and nickel values by contacting the heavy hydrocarbon feedstocks with water, in the absence of externally added catalyst and hydrogen, at selected pressure and temperature ranges. The pressure range selected to produce a light hydrocarbon product substan-tially free of vanadium and nickel values depended uponthe heavy hydrocarbon feedstock; thereafter, temperature range was selected to provide a sufficient quantity of light hydrocarbon product at acceptable reaction rates while avoiding coke formation. Accordingly, the present invention provides a process for converting heavy hydro-carbons into light hydrocarbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25C of less than about 20 with a liquid comprising water, in the absence of exter-nally added catalyst and hydrogen, at a temperaturebetween about 380C - 480C and at a pressure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 atm), and for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of 30 the first zone, in the absence of externally added cata- ¦~
lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and light hydrocarbon product having an API gravity at 25C of greater than about 20 -7~ 2~
and substantially free of vanadium and nickel values;
and (f) recovering said light hydrocarbon product.
The present invention also provides a process for 5 converting heavy hydrocarbons into light hydrocarbons which compriseso (a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25C of less than about 20 and a total vanadium and nickel content between about 10 1000 and 2000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380C and about 480C, and at a pressure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 15 atm) for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second 20 zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and light hydrocarbon product having an API gravity at 25C of between about 20 and ~0 30 and substantially free of vanadium and nickel values;
and (f) reco~rering said light hydrocarbon product.
The present invention still further provides a pro-cess for converting heavy hydrocarbons into light hydro-35 carbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25C of less than about 20 and a total vanadium and nickel content of between about -8-- ~2~
100 and 1000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380 and 480C and at a pres-sure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psiy, about 148 atm) for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and light hydrocarbon product 20 having an API gravity at 25C of between about 20 and 40 and substantially free of vanadium and nickel values;
and (f) recovering said light hydrocarbon product.
BRIEF DESCRIPTION OF THE DRAWI~GS
Figure 1 graphically displays the variation of the vanadium and nickel concentration in the light hydrocar-bon product obtained by treatment, in a semi-continuous reactor, of a Boscan heavy oil with water at 410C as a function of pressure.
Figure 2 graphically displays the variation of the API gravity and viscosity (at 25C) of the light hydro-carbon product obtained by treatment, in a semi-continu-ous reactor, of a Boscan heavy oil with water at 410C
as a function of pressure.
Yigure 3 is a schematic of a preferred embodiment of the process of the present invention operated in a flow reactor.
Figure 4 is a schematic of another preferred embod-9 ~2~
-iment of the process of the present invention operated in a flow reactor.
DETAILED DESCRIPTION OF THE INVENTION AND
OF THE PREFERRED EMBODIMENTS
-In accordance with the present invention, heavy hydrocarbons having an API gravity at 25C of less than about 20 are treated with water under elevated tempera-ture and pressures in the absence of externally added catalyst and/or hydrogen to produce a light hydrocarbon product having an API gravity at 25C of greater than about 20 and substantially free of vanadium and nickel values. The light hydrocarbon product, substantially free of vanadium and nickel values, has a carbon number distribution similar to that of gasoline, kerosene and diesel oil and as such can be catalytically reformed, at low catalyst consumption rates, into kerosene, diesel oil and gasoline, compared to heavy hydrocarbon feed-stocks. By the term "substantially free of vanadium and nickel values" is meant a light hydrocarbon product containing generally less than about 50 ppm of vanadium and nickel values and as such suitable for catalyic reforming, at low catalyst consumption rates, compared to heavy hydrocarbon feedstocks. In addition, the light hydrocarbon product has a lower specific gravity (API
gravity at 25C greater than about 20), a lower viscos-ity and is usually substantially free of nitrogen and usually contains only about 75% of the sulfur contained in the heavy hydrocarbon starting material. ~urpris-ingly, it was discovered that the concentration of the vanadium and nickel in, and the values of the specific gravity and viscosity for the light hydrocarbon product were minimized by operating within the pressure range of the process of the present invention; See Figures l and
~ESCRIPTION
PROCESS FOR PRODUCTION OF LIGHT HYDROCARBONS BY
TREATMENT OF HEAVY HYDROCARBONS WITH WATER
BACKGROUND OF THE INVENTION
The present invention relates to a process for treating heavy hydrocarbons with water to form ligllt hydrocarbons, a gaseous product and a residue. More particularly, the present invention is directed to a process for treating heavy hydrocarbons containing organometallics, for example vanadium and nickel, organosulfur and organonitrogen compounds, and asphalt-enes with water at elevated temperatures and pressures, in the absence of externally added catalyst and hydro-yen, for a time sufficient to form a light hydrocarbon product, substantially free of vanadium and nickel, a gaseous product and a residue.
There exist enormous quantities of heavy hydrocar-bons such as heavy petroleum crude oils and tar sand bitumen (the heavy hydrocarbons extracted from tar sands), as well as residual heavy hydrocarbon fractions obtained from heavy hydrocarbon crudes such as atmos-pheric tower bottoms products, vacuum tower bottoms products, crude oil residuum and heavy vacuum gas oils. These heavy crude and residual hydrocarbon streams contain large amounts of organometallic com-pounds, especially those containing nickel and vanadium, !~
,i ,~1" ~
~;~2~
organosulfur and organonitrogen compounds, and asphalt-enes (high molecular weight polycyclic, pentane insolu-ble materials). In addition, these heavy crude and residual hydrocarbons are viscous and as such require a greater degree of processing to convert them into liquid materials that can be transported easily.
A number of alternate physical and chemical routes have been and are still being developed for converting heavy hydrocarbon materials into lighter liquid and gas-eous fuels. Among the approaches are physical separa-tion processes such as vacuum distillationl steam dis-tillation, and solvent deasphalting, various thermal conversion processes such as visbreaking, delayed cok-ing, fluid coking and coke gasification, catalytic pro-cesses such as hydrotreating, hydrorefining and hydro-cracking, as well as multistage catalytic and non-catalytic processes. Each of these approaches has one or more drawbacks. In physical separation processes such as vacuum distillation, steam distillation and sol-vent deasphalting, a liquid hydrocarbon fraction isrecovered in low yield but the asphaltene and resinous materials are not converted into product and must be disposed of separately. The various thermal conversion processes such as visbreaking, delayed coking, fluid coking and coke gasification require high temperatures above 500C and yenerate a low quality by-product coke. In coke gasification, treatment of heavy hydro-carbons with steam and oxygen at high temperatures is necessary to produce a product gas, which must be uti-lized locally, and a limited yield of lighter liquid hydrocarbon product. Recently, a thermal conversion i process called the Eureka process was disclosed in Chemical Engineering Progress, Februar~ L, ~ages 37-44 and in U.S. Patent 4,242,196. The Eureka process converts petroleum residues, such as mixtures of vacuum residues from Khafij crude oil, or Iranian heavy crude oil, into a low sulfur petroleum oil and petroleum pitch by preheating the mixture of vacuum residues to about ~2;2~15~
450 to 520C, feeding the preheated mixture to a frac-tionator and then to a charge heater at 500C before stripping the thermally cracked low molecular weight hydrocarbons with superheated steam in a delayed coker reactor at 420-430C under atmospheric pressure~ Cata-lytic hydrogenation processes such as hydrotreating, hydrorefining, and hydrocracking may be used for con-verting heavy hydrocarbon feedstocks into a good quality material in high yield. However the hydrogenation cata-lyst employed in each of these processes is rapidly poi-soned by the exceedingly large amounts of organometallic compounds and asphaltenic material in the heavy hydro-carbon feedstocks. The high levels of organometallic compounds in the feedstocks interfere considerably with the activity of the catalyst with respect to destructive removal of nitrogen and sulfur and oxygenated compounds such that the consumption of more than 3 kilograms of catalyst per 1000 kilograms of oil processed is normally required.
The prior art has also converted organic heavy hydrocarbons and other organic liquids to fuels by reac-tion with water. U.S. Patent No. 4,113,446 (Modell et al.) discloses that liquid or solid organic materials can be converted into high BTU gas, with little or no formation of undesirable char or coke, when organic material is reacted with water at a temperature at or above the critical temperature of water and at or above the critical pressure of water to achieve the critical density of water. While U.S. Patent 4,113,446 discloses that the process may be conducted either in the presence or absence of a catalyst, only gas and no liquid hydro-carbon Eractions are recovered. International Publica-tion No. WO 81/00855 discloses that organic solid or liquid material is admixed with water (in the region of the critical density of water, i.e., densities of water from 0.2 to 0.7 gms/cm3) at pressures from 200-2500 atoms-_4~ 52 pheres and at temperatures from 374C to at least about450C to restructure the organic mat~rials to form use-ful volatile organic liquids.
U.S. Patent No. 3,983,027 tMcCollum et al.) dis-closes a process for cracking, desulf~rizing anddemetallizing heavy hydrocarbon feed~tocks such as vacuum gas oil, tar sand oils and at~ospheric residual oils to produce gases, liquids (heavy ends and light ends), and a solid residue by contacting the heavy hydrocarbons with a dense-water containing fluid at a temperature in the range of 349C to 400C (660-752F) and at a pressure in the range of 2S~0 psig to 4400 psig in the absence of an externally supplied catalyst and hydrogen or other reducing gas. The density of water in the dense-water containing fluid was at least about 0.1 g/mL, and sufficient water was present to serve as an effective solvent for recovered liquids and gases. How-ever, in the examples which disclose a process for removal of vanadium and nickel, straight tar sands hav-ing no more than 256 ppm of vanadium and nickel weretreated with water at 400C and 4100-4350 psig for at least one hour. To produce a hydrocarbon product having an API density of 21 and low (10 ppml nickel and vana-dium content, the presence of alundum balls in the reac-tion zone at 400C and 4100 psig and extremely low flowrates (1 mL of tar sands and oil per ~our) were required. In another example run under identical condi-tions except that the flow rate was 2 mL/hour, the hydrocarbon product had an API density of 17.8 and an unacceptably higher (77 ppm) nickel and vanadium con-tent.
U.S. Patent No. 2,135,332 (Gary~ discloses a pro-cess for the cracking of relatively heavy oil, such as reduced crude, other heavy oils of residual nature or a heavy gas oil consisting principally of constituents boiling above 700F to produce gases, liquids (lower boiling hydrocarbons of the gasoline range) and a solid or liquid residue including coke by admixing the heavy -5~ 2 oil with a diluent such as steam, low boiling hydrocar-bon gases or fixed gases at temperatures in the range of 650-975F (343-524C) and at pressures as low as 300 lbs/sq in, preferably in the neiyhborhood of 2,000-3,000 lbs/sq in. Gary discloses the admixture is treated in three coils in a furnace; the admixture is preheated to a temperature just below the cracking temperature, such as 650-700F (343-371C), followed by passing the pre-heated mixture to a zone wherein it i5 rapidly heated to a temperature in excess of 900F (>482C) followed by heating in another portion of the furnace at a tempera-ture below the cracking temperature wherein the desired conversion is carried to completion. The converted products from the furnace are passed through a pressure 15 letdown valve and forwarded thence to an evaporator where vapors separate from a residue which may be solid coke or liquid. In the evaporator the residue is sepa-rated from the vapors and the vapors are forwarded to a fractionation zone to separate out the higher boiling 20 components and recover liquid boiling in the gasoline range. Further, Gary discloses that coke is formed within the heating coil by conversion of heavy asphaltenes and viscous materials due to the higher tem-perature and prolonged heating within the heating zone, 25 but that less coking difficulties are encountered within the heating coil when operating under his high tempera-ture (>480C) and high pressure (2000-3000 psi) condi-tions than are encountered under low temperature, low pressure conditions. However, Gary does not suggest a 30 method of converting heavy oil containing high metal values, e.g., nickel and vanadium, into a light hydro-carbon oil substantially free of such metal values. e In addition, there are various catalytic processes for treating heavy hydrocarbons with water with specific 35 externally supplied catalyst systems and externally sup-plied hydrogen at specified temperatures above the cri-tical temperature of water and at specified pressures, from below to above the critical pressure of water.
