CN1068336C - Process for polymerizing monomers in fluidized beds - Google Patents

Abstract

The present invention relates to a method for determining a stable operating area for polymerizing a gas phase fluidized bed and a gas phase polymerizing method. Specifically, a method for determining a stable operating area for a polymerization reactor of the gas phase fluidized bed operating in a condensation mode comprises the steps that FBD variation relative to the variation of fluidizing agent in a reactor is observed, the cooling power of the circulating material flow is enhanced by changing the components, and simultaneously, the circulating material flow can not exceed FBD to drop to an irreversible level.

Description

Process for polymerizing monomers in the fluidized-bed

The stable operation district that the present invention relates to gas fluidised bed polymerisation determines method and gas phase polymerization process, " gas fluidised bed polymerisation " refers to that wherein polymer beads is by containing monomeric air-flow cooling herein, and fluidisation and stirring also add or do not add churned mechanically polymerization process in addition.

Gas fluidised bed polymerisation equipment adopts circulation continuously, in its a part of reactor, use heat of polymerization heating cycle air-flow, and another part that should heat is removed in round-robin another part by the outer cooling system of reactor, wherein add catalyzer continuously or intermittently and add the monomer that monomer replaces consumption in addition, take out polymer particle and promptly come to an end.

Large-scale equipment is very expensive and productivity is high, and lose greatly stoppage time, and the danger of test therein is big, so sees the boundary that is difficult to definite design and operates from expense and dangerous angle.

The present invention proposes to promote the stable operation district of gas fluidised bed polymerisation of Optimum Design and the processing condition that require in the just given equipment design to determine method.

The gas fluidized bed bioreactor of may command and meet the requirements of melt index and optimize density polymer under the productive rate, wherein care should be used to is avoided occurring forming the unstable fluidized bed that formation can be collapsed under bulk or band or the worse situation or is made polymer beads clinkering condition together, therefore must control fluidized-bed to reduce the formation of bulk and band and to prevent from bed to collapse or exempt the operation of termination reaction and off-response device, just why industrial reactor will be in verified stable operational zone excellent operation and the reason of using in the mode of careful design for this.

Even under the safe operational constraints condition of routine, if want to seek new improvement operational condition, control is complicated too, can further increase the difficulty and the uncertainty of test.

Can determine service temperature by polymkeric substance and catalyzer, comonomer and monomeric ratio and hydrogen and monomeric ratio target value, again reactor and cooling system are located in the compression set, material is wherein monitored, and do not go unnecessarily to disturb fluidisation, wherein measure (1) top pressure, (2) different heights pressure reduction in the bed, (3) bed upstream temperature, (4) temperature and bed downstream temperature and (5) gas composition and (6) gas flow rate in the fluidized-bed, use these measured value control catalyst feeding quantity then, monomer dividing potential drop and circulation gas flow velocity, and in some cases according to the equipment design scheme with ash content limit polymerization thing extraction amount in deposition loose density (not fluidisation) or fluidisation loose density (this also must monitor) and the polymkeric substance.Equipment is closed system, and the variation of one or more measured value can cause other place to follow variation in the operation, and the factor that provides constraints most in the overall design is depended in the optimization of capacity when equipment design.

What reason to cause the formation of bulk or band as for, the general not consistent viewpoint of accepting, the part that wherein obviously comprises polymer beads is molten sticking, this may be that heat transfer that cause causes inadequately because fluidisation in the fluidized-bed is improper, but up to the present not finding has tangible relation between the formation of each component and measured value and bulk and band, therefore often whole measured values and measure of control are remained in the operating restraint of known safe for given equipment design scheme.

This just requires to develop the gas fluidised bed polymerisation technology that reactor reaches maximum yield.

Jenkins et al has illustrated the difficulty and the complicacy of overall control and has attempted to expand the stable operation district that can improve space-time yield in US4588780 and 4543399.

Jenkins et al adds reactor with circulation gas cooling back, temperature is lower than dew point, phlegma is evaporated in reactor, the circulation gas cooling capacity further increases, certainly the Cooling Heat Transfer medium under the fixed temperature, wherein one of said scheme is to add the non-polymeric material (iso-pentane) that improves dew point, but because the greater amount cooling makes more heat abstraction, so allegedly can reach higher space-time yield.Be no more than 20wt% in the Jenkins et al suggestion circulation gas, the phlegma of preferred 2-12wt%, the potential hazard of wherein mentioning comprises formation " mud " (US4588790, col.5, lines 35-39), therefore to keep sufficiently high circulation gas speed (col.6, lines12-20) or avoid liquid on distribution plate, to gather (col.6, lines 28-32).Have only and the condensation material is directly added fluidized-bed (col.8 lines16-20), just may use the condensation product more than 20%.

Angle from this invention, particularly advantageous is example 6,7 and 10a, wherein in circulation gas, use 14.2 respectively, 10.5, it is as cold as 65.9,34.0 and 53.5 ℃ respectively with the 12.9mol% iso-pentane, thereby reach the phlegma level and 7.0,10.7 and 6.2lb/hr-ft of 11.510.5 and 14.3wt% respectively ³(111.6,170.5 and 98.8kg/hr-m ³) the time yield.

Jenkins et al。How many upper limits of not speaking of polymerizable not or polymerizable condensation material is, also do not speak of and how to optimize space-time yield with condensing mode.Jenkins etal。Also do not give the fluidisation loose density any special effect, the component relationship that does not more propose recycle stream is to any suggestion determined to the stable operation district of high space-time yield.

Therefore the present invention seeks to propose to help to determine the measure of fluidized-bed process stable operation district and equipment design scheme, seek dangerous low safety operation technology of abnormal operation and the reactor productive rate is high simultaneously criterion and/or avoid because of the reactor productive rate may be to any restriction of equipment total volume.

The present invention can utilize for given other polymkeric substance of level and/or catalyzer composition variation fluidisation loose density (FBD) and optimize processing condition and equipment design scheme.Jenkins etal。Thinking that phlegma per-cent helps to limit the upper limit of the amount of cooling water that can carry out and therefore determines can reach how high space-time yield, and the present invention uses the FBD qualification and may comprise the al than Jenkins et.The area of safe operation of described amount greater amount phlegma.

Therefore first aspect present invention relates to the fluidised bed polymerisation method, comprise monomeric gaseous stream and flow through and have the fluidized-bed reactor of catalyzer and make polymerisate and comprise the logistics of unreacted monomer gas comprising under reaction conditions, allowing, to mix with the charging composition after this logistics compression and the cooling and send gas phase and liquid phase back to reactor, the method of wherein determining steady operation conditions comprises in (a) observing response device forming with fluidizing medium and changes relevant fluidized-bed loose density or its indication parameter changes and (b) improve the recycle stream cooling power by forming to change, and forms to change to be no more than fluidisation loose density or its indication parameter to be reduced become irreversible level.The fluidisation loose density is called FBD in the following text, and the deposition loose density is called SBD in the following text.In general, the ratio of FBD and SBD drops to and just has the danger that fluidized-bed collapses below 0.59, should be avoided.

FBD is upwards through the mensuration pressure drop of center fixation part and the ratio of this section height in the reactor.Should see, under some condition known to those skilled in the art, can record the mean value that is greater than or less than actual bed loose density.

