CA1038165A - Fuel gas manufacture - Google Patents
Fuel gas manufactureInfo
- Publication number
- CA1038165A CA1038165A CA222,596A CA222596A CA1038165A CA 1038165 A CA1038165 A CA 1038165A CA 222596 A CA222596 A CA 222596A CA 1038165 A CA1038165 A CA 1038165A
- Authority
- CA
- Canada
- Prior art keywords
- sulfur
- process according
- gaseous mixture
- gasifying
- gaseous
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/46—Gasification of granular or pulverulent flues in suspension
- C10J3/54—Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/02—Fixed-bed gasification of lump fuel
- C10J3/06—Continuous processes
- C10J3/14—Continuous processes using gaseous heat-carriers
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/02—Fixed-bed gasification of lump fuel
- C10J3/20—Apparatus; Plants
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/46—Gasification of granular or pulverulent flues in suspension
- C10J3/48—Apparatus; Plants
- C10J3/482—Gasifiers with stationary fluidised bed
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/72—Other features
- C10J3/78—High-pressure apparatus
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J3/00—Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
- C10J3/72—Other features
- C10J3/82—Gas withdrawal means
- C10J3/84—Gas withdrawal means with means for removing dust or tar from the gas
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0913—Carbonaceous raw material
- C10J2300/0943—Coke
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0953—Gasifying agents
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0953—Gasifying agents
- C10J2300/0956—Air or oxygen enriched air
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/09—Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
- C10J2300/0983—Additives
- C10J2300/0993—Inert particles, e.g. as heat exchange medium in a fluidized or moving bed, heat carriers, sand
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/16—Integration of gasification processes with another plant or parts within the plant
- C10J2300/1603—Integration of gasification processes with another plant or parts within the plant with gas treatment
- C10J2300/1606—Combustion processes
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10J—PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
- C10J2300/00—Details of gasification processes
- C10J2300/18—Details of the gasification process, e.g. loops, autothermal operation
- C10J2300/1807—Recycle loops, e.g. gas, solids, heating medium, water
Abstract
FUEL GAS MANUFACTURE
ABSTRACT OF THE DISCLOSURE
A process for gasifying char or coke with heated sulfur dioxide to produce a combustible fuel gas.
ABSTRACT OF THE DISCLOSURE
A process for gasifying char or coke with heated sulfur dioxide to produce a combustible fuel gas.
Description
Ca5 e l~ 011 o 103~165 BACKG~OUND OF THE INVENTION
The present invention relates to gasifica-tion and more particularly to a continuous process for yielding a combustible gas from the gasification of char or coke.
There is a present day growing concern with the rapid depletion of natural gas and oil resources resulting from the rise in the industrial civilization level throughout the world. With this concern comes an acute awareness that immediate steps must be taken to conserve our gas and oil resources and to develop prccesses whereby greater use can be made of our ample coal reserves.
The use of coal as a fuel in e~ectric gen-erating power plants has been on a decline in recent years due to environmental constraints which rendered the conversion of coal to electricity uneconomical.
; Since coal is by far the most abundant of all fossil fuel reserves, the development of a process for pro-ducing clean fuel gas from coal or its by-products would reduce our dependence on natural gas and oil while providing an economical fuel capable of meeting ~ -the new environmental standards.
The basic process for converting solid coal to fuel gas in the form of carbon monoxide is well ~no-~n. In fact, the "town gas", used before the a~ailability of nat~ral gas, was produced by burning coal under a reducing atmosphere.
.. . .
-1- ~ ~ .
.
:
-, Case 4040 10a~1~5 , Present day coal gasification processes inuolve the combustion of char or coke with oxygen to yield a combustible gas through the following reaction:
C + 1/2 2 D C0 Another process for the use of air in lieu of oxygen and its reaction is expressed below:
- C + 1/2 2 + 1.88 N~ ~ C0 + 1.88 N2 .
Depending on the type of process, the upper temperature level during gasification is of prime concern due to reaction rates or kinetics.
