Abstract: A multi-level tubular reactor operable to facilitate a chemical reaction in a reaction medium flowing therethrough. The tubular reactor can include a plurality of horizontally elongated and vertically spaced reactor segments coupled to and extending outwardly from a common header. One or more of the reactor segments can contain a tray that divides the internal volume of the reactor segment into upper and lower chambers. The reaction medium can flow away from the header in the upper chambers and back to the header in the lower chambers.

Abstract: The invention discloses a metallocene catalysed slurry polymerisation process of ethylene in the presence of a low concentration of scavenger. This allows improving the anti-sheeting of the reactor during the polymerisation process.

Abstract: The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridged ?5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and an activator. The bridged ?5-cyclopentadienyl-type ligands are connected by a cyclic substituent.

Abstract: A process for the multistage polymerization of olefins in a sequence of an upstream slurry reactor and a downstream gas-phase reactor, the transfer of polymer from the upstream reactor to the downstream reactor comprising the following steps: a) heating the slurry of polyolefin particles to evaporate the liquid polymerization medium; b) separating the polyolefin particles from the obtained gaseous phase in at least a separation chamber; c) transferring the polyolefin particles to said downstream reactor by means of a couple of lock hoppers working intermittently in parallel, where one of said lock hoppers is continuously filled with the polymer coming from said separation chamber, while simultaneously the other one is continuously pressurized by means of a gas comprising the reaction mixture coming from said downstream reactor.

Abstract: The invention pertains to a process for preparing resorbable polyesters by bulk polymerization, wherein the reaction components are melted and homogenized in a reactor, the reaction mixture is then transferred into a polymerization reactor having a lumen defined by a reaction wall, wherein said reactor wall comprises at least two components which are releasably fitted to each other and wherein the shortest distance of any point within said lumen to the reaction wall is less than 8 cm, the reaction mixture is polymerized and the resulting polymer is removed from the polymerization reactor by releasing the components of the reactor wall exposing the resulting polymer lengthwise. The invention further relates to a polymerization reactor having a lumen defined by a reaction wall for performing said process.

Abstract: A sloped tubular reactor operable to facilitate a chemical reaction in a reaction medium flowing therethrough. The reactor can include a downwardly sloped tubular member, a flow divider disposed in the tubular member, and one or more internal trays disposed in the tubular member. The flow divider divides flow of the reaction medium among the trays and the bottom of the tubular member.

Abstract: The invention is directed to polyester processes where the esterification process at utilizes a vapor removing device, wherein the vapor removing device is substantially horizontally oriented, wherein the esterification effluent forms a two-phase laminar, stratified, non-circular vapor/liquid flow in at least a portion of said vapor removing device.

Abstract: A process for production of polyisobutylene includes subjecting a reaction admixture comprising isobutylene, a diluent for the isobutylene, which may be isobutane, and a catalyst composition, that may include a BF3/methanol catalyst complex, to reaction conditions suitable for causing at least a portion of the isobutylene to undergo polymerization to form a polyisobutylene product including polyisobutylene molecules. At least a fraction of the polyisobutylene molecules thus produced have alpha position double bonds and the polyisobutylene product has a number average molecular weight (MN) and a polydispersity index (PDI). The concentration of the diluent in the reaction admixture may be manipulated to control or change any one or more of (a) the relative size of the fraction, (b) the number average molecular weight of the product, (c) the polydispersity index of the product and (d) the relative size of the portion.

Abstract: The present invention relates to an improved method for preparing an ethylene-silane copolymer comprising hydrolysable silane groups by radical-initiated polymerisation of ethylene and an olefinically unsaturated silane compound, such as vinyl trimethoxysilane (VTMS). Said method is performed in a multi-zone reactor comprising two or more reaction zones, wherein advantageously essentially all of the silane compound is introduced into the first reaction zone to provide a higher conversion of silane monomer into polymer.

Abstract: A process for producing polymer and more particularly adhesive using a recirculating loop reactor. In one embodiment the reactor includes one or more mixers to mix feed stock with the polymerized material recirculating in the reactor. In another embodiment a planetary roller extruder (PRE) may be used for this purpose. In still another embodiment, a combination of one or more static mixers and one or more PREs may be used.

