Abstract: The invention relates to a process and a device that are suitable for the preparation of a polymer based on an olefinic monomer and optionally one or more comonomers that are copolymerisable therewith, in a horizontal reactor, divided into at least two zones and fitted with a stirring mechanism, which is operated under subfluidization conditions, the polymer formed being discharged from the reactor separately from other reactor effluent, it being possible to vary the composition of the overall feed to be supplied to a zone between two zones at least and the reactor effluent separated from polymer leaving the reactor as a single stream, at least part of this stream being returned to the reactor as feed after one or more separating steps.

Abstract: A process for regenerating unreacted vinyl chloride monomers is provided which has the step of compressing by means of an compressor an unreacted vinyl chloride monomer recovered from a process of vinyl chloride polymer production; compressing the same in contact with a lubricating oil fed into the compressor. In this process, the lubricating oil contains a polymerization inhibitor. Hence, even when this lubricating oil is circulated and reused as a lubricating oil after its separation from the unreacted vinyl chloride monomer, any vinyl chloride monomer remaining in the lubricating oil can effectively be kept from polymerizing in lubricating-oil circulation lines.

Abstract: The present invention relates to a process for controlling a continuous fluidized bed reactor (co-)polymerisation process which comprises (1) withdrawing from the reactor a hot recycle stream comprising a principal monomer and at least one other unreacted reactant, (2) cooling part or all of said recycle stream withdrawn from said reactor, and (3) recycling part or all of said cooled recycle stream comprising the principal monomer and the unreacted reactant(s) through the polymerisation zone in said reactor in the presence of a polymerisation catalyst under reactive conditions, characterised in that the said controlling process consists in maintaining at least one of the reactant gradients (Gri) within a range of values outside which sheeting or unstable operations would otherwise occur.

Abstract: A continuous, solvent-free process for obtaining solvent-free, fine white powders of high molecular weight alternating copolymers of maleic anhydride and a C1-C4 alkyl vinyl ether, without odor or taste, having the molecular structure (A-B)n, where A is maleic anhydride, B is an alkyl vinyl ether and n is an integer indicative of the molecular weight of the copolymer, which comprises feeding alkyl vinyl ether as reactant and solvent in excess over the desired 1:1 mole ratio of A:B in the copolymer, molten maleic anhydride and a free radical initiator, continuously at predetermined feeding rates into a reactor heated at a reaction temperature of about 50° to 100° C.

Abstract: This invention relates to a method of making polymer compositions, e.g. EPDM compositions, in a multistage reactor with monomers chosen from ethylene, C3-C8 alpha olefins, and a non conjugated diene. In particular, the invention relates to a process for improving diene conversion during the manufacture of the aforementioned polymer compositions by use of a multistage reactor and a metallocene catalyst system.

Abstract: This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a cobalt catalyst and a monobasic acid, such as acetic acid, by treating the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. In one preferred embodiment, the catalyst is reduced to contain, preferably predominantly and more preferably substantially, cobalt ions in valence II, and at least partially precipitated by de-watering and/or thermal treatment. In a different preferred embodiment, the catalyst in the reaction mixture is first oxidized or maintained, preferably predominantly and more preferably substantially, at valence III, the reaction mixture is de-watered, the catalyst is reduced preferably predominantly and more preferably substantially, to valence II, causing precipitation either spontaneously at a predetermined temperature or after further thermal treatment.

Abstract: A process for the continuous production of substantially purified lactide and lactide polymers from lactic acid or an ester of lactic acid including the steps of forming crude polylactic acid, preferably in the presence of a catalyst means in the case of the ester of lactic acid, to form a condensation reaction by-product and polylactic acid, and depolymerizing the polylactic acid in a lactide reactor to form crude lactide, followed by subsequent purification of the crude lactide in a distillation system. A purified lactide is then polymerized to form lactide polymers.