In air-blown entrainment gasification, the short residence time in the high-temperature zone determines gas quality and the fraction of coal gasi-fied. Any variable that reduces temperature, such as a heat loss or presence of steam, detracts from gas quality. The disadvantage of this proces$ stems from the fact that air tends to dilute the coal gas pro-duced to an unsatisfactory low heat content and intro-duces nitrogen which cannot be economically removed from the produced coal gas.
- Where the process uses oxygen instead of air, there are generated such extreme temperatures that some steam addition is necessary to moderate the ~asification temperature. With steam addition, a second consuming reaction occurs to reduce heat liber-ation and produce hydrogen and carbon monoxide. 'rhe _~_ .. . .
.. , ............. i.. - .. .:-, - : .
Case 4040 disadvantage of oxygen-blown gas~fication is the high - cost of the associated oxygen plant.
SUMMA~Y OF THE INVENTION
The present invention relates to processes for obtaining carbon monoxide fuel gas from the reaction of gaseous sulfur dioxide with char or coke.
Accordingly, there is provided a main embodi-ment whereby hot char or coke is brought into direct contact with heated gaseous sulfur dioxide to produce a gaseous mixture of carbon monoxide and elemental sulfur. En-trained solids are removed from the gaseous mixture and the latter is cooled through indirect heat exchange so as to condense the sulfur thereby leaving a gas com-prised primarily of carbon monoxide and having the pre-- requisite heat value to qualify as a fuel.
The condensed sulfur is burned in the presence of heated air to produce a gaseous mixture of sulfur dioxide and nitrcgen which is then passed through a con- -ventional sulfur dioxide recovery system to effect separation of the nitrogen and sulfur dioxide, the latter is then heated preparatory to use as the gasifying agent.
Oxygen, from a separate source, may be added during the sulfur dioxide heating stage in the event that the gasi-fication temperature drops below the level required for sustained reaction.
An alternate embodiment of the invention dispenses with the need for a separate source of oxygen by providing a process whereby the heated gaseous sulfur dioxide used for the gasification stage can be enriched 3 with up to 33% oxygen. This is achieved by conveying :
. ~ . :. .
.
- Case 4040 the gaseous mixture of sulfur dioxide and nitrogen, produced in the sulfur burning stage, through a eon-ventional system,-such as that used for the manu-facture of oleum, and whieh subjects the gaseous mixture to eatalytie oxidation in the presenee of air ~ `
thereby producing a gaseous mixture of sulfur trioxide and nitrogen and which thereafter separates the nitrogen and the sulfur trioxide, the latter is then heated to a temperature level causing the dissociation of sulfur trioxide into oxygen enriched sulfur dioxide to be used as the gasifying agent.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation of a system embodying the invention as related to a process for yielding a eombustible gas from the gasification of ehar or coke.
Figure 2 is a schematic representation o~ an alternate system embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE I~ENTION
Figures 1 and 2 are schematic illustrations of systems which are related to processes whereby sulfur dioxide is used to gasify earbonaeeous matter to yield a eombustible fuel gas.
In aeeordanee with the present invention, hot earbonaceous matter 12 is supplied to a gasifier 14 to be contacted therein by a heated eontinuous stream 16 of eoneentrated sulfur dioxide. The earbonaeeous matter 12 must contain less than 1%, by weight~ of hydrogen and is either ehar derived from a conventional gasificatlon proeess or eoke sueh as that used for various metal-_4_ ~ . .
:- Case 4040 lurgical processes.
The sulfur dioxide reacts with the char or coke to produce a gaseous mixture 18 of carbon monoxide and elemental sulfur.
The reaction in the system depicted in Figure 1 is as follows:
2C (Char or Coke) + S02 ~ 2C0 + 1/2 S
The reaction in the system depicted in Figure 2 includes enrichment with up to 33% oxygen and is as follows:
3C + S02 + 1/2 2 ~ 3C0 + 1/2 S2 The char or coke contained within the gasifier 14 may be either in a fixed or fluidized state, the latter condi~ion being maintained by the flowing stream of heated sulfur dioxide.