-6-- 122~15~ `
SUMMARY OF THE INVENTION
It has been discovered that heavy hydrocarbons feedstocks containing vanadium and nickel values, may be converted into light hydrocarbon products substantially free of vanadium and nickel values by contacting the heavy hydrocarbon feedstocks with water, in the absence of externally added catalyst and hydrogen, at selected pressure and temperature ranges. The pressure range selected to produce a light hydrocarbon product substan-tially free of vanadium and nickel values depended uponthe heavy hydrocarbon feedstock; thereafter, temperature range was selected to provide a sufficient quantity of light hydrocarbon product at acceptable reaction rates while avoiding coke formation. Accordingly, the present invention provides a process for converting heavy hydro-carbons into light hydrocarbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25C of less than about 20 with a liquid comprising water, in the absence of exter-nally added catalyst and hydrogen, at a temperaturebetween about 380C - 480C and at a pressure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 atm), and for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of 30 the first zone, in the absence of externally added cata- ¦~
lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and light hydrocarbon product having an API gravity at 25C of greater than about 20 -7~ 2~
and substantially free of vanadium and nickel values;
and (f) recovering said light hydrocarbon product.
The present invention also provides a process for 5 converting heavy hydrocarbons into light hydrocarbons which compriseso (a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25C of less than about 20 and a total vanadium and nickel content between about 10 1000 and 2000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380C and about 480C, and at a pressure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 15 atm) for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second 20 zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and light hydrocarbon product having an API gravity at 25C of between about 20 and ~0 30 and substantially free of vanadium and nickel values;
and (f) reco~rering said light hydrocarbon product.
The present invention still further provides a pro-cess for converting heavy hydrocarbons into light hydro-35 carbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25C of less than about 20 and a total vanadium and nickel content of between about -8-- ~2~
100 and 1000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380 and 480C and at a pres-sure between about 5000 kPa (about 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psiy, about 148 atm) for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and light hydrocarbon product 20 having an API gravity at 25C of between about 20 and 40 and substantially free of vanadium and nickel values;
and (f) recovering said light hydrocarbon product.
BRIEF DESCRIPTION OF THE DRAWI~GS
Figure 1 graphically displays the variation of the vanadium and nickel concentration in the light hydrocar-bon product obtained by treatment, in a semi-continuous reactor, of a Boscan heavy oil with water at 410C as a function of pressure.
Figure 2 graphically displays the variation of the API gravity and viscosity (at 25C) of the light hydro-carbon product obtained by treatment, in a semi-continu-ous reactor, of a Boscan heavy oil with water at 410C
as a function of pressure.
Yigure 3 is a schematic of a preferred embodiment of the process of the present invention operated in a flow reactor.
Figure 4 is a schematic of another preferred embod-9 ~2~
-iment of the process of the present invention operated in a flow reactor.
DETAILED DESCRIPTION OF THE INVENTION AND
OF THE PREFERRED EMBODIMENTS
-In accordance with the present invention, heavy hydrocarbons having an API gravity at 25C of less than about 20 are treated with water under elevated tempera-ture and pressures in the absence of externally added catalyst and/or hydrogen to produce a light hydrocarbon product having an API gravity at 25C of greater than about 20 and substantially free of vanadium and nickel values. The light hydrocarbon product, substantially free of vanadium and nickel values, has a carbon number distribution similar to that of gasoline, kerosene and diesel oil and as such can be catalytically reformed, at low catalyst consumption rates, into kerosene, diesel oil and gasoline, compared to heavy hydrocarbon feed-stocks. By the term "substantially free of vanadium and nickel values" is meant a light hydrocarbon product containing generally less than about 50 ppm of vanadium and nickel values and as such suitable for catalyic reforming, at low catalyst consumption rates, compared to heavy hydrocarbon feedstocks. In addition, the light hydrocarbon product has a lower specific gravity (API
gravity at 25C greater than about 20), a lower viscos-ity and is usually substantially free of nitrogen and usually contains only about 75% of the sulfur contained in the heavy hydrocarbon starting material. ~urpris-ingly, it was discovered that the concentration of the vanadium and nickel in, and the values of the specific gravity and viscosity for the light hydrocarbon product were minimized by operating within the pressure range of the process of the present invention; See Figures l and
2. As additional advantages of the present invention, there is produced a minimum amount of gaseous product as well as a residue that is usually soluble in the heavy hydrocarbon starting material and that contains no coke or pitch which would interfere with the operation of the present invention. All of these advantages are achieved by the process of the present invention in the absence of externally added catalyst and/or hydrogen.
The temperature of the first and second zones is between about 380 and about 480C, preferably between about 400 and about 470C and more preferably between about 430 and 460C. The pressure of the first and second zones is between about 5000 kPa tabout 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 atm), preferably between about 7,000 kPa (about 1015 psig, about 69 atm) and about 13,000 kPa (about 1885 psig, about 128 atm) and more preferably between about 9000 kPa (about 1305 psig, about 89 atm) and 13,000 kPa ~about 1885 psig, about 128 atm).
It is a feature of the present invention that the range of temperature and pressure recited hereinabove is maintained in both the first and second zones. In the first zone the heavy hydrocarbons are contacted with a liquid comprising water under temperature and pressure conditions and for a time sufficient to form a uniform mixture. The uniform mixture is forwarded to a second zone while maintaining the temperature and pressure con-ditions of the first zone. In the second zone the uni-form mixture is maintained under temperature and pres-sure conditions of the first zone for a time sufficientto separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water. It is a special feature of the present invention that the separation step is effected while maintaining the tem-perature and pressure conditions of the first zone inthe second zone. The residue and the phase in the form of vapors comprising light hydrocarbons, gas and water are withdrawn from the second zone at the temperature and pressure of the first zone. In a preferred embodi-ment of the present invention, the phase comprising thevapor phase withdrawn from the second zone is separated into a gaseous product, a liquid comprising water and light hydrocarbon products, and the liquid hydrocarbon product is recovered. In another preferred embodiMent of the present invention, the separation of the vapor phase into its components is effected by reducing the pressure and temperature of the second zone to values sufficient to allow phase separation. In another pre-ferred embodiment of the present invention, the phase separation is effected at the temperature and pressure values maintained in the second zone and only after the liquid hydrocarbons are removed from the gas and the liquid comprising water is the pressure and temperature reduced to ambient values.
By the term "uniform mixture" as used herein, is meant an emulsion, or a solution of vapors in liquid or of vapors in vapor or liquid in liquid or any mi~ture thereof sufficient to provide intimate contacting so as to facilitate conversion of the heavy hydrocarbons into light hydrocarbon product.
By the term "phase" as used herein to describe the phase comprising the liquid hydrocarbons, gas and water that are formed and removed from the second zone, is meant a mixture of vapor and liquid or vapor, gas and liquid or all vapors.
Surprisingly, when the heavy hydrocarbons were treated with water at between 370 and 460C and at atmospheric pressure, the atmospheric steam distillation process produced only a small amount of hydrocarbon extract having a high (50-200 ppm) vanadium and nickel. When the heavy hydrocarbons were treated in the semi-continuous reactor with water at 410C and pres-30 sures in excess of 15,000 kPa (2175 psig), such as 17,238 kPa (2500 psig), a higher yield of light hydro-carbons (about 72%) was obtained than when the pressure was maintained at no more than about 13,782 kPa (about 2000 psig). However/ when a heavy hydrocarbon, Boscan heavy crude oil, was treated with water at 410C and at a preferred range pressure of about 9000 kPa to 13,000 kPa (1305 psig to about 1885 psiy), a light hydrocarbon product was obtained containing less vanadium and nickel -12~
and having a lower viscosity and density (the inverse of API gravity) than the light hydrocarbon produced when the heavy hydrocarbon Boscan heavy oil was treated with water, in a semi-continuous reactor at 410C and at pressures greater than 15,000 kPa (2175 psig), for exam-ple 17,235 to 24,129 kPa (2500 to 3500 psig). The results (illustrated in Figure 1) of the variation of the vanadium and nickel concentration in light hydrocar-bon product obtained by treatment of Boscan heavy oil with water in a semi-continuous reactor at 410C under varying pressure conditions are expected to be similar if Boscan heavy oil or tar sand bitumen were treated with water in the flow reactor illustrated in Figures 3 or 4. Similarly, the results (illustrated in Figure 2) of the variation of the API gravity and viscosity (25C) of the light hydrocarbon product obtained by treatment of Boscan heavy oil with water in a semi-continuous reactor at 410C under varying pressure conditions are expected to be similar if Boscan heavy oil or tar sand bitumen were treated with water in the flow reactor illustrated in Figure 3 or 4.
The water to oil volume ratio may be varied from about 1:2 to about 10:1, preferably about 1:1 to about
The temperature of the first and second zones is between about 380 and about 480C, preferably between about 400 and about 470C and more preferably between about 430 and 460C. The pressure of the first and second zones is between about 5000 kPa tabout 725 psig, about 49 atm) and about 15,000 kPa (about 2175 psig, about 148 atm), preferably between about 7,000 kPa (about 1015 psig, about 69 atm) and about 13,000 kPa (about 1885 psig, about 128 atm) and more preferably between about 9000 kPa (about 1305 psig, about 89 atm) and 13,000 kPa ~about 1885 psig, about 128 atm).
It is a feature of the present invention that the range of temperature and pressure recited hereinabove is maintained in both the first and second zones. In the first zone the heavy hydrocarbons are contacted with a liquid comprising water under temperature and pressure conditions and for a time sufficient to form a uniform mixture. The uniform mixture is forwarded to a second zone while maintaining the temperature and pressure con-ditions of the first zone. In the second zone the uni-form mixture is maintained under temperature and pres-sure conditions of the first zone for a time sufficientto separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water. It is a special feature of the present invention that the separation step is effected while maintaining the tem-perature and pressure conditions of the first zone inthe second zone. The residue and the phase in the form of vapors comprising light hydrocarbons, gas and water are withdrawn from the second zone at the temperature and pressure of the first zone. In a preferred embodi-ment of the present invention, the phase comprising thevapor phase withdrawn from the second zone is separated into a gaseous product, a liquid comprising water and light hydrocarbon products, and the liquid hydrocarbon product is recovered. In another preferred embodiMent of the present invention, the separation of the vapor phase into its components is effected by reducing the pressure and temperature of the second zone to values sufficient to allow phase separation. In another pre-ferred embodiment of the present invention, the phase separation is effected at the temperature and pressure values maintained in the second zone and only after the liquid hydrocarbons are removed from the gas and the liquid comprising water is the pressure and temperature reduced to ambient values.
By the term "uniform mixture" as used herein, is meant an emulsion, or a solution of vapors in liquid or of vapors in vapor or liquid in liquid or any mi~ture thereof sufficient to provide intimate contacting so as to facilitate conversion of the heavy hydrocarbons into light hydrocarbon product.
By the term "phase" as used herein to describe the phase comprising the liquid hydrocarbons, gas and water that are formed and removed from the second zone, is meant a mixture of vapor and liquid or vapor, gas and liquid or all vapors.
Surprisingly, when the heavy hydrocarbons were treated with water at between 370 and 460C and at atmospheric pressure, the atmospheric steam distillation process produced only a small amount of hydrocarbon extract having a high (50-200 ppm) vanadium and nickel. When the heavy hydrocarbons were treated in the semi-continuous reactor with water at 410C and pres-30 sures in excess of 15,000 kPa (2175 psig), such as 17,238 kPa (2500 psig), a higher yield of light hydro-carbons (about 72%) was obtained than when the pressure was maintained at no more than about 13,782 kPa (about 2000 psig). However/ when a heavy hydrocarbon, Boscan heavy crude oil, was treated with water at 410C and at a preferred range pressure of about 9000 kPa to 13,000 kPa (1305 psig to about 1885 psiy), a light hydrocarbon product was obtained containing less vanadium and nickel -12~
and having a lower viscosity and density (the inverse of API gravity) than the light hydrocarbon produced when the heavy hydrocarbon Boscan heavy oil was treated with water, in a semi-continuous reactor at 410C and at pressures greater than 15,000 kPa (2175 psig), for exam-ple 17,235 to 24,129 kPa (2500 to 3500 psig). The results (illustrated in Figure 1) of the variation of the vanadium and nickel concentration in light hydrocar-bon product obtained by treatment of Boscan heavy oil with water in a semi-continuous reactor at 410C under varying pressure conditions are expected to be similar if Boscan heavy oil or tar sand bitumen were treated with water in the flow reactor illustrated in Figures 3 or 4. Similarly, the results (illustrated in Figure 2) of the variation of the API gravity and viscosity (25C) of the light hydrocarbon product obtained by treatment of Boscan heavy oil with water in a semi-continuous reactor at 410C under varying pressure conditions are expected to be similar if Boscan heavy oil or tar sand bitumen were treated with water in the flow reactor illustrated in Figure 3 or 4.
