Abstract: A process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor using a metallocene catalyst in that the polymerization is preformed in the presence of a process aid additive selected from at least one of 1) a polysulfone copolymer, 2) a polymeric polyamine, or 3) an oil-soluble sulfonic acid.

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 for producing polyamides by reacting at least one lactam and optionally further polyamide-forming monomers with aqueous monomer and oligomer extracts obtained during the extraction with water of the polymer product obtained in the production of polyamides, the water content of the reaction mixture being in the range from 0.5 to 13% by weight comprises conducting the reaction in the presence of metal oxides, beta-zeolites, sheet-silicates or silica gels, which may be doped, as heterogeneous catalysts, the heterogeneous catalysts being used in the form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture in the course of the polymerization or after it has ended.

Abstract: The present invention relates to a method and apparatus for controlling static charges in a fluidized bed olefin polymerization reactor. Static charges which develop in the polymer products are measured and, if they fall outside a predetermined range, static charge control agents are introduced into the reactor. By controlling the static charges in the reactor, sheeting and drooling can be controlled.

Abstract: The space time yield of a gas phase reactor, particularly a polyethylene reactor may be increased by replacing at least 80 weight % of the ballast gas with a gas having a higher heat capacity than the ballast gas. Preferably the gas replacing the ballast gas is a stream of dilute ethylene having a high concentration of ethane.

Abstract: A process for preparing linear organohydrogensiloxanes. The process comprises contacting an organohydrogendichlorosilane in the presence of trimethylchlorosilane with water to form an M-stopped hydrolyzate. The hydrolyzate is optionally preheated prior to being contacted with an acidic rearrangement catalyst to effect formation of linear organohydrogensiloxanes. The linear organohydrogensiloxanes are separated from cyclic organohydrogensiloxanes and recovered. The cyclic organohydrogensiloxanes may then be recycled to the process for further contact with the acidic rearrangement catalyst for maximum overall conversion rate.

Abstract: The invention relates to a process for the production of polyamide-6 by polymerization of &egr;-caprolactam with full re-use of extracted caprolactam and oligomers. The extract is not subjected to a pretreatment for reduction of the cyclic dimer content. By carrying out the polymerization in two steps, the first at an elevated pressure, but lower than the vapor pressure of the reaction mixture supplied, and the second at approximately atmospheric or reduced pressure, the cyclic dimer content of the polymerizate leaving the second polymerization step is kept at a constant level. The process offers a high degree of flexibility in terms of production capacity and composition and proportion of recycled lactam in the lactam feed for the polymerization.

Abstract: The present invention provides: a production process that enables to keep foaming state within a constant level and to obtain a polymer with good productivity and reproducibility with a practical plant by defining an appropriate vapor velocity from a weight-average molecular weight of the polymer that is finally intended to obtain; and a polymerization apparatus therefor. A production apparatus for producing a polymer, which comprises a reactor 1 in order to produce the polymer, a stirrer 2 in order to stir a reaction solution in the reactor 1, and a condenser 3 so that a vaporized reaction solution can be cooled and returned to the reactor 1, and further comprises a vapor velocity measuring means of monitoring a vapor velocity in the condenser, and an vapor velocity adjusting means of adjusting the vapor velocity, is used. Then, the vapor velocity is adjusted in the range of 0.001 to 0.

Abstract: In a process for the gas-phase polymerization of &agr;-olefins at from 20 to 130° C. and pressures of from 1 to 100 bar, the polymerization is carried out in a tubular reactor having a length:diameter ratio of >100 and the growing polymer particles pass through the tubular reactor in its longitudinal direction without a significant part of the polymer particle stream being circulated.