The gaseous mixture 18 is conveyed from the gasifier 14 to a gas-solids separator for the removal of ungasified parti-culates 22. The gas-solids separator 20 is one of many presently known in the art, for example, a mechanical or bed-filter type separator.
The substantially solids-free gaseous mixture 24 of carbon monoxide and elemental sulfur exiting from the separator 20 is conveyed to a sulfur condenser 26 which is a known indirect type heat exchanger, for example, a shell and tube heat exchanger, preferably one having the gaseous mixture 24 flowing through theltubes and the entering coolant 28 passing over the tubes, and exiting as shown by 28A. The heat exchanger parameters are such that the gaseous mixture 24, within the con- ;
denser 26, is maintained at a controlled temperature in the range of 280F to 315F to dissociate the carbon monoxide and elemental sulfur as follows:
-. - : , . : :
- - Case 4040 2co + 1/2 S2(Gas) . ~ 2cO (100% CO) + S(Li id) - The combustible fuel gas 30, produced in accordance with the present invention,has a carbon monoxide content in the range of 95% to 100% and a heat value in excess of 300 Btu/scf. The fuel gas 30 leaving the condenser 26 is a high quality clean gas which may be used as fuel in a second stage combustion device or as a feed gas for petrochemical applications.
- The elemental sulfur contained within thegaseous mixture 24 is liquified in the condenser 26 and is thereafter conveyed as liquid sulfur 32 to a sulfur burner 34 and associated combustion chamber 36 of a type known in the art, for example, the burner and combustion chamber disclosed in U.S. Pat. No. 3,723,068 issued on March 27, 1973, in the name of R.A. McIlroy et al. The liquid sulfur 32 is entrained by a regulated quantity of heated air 38 and burned to produce a gaseous ;~
mixture 40 of sulfur dioxide and nit~ogen as follows:
s + 4.76 Air ~ S02 + 3 - 76 N2 .
The gaseous mixture 40 is conveyed, to a fluid heater 42 of a type known in the art, for example, the fluid heater disclosed in U.S. Pat. No. 2,447,306 issued on August 17, 1948, in the name of E.G. Bailey et al.
The fluid heater 42 has communicating upper and lower chambers 44 and 46, respectively, and includes an elevator 48 which receives cooled refractory particles from the lower chamber 46 and returns them to the upper chamber 44 to be reheated. The gaseous mixture 40 gives up heat to the refractory particles as it passes through the upper chamber 44. The heated refractory particles - Case 4040 ~038165 flow into the lower chamber 46 where they, in turn~
- give up heat to the gases passing therethrough.
Referring specifically to Figure 1, the cooled gaseous mixture 40A, exiting from the fluid heater 42, is conveyed to a sulfur dioxide concentrator 50 wherein the nitrogen 52 is removed thereby leaving a concentrated gaseous stream 16A containing in excess of 99% of sulfur dioxide. The concentrator 50 is of a type known in the art, for example~ the recovery system disciosed in U.S. Pat. No. 3,758,668 issued on September 11, 1973, in the name of W.C. Lapple et al, and which employs a slurry, containing magnesium oxide, to absorb the sulfur dioxide from the gaseous mixture 40A, and to form magnesium sulfide crystals which are thereafter separated from ~e slurry and heated to re-duce the water of crystallization, and are pelletized - with carbon and a binder to form pellets which are thermally treated for dissociation into reactive magnesium oxide particles and gaseous sulfur dioxide, ~he former being returned to the absorption ~one of the recovery system. s~
The gaseous stream 16A of sulfur dioxide, exiting from the concentrator 50 is routed to the lower ~ -chamber 46 of fluid heater 42 to be heated by the re-fractory particles circulating therethrough. The heated gaseous stream'16 of sulfur dioxide leaving the lower chamber 46 is conveyed to the gasifier 14 for the manu-facture of combustible fuel gas. A separate source 54 of nitrogen-free oxygen is available to supply a re-gulated quantity of oxygen 56 to the lower chamber 46 for oxygen enrichment of the gaseous stream 16 of sulfur dioxide, whenever required, to maintain the temperature --7~
.