The applicant finds, along with the condensable components concentration in the gaseous stream of the bed of flowing through raises, can reach a discernible point, just might make technology cause the danger of ruining and losing efficacy if concentration continue to raise and surpass this, the feature of this point is that condensable fluid concentrations improves and will make fluidized bed densities that irreversible variation takes place in the gas.The amount of liquid that enters the recycle stream of reactor may be not directly related, FBD reduces generally can't make the finished product particulate SBD respective change, so the fluid effect variation that the FBD reduction is reflected can't make polymer beads characteristic generation permanent change significantly.

The condensable fluid concentrations of gas that FBD is reduced depends on polymer type and other processing condition of manufacturing, and its discrimination method is to improve condensable fluid concentrations in the gas and monitor FBD for given polymer type and other processing condition.

Condensable fluid concentrations in gas and, FBD depends on other variation, the gas superficial velocity that comprises the reactor of for example flowing through, fluidized bed height and product SBD and gas and pellet density, temperature and pressure, therefore change in the test that causes the FBD variation at the condensable fluid concentrations of gas, should avoid the noticeable change of other condition.

Can be not out of control although FBD to a certain degree descends, but the gas composition or the further variation of other variable that can improve dew point simultaneously may make FBD that tangible irreversible reduction takes place, thereby " focus " takes place in reactor beds and/or emerge frit, this can make reactor shutdowns in case of necessity.

Other actual result directly related with the FBD reduction comprises that the polymkeric substance capacity of fixed volume reactor blowdown system descends and polymkeric substance/hydrogen-catalyst reactor residence time shortening under constant production rate of polymer, for given catalyzer, this latter can reduce catalyst production and improve in the product polymer catalyst residue water gaging flat.In using practice of the present invention,, require to reduce as far as possible condensable fluid concentrations in the gas for given goal response device production rate and accessory cooling requirement.

Using this FBD changes, can determine the stable operation district, in case think through discriminating to reach stable composition, then can use said composition to make recycle stream reach higher cooling capacity (can not cause the bed instability), wherein cooling off said composition to a greater extent.Specified phase with appropriate amount add condensable can not polymer material and reach high reactor productive rate, can in fluidized-bed, keep good condition again simultaneously, wherein hold it in so definite stable operation district.But the reactor productive rate of Da Genggao or the equipment of designing bigger throughput when equipment design with quite little reactor diameter maybe can improve existing installation to improve throughput under the situation that does not change reactor size in technology.

Under higher reactor productive rate, found to be in FBD changes and can reach in the border that limits be much higher than 15%, 20% or even 25% phlegma level, can avoid fluidized-bed remarkable bulk or the band that causes that collapse to form level simultaneously again.

Be not subject to the pressure difference observation FBD that interferential is partly measured in the advantageous applications fluidized-bed more than the distribution plate, and be to collapse with the bed above the normal indication of the FBD variation distribution plate of bed bottom under normal conditions, wherein the top FBD that records away from distribution plate is used as steadiness parameter, but sees shockingly that now top FBD changes relevant with the variation of logistics composition and the stable operation district is sought and limited to available its.

Cooling power improves by different way, preferably increase can improve the component ratio of dew point and improve cooling capacity, comprising strengthening polymerizable higher hydrocarbon content ratio not or strengthening the ratio of the polymerisable monomer that comprises 3-12 carbon comonomer on the other hand, wherein reduce not condensable inert component ratio.In special process, can further improve the cooling capacity of recycle stream in case of necessity by the temperature of for example refrigeration reduction fluidizing medium.The processing condition that behind the operational zone of determining safety, can be improved.

Therefore second aspect present invention is the phase fluid bed polymerizing method that proposes polymkeric substance, wherein under reaction conditions, allow and comprise that monomeric gas stream makes polymerisate and comprise the logistics of unreacted monomer by the fluidized-bed reactor that has catalyzer, to mix with the charging composition after this logistics compression and the cooling and gas phase and liquid phase loopback be gone into reactor, its improvement comprises that this logistics of cooling makes liquid phase reach 15 of loopback logistics gross weight, preferred 20wt% is above and allow the logistics composition make the ratio of FBD and SBD reach above 17.8: 30.2 preferred 18.1: 30.2.

Third aspect present invention is the phase fluid bed polymerizing method that proposes polymkeric substance, wherein under reaction conditions, allow and comprise that monomeric gas stream makes polymerisate and comprise the logistics of unreacted monomer gas by the fluidized-bed reactor that has catalyzer, will this logistics compression and the cooling back mix with the charging composition and gas phase and liquid phase loopback gone into reactor, its improvement comprise the polymerizable that contains at least 3 carbon or not the polymerizable components amount make these group components FBD when increase 1mol% reversibly reduce.

Advantageously allow logistics cooling and its speed make its cooling power be enough to allow reactor productive rate (lbs polymkeric substance/hr-ft through reactor ²Cross-sectional reactor area) surpasses 500lb/hr-ft ²(2441kg/hr-m ²), 600lb/hr-ft especially ²(2929kg/hr-m ²), comprising from the enthalpy change of the recycle stream under the reactor outlet condition under reactor inlet condition 40Btu/lb (21.9cal/g) at least, preferred 50Btu/lb (27.4cal/g).Preferably, the liquids and gases component of this logistics adds below the reactor distribution plate to mix states of matter.This reactor productive rate equals space-time yield and takes advantage of fluidized bed height.

In another program of the present invention, recycle stream can be divided into two or the independent logistics of multiply, wherein one or the multiply logistics can directly introduce fluidized-bed, just fluidized-bed gas velocity following and the process fluidized-bed is enough to make bed to suspend, and can be divided into the liquids and gases logistics that can introduce reactor more respectively as recycle stream.

Improve one's methods when implementing in the present invention, can under the condition that generation is comprised the biphase logistics, inject liquid and circulation gas respectively with the recycle stream that comprises gas phase and liquid phase mixture of lower section and form at the reactor distribution plate.

Improve cooling power and can obviously improve the reactor productive rate through carefully controlling the composition of gaseous stream, reduce the danger that causes fluidized-bed to collapse, even available condensation greatly, wherein make liquid percentage raising in the recycle stream.For any given liquid percentage in the recycle stream, gas composition in the reactor, temperature, pressure and superficial velocity should be according to product particle composition and physical propertys and are controlled to keep variable fluidized-bed.

In the methods of the invention, can be by phlegma of carrying secretly in the vaporization cycle logistics and the cooling power that obviously improves recycle stream owing to have the bigger temperature difference between recycle stream that enters and the fluidized-bed temperature.Suitable finished product polymkeric substance can be selected from the film-grade material, its MI value 0.01-5.0, preferred 0.5-5.0 and density 0.900-0.930 or molding graae material, its MI value 0.10-150.0, preferred 4.0-150.0 and density 0.920-0.939 or high density material, its MI value 0.01-70.0, preferred 2.0-70.0 and density 0.940-0.970, all g/Cm of density unit ³, the g/10min of melt index unit all measures by ASTM-1238 condition E.

Above-mentioned purpose characteristics of the present invention and advantage can see for details in following and referring to accompanying drawing.

Fig. 1 is the reactor preferred version synoptic diagram that is used for the improvement phase fluid bed polymerizing method of polymkeric substance of the present invention.

Fig. 2 is iso-pentane mol% and a FBD line chart in the table 1.

Fig. 3 is iso-pentane mol% and a FBD relation line figure in the table 2.

Fig. 4 is the line chart that comprises Fig. 2 and Fig. 3.

Same parts is represented with same reference number in this paper and the accompanying drawing, and figure draws in proportion, and wherein some part has been amplified more to clearly demonstrate the present invention.