Abstract: The present invention provides a method for substantially continuously polymerizing olefins comprising: introducing into a first reaction zone a fresh olefin polymerization catalyst; contacting said fresh olefin polymerization catalyst in said first reaction zone with a first vent mixture at a first feed rate and under conditions sufficient to form and avoid melting a polyolefin, wherein first vent mixture comprises unreacted olefins and a diluent vented from a second reaction zone; withdrawing a vent product of unreacted olefins and diluent from said first reaction zone; withdrawing from said first reaction zone a first product mixture comprising said catalyst and said polyolefin; passing said first product mixture to said second reaction zone; contacting said first product mixture in said second reaction zone with a second vent mixture at a second feed rate and under conditions sufficient to form and avoid melting said polyolefin, wherein said second vent mixture comprises a material selected from the group

Abstract: For the semi-continuous production polyadducts of alkylene oxide by an addition reaction of alkylene oxide on a chain initiator having at least one active hydrogen, there is provided a reactor (1) constituted by a cylindrical body with two diameters, the upper part being of larger diameter than the lower part, heat-exchange means (2) and recycling ducts (13, 15) for the recycling of the reaction mixture from the bottom to the head of the reactor in order to obtain the final desired product, thereby enabling the production to be carried out with greater flexibility and reduced down times.

Abstract: The present invention relates to a process for continuous gas phase polymerization of olefin(s) in a reactor containing a fluidized bed, consisting of a cylinder with a vertical side wall and of a desurging or disengagement chamber (3) mounted above the said cylinder, characterized in that the fluidized bed occupies at least all of the cylinder with a vertical side wall of the reactor.

Abstract: A process for the manufacture of olefin polymers in a continuous gas phase polymerization reaction wherein monomer, after passage through the fluidized bed, is cooled to a temperature below its dew point to produce a mixture of cold gas and liquid. All or nearly all of the cold gas is introduced into the bottom of the reactor to serve as the fluidizing gas stream for the fluidized bed. Cold liquid, separated from the mixture, is either injected directly into the peripheral region around the fluidized bed or onto the walls of the expanded section of the reactor to form a liquid film flowing down the wall of the reactor or alternatively, the cold liquid is warmed to form a heated fluid by passing in indirect heat exchange relation with the fluidized bed and is then injected directly into the peripheral region of the fluidized bed or onto the wall of the expanded section of the reactor to form a downward flowing stream of cold liquid.

Abstract: A falling film of water is applied around the periphery of a fluid bed olefin polymerization reactor to cool the wall and reduce the temperature in the fluid bed near the inside surface of the wall. Cooling has the effect of reducing static in the reactor, which in turn ameliorates a sheeting problem and can enhance production by facilitating control of the relation of the reactor temperature and the dew point of recycled gas. The process may be used concurrently with a gas cooling and condensing recycle system wherein at least some of the condensed recycle gas is injected in the vicinity of the internal wall surface.

Abstract: This invention relates to methods and reactor devices for controlling the oxidation of hydrocarbons to dibasic acids, in the presence of a cobalt catalyst and a monobasic acid, such as acetic acid, by treating the catalyst from the reaction mixture, outside the oxidation zone, after the oxidation has taken place at least partially. In one preferred embodiment, the catalyst is reduced to contain, preferably predominantly and more preferably substantially, cobalt ions in valence II, and at least partially precipitated by de-watering and/or thermal treatment. In a different preferred embodiment, the catalyst in the reaction mixture is first oxidized or maintained, preferably predominantly and more preferably substantially, at valence III, the reaction mixture is de-watered, the catalyst is reduced preferably predominantly and more preferably substantially, to valence II, causing precipitation either spontaneously at a predetermined temperature or after further thermal treatment.

Abstract: In the operation of a gas phase polymerization reactor, a significant amount of production time and material can be lost during the transition from initial process conditions for the production of one product to the desired process conditions for the production of a second product. The present invention recognizes the synergy between the use of a membrane separation zone selective for the removal of hydrogen from the reactor effluent and the operation of the polymerization reactor during the transition period to significantly reduce the transition time and substantially reduce the production of off-specification product during the transition period.

Abstract: The present invention relates to an improved catalyst delivery method for introducing a supported bulky ligand metallocene-type catalyst system to a reactor for polymerizing one or more olefin(s). In particular, the invention provides for a method of introducing a supported metallocene-type catalyst system into a polymerization reactor by and in the presence of a carrier solution of an antistatic agent and a liquid diluent. Also, the invention is directed toward a catalyst feeder for use in a polymerization process.