Case 4040 necessary for sust ~ ne ~reaction within the gasifier 14.
Referring specifically to Figure 2, there is shown a system which provides for the addition of up to 33% oxygen to the heated gaseous stream 16 of sul-fur dioxide, used for gasification, without resort to a cryogenic oxygen plant. The system uses the reversible sulfur dioxide to sulfur trioxide reaction in the manner set forth below:
T< 1800F~
S2 + 1/2 2 so3 ~ > l~OO~F
In accordance with the invention, the gaseous mixture 40A of sulfur dioxide and nitrogen, exiting from the upper chamber 44 of fluid heater 42, is routed to a conventional system, such as that used in the manu-facture of oleum, and including a catalytic oxidizer 62 wherein the sulfur dioxide ccntained in the gaseous mixture 40A is oxidized by the air 60 in the presence of a catalyst, for example, vanadiump~ntoxide orplatinum, which speeds up the reaction without a~fecting the equilibrium. The catalytic oxidation stage'takes place at a reaction temperature of less than 1800F, usually in the range of 700F to 850F and is expressed as foll~ws: .
S2 + 3-76 N2 + 2.38 Air T= 750F to 8000F
The gaseous mixture 64, exiting from the catalytic oxidizer 62, may contain up to 85% diluent nitrogen with sulfur trioxide. The gaseous mixture 64 is fed to a sulfur trioxide co~centrator 66 for the separation of nitrogen 68 and concentrated sulfur tri-oxide 7. The separation stage is effected by using - Case 4040 highly concentrated sulfuric acid to scrub out the sulfur trioxide thereby obtaining sulfur trioxide enriched sulfuric acid, the latter ls then conveyed to an evaporator which gasifies the sulfur trioxide.
The gaseous stream 70 of sulfur trioxide, exiting from the concentrator 66 is routed to thelower chamber 46 of fluid heater 42 to be heated by the re-fractory particles circulating therethrough. The heat supplied in chamber 46 is at a temperature in excess of 1800F thereby decomposing the gaseous sulfur tri-oxide to oxygen enriched sulfur dioxide as expressed below:
T ~ 1800F S0 + 1/2 0 The heated gaseous stream 16 of sulfur dioxide enriched with up to 33% oxygen is conveyed to the gasi-fier 14 for the manufacture of combustible fuel gas.
While in accordance with provisions of the statutes there is illustrated and described herein a specific embodiment of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims; and that certain features of the invention may sometimes be used to advantage without a corresponding use of the other features,
The present invention relates to gasifica-tion and more particularly to a continuous process for yielding a combustible gas from the gasification of char or coke.
There is a present day growing concern with the rapid depletion of natural gas and oil resources resulting from the rise in the industrial civilization level throughout the world. With this concern comes an acute awareness that immediate steps must be taken to conserve our gas and oil resources and to develop prccesses whereby greater use can be made of our ample coal reserves.
The use of coal as a fuel in e~ectric gen-erating power plants has been on a decline in recent years due to environmental constraints which rendered the conversion of coal to electricity uneconomical.
; Since coal is by far the most abundant of all fossil fuel reserves, the development of a process for pro-ducing clean fuel gas from coal or its by-products would reduce our dependence on natural gas and oil while providing an economical fuel capable of meeting ~ -the new environmental standards.
The basic process for converting solid coal to fuel gas in the form of carbon monoxide is well ~no-~n. In fact, the "town gas", used before the a~ailability of nat~ral gas, was produced by burning coal under a reducing atmosphere.
.. . .
-1- ~ ~ .
.