Abstract: Polyisobutenes are prepared by the continuous preparation process, by polymerizing isobutene in the presence of a catalyst comprising boron trifluoride and at least one cocatalyst in an inert organic solvent, a) a part of the reaction mixture obtained thereby being discharged continuously from the polymerization reactor, b) the catalyst being separated from the discharge and/or being deactivated in the discharge, and c) the solvent and any unconverted isobutene being separated from the discharge and recycled to the polymerization reactor, wherein the recycled solvent and, if present, the isobutene are subjected to a wash with water before recycling to the polymerization reactor and are then dried.

Abstract: The space time yield of a gas phase reactor, particularly a polyethylene reactor may be increased by replacing at least 80 weight % of the ballast gas with a gas having a higher heat capacity than the ballast gas. Preferably the gas replacing the ballast gas is a stream of dilute ethylene having a high concentration of ethane.

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: Process for the introduction of liquid into a continuous process for the gas-phase polymerization of a olefin monomer and one or more other alpha-olefins in a fluidized-bed reactor, the liquid being introduced by at least one nozzle having a feed pipe and a sleeve sliding inside and at the end of the pipe, the position of the said sleeve along the feed pipe being determined by the pressure of the feed liquid and the return force of a preloaded spring, the spring having one end fixed to the sleeve and the other end to the feed pipe, the sleeve being provided with one or more recesses along its surface for sliding with the feed pipe, the recesses emerging in a groove around the circumference of the sleeve and below a circular stop integral with the same sleeve, the stop resting, when the nozzle is not in use, on a rim of the end of the feed pipe, the rim and the circular stop of the sleeve each being provided with a bearing surface, the contact area of which is minimized to allow good sealing.

Abstract: Process for polymerizing one or more olefinic monomers in a fluid-bed reactor which is bounded at the bottom by a gas-distributing plate containing apertures, comprising the supply of a gas to the reactor through the gas-distributing plate and optionally the supply of a liquid to the reactor, in which the average rate at which the gas is supplied to the reactor is higher in a first part of the gas-distributing plate whose area equals half that of the gas-distributing plate than the average rate at which the gas is supplied in a second part covering the area of the gas-distributing plate that lies outside the first part and reactor suitable for this process.

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: 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 (I) 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: The present invention relates to a method to polymerize monomer comprising contacting one or more monomer(s) with a catalyst system in a gas phase reactor having a recycle system, for removing a recycle gas and unreacted monomer(s) from the reactor and returning the recycle gas and fresh monomer(s) to the reactor, and a plenum, the method comprising the steps of: (a) cooling the recycle gas to form a cooled recycle gas; (b) optionally combining the cooled recycle gas with additional recycle gas; and (c) injecting the cooled recycle gas into the gas phase reactor through the plenum.

Abstract: The present invention teaches the use of particular soluble metallocene catalysts to produce stereoregular polymers in gas phase polymerizations wherein the catalysts are fed into a particle lean zone in the reactor. The metallocenes catalysts are bridged bis-(substituted indenyl) compounds.

Abstract: A polymer of ethylene and at least one alpha olefin having at least 5, carbon atoms obtainable by a continuous gas phase polymerization using supported catalyst of an activated molecularly discrete catalyst such as a metallocene in the substantial absence of an aluminum alkyl based scavenger which polymer has a Melt Index (MI) as herein defined of from 0.1 to 15; a Compositional Distribution Breadth Index (CDBI) as defined herein of at least 70%, a density of from 0.910 to 0.930 g/ml; a Haze value as herein defined of less than 20%; a Melt Index ratio (MIR) as herein defined of from 35 to 80; an averaged Modulus (M) as herein defined of from 20 000 to 60 000 psi (pounds per square inch) and a relation between M and the Dart Impact Strength in g/mil (DIS) complying with the formula: DIS≧0.8×[100+e(11.71-0.000268×M+2.183×10−9×M2)].