Abstract: The present invention relates to a process for continuous gas phase polymerization of olefin(s) in a reactor containing a fluidized bed, consisting of a cylinder with a vertical side wall and of a desurging or disengagement chamber mounted above the said cylinder, characterized in that the fluidized bed occupies at least all of the cylinder with a vertical side wall of the reactor.

Abstract: A process for the continuous production of polylactide polymers from lactic acid which incorporates removal of water or a solvent carrier to concentrate the lactic acid feed followed by polymerization to a low-molecular-weight prepolymer. This prepolymer is fed to a reactor in which a catalyst is added to facilitate generation of lactide, the depolymerization product of polylactic acid. The lactide generated is continuously fed to a distillation system as a liquid or vapor wherein water and other impurities are removed. The resultant purified liquid lactide is fed directly to a polymerization process.

Abstract: A process for polypropylene manufacturing, including treating a vent stream from the polymerization reactor, to recover propylene for return to the reactor. The process involves using a gas separation membrane to separate propylene from propane in the reactor vent stream. The membrane separation step results in a residue stream typically containing as much as 30% propane or more, which is vented from the polymerization process, and a permeate stream containing 95% or less propylene, which is recirculated to the polymerization reactor.

Abstract: The present invention is directed to a method for polymerizing olefins in a multi-stage polymerization apparatus including a gas-phase polymerization reactor in a subsequent stage. By use of the present method, the composition of gas in the gas-phase reactor is easily adjusted, and moreover, a polymer having an intended composition is produced in a consistent manner. In one aspect, the method for polymerizing olefins is performed in successive, multiple stages by use of a plurality of polymerization reactors disposed in series which include at least one gas-phase polymerization reactor after a first reactor, wherein a multi-component gas is removed from a gas-phase reactor and pressurized and/or cooled to thereby liquefy a portion of the gas; at least a portion of gas is discharged; and the remaining gas and the liquid are returned to the gas-phase reactor.

Abstract: The present invention provides a polymerization process for producing polymers in a continuous gas phase fluidized bed reactor, wherein a recycle stream is allowed to cool down to below its dew point and the resultant two-phase mixture of the gas and liquid phases is recycled to the reactor, the inert condensable agent introduced into the recycle stream to raise the dew point being saturated hydrocarbons, characterized in that the saturated hydrocarbon is cyclopentane.

Abstract: A process and apparatus for passing a polymerization effluent, comprising solid polymer, unreacted monomer, diluent and minor amounts of contaminants, to a high pressure flash where most of the fluid components are flashed and wherein a slip stream comprising diluent and minor amounts of monomer is separated from the bulk of the flashed fluid components. The slip stream is subjected to olefin removal to give an essentially olefin-free stream for recycle to a catalyst mud preparation area. The bulk of the flashed fluid components are recycled directly back to the polymerization zone without expensive olefin removal, although treatment to remove other contaminants can optionally be performed. The polymer and entrained fluid is passed to a low pressure flash zone where the fluids are flashed off, compressed and joined with the flash from the high pressure flash tank.

Abstract: A process is disclosed for removing particulate product from a fluidized bed reactor to optimize, within the constraints of the product removal cycle, conservation of gas in which the product is entrained. Data are compiled on the time required for equalizing pressure between product discharge tanks, and these data are used to determine the optimum times for various valves to be open. Product movement steps and equalization steps can be performed simultaneously.

Abstract: The invention relates to processes for producing polyolefins at pressures substantially below conventional high pressure conditions in two-phase conditions below the cloud point. The invention can involve a continuous system with optional recycle.

Abstract: Mass-continuous process for the production of vinylaromatic polymers which comprises feeding a reaction mixture containing at least one vinylaromatic monomer to at least one tubular reactor of the PFR type and operating with a recycling ratio, referring to the recycling flow-rate/feeding flow-rate, of less than 4.