:
-, Case 4040 10a~1~5 , Present day coal gasification processes inuolve the combustion of char or coke with oxygen to yield a combustible gas through the following reaction:
C + 1/2 2 D C0 Another process for the use of air in lieu of oxygen and its reaction is expressed below:
- C + 1/2 2 + 1.88 N~ ~ C0 + 1.88 N2 .
Depending on the type of process, the upper temperature level during gasification is of prime concern due to reaction rates or kinetics.
In air-blown entrainment gasification, the short residence time in the high-temperature zone determines gas quality and the fraction of coal gasi-fied. Any variable that reduces temperature, such as a heat loss or presence of steam, detracts from gas quality. The disadvantage of this proces$ stems from the fact that air tends to dilute the coal gas pro-duced to an unsatisfactory low heat content and intro-duces nitrogen which cannot be economically removed from the produced coal gas.
- Where the process uses oxygen instead of air, there are generated such extreme temperatures that some steam addition is necessary to moderate the ~asification temperature. With steam addition, a second consuming reaction occurs to reduce heat liber-ation and produce hydrogen and carbon monoxide. 'rhe _~_ .. . .
.. , ............. i.. - .. .:-, - : .
Case 4040 disadvantage of oxygen-blown gas~fication is the high - cost of the associated oxygen plant.
SUMMA~Y OF THE INVENTION
The present invention relates to processes for obtaining carbon monoxide fuel gas from the reaction of gaseous sulfur dioxide with char or coke.
Accordingly, there is provided a main embodi-ment whereby hot char or coke is brought into direct contact with heated gaseous sulfur dioxide to produce a gaseous mixture of carbon monoxide and elemental sulfur. En-trained solids are removed from the gaseous mixture and the latter is cooled through indirect heat exchange so as to condense the sulfur thereby leaving a gas com-prised primarily of carbon monoxide and having the pre-- requisite heat value to qualify as a fuel.
The condensed sulfur is burned in the presence of heated air to produce a gaseous mixture of sulfur dioxide and nitrcgen which is then passed through a con- -ventional sulfur dioxide recovery system to effect separation of the nitrogen and sulfur dioxide, the latter is then heated preparatory to use as the gasifying agent.
Oxygen, from a separate source, may be added during the sulfur dioxide heating stage in the event that the gasi-fication temperature drops below the level required for sustained reaction.
An alternate embodiment of the invention dispenses with the need for a separate source of oxygen by providing a process whereby the heated gaseous sulfur dioxide used for the gasification stage can be enriched 3 with up to 33% oxygen. This is achieved by conveying :
. ~ . :. .
.
- Case 4040 the gaseous mixture of sulfur dioxide and nitrogen, produced in the sulfur burning stage, through a eon-ventional system,-such as that used for the manu-facture of oleum, and whieh subjects the gaseous mixture to eatalytie oxidation in the presenee of air ~ `
thereby producing a gaseous mixture of sulfur trioxide and nitrogen and which thereafter separates the nitrogen and the sulfur trioxide, the latter is then heated to a temperature level causing the dissociation of sulfur trioxide into oxygen enriched sulfur dioxide to be used as the gasifying agent.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation of a system embodying the invention as related to a process for yielding a eombustible gas from the gasification of ehar or coke.
Figure 2 is a schematic representation o~ an alternate system embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE I~ENTION
Figures 1 and 2 are schematic illustrations of systems which are related to processes whereby sulfur dioxide is used to gasify earbonaeeous matter to yield a eombustible fuel gas.
In aeeordanee with the present invention, hot earbonaceous matter 12 is supplied to a gasifier 14 to be contacted therein by a heated eontinuous stream 16 of eoneentrated sulfur dioxide. The earbonaeeous matter 12 must contain less than 1%, by weight~ of hydrogen and is either ehar derived from a conventional gasificatlon proeess or eoke sueh as that used for various metal-_4_ ~ . .
:- Case 4040 lurgical processes.
The sulfur dioxide reacts with the char or coke to produce a gaseous mixture 18 of carbon monoxide and elemental sulfur.