The present invention is not limited in any concrete polymerisation, but especially is suitable for one or more monomers, such as olefinic monomer, such as ethene, propylene, butene-1, amylene-1,4-methylpentene-1, hexene-1, octene-1 and cinnamic polymerisation, other monomer can comprise polar vinyl, conjugation and non-conjugated diene, acetylene and aldehyde monomer.

This catalyst system therefor of improving one's methods can comprise the coordination anion catalyst, cationic catalyst, free radical catalyst, anionic catalyst also comprises transition metal component or metallocene, wherein with list or many cyclopentadiene component of metal alkyl or alkoxyl component or ionic compound component reaction. These catalyst comprise part and activate precursor composition and pre-polymerization or encapsulated when enforcement is of the present invention fully, the speed of gas flow and recycle stream should remain on enough levels so that the liquid phase in the mixture is suspended in the gas phase in the recycle stream, until recycle stream enters fluid bed, thereby liquid can not assembled the bottom below the distribution plate in reactor. The speed of recycle stream should be enough high to support and the mixed fluidized bed layer that in reactor the liquid that also requires to enter fluid bed disperses rapidly and evaporation.

Composition and physical property control gas composition according to polymer, temperature, pressure and superficial linear velocity in a column are very important for keeping feasible fluid bed, feasible fluid bed is defined as under reaction condition with stable state and suspends and good the mixing, and can not form the grain fluidized bed of the caking (bulk or band) that makes in a large number reactor or downstream process operation failure simultaneously.

The condensation of 15wt% recycle stream can be arranged or be in liquid phase, can not make again the fluid technology failure simultaneously, wherein the safety operation border by the definite stable operation district of FBD surpasses or breakthrough.

In polymerization technique, the air-flow of the fluid bed of upwards flowing through that (generally is less than about 10%) on a small quantity reacts, and a large amount of logistics of unreacted enter the zone that is called the free zone more than the fluid bed, this also can be deceleration area, wherein passes the surface by bubble and takes to more than the bed or the large solid polymer particle that is entrained in the air-flow can fall after rise into fluid bed. The little solid polymer particle of industrial being referred to as " fine powder " takes out with recycle stream, because it stops the speed that sinking speed is lower than recycle stream in the free zone.

In preferred version of the present invention, the recycle stream entrance preferably below fluid bed obtaining uniform recycle stream, thereby fluid bed remained suspended state and guarantees upwards uniformity through the recycle stream of fluid bed.

In another program of the present invention, recycle stream can be divided into the liquid and gas composition of introducing respectively reactor.

Advantage of the present invention is not limited in the production polyolefin, therefore any exothermic reaction of carrying out in the available gas fluid bed of the present invention is implemented, and the characteristics that are better than other method with the method for condensing state operation generally are directly to increase with the dew point of the recycle stream degree near reaction temperature in the fluid bed. For given dew point, the liquid phase percentage that the advantage of the method can be directly enters in the recycle stream in the reactor with loopback increases, and can use high percentage liquid in the technique of the present invention.

Be suitable for especially with the gaseous fluidized reactor of the inventive method production polymer clearly shown in the drawings, be referred to as 10 among Fig. 1, it should be noted that reaction system shown in Figure 1 only for schematic, the present invention in fact also is suitable for any conventional fluid bed reaction system.

Reactor 10 comprises reaction zone 12 and free zone among Fig. 1, this in fact also is deceleration area 14 in this case in the present invention, the ratio of the height/diameter of reaction zone 12 can change with the production capacity that requires and the time of staying, wherein comprise again and contain the polymer beads that is forming, the fluid bed of existing generation polymer beads and a small amount of catalyst, fluid bed in this reaction zone 12 is supported by the recycle stream 16 that generally is comprised of feed fluid and circulation of fluid, the distribution plate 18 of this recycle stream in section at the bottom of the reactor enters reactor, and this distribution plate helps to make in reaction zone 12 and reaches even fluidisation in the fluid bed and support this fluid bed. For being remained, reaction area liquefaction bed 12 suspends and reliable state, the empty tower gas velocity (SGV) of the air-flow of process reactor generally surpasses the desired lowest speed of fluidisation, be generally about 0.2ft/ sec (0.061m/s) to 0.5ft/sec (0.153 m/s), preferably be not less than about 0.7ft/sec (0.214m/s), more preferably be not less than 1.0ft/sec (0.305m/s), but preferably should be no more than 5.0ft/sec (1.5m/s), particularly 3.5ft/sec (1.07m/s).

Polymer beads in the reaction zone 12 helps to prevent emerging and keeping of part " focus " and distributes catalyst granules in whole fluid bed. Before introducing recycle stream 16, in reactor 10, add polymer beads matrix during the operation beginning; this polymer beads is preferably same with the novel polymer Particle Phase that will generate; if but not simultaneously then in the circulation beginning; catalyst flow into and set up reaction after its firstling with new formation is taken out, generally this this mixture and follow-up basically new production process are separated. The present invention improves one's methods middle catalyst system therefor usually to oxygen sensitive, therefore preferably is stored in the catalyst tank 20, wherein uses to being deposited the gas that catalyst is inertia, such as argon or nitrogen (but being not limited to this) protection.

The recycle stream 16 of reactor 10 of flowing through reaches the fluid bed fluidisation that can make at a high speed in the reaction zone 12, generally about 10-15 is doubly to the speed of introducing charging in this recycle stream 16 for the speed of recycle stream 16 during operation, and the high like this speed of recycle stream just empty tower gas velocity is enough in reaction zone 12 fluid bed and suspends and mix and be fluidized state.

The fluid bed outer appearnce is similar to the liquid of abundant boiling, and wherein closely knit particle makes its independently moving by diafiltration and the air-blowing bubble of gas process fluid bed. Recycle stream 16 can produce pressure drop after through the fluid bed in the reaction zones 12, and its value is equal to or slightly greater than fluid bed weight in the reaction zone 12 divided by the cross-sectional area of reaction zone 12, so this physical dimension with reactor is relevant.

Combined feed enters recycle stream 16 among Fig. 1, and its position is point 22, but is not limited in this. Gas analyzer 24 receives gaseous sample on the recycle streamlines 16 and monitoring flow through the composition of wherein recycle stream 16, this analyzer also can be regulated the composition of recycle stream line 16 and charging the stable state in the reaction zone 12 is maintained in the compositing range of recycle stream 16, this analyzer general analysis between free zone 14 and heat exchanger 26, the preferred sample that from recycle streamline 16, takes out of the point between compressor 28 and heat exchanger 26.

Recycle stream 16 reaction zone 12 of upwards flowing through, the heat that the absorbing polymer reaction produces, after this part recycle stream 16 of not participating in reaction in reaction zone 12 is discharged from reaction zone 12 through free zone 14. As previously mentioned, this zone is deceleration area, and the polymer that major part is carried secretly falls after rise into fluidized bed reaction zone 12, thereby reduces the load that solid polymer particle enters recycle streamline 16. Recycle stream 16 is in case just take out catalyst in modification from reactor on free zone 14.

Although be not limited in as previously mentioned any concrete polymerisation among the present invention, the following operation discussion of improving one's methods mainly refers to the polymerization of olefinic monomer, such as polyethylene, can find that wherein the present invention is advantageous particularly.