The water to oil volume ratio may be varied from about 1:2 to about 10:1, preferably about 1:1 to about
3:1 and more preferably about 1:1.
The process of the present invention operates in the absence of externally added catalyst and/or hydro-gen; only the hydrogen provided from the water in the absence of externally added catalyst is required for the process of the present invention. In some instances it may be desirable to provide the first and/or second zones with a packed bed of inert materials such as particles of granite, sand, porcelain or bed saddles.
The use of inert materials in first and/or second zones is not critical to operation of the present invention.
In addition, it is preferable to operate the process of the present invention in an atmosphere substantially free of gases such as oxygen which may interfere with the process of the present invention. However, the -13~-presence of small amounts of air are not detri~ental to the process of the present invention.
Deuterium labeling experiments were condu~ted by treatment of heavy hydrocarbons such as Boscan heavy oil with deuterium oxide under conditions of the present invention. Extensive incorporation of deuteriu~ into the light hydrocarbon and gaseous products and residue was observed. Based on chemical spectral analysis of the deuterated light hydrocarbon and gaseous products, some chemical restructuriny of the heavy hydro~arbon feed occurred during the course of the process of the present invention. However, at least some of the hydrogen-deuterium exchange observed might also have occurred after the product was formed. Apparently, water was a reactant and not merely a solvent in the process of the present invention.
The process of the pr~sent invention operates with heavy hydrocarbons having an API gravity at 25C of less than about 20. Among the heavy hydrocarbons found use-ful in the process of the present invention are heavycrude oil, heavy hydrocarbons extracted from tar sands, commonly called tar sand bitumen, such as Athabasca tar sand bitumen obtained from Canada, heavy petroleum crude oils such as Venezuelan Orinoco heavy oil belt crudes (Boscan heavy oil), heavy hydrocarbon fractions obtained from crude petroleum oils particularly heavy vacuum yas oils, vacuum residue as well as petroleum tar and coal tar. The viscosity measur~d at 25C of the hea~y hydro-carbon feedstock material ~ay vary over a wide range from about i,ooo to about ~00,000 cp, normally 20,000 cp to about 65,000 cp. In a preferred embodiment of the present invention ~oscan heavy oil having a viscosity of about 60,000 cp at 25C was treated with water at 410C
and 6,894 to 13,788 kPa (1,000 to 2,000 psig) to produce a light hydrocarbon product having a viscosity at 25C
less than about 10 cp~ In another preferred embodiment of the present invention tar sand bitumen having a vis-cosity of about 30,000 cp at 25C was converted by x~
treatment with water at 410C and 6,894 to 13,788 kPa (1,000 to 2,000 psig) into light hydrocarbon product having a viscosity at 25C less than about 10 cp. Amony the organometallic compounds found in the heavy hydro-carbons, nickel and vanadium are most common althoughother metals including iron, copper, lead and zinc are also often present. In a preferred embodiment of the process of the present invention heavy hydrocarbons hav-ing an API gravity at 25C of less than about 20 and a total vanadium and nickel content between 1,000 and 2,000 ppm was converted into light hydrocarbons having an API gravity of 25C of between about 20 and 40 and a total vanadium and nickel content less than about 50 preferably less than about 30 ppm. In another preferred embodiment of the present invention heavy hydrocarbons having an API gravity at 25 of less than about 20 and a total vanadium and nickel content of between about 100 and 1000 ppm were converted into light hydrocarbon prod-uct having a API density at 25 between about 20 and 40 and a total vanadium and nickel content less than about 50 ppm preferably less than about 30 ppm.
By the term "light hydrocarbon product" as used herein is meant a hydrocarbon having an API gravity at 25C of greater than about 20 preferably between about 20 and about 40. The light hydrocarbon product obtained in accordance with the process of the present invention has a total vanadium and nickel content generally of less than about 50 ppm, preferably less than about 30 ppm and is usually substantially free of organonitrogen compounds and usually contains only about 75% of the organosulfur compounds present in the starting heavy hydrocarbons. The viscosity of the light hydrocarbon product at 25C is less than about 10 cp, preferably less than about 5 cp. The hydrocarbon to carbon ratio of the light hydrocarbon is higher than the hydrogen to carbon ratio of the heavy hydrocarbons~ In a preferred embodiment of the present invention, the heavy hydrocarbon, Boscan heavy oil having a hydrogen-carbon ~2~
ratio equal to about 1.5 was treated with water at 410C
and 10,342 kPa (1500 psig) to produce a light hydro-carbon product having a hydrogen-carbon ratio of about 1.7. ~y gas chromatographic analysis, the weight dis-tribution of carbon units in the light hydrocarbonproduct having the H/C ratio of 1.7 was approximately the same as that found in gasoline, kerosine and diesel oil.
The gaseous product obtained by treatment of the heavy hydrocarbons in accordance with the process of the present invention comprises carbon dioxide, hydrogen sulfide and Cl-C6 alkenes and alkanes as well as a trace amount of hydrogen. The amount of the yaseous product obtained is preferably no more than about 10 weight %, and preferably is less than about 5 weight %, basis starting heavy hydrocarbons.
The residue obtained by treatment of the heavy hydrocarbons in accordance with the process of the present invention is usually soluble in the feedstock heavy hydrocarbons. This residue is not a coke or pitch and as such may be used as a source of fuel, may be recycled or may be treated with steam or lower hydrocar-bons such as pentane to remove light hydrocarbons that may be entrapped therein.
The fluid comprising water may be tap water, river water, lake water or the like and may contain small amounts of salts accompanying the crude oil as obtained from the ground. While the presence of salt in the water may be tolerated, a salt concentration of greater than about 100 ppm is objectionable and is to be avoided.
The process of the present invention may be carried out either as a semi-continuous or batch process or as a continuous process. In the continuous process both the heavy hydrocarbons and water are fed under pressure to a preheated first zone wherein the temperature and pres-sure conditions are maintained for a time sufficient to form a uniform mixture which is forwarded to the second ~2~
zone wherein the temperature and pressure conditions o~
the first zone are maintained for a time sufficient to separate the uniform mixture into a residue and a phase containing the light hydrocarbon and gaseous products;
the phase is continuously removed from the second zone while the residue stream is continuously or periodically removed from the second zone. The residence time in the first and second zones may be varied from a few minutes up to about 20 minutes, depending upon characteristics of heavy hydrocarbon feedstock and light hydrocarbon product desired. In the batch process a total residence time of about 10-20 minutes, preferably about 10 min-utes, is used. In the continuous process, a total resi-dence time of a few minutes to 20 minutes, preferably about 1 minute to less than about 3 minutes is used. In a continuous process, less gas is obtained than in the L
semi-continuous or batch process; less than about 10 weight ~, preferably less than about 5 weight % and usu-ally less than about 2 weight % of the total products are produced as gas in the continuous process.
A preferred embodiment of the reaction of the pres-ent invention practiced in a continuous flow reactor is illustrated in Fiyure 3. Water in storaye vessel 11 is passed via line 13 through valve 15 to high pressure 25 piston pump 17 through line 19 containing check valve 21 to valve 27. Storage vessel 33 equipped with heavy hydrocarbon feed line 2 pressurized with nitrogen via line 29 and a safety valve in line 31 is passed via line 35 equipped with heating tape 37 to high pressure gear 30 pump 39 and then through line 41 check valve 43 to valve 27. In order to promote intimate contact between the heavy hydrocarbon and the water, the water from line 19 and the heated heavy hydrocarbon from line 41 are con-tinuously fed throuyh valve 27 into line 45 which may be equipped with a spiral stirrer to produce small droplets on the order of submicrons to about several microns of heavy hydrocarbon in the water. The intimate mixture in line 45 equipped with pressure transducer 49 is continu-~L2~S~
ously fed to a spiral or tubular heater 51 immersed inthe fluidized sand bath 53 equipped with thermocouple 55. The residence time in the heater 51 is preferably less than about 1 minute, more preferably on the order of about 10 seconds. The intimate heated uniform mix-ture of heavy hydrocarbon and water is passed via line S9 containing thermocouple 57 to high pressure autoclave 61 equipped with heating jacket 63, thermocouples of 65 and safety valve 71. The residence time in the high pressure autoclave is from a few seconds up to about 20 minutes. The light hydrocarbon stream and the gaseous stream produced from the intimate contact in high pres-sure autoclave 61 are continuously removed via line 69 containing pressure transducer 73, air operated pressure control valve 75 to condenser 77 which may be of any convenient design. From condenser 77, the light hydro-carbon and the gaseous streams are passed via line 79 to product receiver 81 for separation of the light hydro-carbon stream from the gaseous stream. The gaseous stream is removed via line 83 containing volumetric flowmeter 85 to gas storaye container 87. Residue is periodically removed via line 60 to valves 66A and 66B
equipped with line 62 to residue container 64.
It is a special feature of the process of the pres-ent invention that, in the second zone, the residue is separated from the vapor phase comprising light hydro-carbons, gas, and water while maintaining the pressure and temperature conditions of the first zone; the resi-due and vapor phase are withdrawn from the second zone and thereafter the pressure and temperature were reduced to values sufficient to allow recovery of the residue and separation of the vapor phase into a gaseous prod-uct, a liquid comprising water and a light hydrocarbon product having the desired properties~
By maintaining the pressure and temperature condi-tions of the first zone in the second zone for a time sufficient to effec-t separation and withdrawal of the residue and vaporous mixture, the residue is obtained -18- ~ 5~
substantially free of coke which would interfere with operation of the process of the present invention. In comparative example, Boscan heavy oil was continuously treated with water at 465-470C and 2300 psiy in a heating coil similar to that of U.S. Patent 2,135,332 at varying residence times and the pressure and temperature reduced to ambient to form a reaction mixture which was thereafter distilled under vacuum to recover light hydrocarbon product. However, when the residence time was increased to provide greater than 50% up to 76% by weight of light hydrocarbons product, the heating coil became plugged with coke and the reaction was termin-ated.
Figure 4 illustrates a schematic of a flow reactor for continuous operation of another preferred embodiment of the present invention. A heavy hydrocarbon feed-stock, such as heavy crude oil in line 101 is premixed with water in line 103 and the mixture is fed via line lOS to pump 107 which pumps mixture via lines 109 and 20 113 to high pressure heat exchangers 111 and 115 which may be of any convenient design and then via line 117 to high temperature preheater 119 which may conveniently be a high pressure direct-fired tubular heater. The reac-tion mixture from preheater 119 is passed via line 121 25 to residue separation unit 123. In separation unit 123, the reaction mixture is separated into a vapor stream 129 suitable for further processing and/or transporta-tion, and containing (1) Cl-C6 alkanes and alkenes, hydrogen sulfide, carbon dioxide and trace amounts of hydrogen, (2) light hydrocarbons, and (3) water vapor, and a residue stream 125 which may be used as fuel or at least partially recycled via line 127 to preheater 119. The gaseous stream 129 is passed through heat exchanger 115 in line 131 to light oil separator 133 wherein the light oil is removed via line 135 containing pressure let-down valve 137~ The pressure let-down valve 137 may also be positioned in line 131. The gase-ous alkanes, alkenes, carbon dioxide, hydrogen and water ~2;~5~ `
vapor removed from light oil in separator 133 via line 139 passes through heat exchanger 111 and line 141 to phase separator 143. Gases are removed from 143 via line 145. Light oil which may be present is removed via line 147. Water removed from phase separator 143 via line 149 is forwarded to water make-up line 103. The design of the separation units 123, 133 and 143 will depend on the type of heavy hydrocarbon feedstock used, the degree of restructuring desired, and other economic factors.
The first and second zones for operating the pro-cess of the present invention may be separate reactors or two reaction zones within the same reactor. The reaction conditions, e.g., temperature and pressure, water:oil ratios chosen will, of course, depend on many considerations such as the heavy hydrocarbon feedstock available and the light hydrocarbon product desired.
The following examples illustrate the present invention and are not intended to limit the same.