The reaction in the system depicted in Figure 1 is as follows:
2C (Char or Coke) + S02 ~ 2C0 + 1/2 S
The reaction in the system depicted in Figure 2 includes enrichment with up to 33% oxygen and is as follows:
3C + S02 + 1/2 2 ~ 3C0 + 1/2 S2 The char or coke contained within the gasifier 14 may be either in a fixed or fluidized state, the latter condi~ion being maintained by the flowing stream of heated sulfur dioxide.
The gaseous mixture 18 is conveyed from the gasifier 14 to a gas-solids separator for the removal of ungasified parti-culates 22. The gas-solids separator 20 is one of many presently known in the art, for example, a mechanical or bed-filter type separator.
The substantially solids-free gaseous mixture 24 of carbon monoxide and elemental sulfur exiting from the separator 20 is conveyed to a sulfur condenser 26 which is a known indirect type heat exchanger, for example, a shell and tube heat exchanger, preferably one having the gaseous mixture 24 flowing through theltubes and the entering coolant 28 passing over the tubes, and exiting as shown by 28A. The heat exchanger parameters are such that the gaseous mixture 24, within the con- ;
denser 26, is maintained at a controlled temperature in the range of 280F to 315F to dissociate the carbon monoxide and elemental sulfur as follows:
-. - : , . : :
- - Case 4040 2co + 1/2 S2(Gas) . ~ 2cO (100% CO) + S(Li id) - The combustible fuel gas 30, produced in accordance with the present invention,has a carbon monoxide content in the range of 95% to 100% and a heat value in excess of 300 Btu/scf. The fuel gas 30 leaving the condenser 26 is a high quality clean gas which may be used as fuel in a second stage combustion device or as a feed gas for petrochemical applications.
- The elemental sulfur contained within thegaseous mixture 24 is liquified in the condenser 26 and is thereafter conveyed as liquid sulfur 32 to a sulfur burner 34 and associated combustion chamber 36 of a type known in the art, for example, the burner and combustion chamber disclosed in U.S. Pat. No. 3,723,068 issued on March 27, 1973, in the name of R.A. McIlroy et al. The liquid sulfur 32 is entrained by a regulated quantity of heated air 38 and burned to produce a gaseous ;~
mixture 40 of sulfur dioxide and nit~ogen as follows:
s + 4.76 Air ~ S02 + 3 - 76 N2 .
The gaseous mixture 40 is conveyed, to a fluid heater 42 of a type known in the art, for example, the fluid heater disclosed in U.S. Pat. No. 2,447,306 issued on August 17, 1948, in the name of E.G. Bailey et al.
The fluid heater 42 has communicating upper and lower chambers 44 and 46, respectively, and includes an elevator 48 which receives cooled refractory particles from the lower chamber 46 and returns them to the upper chamber 44 to be reheated. The gaseous mixture 40 gives up heat to the refractory particles as it passes through the upper chamber 44. The heated refractory particles - Case 4040 ~038165 flow into the lower chamber 46 where they, in turn~
- give up heat to the gases passing therethrough.
Referring specifically to Figure 1, the cooled gaseous mixture 40A, exiting from the fluid heater 42, is conveyed to a sulfur dioxide concentrator 50 wherein the nitrogen 52 is removed thereby leaving a concentrated gaseous stream 16A containing in excess of 99% of sulfur dioxide. The concentrator 50 is of a type known in the art, for example~ the recovery system disciosed in U.S. Pat. No. 3,758,668 issued on September 11, 1973, in the name of W.C. Lapple et al, and which employs a slurry, containing magnesium oxide, to absorb the sulfur dioxide from the gaseous mixture 40A, and to form magnesium sulfide crystals which are thereafter separated from ~e slurry and heated to re-duce the water of crystallization, and are pelletized - with carbon and a binder to form pellets which are thermally treated for dissociation into reactive magnesium oxide particles and gaseous sulfur dioxide, ~he former being returned to the absorption ~one of the recovery system. s~
The gaseous stream 16A of sulfur dioxide, exiting from the concentrator 50 is routed to the lower ~ -chamber 46 of fluid heater 42 to be heated by the re-fractory particles circulating therethrough. The heated gaseous stream'16 of sulfur dioxide leaving the lower chamber 46 is conveyed to the gasifier 14 for the manu-facture of combustible fuel gas. A separate source 54 of nitrogen-free oxygen is available to supply a re-gulated quantity of oxygen 56 to the lower chamber 46 for oxygen enrichment of the gaseous stream 16 of sulfur dioxide, whenever required, to maintain the temperature --7~
.