Abstract: A process for producing polyethylene having improved crack resistance, the process comprising copolymerizing ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, in the presence of a chromium-based catalyst in a first reactor, feeding the polyethylene copolymer thereby produced and the chromium-based catalyst to a second reactor, and in the second reactor copolymerizing ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, in the presence of the chromium-based catalyst thereby to produce a second polyethylene product, the first and second polyethylene products forming a combined polyethylene having a monomodal molecular weight distribution.

Abstract: A process for preparing polytrimethylene terephthalate in which a carbonyl-containing 1,3-propanediol stream is purified for reuse of the 1,3-propanediol. The process involves reacting, under condensation polymerization conditions, terephthalic acid and a molar excess of 1,3-propanediol, with vacuum distillation and condensation of a major portion of the unreacted 1,3-propanediol. To this condensed stream is added a sufficient amount of base to raise the pH to a value greater than 7, and from this base-containing condensate the 1,3-propanediol is distilled and recycled to the polymerization reaction.

Abstract: The present invention relates to an improved catalyst delivery method for introducing a supported bulky ligand metallocene-type catalyst system to a reactor for polymerizing one or more olefin(s). In particular, the invention provides for a method of introducing a supported metallocene-type catalyst system into a polymerization reactor by and in the presence of a carrier solution of an antistatic agent and a liquid diluent. Also, the invention is directed toward a catalyst feeder for use in a polymerization process.

Abstract: A process for the continuous gas fluidised bed polymerisation of olefins, especially ethylene, propylene, or mixtures of these with other alpha olefins, wherein the monomer containing recycle gas employed to fluidise the bed is passed through a separator. The separator is charged with and maintained at least partially filled with liquid. Entrained catalyst and/or polymer particles are separated from the recycle gas in the separator and these separated particles are maintained in a suspended state in the liquid in the separator. The recycle stream can be cooled to condense out at least some liquid hydrocarbon; the condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas in the separator and is fed directly to the bed to produce cooling by latent heat of evaporation. The process reduces fouling of the separator.

Abstract: A continuous process for the manufacture of olefin polymers in a continuous gas phase polymerization reaction wherein monomer, after passage through the fluidized bed, is cooled to a temperature below its dew point to produce a mixture of cold gas and liquid. All or part of the cold gas is introduced into the bottom of the reactor to serve as the fluidizing gas stream for the fluidized bed. Cold liquid separated from the mixture is warmed to form a heated fluid by passing in indirect heat exchange relation with the fluidized bed and the heated fluid is then injected directly into the bed; combined with the fluidizing gas stream; sprayed on top of the bed or combined with gaseous monomer removed from the fluidized bed for cooling.

Abstract: A continuous gas fluidized bed process for the polymerization of olefins, especially ethylene, propylene, or mixtures thereof with other alpha-olefins by cooling the recycle gas stream to condense some liquid (e.g., a comonomer), separating at least part of the liquid and spraying it under pressure through a nozzle (1) directly into the fluidized bed by pressurizing the liquid and feeding it to a spray nozzle (1) having a mechanical device (6) for atomizing the liquid, under conditions such that the spray is formed within a spray-forming zone (5) of the nozzle outlet. The spray-forming zone (5) is preferably shielded from the fluidized bed particles by a wall or walls which can be, for example, a tube or a plate. Also described is a nozzle having two or more series of outlets, each series being fed and controlled independently to enable improved turn-up/turn-down of the liquid supply to the bed.

Abstract: A process/apparatus is disclosed for continuously separating a liquid medium comprising diluent and unreacted monomers from a polymerization effluent comprising diluent, unreacted monomers and polymer solids, comprising a continuous discharge of the polymerization effluent from a slurry reactor through a discharge valve and transfer conduit into a first intermediate pressure flash tank with a conical bottom defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the slurry/polymer solids and an exit seal chamber of such diameter (d) and length (l) as to maintain a desired volume of concentrated polymer solids/slurry in the exit seal chamber such as to form a pressure seal while continuously discharging a plug flow of concentrated polymer solids/slurry bottom product of said first flash tank from the exit seal chamber through a seal chamber exit reducer with inclined sides defined by substantially straight sides inclined at an angle to t

Abstract: A method of reducing the purge gas consumption, dry-down time, or both required for start-up and operation of a gas phase fluidized bed reactor system. The method involves contacting a stream of cycle gas having water and/or a polar hydrocarbon with an adsorbing material while the cycle gas is in a closed circulation loop.