Abstract: Polyolefins, preferably polyethylene, are prepared in a continuous gas-phase polymerization process in which the fluid monomeric component, preferably ethylene, and, optionally, one or more comonomers is/are polymerized in the polymerization zone of a fluidized-bed reactor in the presence of one or more catalysts, optionally with the addition of various auxiliaries, under reaction conditions where the fluidizing gas is circulated to remove the heat of polymerization or reaction and the polymerization product is taken from the circuit and the corresponding amount of monomer and, optionally, comonomers and optionally further auxiliaries are fed in, wherein the fluidizing gas discharged from the fluidized-bed reactor is cooled by means of a direct cooling apparatus in which the coolant is brought into direct contact with the fluidizing gas and heated coolant is passed to at least one further cooling stage in order to cool it and is, after cooling, wholly or partly returned to the direct cooling apparatus and/or

Abstract: The present invention provides a method for producing a polyolefin composition having a narrow composition distribution and is characterized in that when at least two olefins are copolymerized in the presence of a transition metal compound catalyst using at least two gas phase fluidized bed reactors, a saturated aliphatic hydrocarbon is allowed to exist in each reactor in a concentration from 0.1 to 30 mol %, and the ratio of the concentration (C2) of a saturated aliphatic hydrocarbon in a reactor of a second stage to the concentration (C1) of a saturated aliphatic hydrocarbon in a reactor of a first stage (C2/C1) is 0.13 or more.

Abstract: The present invention relates to a method for the isolation of olefins from a gas mixture comprising one or more olefins, inert gas and catalyst poison, where the gas mixture is fed to a separation unit (18) and separated into olefin and inert gas. The method according to the invention has the special feature that an apparatus (17) is installed upstream or downstream of the separation unit (18) and that i) in the case of an upstream apparatus (17), the catalyst poison is at least partially removed from the gas mixture, and ii) in the case of a downstream apparatus (17), the catalyst poison is at least partially removed from the separated-off olefin. The olefins here are preferably isolated from a gas mixture formed as offgas in catalytic gas-phase polymerization for the preparation of polyolefins. The recovery of the olefins from the offgas is of economic importance.

Abstract: The invention relates to a process for the production of polyolefins in a reactor system which comprises at least one gas-phase reactor with at least one monomer is polymerized. According to the process, there is fed into the gas-phase reactor the monomer to be polymerized and possibly a polymer-containing fluid. According to the invention, before being fed into the gas-phase reactor, the fluid is subjected to a phase change in order to separate uncondensed compounds from liquid and possibly solid compounds. The gas including the uncondensed compound is recovered, and hydrogen is separated from the gas by membrane separation. The invention can be applied to the removal of hydrogen from the circulation gas of a gas-phase reactor, for example in order to change the polyolefin grade to be produced.

Abstract: The partially condensed fluid recycle stream of a fluidized bed polyolefin reactor operating in the condensing mode is split into two portions by a stream splitter. In a preferred mode, the smaller stream from the splitter contains a higher ratio of liquid to gas than the larger stream. One portion of the split stream is injected below the fluidized bed and the other, preferably with enhanced liquid content, is injected into the fluidized bed at a level above the distributor plate, preferably above the product withdrawal level.

Abstract: Described herein is a process and an apparatus for preparing propylene homopolymers and copolymers, which comprises polymerizing propylene optionally with comonomers in the presence of a catalyst at elevated temperature and pressure in at least one slurry reactor and at least one gas phase reactor, the polymerization product of at least one slurry reactor, containing unreacted monomers, being conducted to a first gas phase reactor essentially without recycling of the unreacted monomers to the slurry reactor. The invention provides for fast start-ups because the gas phase bed material is available directly from the loop reactor.

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: Polybutylene terephthalate having good heat stability and excellent hydrolysis resistance is continuously produced in a series of a first reactor for reacting an aromatic dicarboxylic acid comprising terephthalic acid as a main ingredient or a derivative thereof with a glycol comprising 1,4-butanediol as a main ingredient, thereby producing an oligomer with an average degree of polymerization of 2.2 to 5, a second reactor for polycondensating the oligomer from the first reactor, thereby preparing a low polymerization product with an average degree of polymerization of 25 to 40, and a third reactor for further polycondensating the low polymerization product from the second reactor, thereby producing a high molecular weight polyester with an average degree of polymerization of 70 to 130, or followed by a fourth reactor for further polycondensing the polyester from the third reactor to an average degree of polymerization of 150 to 200, thereby producing a high molecular weight polyester.