GENERAL EXPERIMENTAL
Description - ~atch Reactor. Water was fed from a graduated cylinder to a high pressure pump (Aminco, cat.
no. 46-14025) provided with a pressure gauge. Water was delivered at a uniform rate through a preheater coil 25 heated to 410C by a Lindbergh electric oven into a 300 cm3 stirred autoclave (from Autoclave Engineering). A
special "gaspersator" magnet drive stirrer was used with a water cooling at the top. A thermocouple measured the extraction temperature while the autoclave was heated by a heating jacket controlled independently. The tubing between preheater and autoclave and release valve was heated with heating tapes controlled by a Variac vari-able poteniometer. A special high temperature, high pressure let down valve was used at exit. The valve was sensitive to plugging. The plugging problem was elimin-ated by releasing steam occasionally through the valve. A mixture of steam and light hydrocarbon was passed through a water-cooled condenser and collected in ~2~
the receiver. The uncondensed material went through a buffer container, suitable for gas sampling and was col-lected in a collapsible balloon. The complete batch reactor was placed in an explosion proof high pressure laboratory cubicle and was operated from outside. The high pressure, high temperature batch experiments on heavy crude oil and tar sand bitumen were performed in this experiment~
Analysis of Extract, Gases and Residue. The graph-ite furnace method was used to determine the amount ofvanadium and nickel in the light hydrocarbon stream, and atomic absorption method used for the residue~ Viscos-ity was recorded either by New Metrec or Cannon Ubhelode instrument. Density measurement was made by a pycono-meter. lH and 13C nmr spectra were recorded in deutero-chloroform. For lH nmr Varian XL200 and for 13C nmr Varian FT 80A instruments were used. Tris(ace-tonylacetyl)chromium [Cr(acac)3] was used to allow com-plete relaxation of the nuclei. Electron spin resonance spectra of flowable hydrocarbons were obtained using dual cavity Varian E-12. Infrared measurement of light hydrocarbons was made in solu~ion (CHC13) on Perkin-Elmer 239 Infrared Spectrophotometer, and of residue was made on Nicolet 7199 FT-IR. Thermogravimetric analysis (TGA) of residue was performed by Dupont 951-TGA instru-ment.
Molecular weight distributions of the light hydro-carbons products and the heavy hydrocarbon feed samples were determined by Gel Permeation Chromatographic tech-niques. The samples were dissolved in THF and elutedthrough ~-styrogel column at ambient temperature. A
differential refractometer (~RI) was used to detect the eluting species. The molecular weight distribution (highest, peak and lowest) were obtained from retention volume. Linear aliphatic hydrocarbon standards were used for distribution of molecular weight calibration of the ~-styrogel column.
Boscan heavy crude oil, tar sand bitumen and the light hydrocarbons produced therefrom and some standards (gasoline, kerosene and diesel) were analyzed by Hewlett-Packard Model No. 5880 gas chromatograph equipped with a flame ionization detector and a capil-lary splitter.
The range of separation for aliphatics, using a capillary gas chromatograph described above, was Cl to C30 hydrocarbons. The aromatic range was benzene to benzo(a)pyrene. Identification of peaks was achieved by comparison with standards representative of each chemi-cal class.
A class separation into aliphatics, aromatics and polars was performed by high pressure liquid chromato-graphy (Varian 500 HPLC equipped with an LDC Spectro Monitor III variable wavelength detector and a Valco ULCI automatic sample injector with 10 and 250 ~L sam-pling loops). Using a 5 ~m cyano bonded stationary phase (Zorban CN 4.6 x 250 mm from Dupont) and employing the following gradient: isocratic elution with hexane 20 for 3 min followed by a 0-100% l-butanol gradient in 5 min at a flow of 1 mL/min. Absorbance was measured at 254 nm. Aliphatic (alkane/alkene) fraction will not exhibit a UV absorbance at 25~ nm but will elute prior to the aromatic fraction. Preparative ~PLC was carried 25 out on a 9.4 x 250 mm, 5~ Zorbax CN semi-preparative column. In semi-preparative separation solvent flow was 5 mL/min and detection was made at 320 nm. As much as 30 mg filtered light hydrocarbon stream in hexane could be loaded on column. The samples were filtered using a 0.45~ to remove insoluble material. Fractions obtained were further analyzed by FID capillary gas chromato-graphy.
Separation of gases was achieved on a gas chromato- !
graph equipped with a gas injector and TC detector using oxidized Porapak Q (1/~" x 3') or 20% dimethylsulfolane on 80/100 chromosorb P (1/8" x 20'; at -25~C). GC/MS of gas samples were obtained on Finnigan 3300 (electron impact) using INCOS DATA system.
s~ ~
Treatment of Bitumen and Boscan Heavy Oil with Water. Athabasca tar sand bitumen (sample #81-02, sub-stantially free of sand, supplied by Alberta Research Council) and Boscan heavy crude oil from Venezuela were used in Example 1 (runs 1-4 and in Example 2 (run 5~, respectively. Generally, 609 of heavy oil or bitumen were charged in a heated (450C) autoclave described in General Experimental purged with nitrogen gas. The material was heated to 410C usually in 10-15 minutes.
During the heating period, some water was added to develop the desired pressure. Once an appropriate pres-sure and temperature were attained, the compressed steam at same temperature was passed at a set flow rate. The pressure was maintained by controlling let-down valve manually. Total of 200 mL water was used for the reac-tion. The amount of water used to develop the desired pressure varied from 12 mL to 50 mL. The extract and the condensed steam were collected in a three neck flask. Most of the light hydrocarbon was separated from the condensed steam by a separatory funnel after allow-ing enough time for phase separation. The remaining light hydrocarbon and condensed steam were diluted with pentane or fluorotrichloromethane and separated in a separatory funnel. Following drying over MgSO~ and fil-tration, solvent was distilled off using a water bath at controlled temperature. The material left in the auto-clave was defined as residue. The results of treatment of Boscan heavy crude oil and of tar sand bitumen with water at 410C and various pressures are reported in Tables I and II, respectively.
5~: `
TABLE I
Comparison of Properties of Boscan ~eavy Oil, and the Light Hydrocarbons and Residue Obtained Therefrcm by Treating Boscan Heavy Oil at 410C and Various Pressures Run #l 3500 psi/410C*
Boscan Property Heavy Oil Light HC Residue API Gravity 10.3 21.8 -Viscosity C.P.60,000 7.9 (Temp) (22C) (25C) C wt% 81.84 81.73 83.56 H 10.41 10.19 4.56 N 0.56 Trace 2.53 S 5.52 3.99 6.61 15 o 1.25 0.89 0.92 H/C Ratio 1.51 1.58 0.65 V wt ppm 1500 150 650U
Ni wt ppm 100 4 600 Aromatic C % 17.9 20.6 20 Pentane Soluble ~ 78 100 none Toluene Soluble ~ 100 100 7 THF Soluble ~ 100 100 11 *yield data for Run #1 (wgt %): 66~ Light HC; 3% Gas; 24~ Residue I
-24~ 5~
TABLE I (cont'd) Run #2 2000 nsi/410Ca**
Boscan Property Heavy Oil Light HC Residue API Gravity 10.3 29.1 Viscosity C.P.60,000 5.08 (Temp) (22C) C wt% 81.84 82.59 85.15 H 10.41 11.39 4.25 10 N 0.56 Trace 1.53 S 5.52 4.~3 6.38 O 1.25 0.295 0.878 H/C Ratio 1.51 1.64 U.59 V wt ppm 1500 7.8 5900 15 Ni wt ppm 100 1.2 600 Arcmatic C ~ 17.9 20.1 Pentane Soluble ~ 78 10D none Toluene Soluble ~ 100 100 THF Soluble ~ 100 100 4 **yield data for Run #2 (wgt%): 64.6% Light HC; 5.2~ Gas; 22.2%
Residue -25~ d TABLE I ~cont'd) Run #3 2000 psi/410C*~*
Boscan Property Heavy Oil Light HC Residue API Gravity 10.3 29.0 Viscosity C.P.60,000 4.54 (Temp) ~22C) C wt% 81.84 82.86 84.62 H 10.41 11.51 3.88 N 0.56 Trace 1.88 S 5.52 4.0 6.82 O 1.25 0.286 0.760 H/C Ratio 1.51 V wt ppm 1500 9O4 6000 Ni wt ppm 100 1.3 580 Arcmatic C ~ 17.9 20.9 Pentane Soluble % 78 100 Toluene Soluble ~ 100 100 THF Soluble % 100 100 ***yield data for Run #3 (wgt%): 63.1~ Light HC; 4.8% Gas; 23.1%
Residue ~2~
TABLE I ~cont'd) Run #4 1500 psi/410C****
Boscan Property Heavy Oil Light HC Residue(C) API Gravity 10.3 32.1 Viscosity C.P.60,000 2.49 (Temp) (22C) C wt% 81.84 83.42 H 10.41 11.75 10 N 0.56 <0.1 S 5.52 4.1 1.25 H/C Ratio 1.51 1.68 V wt ppm 1500 4.5 15 Ni wt ppm 100 3.0 Aromatic C ~ 17.9 20.6 Pentane Soluble % 78 100 Toluene Soluble ~ 100 100 THF Soluble % 100 100 ~'ootnotes to Table I
(a) 240 mL of air were present at start of Run #2.
(b) N2 was present at start of Run #3.
(c) Analysis of residue is expected to be similar to that of Run #2 and 3 of Table I.
25 ****yield data for Run #4 (wgt%): 59.0% Light HC; 6.4%
Gas; 25.2% Residue ~2~5~ `
TABLE II
Comparison of Properties of Tar Sand Bitumen, and of the Light Hydrocarbons and Residue Obtained merefrom by Treatment with H~O at 410 and Various Pressures Run #5*
3500 psi/410C
Property Bit~n Light HC Residue API Gravity (25C) 10.14 23.16 Viscosity cp (25 C) 28,000 7.5 C wt% 83.21 83.42 80.84 10 H 10.44 10.75 4.24 N 0.76 Trace 1.61 S 4.77 3.51 6.50 O 1.2 1.18 2.5 H/C Ratio 1.49 1.53 0.62 15 V wt ppm 150 22 730 Ni wt ppm 55 9 520 Pentane Soluble % 72 72 None Toluene Soluble % 100 100 16 THF Soluble % 100 100 30 *yield data for Run ~1 (wgt%). 79~ Light HC; 7% Gas; 13% Residue Examples 3-4 The procedure and apparatus of Examples 1-2 is used except that tar sand bitumen ~substantially free of 25 sand) is treated with water at 2000 psig and 410C
(Example 2) and at 1500 psig and 410C (Example 3).
Results of Example 3 and 4 are expected to be similar to those of Example 1, Runs 3 and 4 respectively.
Examp~ 5 ~oscan heavy crude oil of Examples 1-2 was treated with water in the flow reactor illustrated in Figure 3. The results are reported in Table III.