Abstract: A continuous gas fluidized bed process for the polymerization of olefin monomer(s) wherein the recycled gaseous stream withdrawn from the reactor is divided into two streams (A and B) and that (a) a first stream (A) having been cooled to a temperature at which liquid condenses out is then reintroduced directly into the fluidized bed in the reactor in such a way that, at any time, the condensed liquid is continuously introduced into the bed at a minimum rate of 10 liters of liquid per cubic meter of fluidized bed material per hour, and (b) a second stream (B), which by-passes the above cooling/condensing step, is passed through an exchanger and is then reintroduced into the reactor. The continuous introduction of a liquid into the reactor reduces or even eliminates fouling problems which can be encountered in conventional gas phase olefin polymerization processes.

Abstract: Process for producing an olefin polymer of a low polydispersity index having low catalyst residues and low chlorine content, by polymerizing olefins in solution in the presence of a cationic catalyst, in a reactor containing a liquid phase comprising a liquid boiling hydrocarbon polymerization medium and having a vapor space above the liquid phase. The polymerization is carried out in the presence of a non-mechanical agent capable of suppressing foam formation during the polymerization.

Abstract: The polymerization process is carried out starting from a monomer that is introduced via pipe (1) and a comonomer that is introduced via pipe (2); the comonomer that is used, which is an alpha-olefin, is introduced into polymerization reactor P in the form of an approximately pure compound. The polymerization effluent is then separated in separator S1 into two fractions: a heavy fraction that is evacuated via pipe (5) and that contains at least one polymer, and a light fraction that is evacuated via pipe (4) and that comprises the monomer that has not reacted, the comonomer that has not reacted, as well as isomers of this comonomer. At least a portion of the light fraction is then treated during an ethenolysis stage E in the presence of an addition of fresh ethylene that is introduced via line (9). The effluent that is produced in the ethenolysis stage is subjected to at least two separations in separation train S2.

Abstract: A process for working up residues containing dihydroxy compounds resulting from the preparation of polyesters, where (1) in a first stage there is esterification or transesterification of a dicarboxylic acid or esters thereof or ester-forming derivatives with a molar excess of a dihydroxy compound, (2) in at least one second stage there is polycondensation of the esterification product obtained in (1), (3) the vapors (a) and (b) resulting from the reactions in (1) and (2) respectively are subjected to a treatment to recover the starting materials, wherein the treatment to recover the starting materials is carried out in the presence of an alkali metal or alkaline earth metal compound in an amount of from 0.5 to 10% by weight, calculated as alkali metal or alkaline earth metal, based on the solids content of the vapors.

Abstract: A process is disclosed for enhancing the production of polymerized monovinyl aromatic compounds, in which process a small polymerization reactor is inserted in the recycle stream to deactivate the polymerization inhibitors in the recycle stream and to further increase the conversion level of monomer to desirable polymer.

Abstract: The present invention relates to a continuous high molecular weight, amorphous polymer-producing process which includes a reactor design, an unreacted monomer and solvent recycling and purification system, a catalyst deactivation and polymer stabilization system, and a polymer isolation process. The present invention relates to the discovery of a continuous process for the production of polymers. The discovery relates particularly to Ziegler-Natta synthesis of amorphous polymers from .alpha.-olefins. In the inventive method, it was discovered that reconfiguration of process streams for the purposes of the product stabilization and catalyst deactivation led to elimination of the need for an elaborate absorption bed train to purify recycled components. Additionally, reconfiguration of process streams resulted in an improvement of process yield where recycled solvent and unreacted monomer previously caused process yield to be marginal in comparison to using entirely new feedstocks.

Abstract: A process for oligomerizing an acyclic monoolefin monomer in which the oligomerization is controlled to produce predetermined relative amounts of at least two preselected oligomers in a higher boiling fraction of the oligomerization products and the lower boiling products are recycled to the oligomerization reaction.