Case 4040 necessary for sust ~ ne ~reaction within the gasifier 14.
Referring specifically to Figure 2, there is shown a system which provides for the addition of up to 33% oxygen to the heated gaseous stream 16 of sul-fur dioxide, used for gasification, without resort to a cryogenic oxygen plant. The system uses the reversible sulfur dioxide to sulfur trioxide reaction in the manner set forth below:
T< 1800F~
S2 + 1/2 2 so3 ~ > l~OO~F
In accordance with the invention, the gaseous mixture 40A of sulfur dioxide and nitrogen, exiting from the upper chamber 44 of fluid heater 42, is routed to a conventional system, such as that used in the manu-facture of oleum, and including a catalytic oxidizer 62 wherein the sulfur dioxide ccntained in the gaseous mixture 40A is oxidized by the air 60 in the presence of a catalyst, for example, vanadiump~ntoxide orplatinum, which speeds up the reaction without a~fecting the equilibrium. The catalytic oxidation stage'takes place at a reaction temperature of less than 1800F, usually in the range of 700F to 850F and is expressed as foll~ws: .
S2 + 3-76 N2 + 2.38 Air T= 750F to 8000F
The gaseous mixture 64, exiting from the catalytic oxidizer 62, may contain up to 85% diluent nitrogen with sulfur trioxide. The gaseous mixture 64 is fed to a sulfur trioxide co~centrator 66 for the separation of nitrogen 68 and concentrated sulfur tri-oxide 7. The separation stage is effected by using - Case 4040 highly concentrated sulfuric acid to scrub out the sulfur trioxide thereby obtaining sulfur trioxide enriched sulfuric acid, the latter ls then conveyed to an evaporator which gasifies the sulfur trioxide.
The gaseous stream 70 of sulfur trioxide, exiting from the concentrator 66 is routed to thelower chamber 46 of fluid heater 42 to be heated by the re-fractory particles circulating therethrough. The heat supplied in chamber 46 is at a temperature in excess of 1800F thereby decomposing the gaseous sulfur tri-oxide to oxygen enriched sulfur dioxide as expressed below:
T ~ 1800F S0 + 1/2 0 The heated gaseous stream 16 of sulfur dioxide enriched with up to 33% oxygen is conveyed to the gasi-fier 14 for the manufacture of combustible fuel gas.
While in accordance with provisions of the statutes there is illustrated and described herein a specific embodiment of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims; and that certain features of the invention may sometimes be used to advantage without a corresponding use of the other features,
Claims (10)
1. A process for converting hot carbonaceous matter to gaseous fuel comprised primarily of carbon monoxide, and including the steps of:
gasifying the carbonaceous matter through direct contact with heated gaseous sulfur oxides to produce a gaseous mixture of carbon monoxide and sulfur, removing entrained solids from said gaseous mixture, obtaining said gaseous fuel from the substantially solids-free gaseous mixture by-condensing the sulfur through indirect heat exchange with a coolant, thermally reacting the condensed sulfur in the presence of air to produce a gaseous mixture of sulfur oxides and nitrogen, separating the sulfur oxides and the nitrogen of said last named gaseous mixture, and heating the sulfur oxides prior to gasifying said carbonaceous matter.
gasifying the carbonaceous matter through direct contact with heated gaseous sulfur oxides to produce a gaseous mixture of carbon monoxide and sulfur, removing entrained solids from said gaseous mixture, obtaining said gaseous fuel from the substantially solids-free gaseous mixture by-condensing the sulfur through indirect heat exchange with a coolant, thermally reacting the condensed sulfur in the presence of air to produce a gaseous mixture of sulfur oxides and nitrogen, separating the sulfur oxides and the nitrogen of said last named gaseous mixture, and heating the sulfur oxides prior to gasifying said carbonaceous matter.