-28~
TABLE III
Results oE Treatment of Boscan Heavy Crude Oil with Water in Flow Reactor at Various Temperatures and Pressures Run #6 1500 psi/412Ca~b Boscan ProE~erty Heavy Oil Light HCbResidueb API Gravity (25~C) 10.3 28.3 Viscosity C.P. 60,600 11.1 (Temp) (22C) C (wt%) 81.84 83.02 81.68 H (wt%) 10041 12.01 8.95 N (wt%) 0.56 na na S (wt%) 5.52 4.09 5.69 O (wt%) 1.25 H/C Ratio 1.51 1.74 1.31 15 V (wt ppm) 1500 28.6 Ni (wt ppm) 100 1.4 Pentane Soluble (%) 78 100 60.5 Toluene Soluble (%) 100 100 THF Soluble (%) 100 100 aExperimental Conditions: Heavy Oil Input Rate(mL/min) = 2.82;
Total Run Time - 107 min; H20/Oil Ratio (v/v) = 3.5 bYield Results (wgt%): 41.6% Light HC; 1.0% Gas; 58.4% Residue -29 ~ 5 TABLE III (cont'd) Run #7 1500 p5i/430ocalb Boscan Property Heavy Oil Light HCResidueC
API Gravity (25C) 10.3 32.6 Viscosity C.P.60,600 4.8 (Temp) (22C) C (wt%) 81.84 83.86 -H (wt%) 10.41 12.05 10 N (wt%) 0.56 na S (wt~) 5.52 4.6 O (wt%) 1.25 - -H/C Ratio 1.51 1.72 V (wt ppm) 1500 22.2 15 Ni (wt ppm) 100 3.8 Pentane Soluble (%) 78 100 49.9 Toluene Soluble (%) 100 100 na THF Soluble (~) 100 100 na aExperimental conditions: Heavy Oil Input Rate = 5.3 mL/min; Total Run Time = 90 min; H2o/oil Ratio (v/v) = 1.3 bYield results (wtg%): S7.6% Liyht HC; 1.0% Gas; 41.4% Residue CResidue stream was discharged frcm autoclave 3 times during Run #7 30- ~%~
TABLE III (cont'd) Run #8 1500 pSi/442oca,b/C
Boscan Property Heavy Oil Light HC ~esidue API Gravity (25C) 10.3 27.3 Viscosity C.P.60,600 S.0 (Temp) (22C) (22C) C (wt%) 81.84 83.98 H (wt%) 10.41 12.06 10 N (wt~) 0.56 na S (wt%) 5.52 3.92 O (wt%) 1.25 na H/C Ratio 1.51 1.72 V (wt ppm) 1500 16.6 15 Ni (wt ppm) 100 1.5 Pentane Soluble (%) 78 100 Toluene Soluble (%) 100 100 THF Soluble (%) 100 100 O aExperimental Conditions: Heavy Oil Input Rate (mL/min) =
Total Run Time (min) = 62 H2O/Oil Ratio (v/v) = 1.4 bYield Results (wgt~): 59.4~ Light HC; 6.5% Gas; 34.1% Residue CAfter completion of Run #8, the residue was stripped with steam 25 and overall yield results (wgt%) were: 67.1% Light HC; 6.5% Gas (unchanged); 26.5% Residue ~L~2~ 5~
TABLE III (cont'd) Run #9 2000 psi/420C
Boscan Property Heavy Oil Light HC Residue API Gravity (25C) 10.3 33.6 Viscosity COP.60,600 4.5 (Temp ? ( 22C) (22C) C (wt%) 81.84 81.38 84.42 H (wt%) 10.41 11.93 8.71 10 N (wt%) 0.56 na S (wt%) 5.52 3.71 O (wt~) 1.25 na H/C Ratio 1.51 1.76 0.~1 V (wt ppm) 1500 23.3 15 Ni (wt ppm) 100 1.0 Pentane Soluble (%) 78 100 Toluene Soluble (~) 100 100 THF Soluble (%)100 100 -aExperimental conditions: Heavy Oil Input Rate = 4.7 mL/min; Total Run Time = 70 min; H2O/Oil Ratio (v/v) = 1.4 bYield Results (wgt%): 56.5% Light ~C; 3.0% Gas; 40.5% Residue Example 6 The tar sand bitumen of Examples 1-2 is treated with water in the flow reactor illustrated in Figure 3 in accordance with procedure of Example 5. Results similar to those reported in Example 5 are expected.
Example 7 Light Hydrocarbon products were obtained by treat-ment of Boscan heavy crude oil with water in semi-con-tinuous reactor of general experimental and in accord-ance with procedure of Example 1 at 410C and at pres-sures from atmospheric to 3500 psig (runs 1, 2, and 4 of Example 1 and other runs not reported herein). The API
gravity and viscosity of these Light Hydrocarbon prod-ucts were measured and are plotted in Figure 1. The results are summarized in Table IV.
T~LE IV
Ccmparison of API Gravity and Viscosity of Boscan Hea~ Oil Run # #l _ #2 #4 Boscan 3500 2500 2000 1500 100() Heavy psi, psi, psi, psi, psi, PropertyOil 410C 410C 410C 410C 410C
API
Gravitya10.3 21.8 26.5 29,1 32.1 31.0 Viscosity 60,600 7.9 6.46 5.08 2.49 3.44 (25C) cp(at 22C) 10 (a) APIGravity =141.5 -131.5 Spec. Gravity Example 8 The light hydrocarbon product from Run #4 of Table was subjected to atmospheric distillation followed by 15 vacuum distillation at successively lower pressures.
The results are reported in Table V. Similar results are expected from distillation of Light Hydrocarbon product obtained from treatment of tar sand bitumen at 410C/1500 psig.
IABLE V
Results from Distillation of Boscan Heavy Crude Oil and the Liaht Hvdrocarbon Product of Run #4 of Table l , FractionBoiling Rangea Boscan HCObLight HCC
Identity (C) (wt%) (wt%) Naphtha 35_90d 3.15 54.85 25 Light Gas Oil 190-260d 5.70 21.76 Heavy Gas Oil 260-343e 6.35 19.02 343_530e 27.70 4.37 >530e Footnotes to Table V
30 aStandard Boiling Points (corrected) bBoscan Heavy Crude Oil used in Example 1-2 CLight Hydrocarbon Product from Run #4 of Table (410C/1500 psig) dDistilled at atmospheric pressure 35 eDistilled at reduced pressure; boiling points corrected to one atmospheric pressure This example illlustrates treatment of Boscan heavy s~
crude oil with water in an apparatus similar to that disclosed in USP No. 2,135,332 IGary). The apparatus and procedure of Figure 3 were used with the modifica-tion detailed herein below to provide for reduction of temperature and pressure to ambient before separation of residue from reaction mixture from which light hydro-carbon product is obtained.
In a typical experiment, Boscan heavy oil and water were pumped into a tubular reactor. The oil/~2O ratio and pump rate were varied. The tubular reactor 51 was heated to about ~465-470C in a fluidized sand bath.
The mixture product formed was directly transferred from tubular reactor 31 to a condensing flask 77 via line 69 through pressure control valve 75. Condensed oil and H2O were worked up in two steps: first, water was dis-tilled off in vacuum. Second, the oil obtained was dis-tilled according to ASTM type distillation methods. The results for a series of experiments wherein residence time in tubular heater 51 of Figure 3 was varied are summarized in Table VI.
TABLE VI
Conversion of Boscan at 465C-470C, 2000 psi in a Continuous Flow Tubular Reactor 51 of Figure 3 Residence Time Light Oila Gas Min, Sec. wt% wt%
256, 35b 76 1.25 1, 40C 53.5 1.00 1, 15 49.6 0.8 , 30 44.9 0.6 Virgin Boscan 37.7d aProcessed oil distilled after temperature and pressure letdown to ambient according to ASTM type methodO Max.
pot temp. 325C, heating rate 2C/min. Max. distillate temperature 225C, Vac. 0.1 mm.
bAt 6 min. 35 sec. residence time all the residue which might have been coke stayed in the coil. Plugging occurred. Reaction was terminated after 100 g of Boscan heavy oil was fed to tubular reactor 51 (reactor volume equal to 73 g of oil).
1%;2 ~52 CSlow build-up of coke formation in the tubular reactor.
dVacuum distillate.
Two other experiments were run in the continuous flow tubular reactor 51 of Figure 3 under identical con-ditions to those detailed above, except that the pres-sure was 2500 and 3500 psi, respectively. In both experiments, coke formation occurred thereby clogging the tubular reactor and the reaction was terminated after 100 g of Boscan heavy crude oil had been Eed to tubular reactor 51.
30' i
The process of the present invention operates in the absence of externally added catalyst and/or hydro-gen; only the hydrogen provided from the water in the absence of externally added catalyst is required for the process of the present invention. In some instances it may be desirable to provide the first and/or second zones with a packed bed of inert materials such as particles of granite, sand, porcelain or bed saddles.
The use of inert materials in first and/or second zones is not critical to operation of the present invention.
In addition, it is preferable to operate the process of the present invention in an atmosphere substantially free of gases such as oxygen which may interfere with the process of the present invention. However, the -13~-presence of small amounts of air are not detri~ental to the process of the present invention.
Deuterium labeling experiments were condu~ted by treatment of heavy hydrocarbons such as Boscan heavy oil with deuterium oxide under conditions of the present invention. Extensive incorporation of deuteriu~ into the light hydrocarbon and gaseous products and residue was observed. Based on chemical spectral analysis of the deuterated light hydrocarbon and gaseous products, some chemical restructuriny of the heavy hydro~arbon feed occurred during the course of the process of the present invention. However, at least some of the hydrogen-deuterium exchange observed might also have occurred after the product was formed. Apparently, water was a reactant and not merely a solvent in the process of the present invention.
The process of the pr~sent invention operates with heavy hydrocarbons having an API gravity at 25C of less than about 20. Among the heavy hydrocarbons found use-ful in the process of the present invention are heavycrude oil, heavy hydrocarbons extracted from tar sands, commonly called tar sand bitumen, such as Athabasca tar sand bitumen obtained from Canada, heavy petroleum crude oils such as Venezuelan Orinoco heavy oil belt crudes (Boscan heavy oil), heavy hydrocarbon fractions obtained from crude petroleum oils particularly heavy vacuum yas oils, vacuum residue as well as petroleum tar and coal tar. The viscosity measur~d at 25C of the hea~y hydro-carbon feedstock material ~ay vary over a wide range from about i,ooo to about ~00,000 cp, normally 20,000 cp to about 65,000 cp. In a preferred embodiment of the present invention ~oscan heavy oil having a viscosity of about 60,000 cp at 25C was treated with water at 410C
and 6,894 to 13,788 kPa (1,000 to 2,000 psig) to produce a light hydrocarbon product having a viscosity at 25C
less than about 10 cp~ In another preferred embodiment of the present invention tar sand bitumen having a vis-cosity of about 30,000 cp at 25C was converted by x~
treatment with water at 410C and 6,894 to 13,788 kPa (1,000 to 2,000 psig) into light hydrocarbon product having a viscosity at 25C less than about 10 cp. Amony the organometallic compounds found in the heavy hydro-carbons, nickel and vanadium are most common althoughother metals including iron, copper, lead and zinc are also often present. In a preferred embodiment of the process of the present invention heavy hydrocarbons hav-ing an API gravity at 25C of less than about 20 and a total vanadium and nickel content between 1,000 and 2,000 ppm was converted into light hydrocarbons having an API gravity of 25C of between about 20 and 40 and a total vanadium and nickel content less than about 50 preferably less than about 30 ppm. In another preferred embodiment of the present invention heavy hydrocarbons having an API gravity at 25 of less than about 20 and a total vanadium and nickel content of between about 100 and 1000 ppm were converted into light hydrocarbon prod-uct having a API density at 25 between about 20 and 40 and a total vanadium and nickel content less than about 50 ppm preferably less than about 30 ppm.
By the term "light hydrocarbon product" as used herein is meant a hydrocarbon having an API gravity at 25C of greater than about 20 preferably between about 20 and about 40. The light hydrocarbon product obtained in accordance with the process of the present invention has a total vanadium and nickel content generally of less than about 50 ppm, preferably less than about 30 ppm and is usually substantially free of organonitrogen compounds and usually contains only about 75% of the organosulfur compounds present in the starting heavy hydrocarbons. The viscosity of the light hydrocarbon product at 25C is less than about 10 cp, preferably less than about 5 cp. The hydrocarbon to carbon ratio of the light hydrocarbon is higher than the hydrogen to carbon ratio of the heavy hydrocarbons~ In a preferred embodiment of the present invention, the heavy hydrocarbon, Boscan heavy oil having a hydrogen-carbon ~2~
ratio equal to about 1.5 was treated with water at 410C
and 10,342 kPa (1500 psig) to produce a light hydro-carbon product having a hydrogen-carbon ratio of about 1.7. ~y gas chromatographic analysis, the weight dis-tribution of carbon units in the light hydrocarbonproduct having the H/C ratio of 1.7 was approximately the same as that found in gasoline, kerosine and diesel oil.
The gaseous product obtained by treatment of the heavy hydrocarbons in accordance with the process of the present invention comprises carbon dioxide, hydrogen sulfide and Cl-C6 alkenes and alkanes as well as a trace amount of hydrogen. The amount of the yaseous product obtained is preferably no more than about 10 weight %, and preferably is less than about 5 weight %, basis starting heavy hydrocarbons.
The residue obtained by treatment of the heavy hydrocarbons in accordance with the process of the present invention is usually soluble in the feedstock heavy hydrocarbons. This residue is not a coke or pitch and as such may be used as a source of fuel, may be recycled or may be treated with steam or lower hydrocar-bons such as pentane to remove light hydrocarbons that may be entrapped therein.
The fluid comprising water may be tap water, river water, lake water or the like and may contain small amounts of salts accompanying the crude oil as obtained from the ground. While the presence of salt in the water may be tolerated, a salt concentration of greater than about 100 ppm is objectionable and is to be avoided.