Abstract: A process comprising contacting one or more monomers with a catalyst, in the gas phase, under polymerization conditions, in a fluidized bed reactor, with the proviso that the reactor is at least partially cooled internally by the vaporization of a liquid cryogen directly into the reactor.

Abstract: Disclosed herein are novel polymers and copolymers of alphaolefins produced using various Ziegler/Natta and Metallocene catalysts. Commercial production of these polymers is now possible for the first time owing to the polymer harvesting technology also disclosed herein.

Abstract: The invention teaches a novel design for a fluidized bed polymerization reactor which utilizes a primary fluidization grid to provide mixing and fluidization of the polymer and at least one secondary distribution plate located above the first distribution plate to promote segregation of polymer particles by size, the larger particles falling into the lower fluidization zone and the smaller particles being entrained up from the primary fluidization grid and through the secondary distribution grid into an upper reaction zone.

Abstract: The present invention relates to a gas phase process for the polymerization of monomer(s) utilizing a metallocene catalyst system to produce easy processing polyolefin polymers.

Abstract: The invention teaches a novel design for a fluidized bed polymerization reactor which utilizes a primary fluidization grid to provide mixing and fluidization of the polymer and at least one secondary distribution plate located above the first distribution plate to promote segregation of polymer particles by size, the larger particles falling into the lower fluidization zone and the smaller particles being entrained up from the primary fluidization grid and through the secondary distribution grid into an upper reaction zone.

Abstract: Addition of water to a gas phase olefin polymerization reactor in amounts greater than 3 ppmv permits an increase in the level of condensable gas and facilitates operation of the reactor at an elevated dew point by ameliorating electrostatic phenomena in the reactor; the process inhibits sheeting.

Abstract: Disclosed herein is a fluid bed polymerization process including an improved method for cooling the fluid bed. The recycled fluid stream is cooled by a method comprisinga) cooling said gas sufficiently to condense a portion of said gas to a liquid,b) thereafter separating said liquid from said cooled gas,c) compressing said cooled gas,d) thereafter recooling said cooled gas sufficiently to condense a portion thereof to a liquid,e) reintroducing said liquid portions and said recooled gas into said reactor sufficiently to maintain reactive conditions.

Abstract: A method for continuously producing a polyester by continuously melt-polymerizing a raw material consisting of a dicarboxylic acid component composed of mainly an aromatic dicarboxylic acid and containing an alicyclic dicarboxylic acid or an aliphatic dicarboxylic acid, or their ester-forming derivatives with a diol component, characterized in that said diol component as a distillate in the polycondensation reaction, including an adhering material, is condensed, said adhering material is separated centrifugally, and then the residual diol component, after distillation, is supplied to an esterification reaction or an ester interchange reaction.

Abstract: A process for producing polymer in a gas phase reactor by introducing a stream of monomer and gas into a polymerization zone while providing at least one liquid component in the polymerization zone.

Abstract: A continuous gas fluidized bed process for the polymerization of an olefin monomer, especially ethylene, propylene, or mixtures of these with other alpha-olefins, wherein monomer-containing recycle gas employed to fluidize the bed is cooled to condense out at least some liquid hydrocarbon. The condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas and fed directly to the fluidized bed, through a gas-induced atomizer nozzle, to produce cooling by latent heat of evaporation. The nozzle is provided with a mechanical device within the liquid inlet of the atomizing chamber, that preatomizes the liquid so that the nozzle requires reduced amounts of gas compared with conventional gas-induced atomizer nozzles.

Abstract: An apparatus for continuously producing polyester comprises three single reactors, i.e. a single esterification reactor (first reactor), a single initial polymerization reactor (second reactor) and a single final polymerization reactor (third reactor or final polymerizer), where at least one of the first reactor and the second reactor is free from an external stirring power source, or the third reactor is a horizontal, one-shaft-type, low speed rotation type reactor. Necessary number of reactors for the esterification and polycondensation reactions can be a minimum and necessary stirring power consumption for the reaction can be a miminum, and thus polyester polymers of good quality can be efficiently produced at a minimum energy cost in a necessary minimum reactor structure.