The technological operation temperature is decided to be or is adjusted to the melting of making polymer beads or below the fusible temperature, it is very important that the polymer bulk that keeps this temperature to form rapidly when preventing that temperature from raising is stopped up reactor, wherein these polymer bulks may can not be extracted out from reactor as polymerizate too greatly, and may make technique and reactor invalid, and the bulk that enters polymer downstream technique also may be destroyed and for example transmits system, drying device or extruder.

Improve obviously augmenting response device productive rate of fluidised bed polymerisation method with the present invention, and can not make product quality or performance generation marked change simultaneously. In this preferred version, the whole polymerization techniques of the present invention carry out continuously.

For reaching higher cooling capacity and therefore reaching higher reactor productivity, may require to improve the dew point of recycle stream so that the heat that removes from fluid bed strengthens, wherein can improve the operating pressure of reaction/recycle stream and/or improve the percentage of condensable fluid and reduce in the recycle stream the not percentage of condensable gases, method has seen Jenkins et al., US4588790 and 4543399. Condensable fluid is to catalyst, and reactant and polymerizate may be natural instincts, also can comprise comonomer, can see for details in Fig. 1 at any its introducing reaction/circulating system of naming a person for a particular job of process system, its suitable example is volatile liquid hydrocarbon, can be selected from 2-8 carbon saturated hydrocarbons, such as propane, normal butane, iso-butane, pentane, isopentane is newly defended alkane, n-hexane, isohexane and other saturated C₆Hydrocarbon, normal heptane, normal octane and other C₇And C₈Hydrocarbon or its mixture, preferred C₅And C₆Saturated hydrocarbons wherein also can comprise the condensable comonomer of polymerizable, and such as alkene, alkadienes or its mixture wherein contain some above-mentioned monomer that can partially or completely add the said goods. Then compression passes through heat exchanger 26 in the compressor 28, its loopback is entered the reaction zone 12 in the reactor 10 after wherein the heat of polymerisation and gas compression generation is taken out from recycle stream 16 again. Heat exchanger 26 also can be placed in the recycle stream pipeline 16 by vertical or horizontal mode for general type, is provided with heat transfer zone or compressional zone more than one in another program of the present invention in the recycle stream pipeline 16.

Recycle stream 16 among Fig. 1 is in case out just enter reactor 10 bottoms from heat exchanger 26, preferably at gas distribution plate fluid deflection plate 30 is set below 18, enter solid portion in order to prevent the polymer sedimentation from dropping out and in the recycle stream 16 of distribution plate below 18, keep liquid and polymer beads to carry secretly, preferred deflection plate is the ring dish type, as described in US4933149, can reach like this center upwards and outward flange flow, the center helps at the bottom entrained drip to the upper reaches, and outwards marginal flow helps to reduce as far as possible polymer beads in the bottom and piles up. Distribution plate 18 is in the center in the logistics or jet at upper reaches with this logistics that recycle stream 16 disperses to avoid entering reaction zone 12, because this may make the fluid bed fluidisation failure in the reaction zone 12.

The temperature of fluid bed can be determined according to the particle stick point, but basically depend on three factors: (1) catalyst activity and catalyst injection rate, the speed that this can control polymerization speed and produce heat, (2) introduce the circulation of reactor and mix stream temperature, pressure and forming and the flow through volume of fluid bed of (3) recycle stream. To affect temperature especially with recycle stream or such as the above-mentioned amount of liquid that is introduced separately into bed, reduce the temperature of fluid bed because liquid evaporates in reactor, usually add the rate controlling polymers formation speed with catalyst.

The fluidized-bed temperature of reaction zone 12 keeps constant in steady state in preferred version, wherein take out reaction heat continuously, generate the steady state that will occur reaction zone 12 when heat obtains balance by the heat that takes out in technology, the total inventory that wherein requires to enter polymerization technique obtains balance by the polymkeric substance of taking-up and the amount of other material.Therefore, any set point temperature in technology, pressure and composition are constant in time, in most of fluidized-bed of reaction zone 12, there is not tangible thermograde, but it is to there are differences between the fluidized-bed temperature of the temperature of the recycle stream 16 that distribution plate 18 enters and reaction zone 12 in the bottom of reactor 10 that the fluidized-bed of the reaction zone 12 in the zone on the gas distribution plate 18 bottom exists thermograde, reason.

The valid function of reactor 10 requires well distributed recycle stream 16, if forming or established polymkeric substance and granules of catalyst can sedimentations from fluidized-bed, polymkeric substance just may melt, and this can cause forming solid matter in whole reactor under extreme case.The reactor of commercially available size all contains into the polymer beads of kip or kilogram at any given time, remove a large amount of like this polymer solids materials and just may bring very big difficulty, and this requires to do very big effort and will stop for a long time.Measure definite stable operational zone by FBD, just can carry out improved polymerization process, wherein in the reaction zone 12 of reactor 10, keep the fluidisation and the support of fluidized-bed.

In preferred version of the present invention, introduce the liquid evaporation of reactor 10 and reach the increase superiority of the reactor cooling ability of this polymerization technique.Big quantity of fluid can promote oarse-grained formation in the bed, and this can not be broken with the mechanical force in the bed, thereby might cause fluidisation to lose efficacy, and bed collapses and reactor shutdowns.In addition, exist liquid may influence local bed temperature and have the ability of the polymkeric substance of constant performance with this explained hereafter, because this requires to reach in the bed temperature of substantially constant, the amount of liquid of for this reason introducing fluidized-bed under specified criteria should be not more than the amount that the fluidized-bed bottom will be evaporated, and wherein recycle stream enters and be enough to make by the mechanical force of distribution plate the piece material fragmentation of liquid-particle interaction formation.

Find among the present invention, given composition and physical property and other given or relevant reactor and cycling condition for product particle in the fluidized-bed, by the definition final condition relevant, can under height cooling level, keep reliable fluidized-bed with the gas composition of the bed of flowing through.

Observed FBD reduction can reflect the expansion of the close phase of particle in the fluidized-bed and the variation of bubbling operation, but reason also imperfectly understands.

As shown in Figure 1, generally add catalyst activator in interchanger 26 downstreams, add according to catalyst system therefor in case of necessity, can this catalyst activator be introduced recycle stream 16 from loader 32, but the present invention improves one's methods and is not limited in catalyst activator or any other requires composition, adds the implantation site as this of promotor.

Catalyzer intermittently or continuously can be injected fluidized bed reaction zone 12 with favor speed from its basin, the position is at the point 34 of gas distribution plate more than 18.In above-mentioned preferred version, catalyzer in fluidized-bed 12 with can change the point finished mixing of polymer beads most and inject, wherein because some catalyzer has activity, thus preferably should be more than 18 to the decanting point of reactor 10 at gas distributor, rather than below.Can make product at this region clustering at the regional injecting catalyst of gas distribution plate below 18, this may cause gas distribution plate 18 blocked again.And, help uniformly distributing catalyzer in fluidized-bed 12 at gas distribution plate 18 above injecting catalysts, therefore can avoid local catalyst concn too high and form " focus ".Preferably catalyzer is injected reaction zone 12 fluidized-bed bottoms to reach uniformly distributing and to reduce the possibility that catalyzer is brought into circulation tube as far as possible, because just may cause circulation tube and interchanger blocked if polymerization takes place in the circulation tube.

Available many catalyzer implantttion techniques in the present invention improves one's methods, as seen in the described technology of US3779712, its disclosure is for this paper reference.Preferably with indifferent gas such as nitrogen or under reactor condition volatile inert liq bring catalyzer into fluidized bed reaction zone 12, monomer concentration has been determined production rate of polymer in the fluidized bed reaction zone 12 in catalyzer injection speed and the recycle stream 16, but simple adjustment catalyzer injection speed and the production rate of controlling polymers.