Abstract: Process for the introduction of liquid into a continuous process for the gas-phase polymerisation of an olefin monomer and one or more other alpha-olefins in a fluidised-bed reactor, characterised in that the liquid is introduced by means of at least one nozzle comprising a feed pipe (1) and a sleeve (2) sliding inside and at the end of the said pipe, the position of the said sleeve along the feed pipe being determined by the pressure of the feed liquid (3) and the return force of a preloaded spring (4) the said spring having one end fixed to the sleeve and the other end to the feed pipe, the sleeve being provided with one or more recesses (10) along its surface for sliding with the feed pipe, the said recesses emerging in a groove (11) around the circumference of the sleeve and below a circular stop (8) integral with the same sleeve, the said stop resting, when the nozzle is not in use, on a rim (9) of the end of the feed pipe, the said rim and the circular stop of the sleeve each being provided with a beari

Abstract: A process for the polymerization of olefins in a gas phase reactor operating in a non-condensed mode, in which the process is carried out in the presence of a catalyst system containing (a) a metallocene supported on a solid support and (b) an activator, and adding a lower alkane to the gas phase reactor.

Abstract: A process is provided for producing an essentially linear copolymer of ethylene and a minor amount of a 1-olefin containing more than 2 carbon atoms comprising contacting said ethylene and 1-olefin with a Ziegler catalyst in a polymerization reaction zone at elevated temperature and pressure, contacting the polymerization reaction mixture containing polymer and unreacted monomers with a fresh supply of ethylene in a high pressure separation zone (HPS) operating at a lower pressure than the reaction zone such that the contents of the separation zone separates into a dense phase containing a major proportion of polymer, and a light phase containing a major proportion of unreacted monomers, and separately withdrawing the two phases from the separation zone.

Abstract: The polymer recovery capacity of solution polymerization units is increased by flashing a polymer solution exiting olefin polymerization reactors to produce a concentrated polymer solution having a reduced temperate and a solids content from 10 percent to 40 percent by weight. Flashing of the polymer solution preferably occurs at a temperature at least 20° C. higher than the crystallization temperature of the concentrated polymer solution The concentrated polymer solution can be prepared adiabatically and can be subsequently finished in conventional polymer recovery units without increasing the risk of gel formation.

Abstract: Agglomerates 20 in a mixed phase container 1 are detected by measuring strain in a detecting rod 50 disposed in the mixed phase container 1 in which a mixed phase of gas and powders is formed. The detecting rod 50 is disposed at an insertion angle &thgr; in the range from 20 degrees to 70 degrees with relation to the flow of gas and powders.

Abstract: A protecting tube 51 is disposed inside the mixed phase container 1 with one end fixed to the inside of the mixed phase container 1 and the other end projecting freely into the mixed phase container 1. A detecting rod 60 is inserted into the free end of said protecting tube 51 and fixed to the protecting tube 51 with a part of the detecting rod 60. Magnets 61 are mounted in a uniform magnetic flux on the free end of the detecting rod 60 and is movable about a point F1 of the detecting rod 60 as a fulcrum. Agglomerates 20 in the mixed phase container 1 are detected by measuring magnetic flux fluctuations produced by movement of the magnets 61.