Abstract: A horizontal trayed reactor operable to facilitate a chemical reaction in a reaction medium flowing therethrough. The reactor can include a plurality of vertically spaced trays disposed within the horizontally elongated vessel shell. The reaction medium can flow in generally opposite directions on vertically adjacent trays so that the reaction medium flows generally back-and-forth through the reactor.

Abstract: Process for producing a multimodal polyethylene in at least two loop reactors connected in series, in which 20-80 wt % of a high molecular weight (HMW) polymer is made in suspension in a first reactor and 20-80 wt % of a low molecular weight (LMW) polymer is made in suspension in a second reactor, one polymer being made in the presence of the other in either order, wherein the ratio of the average activity in the LMW reactor to the average activity in the HMW reactor is from 0.25 and 1.5, where average activity in each reactor is defined as the rate of polyethylene produced in the reactor (kgPE/hr)/[ethylene concentration in the reactor (mol %)×residence time in the reactor (hours)×feed rate of catalyst into the reactor (g/hr)], residence time being defined as the mass of the polymer in the reactor (kg)/the output rate of polymer from the reactor (kg/hr), and the volumes of the two reactors differ by less than 10%.

Abstract: Reactor systems suitable for the polymerization of an olefin monomer including first and second loop reactors effective for the polymerization of an olefin monomer and polymers formed therefrom are described herein.

Abstract: A process comprising polymerizing an olefin monomer optionally together with an olefin comonomer in the presence of a polymerization catalyst in a diluent in a loop reactor which comprises at least 2 horizontal sections and at least 2 vertical sections to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the Froude number in at least 20% of the length of the vertical sections of the reactor loop is less than 85% of the Froude number in at least 20% of the length of the horizontal sections of the loop is disclosed.

Abstract: The invention relates to a process for the preparation of a copolymer of ethylene and a monomer copolymerizable therewith. The polymerization takes place in a tubular reactor at a peak temperature between 290° C. and 350° C., the co monomer is a di- or higher functional (meth)acrylate and the co monomer is applied in an amount between 0.008 mol % and 0.200 mol % relative to the amount of ethylene copolymer.

Abstract: A process for the preparation of a propylene random copolymer, wherein propylene is polymerised with ethylene and/or a C4-C20 alpha-olefin in the presence of a catalyst system comprising solid catalyst particles, wherein the solid catalyst particles (a) have a specific surface area of less than 20 m2/g, (b) comprise a transition metal compound which is selected from one of the groups 4 to 10 of the periodic table or a compound of actinide or lanthanide, 10 (c) comprise a metal compound which is selected from one of the groups 1 to 3 of the periodic table, and (d) comprise inclusions not having catalytically active sites.

Abstract: Methods for supplying a catalyst to an ethylene slurry loop polymerization reactor and polymers formed therefrom are described herein. The method generally includes preparing a catalyst slurry in a preparation vessel wherein the slurry includes a hydrocarbon diluent liquid which contains a Ziegler-Natta catalyst; supplying the catalyst slurry from the preparation vessel to a buffer vessel; withdrawing the catalyst slurry from the buffer vessel and supplying the catalyst slurry to a slurry loop polymerization reactor in which ethylene is polymerized; mixing a co-catalyst with the Ziegler Natta catalyst in the slurry prior to the supplying of the catalyst slurry to the slurry loop polymerization reactor; and controlling the transfer of catalyst slurry from the preparation vessel to the buffer vessel and the withdrawal of catalyst slurry from the buffer vessel to maintain the level of catalyst slurry in the buffer vessel substantially constant relative to the level of catalyst slurry in the preparation vessel.

Abstract: Process and apparatus for continuously producing olefin polymers in a slurry phase reactor in a hydrocarbon diluent or liquid monomer. The process comprises continuously withdrawing from the slurry phase reactor a polymer slurry containing polymer and a fluid phase, which contains hydrocarbons and optionally hydrogen, and concentrating the slurry with a self-cleaning screen by removing a part of the fluid phase to provide a concentrated slurry. The openings of the screen, which can have a planar or cylindrical configuration, are smallest at the inflow surface of the screen and increases towards the outflow surface. By the present invention, the need for service and maintenance is significantly reduced.