In using reactor 10 preferred method of operation that the present invention improves one's methods, the fluidized bed height of reaction zone 12 can be by extracting partially polymerized product out and keep forming consistent speed with polymerisate.The condition of fluidized-bed variation in the instruments monitor reaction zone 12 of any temperature or pressure change in available energy assaying reaction device 10 and the recycle stream 16.And this instrument also can be by hand or the temperature of regulating catalyzer injection speed or recycle stream automatically.

Product is discharged from reactor through discharge system 36 when levying reactor 10 operations, preferably the tight thing of fluid and polymerization is separated afterwards, fluid can levy a little 38 as gas and/or levy a little 40 as phlegma loopback go into recycle stock pipeline 16, the tight thing of polymerization is then sent at point 42 and is carried out following process, but the discharge mode of polymerisate is not limited in shown in Figure 1, in fact Fig. 1 only shows a kind of special discharging method, certain available other discharge system is as seen in US4543399 and US4588790 (Jenkins et al.).

The present invention also proposes to levy the method that improves the polymer yield of reactor in the fluidized-bed reactor of using exothermic polymerization reaction, wherein recycle stream is cooled to its recycle stream loopback that also will obtain like this below the dew point and goes into reactor, the recycle stream that contains the above liquid of 15wt% can be recycled to reactor and require under the temperature so that fluidized-bed is remained on.

Can adopt different cycling conditions to reach the reactor output level that can not reach in the past according to the purpose material.

At first can be made into for example film-grade material, wherein butylene in the recycle stream/ethene mol compares 0.00-0.60, preferred 0.30-0.50 or 4-methylpentene-1/ ethene mol be than 0.00-0.50, and preferred 0.08-0.33 or hexene/ethene mol be than 0.00-0.30, preferred 0.05-0.20; Or octene-1/ethene mol is than 0.00-0.10, preferred 0.02-0.07; Hydrogen/ethene mol is than 0.00-0.4, preferred 0.1-0.3; And the cooling power of iso-pentane amount 3-20mol% or isohexane amount 1.5-10mol% and recycle stream is 40Btu/lb (21.9cal/g) at least, preferably 50Btu/lb (27.4cal/g) or condensation wt% at least 15 at least.

Next available this manufactured molding graae material, wherein recycle stream butene-1/ethene mol compares 0.00-0.60, preferred 0.10-0.50 or 4-methyl-amylene-1/ ethene mol compare 0.00-0.50, preferred 0.08-0.20 or hexene/ethene mol compare 0.00-0.30, preferred 0.05-0.12 or octene-1/ethene mol be than 0.00-0.10, preferred 0.02-0.04; Hydrogen/ethene mol is than 0.00-1.6, preferred 0.3-1.4; And iso-pentane amount 3-30mol% or isohexane amount 1.5-15mol% and recycle stream cooling power 40Btu/lb (21.9cal/g) at least, preferably 50Btu/lb (27.4cal/g) or condensation weight % at least 15 at least.

And can be made into high-density level material, recycle stream butylene/ethene mol compares 0.00-0.30 in its manufacture method, preferred 0.00-0.15 or 4-methyl-amylene-1/ ethene mol compare 0.00-0.25, preferred 0.00-0.12 or hexene/ethene mol compare 0.00-0.15, preferred 0.00-0.07 or octene-1/ethene mol be than 0.00-0.05, preferred 0.00-0.02; Hydrogen/ethene mol is than 0.00-1.5, preferred 0.3-1.0; And iso-pentane amount 10-40mol% or isohexane amount 5-20mol% and recycle stream cooling power 60Btu/lb (32.9cal/g) at least, preferred 73Btu/lb (40.0cal/g) at least, more preferably 75Btu/lb (41.1cal/g) or condensation wt% at least 12 at least.

Embodiment 1

Operations flows gasification phase reactor and make the multipolymer that contains ethene and butylene, catalyst system therefor is a tetrahydrofuran (THF), magnesium chloride and titanium chloride usefulness diethyl aluminum muriate (diethyl aluminum muriate/tetrahydrofuran (THF) mol is than 0.50) and tri-n-hexyl aluminum (tri-n-hexyl aluminum/tetrahydrofuran (THF) mol is than 0.30) reduction and the mixture that floods with the silicon-dioxide that triethyl aluminum is handled, activator is triethyl aluminum (TEAL).

Table 1 and data shown in Figure 2 show to be increased gradually along with the iso-pentane amount and reaches the reactor parameter of the necessary raising cooling power of high reactor productive rate, this example shows that excessive iso-pentane causes the fluidized-bed variation and collapse necessary off-response device because of forming focus and caking under extreme case.Along with iso-pentane concentration improves, FBD reduces, and shows that the bed fluidized state changes, and this can make bed height increase.Reduce catalyst velocity and reduce the bed level, can reduce iso-pentane concentration in addition so that the fluidized-bed inverse change, in this, though that bed height recovers is normal, but the bed that focus and caking cause to collapse be irreversible, so reactor need be closed.

And, in test for the second time, table 2 and Fig. 3 show along with iso-pentane concentration raises gradually, FBD reduction as shown in table 1, but current improved FBD gradually owing to reduced iso-pentane concentration, therefore in this case in the bed fluidized state change and can recover and can reverse.

Therefore, Fig. 4 shows the result of Fig. 1 and Fig. 2, clearly illustrates that wherein bed fluidisation change point is irreversible, because excessively used condensable fluid, the ratio that this point is defined as reactor bed FBD and SBD is less than 0.59 point.Example 1 clearly illustrates that to can be used to optimize with the space-time yield of the reactor of condensing mode operation or the condensable material of reactor productive rate certain limit.

Embodiment 2

Following examples are same as example 1 basically carries out, and wherein uses homopolymer and ethylene/butylene copolymers that similar catalyst and activator are produced various density and melt index range.

These tests show in the phlegma scale of construction situation that surpasses 20wt% and are issued to higher reactor productive rate, and keep the superiority of FBD and the ratio at least 0.59 of SBD simultaneously.

Because downstream processing technology is discharged system and forcing machine etc. as product, some reactor condition must be regulated so that be no more than total capacity of equipment, and therefore whole advantages of the present invention can not be shown by table 3 illustrated embodiment.

For example, in the listed test 1 of table 3, it is very low that superficial gas velocity keeps, about 1.69ft/sec (0.52m/sec), and therefore the space-time yield that reflects is just than much lower under other situation.If speed keeps about 2.4ft/sec (0.73m/sec), then estimate and to reach above 15.3lb/hr-ft ³(243.8kg/hr-m ³) space-time yield.The test 2 of table 3 and 3 the altitude tower gas velocity and under 20% the weight % condensation situation effect of operation reactor.The space-time yield that reaches is about 14.3lb/hr-ft ³(227.9kg/hr-m ³) and 13.0lb/hr-ft ³(207.2kg/hr-m ³), showing that production rate obviously improves, high like this STY or production rate are unexposed at all or mention in the document of Jenkins et al.Similar with test 1, the test 4 of table 3 shows superficial gas velocity 1.74ft/sec (0.53m/sec) under 21.8wt% condensed fluid situation, but if test 4 medium velocities are brought up to 3.0ft/sec (0.91m/sec), then accessible STY (space-time yield) can be from 7.7lb/hr-ft ³(122.7kg/hr-m ³) be raised to 13.3lb/hr-ft ³(212.0kg/hr-m ³), and if test 5 medium velocities are raised to 3.0ft/sec (0.91m/sec), then accessible space-time yield can be from 9.8lb/hr-ft ³(156.2kg/hr-m ³) be raised to 17.0lb/hr-ft ³(270.9kg/hr-m ³).For all test 1-4, FBD keeps more than at least 0.59 with the ratio of SBD.