Abstract: Process for the preparation of a composition containing ethylene polymers comprising a polymer of melt index MI2 of 5 to 1000 g/10 min and a polymer of melt index MI5 of 0.01 to 2 g/10 min, the ratio of these indices being from 500 to 50,000 and the weight ratio of the two polymers being equal to (30 to 70):(70 to 30), according to which part of the ethylene, a catalyst derived from a transition metal having an intrinsic molecular weight distribution defined by an intrinsic Mw/Mn ratio less than or equal to 10 and a deactivation constant less than or equal to 0.5 h−1, and a cocatalyst are introduced into a first reactor, polymerization of the ethylene is carried out therein, a mixture comprising one of the polymers, the catalyst and the cocatalyst is drawn off from this reactor and the mixture and another part of the ethylene are introduced into a second reactor, which ethylene is polymerized to form the other polymer.

Abstract: A method of multistage gas phase polymerization is provided comprising performing polymerization of a feed gas mixture at least containing ethylene gas, an &agr;-olefin gas and hydrogen gas in an upstream fluid bed reactor to thereby produce a polymer powder, recovering the thus-produced polymer powder and performing further polymerization of the polymer powder in a downstream fluid bed reactor, the downstream fluid bed reactor being continuously connected to the upstream fluid bed reactor so that the polymer powder recovered from the upstream fluid bed reactor is introduced into the downstream fluid bed reactor, which method comprises the steps of: recovering polymer powder from the upstream fluid bed reactor, treating the recovered polymer powder so as to lower the content of &agr;-olefin gas and hydrogen gas therein by contacting the polymer powder with a stream of gas comprising ethylene or an inert gas, and introducing the treated polymer powder into the downstream fluid bed reactor.

Abstract: The invention provides a process for heterophase reactions in a liquid or supercritical dispersion medium, in which the starting materials are introduced into the reaction zone of a reactor provided with one or more enrichment zones and the reaction product or unreacted starting material or both starting material and reaction product are discharged via one enrichment zone in each case, wherein a) the reaction product together with the dispersion medium is discharged from the reactor via an enrichment zone, the reaction product is separated off and the dispersion medium is, if desired in countercurrent to the reaction product/dispersion medium mixture and via an enrichment zone, returned to the reaction zone, or b) unreacted starting material together with the dispersion medium is discharged, the starting material is separated from the dispersion medium and returned directly to the reaction zone and the dispersion medium is, if desired, in countercurrent to the reaction product/dispersion medium mixture and vi

Abstract: Fluidized bed reactor process for the polymerization of one or more olefin monomers, wherein the reactor comprises a reaction zone which is confined at the underside by a gas distribution plate and at the top side by a virtual end surface, in which, under operating conditions, a fluidized bed is maintained between the underside and the top side, which reactor is provided with a gas inlet which terminates in the reactor below the gas distribution in which the reaction zone is divided into two or more compartments by one or more substantially vertical partition walls extending from a point located above the gas distribution plate to a point located below the end surface.

Abstract: A blower 100 for recycling a powder containing gas or for conducting a cyclone treatment thereof, which comprises a casing of blower body 108 having therein a slide or rotational slide part between its discharge side as a high pressure side and its suction side as a low pressure side, the above slide or rotational slide part being provided with a noncontacted gas leakproof seal part 166 at a clearance ranging from 0.7 to 2.5 mm. A vapor phase polymerization method is provided which is free from the problem that recycling gas such as unreacted gaseous olefin having been discharged from a fluidized bed reactor is formed into a stringy melt polymer or combined into powder to thereby clog a gas recycling pipe or is entrained to a gas recycling pipe or a distributor plate of a polymerizer to thereby cause clogging.

Abstract: The present invention relates to a method to polymerize monomer comprising contacting one or more monomer(s) with a catalyst system in a gas phase reactor having a recycle system, for removing a recycle gas and unreacted monomer(s) from the reactor and returning the recycle gas and fresh monomer(s) to the reactor, and a plenum, the method comprising the steps of: (a) cooling the recycle gas to form a cooled recycle gas; (b) optionally combining the cooled recycle gas with additional recycle gas; and (c) injecting the cooled recycle gas into the gas phase reactor through the plenum.