Abstract: The present invention relates to a polymerisation reactor for continuous polymerisation, the reactor being constructed in two stages and comprising a prepolymerisation stage which is configured as a stirred vessel or as a loop-type bubble column and also a main polymerisation stage which is configured as a tubular reactor. Furthermore, the present invention relates to a method for the production of biodegradable polyester, in particular polylactide, the reactor according to the invention being used. Likewise, the invention relates to a polymerisation device which comprises further components in addition to the polymerisation reactor.

Abstract: The invention relates to a method of operating a high pressure ethylene polymerisation unit comprising a tubular reactor, the method characterised in that the electrical conductivity of the aqueous cooling medium is monitored in at least one location. Furthermore, the invention also covers a high pressure ethylene polymerisation unit comprising a tubular reactor, the unit characterised in that one or more cooling circuits comprise an electrical conductivity metre. The use of such a polymerisation unit is also disclosed.

Abstract: A process for polymerizing or oligomerising a hydrocarbon includes feeding at a low level a liquid hydrocarbon reactant into a bulk liquid phase comprising polymeric or oligomeric product admixed with a catalyst. The liquid hydrocarbon reactant is allowed to vapourise to form bubbles rising through the bulk liquid phase and to polymerise or oligomerise to form the polymeric or oligomeric product, with the rising bubbles creating turbulence in the bulk liquid phase, thereby mixing the bulk liquid phase. Gaseous components comprising any unreacted vapourised hydrocarbon reactant and any gaseous product that may have formed are withdrawn from a head space above the bulk liquid phase. Liquid phase from the bulk liquid phase is withdrawn to maintain the bulk liquid phase at a desired level.

Abstract: A process for producing polyolefins, which includes polymerizing at least one olefin monomer, separating at least a part of the reaction mixture, dividing the separated reaction mixture into a polymer-lean fraction and a polymer-rich fraction, and subjecting at least a part of the polymer-lean fraction to a purification step prior to recycling back to the polymerization of at least one olefin monomer. The obtained polyolefins particularly have a low content of volatile low molecular weight compounds, a low content of low-molecular weight polyolefin waxes and a low content of residues derived from the catalyst employed.

Abstract: Method and apparatus of producing polymers in a gas phase polymerization reactor, which has an elongated reactor body, and an essentially vertically disposed central axis. The reactor comprises an upper part and a lower part, which are separated by a distribution plate, which promotes distribution into the fluidized bed of monomers flowing from the lower part into the upper part. According to the invention, at least a part of the gas stream fed into the lower part of the reactor is conducted along the inside of the reactor walls past the distribution plate to prevent the formation of stagnant zones in the fluidized bed at the reactor walls in the vicinity of the distribution plate.

Abstract: The invention provides a continuous-flow process for producing a polymeric material. The process of the invention comprises the steps of: introducing at least two solutions, each comprising one or more reactants, into a microreactor to mix the two solutions to form a reacting solution, wherein the one or more reactants are selected from the group consisting of a monomer, an initiator, a coupling agent, a prepolymer, a macromer, and mixtures thereof; feeding continuously the reacting solution into a flow-through polymerization reactor in a coil form, wherein the flow-through polymerization reactor is capable of providing a residence time sufficient for (co)polymerizing the reactants to form a polymer with a desired polydispersity, wherein the flow-through polymerization reactor is immersed in an ultrasonic bath to minimize or substantially eliminate unwanted high-molecular-weight fractions of the polymer.

Abstract: A method comprising preparing a multi-component catalyst system comprising a catalyst and a cocatalyst, and adjusting the level of at least one component of the catalyst system to maintain a user-desired level of catalyst activity throughout a process, wherein the component comprises a catalyst activator and wherein the catalyst activator comprises the catalyst or the cocatalyst. A method comprising contacting a polymerization catalyst system comprising a Ziegler-Natta catalyst and a cocatalyst with a catalyst activator at least twice during a polymerization process, wherein the polymerization process is carried out in a reactor system comprising multiple reactor types.