Embodiment 3

In the table 4 of embodiment 3 under each situation institute's column data with this professional known heat equation formula the actually operating situation is extrapolated under the intended target condition and obtains.Data in the table 4 show, the superiority under the limited case of removal assisted reaction equipment.

In test 1, superficial gas velocity is raised to 2.40ft/sec (0.73m/sec) from 1.69ft/sec (0.52m/sec), with initial 10.8lb/hr-ft ³(172.1kg/hr-m ³) relatively, this can reach 15.3lb/hr-ft ³(243.8kg/hr-m ³) higher STY.Further, the import recycle stream is cooled to 40.6 ℃ from 46.2 ℃.This cooling makes the circulating condensing amount be increased to 34.4wt%, and STY can be brought up to 18.1lb/hr-ft again ³(288.5kg/hr-m ³).In the end a step, gas composition changes by the concentration that improves condensable inertia iso-pentane, thereby has improved cooling power.By this measure, the circulating condensing amount is brought up to 44.2wt% again, makes STY reach 23.3lb/hr-ft ³(371.3kg/hr-m ³).Generally speaking, ever-increasing step makes throughput improve 116% in the reactor system.

In test 2, the loop head temperature drops to 37.8 ℃ from 42.1 ℃, and this cooling makes the circulating condensing amount be raised to 27.1wt% and STY from 14.3lb/hr-ft from 25.4wt% ³(227.9kg/hr-m ³) be raised to 15.6lb/hr-ft ³(248.6kg/hr-m ³).Further again, 6 carbon hydrocarbon concentration are raised to 10mol% from 7mol%, and the raising of this cooling power can make STY be raised to 17.8lb/hr-ft ³(283.7kg/hr-m ³).As showing this improved final step, the loop head temperature drops to 29.4 ℃ again, and this further cooling can reach 19.8lb/hr-ft ³(315.6kg/hr-m ³) STY, wherein the condensation number of recycle stream reaches 38.6wt%.Generally speaking, ever-increasing step makes throughput improve 39% in the reactor system.

Table 1

Time (h)	1	7	10	13	15	17	18
								Resin M I (dg/10min)	1.01	1.04	1.03	1.12	1.09	1.11	1.11
Resin density (g/cc)	0.9176	0.9183	0.9190	0.9190	0.9183	0.9193	0.9193
Recycle stream is formed:
								Ethene	47.4	46.0	44.7	44.1	44.0	45.9	46.3
Butene-1	19.0	18.1	17.3	17.0	16.9	18.5	19.5
								Hexene-1
Hydrogen	9.5	9.4	9.3	9.3	8.9	8.7	8.9
								Iso-pentane	8.0	10.8	13.7	15.1	15.4	14.3	13.2
6 carbon stable hydrocarbon
								Nitrogen	14.3	13.9	13.3	12.8	13.2	11.2	10.7
Ethane	1.8	1.8	1.7	1.7	1.6	1.4	1.4
								Methane
8 carbon stable hydrocarbon
The circulation gas dew point (°F)	142.9	153.5	163.8	168.3	170.1	168.8	165.0
								The circulation gas dew point (℃)	61.6	67.5	73.2	75.7	76.7	76.0	73.9
								Reactor inlet temperature (°F)	126.2	135.6	143.5	144.0	149.0	150.2	146.3
Reactor inlet temperature (℃)	52.3	57.6	61.9	62.2	65.0	65.7	63.5
Liquid in the circulation gas (wt%)	11.4	12.1	14.3	17.4	14.5	11.6	12.3
The counter pressor temperature (°F)	182.4	182.1	182.7	182.8	183.1	184.8	185.2
								Temperature of reactor (℃)	83.6	83.4	83.7	83.8	83.9	84.9	85.1
								Reactor pressure (psig)	311.9	311.5	314.2	313.4	314.7	313.5	312.6
Counter pressor pressure (kPag)	2150.5	2147.7	2166.3	2160.8	2169.8	2161.5	2155.3
Reactor empty tower gas velocity (Ft/sec)	2.29	2.30	2.16	2.10	1.92	2.00	2.11
								Reactor empty tower gas velocity (m/sec)	0.70	0.70	0.66	0.64	0.59	0.61	0.64
								Reactor beds layer height (ft)	43.4	43.3	43.5	49.3	51.3	45.8	45.4
Reactor beds layer height (m)	13.2	13.2	13.3	15.0	15.6	14.0	13.8
Resin SBD (lb/ft 3)	30.1	30.2	30.2	30.2	30.0	29.9	29.9
								Resin SBD (kg/m 3)	482.2	483.8	483.8	483.8	480.6	479.0	479.0
								Reactor bed FBD (lb/ft 3)	18.9	19.6	18.1	17.8	17.2	16.4	15.8
Reactor bed FBD (kg/m 3)	302.8	314.0	290.0	285.2	275.5	262.7	253.1
The ratio of FBD/SBD	0.63	0.65	0.60	0.59	0.57	0.55	0.53
Space-time yield (lb/hr-ft 3)	9.6	9.5	9.3	8.5	6.6	7.1	7.3
								Space-time yield (kg/hr-m 3)	153.0	151.8	149.3	136.0	106.0	113.8	117.2
								Production rate (klb/hr)	68.5	67.8	67.0	69.2	56.1	53.8	54.9
Production rate (Tohs/hr)	31.1	30.7	30.4	31.4	25.4	24.4	24.9
Reactor productive rate (lb/hr-ft 2)	415	411	406	419	340	326	332
								Counter pressor productive rate (kg/hr-m 2)	2026	2006	1982	2045	1660	1591	1621
								Recycle stream enthalpy change (Btu/lb)	42	40	40	42	37	34	33
Recycle stream enthalpy change (Cal/g)	23	22	22	23	21	19	18