The process of the present invention may be carried out either as a semi-continuous or batch process or as a continuous process. In the continuous process both the heavy hydrocarbons and water are fed under pressure to a preheated first zone wherein the temperature and pres-sure conditions are maintained for a time sufficient to form a uniform mixture which is forwarded to the second ~2~
zone wherein the temperature and pressure conditions o~
the first zone are maintained for a time sufficient to separate the uniform mixture into a residue and a phase containing the light hydrocarbon and gaseous products;
the phase is continuously removed from the second zone while the residue stream is continuously or periodically removed from the second zone. The residence time in the first and second zones may be varied from a few minutes up to about 20 minutes, depending upon characteristics of heavy hydrocarbon feedstock and light hydrocarbon product desired. In the batch process a total residence time of about 10-20 minutes, preferably about 10 min-utes, is used. In the continuous process, a total resi-dence time of a few minutes to 20 minutes, preferably about 1 minute to less than about 3 minutes is used. In a continuous process, less gas is obtained than in the L
semi-continuous or batch process; less than about 10 weight ~, preferably less than about 5 weight % and usu-ally less than about 2 weight % of the total products are produced as gas in the continuous process.
A preferred embodiment of the reaction of the pres-ent invention practiced in a continuous flow reactor is illustrated in Fiyure 3. Water in storaye vessel 11 is passed via line 13 through valve 15 to high pressure 25 piston pump 17 through line 19 containing check valve 21 to valve 27. Storage vessel 33 equipped with heavy hydrocarbon feed line 2 pressurized with nitrogen via line 29 and a safety valve in line 31 is passed via line 35 equipped with heating tape 37 to high pressure gear 30 pump 39 and then through line 41 check valve 43 to valve 27. In order to promote intimate contact between the heavy hydrocarbon and the water, the water from line 19 and the heated heavy hydrocarbon from line 41 are con-tinuously fed throuyh valve 27 into line 45 which may be equipped with a spiral stirrer to produce small droplets on the order of submicrons to about several microns of heavy hydrocarbon in the water. The intimate mixture in line 45 equipped with pressure transducer 49 is continu-~L2~S~
ously fed to a spiral or tubular heater 51 immersed inthe fluidized sand bath 53 equipped with thermocouple 55. The residence time in the heater 51 is preferably less than about 1 minute, more preferably on the order of about 10 seconds. The intimate heated uniform mix-ture of heavy hydrocarbon and water is passed via line S9 containing thermocouple 57 to high pressure autoclave 61 equipped with heating jacket 63, thermocouples of 65 and safety valve 71. The residence time in the high pressure autoclave is from a few seconds up to about 20 minutes. The light hydrocarbon stream and the gaseous stream produced from the intimate contact in high pres-sure autoclave 61 are continuously removed via line 69 containing pressure transducer 73, air operated pressure control valve 75 to condenser 77 which may be of any convenient design. From condenser 77, the light hydro-carbon and the gaseous streams are passed via line 79 to product receiver 81 for separation of the light hydro-carbon stream from the gaseous stream. The gaseous stream is removed via line 83 containing volumetric flowmeter 85 to gas storaye container 87. Residue is periodically removed via line 60 to valves 66A and 66B
equipped with line 62 to residue container 64.
It is a special feature of the process of the pres-ent invention that, in the second zone, the residue is separated from the vapor phase comprising light hydro-carbons, gas, and water while maintaining the pressure and temperature conditions of the first zone; the resi-due and vapor phase are withdrawn from the second zone and thereafter the pressure and temperature were reduced to values sufficient to allow recovery of the residue and separation of the vapor phase into a gaseous prod-uct, a liquid comprising water and a light hydrocarbon product having the desired properties~
By maintaining the pressure and temperature condi-tions of the first zone in the second zone for a time sufficient to effec-t separation and withdrawal of the residue and vaporous mixture, the residue is obtained -18- ~ 5~
substantially free of coke which would interfere with operation of the process of the present invention. In comparative example, Boscan heavy oil was continuously treated with water at 465-470C and 2300 psiy in a heating coil similar to that of U.S. Patent 2,135,332 at varying residence times and the pressure and temperature reduced to ambient to form a reaction mixture which was thereafter distilled under vacuum to recover light hydrocarbon product. However, when the residence time was increased to provide greater than 50% up to 76% by weight of light hydrocarbons product, the heating coil became plugged with coke and the reaction was termin-ated.
Figure 4 illustrates a schematic of a flow reactor for continuous operation of another preferred embodiment of the present invention. A heavy hydrocarbon feed-stock, such as heavy crude oil in line 101 is premixed with water in line 103 and the mixture is fed via line lOS to pump 107 which pumps mixture via lines 109 and 20 113 to high pressure heat exchangers 111 and 115 which may be of any convenient design and then via line 117 to high temperature preheater 119 which may conveniently be a high pressure direct-fired tubular heater. The reac-tion mixture from preheater 119 is passed via line 121 25 to residue separation unit 123. In separation unit 123, the reaction mixture is separated into a vapor stream 129 suitable for further processing and/or transporta-tion, and containing (1) Cl-C6 alkanes and alkenes, hydrogen sulfide, carbon dioxide and trace amounts of hydrogen, (2) light hydrocarbons, and (3) water vapor, and a residue stream 125 which may be used as fuel or at least partially recycled via line 127 to preheater 119. The gaseous stream 129 is passed through heat exchanger 115 in line 131 to light oil separator 133 wherein the light oil is removed via line 135 containing pressure let-down valve 137~ The pressure let-down valve 137 may also be positioned in line 131. The gase-ous alkanes, alkenes, carbon dioxide, hydrogen and water ~2;~5~ `
vapor removed from light oil in separator 133 via line 139 passes through heat exchanger 111 and line 141 to phase separator 143. Gases are removed from 143 via line 145. Light oil which may be present is removed via line 147. Water removed from phase separator 143 via line 149 is forwarded to water make-up line 103. The design of the separation units 123, 133 and 143 will depend on the type of heavy hydrocarbon feedstock used, the degree of restructuring desired, and other economic factors.
The first and second zones for operating the pro-cess of the present invention may be separate reactors or two reaction zones within the same reactor. The reaction conditions, e.g., temperature and pressure, water:oil ratios chosen will, of course, depend on many considerations such as the heavy hydrocarbon feedstock available and the light hydrocarbon product desired.
The following examples illustrate the present invention and are not intended to limit the same.
GENERAL EXPERIMENTAL
Description - ~atch Reactor. Water was fed from a graduated cylinder to a high pressure pump (Aminco, cat.
no. 46-14025) provided with a pressure gauge. Water was delivered at a uniform rate through a preheater coil 25 heated to 410C by a Lindbergh electric oven into a 300 cm3 stirred autoclave (from Autoclave Engineering). A
special "gaspersator" magnet drive stirrer was used with a water cooling at the top. A thermocouple measured the extraction temperature while the autoclave was heated by a heating jacket controlled independently. The tubing between preheater and autoclave and release valve was heated with heating tapes controlled by a Variac vari-able poteniometer. A special high temperature, high pressure let down valve was used at exit. The valve was sensitive to plugging. The plugging problem was elimin-ated by releasing steam occasionally through the valve. A mixture of steam and light hydrocarbon was passed through a water-cooled condenser and collected in ~2~
the receiver. The uncondensed material went through a buffer container, suitable for gas sampling and was col-lected in a collapsible balloon. The complete batch reactor was placed in an explosion proof high pressure laboratory cubicle and was operated from outside. The high pressure, high temperature batch experiments on heavy crude oil and tar sand bitumen were performed in this experiment~
Analysis of Extract, Gases and Residue. The graph-ite furnace method was used to determine the amount ofvanadium and nickel in the light hydrocarbon stream, and atomic absorption method used for the residue~ Viscos-ity was recorded either by New Metrec or Cannon Ubhelode instrument. Density measurement was made by a pycono-meter. lH and 13C nmr spectra were recorded in deutero-chloroform. For lH nmr Varian XL200 and for 13C nmr Varian FT 80A instruments were used. Tris(ace-tonylacetyl)chromium [Cr(acac)3] was used to allow com-plete relaxation of the nuclei. Electron spin resonance spectra of flowable hydrocarbons were obtained using dual cavity Varian E-12. Infrared measurement of light hydrocarbons was made in solu~ion (CHC13) on Perkin-Elmer 239 Infrared Spectrophotometer, and of residue was made on Nicolet 7199 FT-IR. Thermogravimetric analysis (TGA) of residue was performed by Dupont 951-TGA instru-ment.
Molecular weight distributions of the light hydro-carbons products and the heavy hydrocarbon feed samples were determined by Gel Permeation Chromatographic tech-niques. The samples were dissolved in THF and elutedthrough ~-styrogel column at ambient temperature. A
differential refractometer (~RI) was used to detect the eluting species. The molecular weight distribution (highest, peak and lowest) were obtained from retention volume. Linear aliphatic hydrocarbon standards were used for distribution of molecular weight calibration of the ~-styrogel column.
Boscan heavy crude oil, tar sand bitumen and the light hydrocarbons produced therefrom and some standards (gasoline, kerosene and diesel) were analyzed by Hewlett-Packard Model No. 5880 gas chromatograph equipped with a flame ionization detector and a capil-lary splitter.
The range of separation for aliphatics, using a capillary gas chromatograph described above, was Cl to C30 hydrocarbons. The aromatic range was benzene to benzo(a)pyrene. Identification of peaks was achieved by comparison with standards representative of each chemi-cal class.
A class separation into aliphatics, aromatics and polars was performed by high pressure liquid chromato-graphy (Varian 500 HPLC equipped with an LDC Spectro Monitor III variable wavelength detector and a Valco ULCI automatic sample injector with 10 and 250 ~L sam-pling loops). Using a 5 ~m cyano bonded stationary phase (Zorban CN 4.6 x 250 mm from Dupont) and employing the following gradient: isocratic elution with hexane 20 for 3 min followed by a 0-100% l-butanol gradient in 5 min at a flow of 1 mL/min. Absorbance was measured at 254 nm. Aliphatic (alkane/alkene) fraction will not exhibit a UV absorbance at 25~ nm but will elute prior to the aromatic fraction. Preparative ~PLC was carried 25 out on a 9.4 x 250 mm, 5~ Zorbax CN semi-preparative column. In semi-preparative separation solvent flow was 5 mL/min and detection was made at 320 nm. As much as 30 mg filtered light hydrocarbon stream in hexane could be loaded on column. The samples were filtered using a 0.45~ to remove insoluble material. Fractions obtained were further analyzed by FID capillary gas chromato-graphy.
Separation of gases was achieved on a gas chromato- !
graph equipped with a gas injector and TC detector using oxidized Porapak Q (1/~" x 3') or 20% dimethylsulfolane on 80/100 chromosorb P (1/8" x 20'; at -25~C). GC/MS of gas samples were obtained on Finnigan 3300 (electron impact) using INCOS DATA system.
s~ ~
Treatment of Bitumen and Boscan Heavy Oil with Water. Athabasca tar sand bitumen (sample #81-02, sub-stantially free of sand, supplied by Alberta Research Council) and Boscan heavy crude oil from Venezuela were used in Example 1 (runs 1-4 and in Example 2 (run 5~, respectively. Generally, 609 of heavy oil or bitumen were charged in a heated (450C) autoclave described in General Experimental purged with nitrogen gas. The material was heated to 410C usually in 10-15 minutes.
During the heating period, some water was added to develop the desired pressure. Once an appropriate pres-sure and temperature were attained, the compressed steam at same temperature was passed at a set flow rate. The pressure was maintained by controlling let-down valve manually. Total of 200 mL water was used for the reac-tion. The amount of water used to develop the desired pressure varied from 12 mL to 50 mL. The extract and the condensed steam were collected in a three neck flask. Most of the light hydrocarbon was separated from the condensed steam by a separatory funnel after allow-ing enough time for phase separation. The remaining light hydrocarbon and condensed steam were diluted with pentane or fluorotrichloromethane and separated in a separatory funnel. Following drying over MgSO~ and fil-tration, solvent was distilled off using a water bath at controlled temperature. The material left in the auto-clave was defined as residue. The results of treatment of Boscan heavy crude oil and of tar sand bitumen with water at 410C and various pressures are reported in Tables I and II, respectively.