Abstract: A method for purifying a 2-aryl-3,3-bis(hydroxyaryl)phthalimidine comprises contacting a crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine with a purification agent, removing a 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound from the crude 2-aryl-3,3-bis(hydroxyaryl)phthalimidine, and producing a purified 2-aryl-3,3-bis(hydroxyaryl)phthalimidine product comprising less than 200 parts per million of the 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound. The purification agent is selected from the group consisting of an acidic material, an organic acid chloride, an organic anhydride, or a combination thereof. The 2-aryl-3-(aminoaryl)-3-(hydroxyaryl)phthalimidine compound has a formula: wherein each R1 is independently selected from a group consisting of a hydrocarbyl radical, a nitro radical, and a halogen atom; “a” is an integer from 0 to 4; and Ar1 and Ar2 are independently at each occurrence an aromatic radical.

Abstract: A process comprising polymerising in a loop reactor an olefin monomer optionally together with an olefin commoner in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the Froude number is maintained at or below 20 is disclosed.

Abstract: A process comprising polymerising in a loop reactor of continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the internal diameter of at least 50% of the total length of the reactor is at least 700 millimeters and the solids concentration in the reactor is at least 20 volume % is disclosed.

Abstract: The present invention relates to a process for the catalytic polymerization of olefins comprising the steps of; i) a first polymerization in a first reactor, wherein olefins are polymerized with a particulate catalyst, hydrogen and optional a comonomer in a fluidum of an inert low boiling hydrocarbon medium into an reaction mixture comprising polymerized olefins; and ii) a second polymerization in a second reactor, wherein the polymerized olefins are further polymerized in a fluidized bed and in a moving bed under such conditions that the residence time in the fluidized bed and the residence time in the moving bed are independently controlled to a reactor system for carrying out said process, to the use of the reactor system, the polyolefins obtainable with said method and to the use of these polyolefins.

Abstract: A transfer method and system (8) to discharge overflow slurry from a polymerization reactor (10) to a tank (14). The method includes thermally isolating a conduit extension (28) at a distal end of a transfer line (20) from a quench fluid inlet (42) to a quench chamber (12). The transfer system (8) is characterized by an annular thermal barrier around the conduit extension (28) that can include insulation (34) and/or thermally resistant support ring (36), and a trap-free conduit (20) in fluid communication between the reactor (10) and the conduit extension (28). The transfer method and system can reduce or eliminate incidents of transfer line (20) plugging in the manufacture of isoolefin polymers and copolymers.

Abstract: The process for preparing a polyamide based on dicarboxylic acids and diamines has the following stages: 1) providing an aqueous monomer mixture of dicarboxylic acids and diamines, the molar ratio of dicarboxylic acids to diamines being adjusted such that a molar deficiency of dicarboxylic acids or diamines of from 1 to 10 mol % is present at the outlet of stage 3), based on the other component in each case, 2) transferring the aqueous mixture from stage 1) to a continuous evaporator reactor in which diamines and dicarboxylic acids are reacted at a temperature in the range from 100 to 370° C. and a pressure in the range from 1 to 50 bar, 3) transferring the mixture from stage 2) to a separator which is operated at a temperature in the range from 100 to 370° C.

Abstract: A method of discharging polymer from a continuously operated polymerization reactor, wherein at least a monomer is polymerized to form polymer particles, the method comprising adjusting the discharge rate of the polymer particles by means of a piston valve having a piston element connected to an actuator, said actuator being able to modulate the piston stroke inside said piston valve.

Abstract: The invention relates to finely divided water-absorbing polymeric particles having high fluid transportation and absorption performance, the Centrifuge Retention Capacity (CRC) being not less than 26 g/g, the absorbency under a load of 4.83 kPa (AUL0.7 psi) not less than 23 g/g and the Transportation Value (TV) not less than 15,000 cm3s, the Transportation Value (TV) being the product of Saline Flow Conductivity (SFC) and wicking absorption after 60 minutes (DA60) multiplied by 107, and wherein the wicking absorption after 60 minutes (DA60) is the weight of 0.9% by weight sodium chloride solution absorbed by 70 g of the water-absorbing polymeric particles in 60 minutes, wherein the water-absorbing polymeric particles are situated, during measurement, in a circularly round vessel which has an internal diameter of 6 cm and is sealed at its lower end by a sieve base of 36 ?m mesh size, and the sieve base is in atmospheric contact with 0.