Table 2

Time (h)	1	3	5	7	9	11	14	16	18
										Resin M I (dg/10min)	0.92	0.99	1.08	1.02	1.05	1.09	1.11	1.05	0.98
Resin density (g/cc)	0.9187	0.9184	0.9183	0.9181	0.9178	0.9177	0.9186	0.9184	0.9183
The I recycle stream is formed:
										Ethene	52.6	53.2	52.6	52.0	52.1	51.6	52.9	52.8	52.8
T alkene-1	20.0	19.8	19.7	20.4	19.7	19.8	19.1	20.1	20.1
										Hexene-1
Hydrogen	9.7	10.2	10.3	9.9	9.9	9.9	10.4	10.0	9.6
										Iso-pentane	9.9	9.5	10.7	11.2	12.2	12.8	11.5	10.4	9.6
6 carbon stable hydrocarbon
										Nitrogen	8.7	8.0	7.3	6.7	6.3	6.0	6.5	7.3	8.1
Ethane	1.2	1.2	1.1	1.1	1.1	1.1	1.2	1.2	1.3
										Methane
8 carbon stable hydrocarbon
The circulation gas dew point (°F)	154.1	152.5	156.9	160.0	161.9	165.0	159.4	155.9	153.3
										The circulation gas dew point (℃)	67.8	66.9	69.4	71.1	72.2	73.9	70.8	68.8	67.4
										Reactor inlet temperature (°F)	124.2	118.3	119.7	125.3	127.3	13.2	128.0	126.2	123.0
Reactor inlet temperature (℃)	51.2	47.9	48.7	51.8	52.9	56.2	53.3	52.3	50.6
Liquid in the circulation gas (wt%)	22.2	24.9	27.4	26.4	27.0	24.3	23.2	22.1	22.2
Temperature of reactor (°F)	184.6	185.2	184.1	183.4	183.5	183.3	182.8	181.9	181.8
										Temperature of reactor (℃)	84.8	85.1	84.5	84.1	84.2	84.0	83.8	83.3	83.2
										Reactor pressure (psig)	314.7	315.2	315.2	315.1	315.3	314.8	312.9	312.9	313.4
Reactor pressure (kPag)	2170.0	2173.3	2173.3	2172.5	2174.2	2170.7	2157.6	2157.7	2160.6
Reactor empty tower gas velocity (Ft/see)	1.73	1.74	1.75	1.76	1.77	1.76	1.75	1.74	1.74
										Reactor empty tower gas velocity (m/see)	0.53	0.53	0.53	0.54	0.54	0.54	0.53	0.53	0.53
										Reactor beds layer height (ft)	44.7	45.0	44.6	44.9	46.0	47.0	45.5	45.6	45.2
Reactor dung layer height (m)	13.6	13.7	13.6	13.7	14.0	14.3	13.9	13.9	13.8
Resin SBD (l/ft 3)	29.9	29.9	29.7	28.8	29.O	29.1	29.3	29.4	29.4
										Resin SBD (kg/m 3)	479.0	479.0	475.8	461.4	464.6	465.4	468.6	471.3	471.8
										Reactor bed FBD (Ib/ft 3)	20.2	20.7	19.6	19.3	18.2	17.1	18.5	19.2	20.0
Reactor bed FBD (kg/m 3)	323.9	330.9	314.4	309.9	291.1	274.3	296.2	308.1	321.1
The ratio of FBD/SBD	68	69	66	67	63	59	63	65	68
Space-time yield (lb/hr-ft 3)	9.7	10.3	11.1	11.1	11.1	9.9	9.3	9.1	9.2
										Space-time yield (kg/hr-m 3)	154.9	165.1	178.1	178.0	177.0	158.4	149.1	144.9	147.3
										Production rate (klb/hr)	71.3	76.6	82.2	82.3	84.0	76.8	69.9	68.0	68.5
Production rate (Tons/hr)	32.3	34.7	37.3	37.3	38.1	34.8	31.7	30.8	31.1
Reactor productive rate (lb/hr-ft 2)	432	464	498	498	509	465	423	412	415
										Reactor productive rate (kg/hr-m 2)	2109	2265	2413	2413	2485	2270	2065	2011	2026
										Recycle stream enthalpy change (Btu/lb)	54	59	61	60	61	55	52	51	52
Recycle stream enthalpy change (Cal/g)	30	33	34	33	34	31	29	28	29

Table 3

Test	1	2	3	4	5
Resin M I (dg/10min)	0.86	6.74	7.89	22.22	1.91
						Resin density (g/cc)	0.9177	0.9532	0.9664	0.9240	0.9186
						Recycle stream is formed:
Ethene	53.1	40.5	49.7	34.1	44.0
						Butene-1	20.2			14.9	18.2
Hexene-1		0.6
						Hydrogen	8.9	17.7	26.5	25.0	11.9
Iso-pentane	9.7	3.7	0.7	14.1	9.6
						6 carbon stable hydrocarbon		7.0	10.2
Nitrogen	8.7	19.2	8.8	9.4	14.9
						Ethane	1.7	9.4	4.0	2.5	3.3
Methane		1.1	0.3
						8 carbon stable hydrocarbon		0.4	0.5
						The circulation gas dew point (°F)	154.0	172.6	181.6	162.1	148.5
The circulation gas dew point (℃)	67.8	78.1	83.1	72.3	64.7
Reactor inlet temperature (°F)	115.2	107.8	117.7	135.0	114.2
						Reactor inlet temperature (℃)	46.2	42.1	47.6	57.2	45.7
						Liquid in the circulation gas (wt%)	28.6	25.4	27.6	21.8	24.4
						Temperature of reactor (°F)	183.3	208.4	209.3	178.0	183.7
Temperature of reactor (℃)	84.1	98.0	98.5	81.1	84.3
Counter pressor pressure (psig)	315.7	300.2	299.8	314.7	314.3
						Reactor pressure (kPag)	2176.7	2069.7	2066.8	2169.8	2167.2
						Reactor empty tower gas velocity (Ft/sec)	1.69	2.76	2.36	1.74	1.73
Reactor empty tower gas velocity (m/sec)	0.52	0.84	0.72	0.53	0.53
Reactor beds layer height (ft)	47.2	43.0	42.0	44.3	45.6
						Reactor beds layer height (m)	14.4	13.1	12.8	13.5	13.9
						Resin SBD (lb/ft 3)	28.3	23.2	29.0	24.5	29.3
Set cured SBD (kg/m 3)	453.4	371.0	464.0	392.5	468.6
Reactor bed FBD (lb/ft 3)	19.6	16.7	21.7	15.7	19.1
						Reactor bed FBD (kg/m 3)	314.0	267.9	347.4	251.5	305.7
						The ratio of FBD/SBD	0.69	0.72	0.75	0.64	0.65
						Space-time yield (lb/hr-ft 3)	10.8	14.3	13.0	7.7	9.8
Space-time yield (kg/hr-m 3)	172.8	228.8	208.0	123.2	157.2
Production rate (klb/hr)	83.7	101.2	90.2	56.6	73.7
						Production rate (Tons/hr)	38.0	45.9	40.9	25.7	33.4
						Reactor productive rate (lb/hr-ft 2)	507	613	546	343	446
Reactor productive rate (kg/hr-m 2)	2475	2992	2665	1674	2177
Recycle stream enthalpy change (Btu/lb)	65	67	75	49	60
						Recycle stream enthalpy change (Cal/g)	36	37	42	27	33