Abstract: A fluidized bed olefin polymerization process is operated in the turbulent regime while utilizing greater than 17.5% liquid in the recycle fluid to remove the heat of reaction. The ratio of fluidized bed density to settled bed density may, contrary to prior art predelictions, be maintained at lower than 0.59.

Abstract: A process, carried out in the gas phase, comprising contacting one or more olefins with a catalyst system containing a carrier gas and a mixture of solids comprising a transition metal compound or complex and a liquid organic solvent, under polymerization conditions, in a fluidized bed reactor containing resin particles in a fluidized state with the provisos that (a) the mixture of solids and solvent contains at least about 95 percent by weight solids and (b) the mixture is sprayed with the carrier gas into a particle-lean zone, or the fluidized bed, of the reactor.

Abstract: A process for preparing halogen-free, reactive polyisobutene having a terminal double bond content of more than 60 mol % and an average molecular weight Mn of 800-3000 dalton by cationic polymerization in the liquid phase of isobutene over an acidic, essentially halogen-free heterogeneous catalyst, where a) a hydrocarbon mixture of essentially C4-hydrocarbons comprising isobutene in an amount of from 10 to 80% by weight is used as the starting material and b) polymerization is carried out continuously at from −30 to 0° C. with average starting material residence times of one hour or less, where the temperature and the residence time are selected such that the isobutene conversion is less than 60% and, after separation from the resulting polyisobutene, the isobutene is either enriched in the partially converted hydrocarbon mixture and returned to the polymerization or passed to another isobutene reaction coupled with the polymerization.

Abstract: A method is provided to monitor, detect and correct local defluidization and channeling in fluidized-bed reactors for polymerization of olefin and/or diolefin polymers. The detection is preferably conducted by (i) continuously and/or intermittently comparing a signal which is a function of the currently measured fluidization bulk density with a signal which is a function of the time-averaged baselines of fluidized bulk density.

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: In a process for preparing formaldehyde from methanol by dehydrogenation in a reactor in the presence of a catalyst at a temperature in the range from 300 to 1000° C., a circulating gas stream comprising by-products of the dehydrogenation is passed through the reactor.

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: The invention relates to a process for producing a polymer or copolymer from monomer material comprising an acrylate, methacrylate, or mixture of such monomers, which comprises the steps of: (a) charging into a continuous tube reactor a feedstock comprising said monomer material and a polymerization initiator; (b) maintaining a flow rate of said material through the reactor at a reaction temperature in the reactor and under pressure sufficient to provide a residence time of the feedstock in the reactor during which polymerization will occur, to form a resin product in the reactor, and said resulting resin product comprising unreacted monomer, and (c) devolatilizing said resin product exiting the reactor to remove unreacted monomers, to provide a substantially monomer-free resin product. Further, the invention relates to resin product made by the process.

Abstract: Disclosed is a process for producing polyolefins wherein the solids are conveyed by a gas throughout the polymerization process, thereby resulting in improved operability.

Abstract: The present invention relates to a polymerization process in the presence of a bulky ligand metallocene-type catalyst compound having an abstractable fluoride or fluorine containing leaving group.

Abstract: A continuous process for the production of poly(trimethylene terephthalate) is disclosed. According to the process, a liquid feed mixture comprising bis-3-hydroxypropyl terephthalate and/or low molecular weight polyesters of 1,3-propanediol and terephthalic acid, the liquid feed mixture having a mole ratio of propylene groups to terephthalate groups of 1.1 to 2.2 is fed to a prepolymerizer. Bis-3-hydroxypropyl terephthalate and the low molecular weight polyesters are continuously polymerized to form a poly(trimethylene terephthalate) prepolymer and a first stream of gaseous by-products. Poly(trimethylene terephthalate) prepolymer having a relative viscosity of at least about 5 is continuously withdrawn from the prepolymerizer and continuously fed to a final polymerizer, where it is continuously polymerized to form a higher molecular weight poly(trimethylene terephthalate) and a second stream of gaseous by-products.