5~: `
TABLE I
Comparison of Properties of Boscan ~eavy Oil, and the Light Hydrocarbons and Residue Obtained Therefrcm by Treating Boscan Heavy Oil at 410C and Various Pressures Run #l 3500 psi/410C*
Boscan Property Heavy Oil Light HC Residue API Gravity 10.3 21.8 -Viscosity C.P.60,000 7.9 (Temp) (22C) (25C) C wt% 81.84 81.73 83.56 H 10.41 10.19 4.56 N 0.56 Trace 2.53 S 5.52 3.99 6.61 15 o 1.25 0.89 0.92 H/C Ratio 1.51 1.58 0.65 V wt ppm 1500 150 650U
Ni wt ppm 100 4 600 Aromatic C % 17.9 20.6 20 Pentane Soluble ~ 78 100 none Toluene Soluble ~ 100 100 7 THF Soluble ~ 100 100 11 *yield data for Run #1 (wgt %): 66~ Light HC; 3% Gas; 24~ Residue I
-24~ 5~
TABLE I (cont'd) Run #2 2000 nsi/410Ca**
Boscan Property Heavy Oil Light HC Residue API Gravity 10.3 29.1 Viscosity C.P.60,000 5.08 (Temp) (22C) C wt% 81.84 82.59 85.15 H 10.41 11.39 4.25 10 N 0.56 Trace 1.53 S 5.52 4.~3 6.38 O 1.25 0.295 0.878 H/C Ratio 1.51 1.64 U.59 V wt ppm 1500 7.8 5900 15 Ni wt ppm 100 1.2 600 Arcmatic C ~ 17.9 20.1 Pentane Soluble ~ 78 10D none Toluene Soluble ~ 100 100 THF Soluble ~ 100 100 4 **yield data for Run #2 (wgt%): 64.6% Light HC; 5.2~ Gas; 22.2%
Residue -25~ d TABLE I ~cont'd) Run #3 2000 psi/410C*~*
Boscan Property Heavy Oil Light HC Residue API Gravity 10.3 29.0 Viscosity C.P.60,000 4.54 (Temp) ~22C) C wt% 81.84 82.86 84.62 H 10.41 11.51 3.88 N 0.56 Trace 1.88 S 5.52 4.0 6.82 O 1.25 0.286 0.760 H/C Ratio 1.51 V wt ppm 1500 9O4 6000 Ni wt ppm 100 1.3 580 Arcmatic C ~ 17.9 20.9 Pentane Soluble % 78 100 Toluene Soluble ~ 100 100 THF Soluble % 100 100 ***yield data for Run #3 (wgt%): 63.1~ Light HC; 4.8% Gas; 23.1%
Residue ~2~
TABLE I ~cont'd) Run #4 1500 psi/410C****
Boscan Property Heavy Oil Light HC Residue(C) API Gravity 10.3 32.1 Viscosity C.P.60,000 2.49 (Temp) (22C) C wt% 81.84 83.42 H 10.41 11.75 10 N 0.56 <0.1 S 5.52 4.1 1.25 H/C Ratio 1.51 1.68 V wt ppm 1500 4.5 15 Ni wt ppm 100 3.0 Aromatic C ~ 17.9 20.6 Pentane Soluble % 78 100 Toluene Soluble ~ 100 100 THF Soluble % 100 100 ~'ootnotes to Table I
(a) 240 mL of air were present at start of Run #2.
(b) N2 was present at start of Run #3.
(c) Analysis of residue is expected to be similar to that of Run #2 and 3 of Table I.
25 ****yield data for Run #4 (wgt%): 59.0% Light HC; 6.4%
Gas; 25.2% Residue ~2~5~ `
TABLE II
Comparison of Properties of Tar Sand Bitumen, and of the Light Hydrocarbons and Residue Obtained merefrom by Treatment with H~O at 410 and Various Pressures Run #5*
3500 psi/410C
Property Bit~n Light HC Residue API Gravity (25C) 10.14 23.16 Viscosity cp (25 C) 28,000 7.5 C wt% 83.21 83.42 80.84 10 H 10.44 10.75 4.24 N 0.76 Trace 1.61 S 4.77 3.51 6.50 O 1.2 1.18 2.5 H/C Ratio 1.49 1.53 0.62 15 V wt ppm 150 22 730 Ni wt ppm 55 9 520 Pentane Soluble % 72 72 None Toluene Soluble % 100 100 16 THF Soluble % 100 100 30 *yield data for Run ~1 (wgt%). 79~ Light HC; 7% Gas; 13% Residue Examples 3-4 The procedure and apparatus of Examples 1-2 is used except that tar sand bitumen ~substantially free of 25 sand) is treated with water at 2000 psig and 410C
(Example 2) and at 1500 psig and 410C (Example 3).
Results of Example 3 and 4 are expected to be similar to those of Example 1, Runs 3 and 4 respectively.
Examp~ 5 ~oscan heavy crude oil of Examples 1-2 was treated with water in the flow reactor illustrated in Figure 3. The results are reported in Table III.
-28~
TABLE III
Results oE Treatment of Boscan Heavy Crude Oil with Water in Flow Reactor at Various Temperatures and Pressures Run #6 1500 psi/412Ca~b Boscan ProE~erty Heavy Oil Light HCbResidueb API Gravity (25~C) 10.3 28.3 Viscosity C.P. 60,600 11.1 (Temp) (22C) C (wt%) 81.84 83.02 81.68 H (wt%) 10041 12.01 8.95 N (wt%) 0.56 na na S (wt%) 5.52 4.09 5.69 O (wt%) 1.25 H/C Ratio 1.51 1.74 1.31 15 V (wt ppm) 1500 28.6 Ni (wt ppm) 100 1.4 Pentane Soluble (%) 78 100 60.5 Toluene Soluble (%) 100 100 THF Soluble (%) 100 100 aExperimental Conditions: Heavy Oil Input Rate(mL/min) = 2.82;
Total Run Time - 107 min; H20/Oil Ratio (v/v) = 3.5 bYield Results (wgt%): 41.6% Light HC; 1.0% Gas; 58.4% Residue -29 ~ 5 TABLE III (cont'd) Run #7 1500 p5i/430ocalb Boscan Property Heavy Oil Light HCResidueC
API Gravity (25C) 10.3 32.6 Viscosity C.P.60,600 4.8 (Temp) (22C) C (wt%) 81.84 83.86 -H (wt%) 10.41 12.05 10 N (wt%) 0.56 na S (wt~) 5.52 4.6 O (wt%) 1.25 - -H/C Ratio 1.51 1.72 V (wt ppm) 1500 22.2 15 Ni (wt ppm) 100 3.8 Pentane Soluble (%) 78 100 49.9 Toluene Soluble (%) 100 100 na THF Soluble (~) 100 100 na aExperimental conditions: Heavy Oil Input Rate = 5.3 mL/min; Total Run Time = 90 min; H2o/oil Ratio (v/v) = 1.3 bYield results (wtg%): S7.6% Liyht HC; 1.0% Gas; 41.4% Residue CResidue stream was discharged frcm autoclave 3 times during Run #7 30- ~%~
TABLE III (cont'd) Run #8 1500 pSi/442oca,b/C
Boscan Property Heavy Oil Light HC ~esidue API Gravity (25C) 10.3 27.3 Viscosity C.P.60,600 S.0 (Temp) (22C) (22C) C (wt%) 81.84 83.98 H (wt%) 10.41 12.06 10 N (wt~) 0.56 na S (wt%) 5.52 3.92 O (wt%) 1.25 na H/C Ratio 1.51 1.72 V (wt ppm) 1500 16.6 15 Ni (wt ppm) 100 1.5 Pentane Soluble (%) 78 100 Toluene Soluble (%) 100 100 THF Soluble (%) 100 100 O aExperimental Conditions: Heavy Oil Input Rate (mL/min) =
Total Run Time (min) = 62 H2O/Oil Ratio (v/v) = 1.4 bYield Results (wgt~): 59.4~ Light HC; 6.5% Gas; 34.1% Residue CAfter completion of Run #8, the residue was stripped with steam 25 and overall yield results (wgt%) were: 67.1% Light HC; 6.5% Gas (unchanged); 26.5% Residue ~L~2~ 5~
TABLE III (cont'd) Run #9 2000 psi/420C
Boscan Property Heavy Oil Light HC Residue API Gravity (25C) 10.3 33.6 Viscosity COP.60,600 4.5 (Temp ? ( 22C) (22C) C (wt%) 81.84 81.38 84.42 H (wt%) 10.41 11.93 8.71 10 N (wt%) 0.56 na S (wt%) 5.52 3.71 O (wt~) 1.25 na H/C Ratio 1.51 1.76 0.~1 V (wt ppm) 1500 23.3 15 Ni (wt ppm) 100 1.0 Pentane Soluble (%) 78 100 Toluene Soluble (~) 100 100 THF Soluble (%)100 100 -aExperimental conditions: Heavy Oil Input Rate = 4.7 mL/min; Total Run Time = 70 min; H2O/Oil Ratio (v/v) = 1.4 bYield Results (wgt%): 56.5% Light ~C; 3.0% Gas; 40.5% Residue Example 6 The tar sand bitumen of Examples 1-2 is treated with water in the flow reactor illustrated in Figure 3 in accordance with procedure of Example 5. Results similar to those reported in Example 5 are expected.
Example 7 Light Hydrocarbon products were obtained by treat-ment of Boscan heavy crude oil with water in semi-con-tinuous reactor of general experimental and in accord-ance with procedure of Example 1 at 410C and at pres-sures from atmospheric to 3500 psig (runs 1, 2, and 4 of Example 1 and other runs not reported herein). The API
gravity and viscosity of these Light Hydrocarbon prod-ucts were measured and are plotted in Figure 1. The results are summarized in Table IV.
T~LE IV
Ccmparison of API Gravity and Viscosity of Boscan Hea~ Oil Run # #l _ #2 #4 Boscan 3500 2500 2000 1500 100() Heavy psi, psi, psi, psi, psi, PropertyOil 410C 410C 410C 410C 410C
API
Gravitya10.3 21.8 26.5 29,1 32.1 31.0 Viscosity 60,600 7.9 6.46 5.08 2.49 3.44 (25C) cp(at 22C) 10 (a) APIGravity =141.5 -131.5 Spec. Gravity Example 8 The light hydrocarbon product from Run #4 of Table was subjected to atmospheric distillation followed by 15 vacuum distillation at successively lower pressures.
The results are reported in Table V. Similar results are expected from distillation of Light Hydrocarbon product obtained from treatment of tar sand bitumen at 410C/1500 psig.
IABLE V
Results from Distillation of Boscan Heavy Crude Oil and the Liaht Hvdrocarbon Product of Run #4 of Table l , FractionBoiling Rangea Boscan HCObLight HCC
Identity (C) (wt%) (wt%) Naphtha 35_90d 3.15 54.85 25 Light Gas Oil 190-260d 5.70 21.76 Heavy Gas Oil 260-343e 6.35 19.02 343_530e 27.70 4.37 >530e Footnotes to Table V
30 aStandard Boiling Points (corrected) bBoscan Heavy Crude Oil used in Example 1-2 CLight Hydrocarbon Product from Run #4 of Table (410C/1500 psig) dDistilled at atmospheric pressure 35 eDistilled at reduced pressure; boiling points corrected to one atmospheric pressure This example illlustrates treatment of Boscan heavy s~
crude oil with water in an apparatus similar to that disclosed in USP No. 2,135,332 IGary). The apparatus and procedure of Figure 3 were used with the modifica-tion detailed herein below to provide for reduction of temperature and pressure to ambient before separation of residue from reaction mixture from which light hydro-carbon product is obtained.
In a typical experiment, Boscan heavy oil and water were pumped into a tubular reactor. The oil/~2O ratio and pump rate were varied. The tubular reactor 51 was heated to about ~465-470C in a fluidized sand bath.
The mixture product formed was directly transferred from tubular reactor 31 to a condensing flask 77 via line 69 through pressure control valve 75. Condensed oil and H2O were worked up in two steps: first, water was dis-tilled off in vacuum. Second, the oil obtained was dis-tilled according to ASTM type distillation methods. The results for a series of experiments wherein residence time in tubular heater 51 of Figure 3 was varied are summarized in Table VI.