2. The process according to claim 1 wherein the step of gasifying the carbonaceous matter comprises gasifying char.
3. The process according to claim 1 wherein the step of gasifying the carbonaceous matter comprises gasifying coke.
4. The process according to claim 1 includ-ing the step of fluidizing said carbonaceous matter.
5. The process according to claim 4 wherein the step of fluidizing said carbonaceous matter comprises fluidizing with heated gaseous sulfur oxides.
6. The process according to claim 1 wherein the step of thermally reacting the condehsed sulfur in the presence of air includes burning the sulfur to pro-duce a gaseous mixture of sulfur dioxide and nitrogen.
7. The process according to claim 6 wherein said gaseous mixture of sulfur dioxide is oxidized in the presence of air and a catalyst to produce a gaseous mixture of sulfur trioxide and nitrogen.
8. The process according to claim 7 wherein the step of heating the gaseous sulfur oxides includes decomposing sulfur trioxide to sulfur dioxide and oxygen.
9. The process according to claim 1 wherein the step of gasifying the carbonaceous matter comprises gasifying carbonaceous matter having less than one per-cent by weight of hydrogen.
10. The process according to claim 1 wherein the step of heating the sulfur oxides comprises heating said sulfur oxides to a temperature in excess of 1800°F.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US500817A US3904387A (en) | 1974-08-26 | 1974-08-26 | Fuel gas manufacture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1038165A true CA1038165A (en) | 1978-09-12 |
Family
ID=23991069
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA222,596A Expired CA1038165A (en) | 1974-08-26 | 1975-03-18 | Fuel gas manufacture |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3904387A (en) |
| CA (1) | CA1038165A (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4483693A (en) * | 1974-11-20 | 1984-11-20 | The Ralph M. Parsons Co. | Reforming of hydrocarbons in the presence of sulfur |
| US4396594A (en) * | 1981-12-28 | 1983-08-02 | Rockwell International Corporation | Sulfur dioxide reduction process |
| US4917024A (en) * | 1989-05-24 | 1990-04-17 | Florida Institute Of Phosphate Research | Coal fired power plant with pollution control and useful byproducts |
| US6024932A (en) * | 1993-05-11 | 2000-02-15 | Gas Research Institute | Method for the conversion of gypsum to elemental sulfur |
| US5686056A (en) * | 1996-02-05 | 1997-11-11 | Bechtel Group, Inc. | Methods and apparatus for purifying hydrogen sulfide |
| US8052949B2 (en) | 2009-05-11 | 2011-11-08 | Thermo Fisher Scientific Inc. | Generation of sulfur trioxide and sulfuric acid |
| US7901646B2 (en) * | 2009-08-05 | 2011-03-08 | General Electric Company | System and method for sulfur recovery |
| WO2017147681A1 (en) | 2016-03-04 | 2017-09-08 | Bogdan Wojak | Sulphur-assisted carbon capture and utilization (ccu) methods and systems |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3745109A (en) * | 1970-10-01 | 1973-07-10 | North American Rockwell | Hydrocarbon conversion process |
| GB1384711A (en) * | 1971-03-19 | 1975-02-19 | Exxon Research Engineering Co | Production of combustible gases |
| US3840354A (en) * | 1972-03-23 | 1974-10-08 | Us Interior | Three-stage gasification of coal |
-
1974
- 1974-08-26 US US500817A patent/US3904387A/en not_active Expired - Lifetime
-
1975
- 1975-03-18 CA CA222,596A patent/CA1038165A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3904387A (en) | 1975-09-09 |
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