Table 4

	Test 1				Test 2
The feelings type									1	2	3	4	1	2	3	4
Resin M I (dg/10min)	0.86				6.74
Resin (g/cc)	0.9177				0.9532
Recycle stream is formed:
Ethene	53.1	53.1	53.1	53.1	40.5	40.5	40.5	40.5
Butene-1	20.2	20.2	20.2	20.2
Hexene-1					0.6	0.6	0.6	0.6
Hydrogen	8.9	8.9	8.9	8.9	17.7	17.7	17.7	17.7
Iso-pentane	9.7	9.7	9.7	9.7	3.7	3.7	3.7	3.7
6 carbon stable hydrocarbon					7.0	7.0	10.0	10.0
Nitrogen	8.7	8.7	8.7	5.9	19.2	19.2	17.2	17.2
Ethane	1.7	1.7	1.7	1.2	9.4	9.4	8.5	8.5
Methane					1.1	1.1	1.0	1.0
8 carbon stable hydrocarbon					0.4	0.4	0.4	0.4
The circulation gas dew point (°F)	154.0	154.0	154.0	167.9	172.6	172.6	188.3	188.3
The circulation gas dew point (℃)	67.8	67.8	67.8	75.5	78.1	78.1	86.8	86.8
Reactor inlet temperature (°F)	115.2	115.2	105.0	105.0	107.8	100.0	100.0	85.0
Reactor inlet temperature (℃)	46.2	46.2	40.6	40.6	42.1	37.8	37.8	29.4
Liquid in the circulation gas (wt%)	28.6	28.6	34.4	44.2	25.4	27.1	35.9	38.6
Temperature of reactor (°F)	183.3	183.3	183.3	183.3	208.4	208.4	208.4	208.4
Temperature of reactor (℃)	84.1	84.1	84.1	84.1	98.0	98.0	98.0	98.0
Reactor pressure (psig)	315.7	315.7	315.7	315.7	300.2	300.2	300.2	300.2
Reactor pressure (kPag)	2176.7	2176.7	2176.7	2176.7	2069.7	2069.7	2069.7	2069.7
Reactor empty tower gas velocity (Ft/sec)	1.69	2.40	2.40	2.40	2.76	2.76	2.76	2.76
Reactor empty tower gas velocity (m/sec)	0.52	0.73	0.73	0.73	0.84	0.84	0.84	0.84
Reactor beds layer height (ft))	47.2	47.2	47.2	47.2	43.0	43.0	43.0	43.0
Reactor beds layer height (m) 1)	14.4	14.4	14.4	14.4	13.1	13.1	13.1	13.1
Space-time yield (lb/hr-ft 2)	10.8	15.3	18.1	23.3	14.3	15.6	17.8	19.8
Space-time yield (kg/hr-m 2)	172.8	245.4	290.3	372.2	228.8	249.9	284.4	317.6
Production rate (klb/hr)	83.7	118.9	140.6	180.3	101.2	110.5	125.8	140.5
Production rate (Tons/hr)	38.0	53.9	53.8	81.7	45.9	50.1	57.0	63.7
Reactor productive rate (lb/hr-ft 2)	507	720	851	1092	613	669	762	851
Reactor productive rate (kg/hr-m 2)	2475	3515	4154	5331	2992	3266	3720	4154
Recycle stream enthalpy change (Btu/lb)	67	67	77	95	69	76	81	90
Recycle stream enthalpy change (Cal/g)	37	37	43	53	38	42	45	50

Claims (27)

1. fluidised bed polymerisation method, be included in to allow under the reaction conditions and comprise monomeric gaseous stream and flow through and have the fluidized-bed reactor of catalyzer and make polymerisate and comprise the logistics of unreacted monomer gas, will be described logistics compression and cooling back mixes with the charging composition and sends gas phase and liquid phase back to described reactor, its improvement comprise the described logistics of cooling make liquid phase reach loopback logistics gross weight greater than the also definite in the following way steady operation conditions of 20wt% to 44.2wt%:

(a) form the relevant fluidisation loose density of variation or the variation of its indication parameter with fluidizing medium in the observing response device; With

(b) form raising recycle stream cooling power by changing logistics, wherein the decline of fluidisation loose density can not make the ratio of this fluidisation loose density and deposition loose density be lower than 0.59.

2. according to the process of claim 1 wherein that liquid phase is the 22.1-44.2wt% of loopback logistics gross weight.

3. according to the method for claim 2, wherein liquid phase is the 25-44.2wt% of loopback logistics gross weight.

4. according to the method for claim 3, wherein liquid phase is the 28.6-44.2wt% of loopback logistics gross weight.

5. according to each method among the claim 1-4, wherein logistics is formed the ratio that makes fluidisation loose density and deposition loose density for above 17.8: 30.2.

6. according to the method for claim 5, wherein logistics is formed the ratio that makes fluidisation loose density and deposition loose density for above 18.1: 30.2.

7. according to each method among the claim 1-4, comprise surveying when reactor is near the condition relevant with fluidized bed densities or the irreversible variation of its indication parameter and in case of necessity with forming variation conditioned reaction device condition so that reactor is remained under the steady operation conditions.

8. adopt the piezometry value that is not subject to interferential fluidized-bed part more than the distribution plate to observe the fluidized-bed loose density according to the process of claim 1 wherein.

9. improve cooling power according to the process of claim 1 wherein by increasing the component proportions that can improve dew point.

10. according to the method for claim 9, wherein improve not polymerizable higher hydrocarbon components in proportions.

11., wherein not can be grouped to and be divided into stable hydrocarbon or its mixture with 2-8 carbon atom according to the method for claim 10.

12. according to the method for claim 11, wherein said stable hydrocarbon is selected from propane, normal butane, Trimethylmethane, Skellysolve A, iso-pentane, neopentane, normal hexane, isohexane and other saturated 6 carbon hydrocarbon, normal heptane, octane and other saturated 7 or 8 carbon hydrocarbon or its mixtures.

13. according to the method for claim 12, wherein said stable hydrocarbon is 5 or 6 carbon stable hydrocarbon or its mixture.

14. according to the method for claim 9, wherein by reducing the ratio that the ratio of condensable inert fraction not improves the polymerisable monomer that comprises 3-12 carbon comonomer.

15. cool off logistics and make it so that accessible reactor productive rate surpasses 2441kg/hr-m according to the process of claim 1 wherein ²Velocity flow through reactor.

16. according to the method for claim 15, wherein the reactor productive rate surpasses 2929kg/hr-m ²

17. according to the process of claim 1 wherein that the liquid and gas component of logistics adds below the reactor distribution plate with form of mixtures.

18. method according to claim 1, wherein butylene in the recycle stream/ethene mol is than being 0.00-0.60, or 4-methylpentene-1/ ethene mol is than being 0.00-0.50, or hexene/ethene mol is than being 0.00-0.30, or octene-1/ethene mol is than being 0.00-0.10, hydrogen/ethene mol is than being 0.00-0.4, and comprises the isohexane of the iso-pentane of 3-20mol% or 1.5-10mol% as condensable inert fluid based on this logistics.

19. according to the method for claim 18, wherein condensable inert fluid is an iso-pentane.

20. method according to claim 1, wherein butylene in the recycle stream/ethene mol is than being 0.00-0.60, or 4-methylpentene-1/ ethene mol is than being 0.00-0.50, or hexene/ethene mol is than being 0.00-0.30, or octene-1/ethene mol is than being 0.00-0.10, hydrogen/ethene mol is than being 0.00-1.6, and comprises the isohexane of the iso-pentane of 3-30mol% or 1.5-15mol% as condensable inert fluid based on this logistics.

21. according to the method for claim 20, wherein condensable inert fluid is an iso-pentane.

22. according to the method for claim 18 or 20, wherein the cooling power of recycle stream is at least 21.9cal/g.

23. according to the method for claim 22, wherein the cooling power of recycle stream is at least 27.4cal/g.

24. method according to claim 1, wherein butylene in the recycle stream/ethene mol is than being 0.00-0.30, or 4-methylpentene-1/ ethene mol is than being 0.00-0.25, or hexene/ethene mol is than being 0.00-0.15, or octene-1/ethene mol is than being 0.00-0.05, hydrogen/ethene mol is than being 0.00-1.50, and comprises the isohexane of the iso-pentane of 10-40mol% or 5-20mol% as condensable inert fluid based on this logistics.

25. according to the method for claim 24, wherein condensable inert fluid is an iso-pentane.

26. according to the method for claim 24, wherein the cooling power of recycle stream is at least 41.1cal/g.

27. according to the method for claim 26, wherein the cooling power of recycle stream is at least 43.8cal/g.

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