TABLE VI
Conversion of Boscan at 465C-470C, 2000 psi in a Continuous Flow Tubular Reactor 51 of Figure 3 Residence Time Light Oila Gas Min, Sec. wt% wt%
256, 35b 76 1.25 1, 40C 53.5 1.00 1, 15 49.6 0.8 , 30 44.9 0.6 Virgin Boscan 37.7d aProcessed oil distilled after temperature and pressure letdown to ambient according to ASTM type methodO Max.
pot temp. 325C, heating rate 2C/min. Max. distillate temperature 225C, Vac. 0.1 mm.
bAt 6 min. 35 sec. residence time all the residue which might have been coke stayed in the coil. Plugging occurred. Reaction was terminated after 100 g of Boscan heavy oil was fed to tubular reactor 51 (reactor volume equal to 73 g of oil).
1%;2 ~52 CSlow build-up of coke formation in the tubular reactor.
dVacuum distillate.
Two other experiments were run in the continuous flow tubular reactor 51 of Figure 3 under identical con-ditions to those detailed above, except that the pres-sure was 2500 and 3500 psi, respectively. In both experiments, coke formation occurred thereby clogging the tubular reactor and the reaction was terminated after 100 g of Boscan heavy crude oil had been Eed to tubular reactor 51.
30' i
Claims (22)
1. A process for converting heavy hydrocarbons into light hydrocarbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25°C of less than about 20 with a liquid comprising water, in the absence of exter-nally added catalyst and hydrogen, at a temperature between about 380°C-480°C and at a pressure between about 5000 kPa and about 15,000 kPa, and for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water and light hydrocarbon product having an API gravity at 25°C of greater than about 20 and substantially free of vanadium and nickel values;
and (f) recovering said light hydrocarbon product.
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25°C of less than about 20 with a liquid comprising water, in the absence of exter-nally added catalyst and hydrogen, at a temperature between about 380°C-480°C and at a pressure between about 5000 kPa and about 15,000 kPa, and for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water and light hydrocarbon product having an API gravity at 25°C of greater than about 20 and substantially free of vanadium and nickel values;
and (f) recovering said light hydrocarbon product.
2. The process of claim 1 wherein the temperature of the first and second zones is between about 400° and about 470°C and the pressure of the first and second zones is between about 7,000 kPa and about 13,000 kPa.
3. The process of claim 1 wherein the first and second zones comprise a flow reactor.
4. The process of claim 1 wherein the light hydro-carbon product has a total vanadium and nickel content of less than about 50 ppm.
5. The process of claim 1 wherein the heavy hydro-carbons have a viscosity at 25°C in the range of about 1,000 cp to about 100,000 cp and wherein the light hydrocarbon product has a viscosity at 25°C of less than about 10 cp.
6. The process of claim 1 wherein in step (e) said phase is separated by reducing the pressure and tempera-ture to values sufficient to allow separation of said phase into the gaseous product, the liquid comprising water and said light hydrocarbon product.
7. A process for converting heavy hydrocarbons into light hydrocarbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25°C of less than about 20 and a total vanadium and nickel content between about 1000 and 2000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380°C and about 480°C, about 5000 kPa and about 15,000 kPa for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and a light hydrocarbon product having an API gravity at 25°C of between about 20 and 40 and substantially free of vanadium and nickel values; and (f) recovering said light hydrocarbon product.
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25°C of less than about 20 and a total vanadium and nickel content between about 1000 and 2000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380°C and about 480°C, about 5000 kPa and about 15,000 kPa for a time sufficient to form a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and a light hydrocarbon product having an API gravity at 25°C of between about 20 and 40 and substantially free of vanadium and nickel values; and (f) recovering said light hydrocarbon product.
8. The process of claim 7 wherein the temperature of the first and second zones is between about 400° and 470°C and the pressure of the first and second zones is between about 7,000 kPa and 13,000 kPa.
9. The process of claim 7 wherein the heavy hydro-carbons have a viscosity at 25°C of at least about 60,000 cp and the light hydrocarbon product has a vis-cosity at 25°C less than about 10 cp.
10. The process of claim 7 wherein the first and second zones form a flow reactor.
11. The process of claim 10 wherein the light hydrocarbon product has a total vanadium and nickel con-tent of less than about 30 ppm.
12. The process of claim 10 wherein the light hydrocarbon product has a total vanadium and nickel con-tent of less than about 30 ppm.
13. The process of claim 10 wherein the gaseous product is less than 10 percent by weight of the heavy hydrocarbon stream.
14. The process of claim 7 wherein in step (e) said phase is separated by reducing the pressure and temperature to values sufficient to allow separation of said phase into the gaseous product, the liquid compris-ing water and said light hydrocarbon product.
15. A process for converting heavy hydrocarbons into light hydrocarbons which comprises:
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25°C of less than about 20 and a total vanadium and nickel content of between about 100 and 1000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380° and 480°C and at a pres-sure between about 5000 kPa and about 15,000 kPa for a time sufficient to produce a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and a light hydrocarbon prod-uct having an API gravity at 25°C of between about 20 and 40 and substantially free of vanadium and nickel values; and (f) recovering said light hydrocarbon product.
(a) contacting, in a first zone, heavy hydrocar-bons having an API gravity at 25°C of less than about 20 and a total vanadium and nickel content of between about 100 and 1000 ppm with a liquid comprising water, in the absence of externally added catalyst and hydrogen, at a temperature between about 380° and 480°C and at a pres-sure between about 5000 kPa and about 15,000 kPa for a time sufficient to produce a uniform mixture;
(b) forwarding the uniform mixture to a second zone while maintaining the temperature and pressure con-ditions of the first zone;
(c) maintaining the uniform mixture in the second zone under the temperature and pressure conditions of the first zone, in the absence of externally added cata-lyst and hydrogen, for a time sufficient to separate the uniform mixture into a residue and a phase comprising light hydrocarbons, gas and water;
(d) withdrawing the residue and said phase from the second zone;
(e) separating said phase into a gaseous product, a liquid comprising water, and a light hydrocarbon prod-uct having an API gravity at 25°C of between about 20 and 40 and substantially free of vanadium and nickel values; and (f) recovering said light hydrocarbon product.
16. The process of claim 15 wherein the tempera-ture of the first and second zones is between about 400°
and 470°C and the pressure of the first and second zones is between about 7,000 kPa and about 13,000 kPa.
and 470°C and the pressure of the first and second zones is between about 7,000 kPa and about 13,000 kPa.
17. The process of claim 15 wherein the heavy hydrocarbons have a viscosity at 25°C of at least about 30,000 cp and the light hydrocarbon product has a vis-cosity at 25°C less than about 10 cp.
18. The process of claim 15 wherein the first and second zones comprise a flow reactor.
19. The process of claim 18 wherein the light hydrocarbon stream has a total vanadium and nickel con-tent less than about 50 ppm.
20. The process of claim 18 wherein the light hydrocarbon stream has a total vanadium and nickel con-tent of less than about 30 ppm.
21. The process of claim 18 wherein the gaseous stream is less than 10 percent by weight of the heavy hydrocarbon stream.
22. The process of claim 18 wherein in step (e) said phase is separated by reducing the pressure and temperature to values sufficient to allow separation of said phase into the gaseous product, the liquid compris-ing water and said light hydrocarbon product.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US45071082A | 1982-12-17 | 1982-12-17 | |
| US450,710 | 1982-12-17 | ||
| US06/517,311 US4446012A (en) | 1982-12-17 | 1983-07-26 | Process for production of light hydrocarbons by treatment of heavy hydrocarbons with water |
| US517,311 | 1983-07-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1220152A true CA1220152A (en) | 1987-04-07 |
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ID=27036109
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000442994A Expired CA1220152A (en) | 1982-12-17 | 1983-12-09 | Process for production of light hydrocarbons by treatment of heavy hydrocarbons with water |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4446012A (en) |
| CA (1) | CA1220152A (en) |
Families Citing this family (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4543177A (en) * | 1984-06-11 | 1985-09-24 | Allied Corporation | Production of light hydrocarbons by treatment of heavy hydrocarbons with water |
| US4818370A (en) * | 1986-07-23 | 1989-04-04 | Cities Service Oil And Gas Corporation | Process for converting heavy crudes, tars, and bitumens to lighter products in the presence of brine at supercritical conditions |
| US4818371A (en) * | 1987-06-05 | 1989-04-04 | Resource Technology Associates | Viscosity reduction by direct oxidative heating |
| US4840725A (en) * | 1987-06-19 | 1989-06-20 | The Standard Oil Company | Conversion of high boiling liquid organic materials to lower boiling materials |
| DE19835479B4 (en) | 1998-08-06 | 2007-06-06 | Kjeld Andersen | Process for the catalytic removal of metal compounds from heavy oils |
| US7279017B2 (en) * | 2001-04-27 | 2007-10-09 | Colt Engineering Corporation | Method for converting heavy oil residuum to a useful fuel |
| JP3724438B2 (en) * | 2002-03-08 | 2005-12-07 | 株式会社日立製作所 | Method and apparatus for treating heavy oil with supercritical water, and power generation system equipped with heavy oil treatment apparatus |
| CA2426253A1 (en) * | 2003-04-22 | 2004-10-22 | Hurdon A. Hooper | Rubber reduction |
| JP4098181B2 (en) * | 2003-08-05 | 2008-06-11 | 株式会社日立製作所 | Heavy oil treatment method and heavy oil treatment system |
| US7435330B2 (en) * | 2003-10-07 | 2008-10-14 | Hitachi, Ltd. | Heavy oil reforming method, an apparatus therefor, and gas turbine power generation system |
| US7947165B2 (en) * | 2005-09-14 | 2011-05-24 | Yeda Research And Development Co.Ltd | Method for extracting and upgrading of heavy and semi-heavy oils and bitumens |
| ATE491861T1 (en) | 2006-02-07 | 2011-01-15 | Diamond Qc Technologies Inc | FLUE GAS INJECTION ENRICHED WITH CARBON DIOXIDE FOR HYDROCARBON EXTRACTION |
| US7922895B2 (en) * | 2006-06-14 | 2011-04-12 | Conocophillips Company | Supercritical water processing of extra heavy crude in a slurry-phase up-flow reactor system |
| US20070289898A1 (en) * | 2006-06-14 | 2007-12-20 | Conocophillips Company | Supercritical Water Processing of Extra Heavy Crude in a Slurry-Phase Up-Flow Reactor System |
| US8062512B2 (en) | 2006-10-06 | 2011-11-22 | Vary Petrochem, Llc | Processes for bitumen separation |
| US7758746B2 (en) | 2006-10-06 | 2010-07-20 | Vary Petrochem, Llc | Separating compositions and methods of use |
| EP2069467B1 (en) | 2006-10-06 | 2014-07-16 | Vary Petrochem, LLC | Separating compositions and methods of use |
| JP2009067951A (en) * | 2007-09-14 | 2009-04-02 | Hitachi Ltd | Apparatus for separating impurity of heavy oil |
| KR101577082B1 (en) * | 2007-11-28 | 2015-12-11 | 사우디 아라비안 오일 컴퍼니 | Process for upgrading heavy and highly waxy crude oil without supply of hydrogen |
| US20090166262A1 (en) * | 2007-12-28 | 2009-07-02 | Chevron U.S.A. Inc. | Simultaneous metal, sulfur and nitrogen removal using supercritical water |
| US8394260B2 (en) | 2009-12-21 | 2013-03-12 | Saudi Arabian Oil Company | Petroleum upgrading process |
| US9382485B2 (en) | 2010-09-14 | 2016-07-05 | Saudi Arabian Oil Company | Petroleum upgrading process |
| US9039889B2 (en) | 2010-09-14 | 2015-05-26 | Saudi Arabian Oil Company | Upgrading of hydrocarbons by hydrothermal process |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1851093A (en) * | 1927-08-03 | 1932-03-29 | Gensecke Maximilian | Method for distilling mineral oils |
| US2135332A (en) * | 1935-12-31 | 1938-11-01 | Gasoline Prod Co Inc | Conversion of hydrocarbon oil |
| US3983027A (en) * | 1974-07-01 | 1976-09-28 | Standard Oil Company (Indiana) | Process for recovering upgraded products from coal |
| US4113446A (en) * | 1975-07-22 | 1978-09-12 | Massachusetts Institute Of Technology | Gasification process |
-
1983
- 1983-07-26 US US06/517,311 patent/US4446012A/en not_active Expired - Fee Related
- 1983-12-09 CA CA000442994A patent/CA1220152A/en not_active Expired
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