Abstract: The object of the present invention is to provide a production method of a high molecular weight aromatic polycarbonate containing a reduced amount of a high melting point product, and having less thermal history received and excellent hue by a melt process. The present invention relates to a production method of an aromatic polycarbonate, characterized in that in producing an aromatic polycarbonate using an aromatic dihydroxy compound and a carbonic diester as raw materials and using plural reactors, a molten reactant temperature T1 (° C.) in at least one reactor A and a molten reactant temperature T2 (° C.) in a reactor B subsequent to the reactor A are satisfied with the relationship of T2<T1, and an evaporation surface area per unit treatment amount of a molten reactant in the reactor to which a molten reactant having a limiting viscosity of 0.1 dl/g or more is supplied is 1.0 m2·hr/m3 or more.

Abstract: The techniques disclosed provide a treatment method for passivating the interior surface of a polymerization reactor to minimize the formation of a polymer coating on the surface. The passivation is performed using a passivating agent that reacts with adsorbed water to form labile passivation products. Both the passivating agent and passivation products may be easily removed from the reactor prior to polymerization. Other embodiments provide a reactor system with a tank configured to automatically add a passivating agent to the reactor and processes for making polymers using a treated reactor.

Abstract: The present invention discloses the use of a chromium-based catalyst system in two serially connected loop reactors for copolymerising ethylene and a comonomer, at reduced productivity, the final polyethylene having a reduced amount of gel.

Abstract: Reactor designs and processes for operating such reactor designs to minimize or eliminate fouling in homogeneous polymerization processes (solution and supercritical). The process includes providing a reactor with one or more feed entry ports, wherein the reactor feed components are fed through each of the one or more feed entry ports at a linear velocity of greater than or equal to 0.3 m/min. The one or more feed entry ports may also be optionally extended beyond the interior reactor wall by greater than or equal to 2% of the internal radius of the reactor to further decrease the propensity for fouling. A stirred reactor may also include a stirrer feed port for purging the stirrer with a stirrer purge stream at a linear velocity of greater than or equal to 0.3 m/min to decrease stirrer fouling.

Abstract: The present invention discloses a slurry loop reactor having at least two loops (1, 2) and comprising a by-pass line (11) connecting two points (12, 13) of the same loop reactor by an alternate route having a different transit time than that of the main route, said by-pass line also collecting the growing polymer of a first loop reactor (1) and sending said growing polymer to an entry point (13) in a second reactor (2).

Abstract: Tubular reactor apparatus and processes are provided for improved polymerization including using chain transfer agents and multiple monomer feeds spaced lengthwise along the tubular reactor providing high conversions of monomer into polymer. The invention also relates to polymers made from such a tubular reactor apparatus and processes including those polymers having a low haze value, a density over 0.92 g/cm3 and/or having terminal carbonyl groups. The apparatus and methods uncouple or reduce the dependency between the monomer concentration and transfer agent concentration. The uncoupling in other embodiments may also be varied leading to multiple desirable effects.

Abstract: This invention relates to a process to polymerize olefins comprising contacting, under supercritical conditions, olefin monomers with a catalyst compound, an activator, optional comonomer, and optional hydrocarbon diluent or solvent.

Abstract: The present invention concerns a process and an apparatus for continuous polymerisation of olefin monomers. In particular, the present invention concerns a process and an apparatus for continuous polymerisation olefin monomers like ethylene and other monomers, wherein an olefin monomer is polymerised in slurry phase in an inert hydrocarbon diluent in at least one loop reactor. According to the invention, a polymer slurry is continuously withdrawn from the loop reactor and concentrated. The concentrated slurry is conducted to a flash unit in order to remove the remaining fluid phase, and gas obtained is compressed in a flash gas compressor before it is being fed to a distillation section. By means of the present invention it is possible reduce the size of the flash gas compressor and the capacity of the distillation sections. This significantly reduces investment cost for a continuously operated polymerization apparatus.

Abstract: The present invention relates to an ethylene homo or copolymer characterized as having long chain branching, and having a molecular weight distribution, Mw/Mn, and a GPC-LALLS CDF, which satisfies the following relationship: y?0.0663x?0.015, wherein y=GPC-LALLS CDF and x=Mw/Mn measured by conventional GPC, a line drawn from where the LS chromatogram intersects with molecular weight 350,000 and molecular weight 1,150,000 has a positive slope, preferably with a melt index between 0.15 and 2000 g/10 minutes and having long chain branching. In addition, the invention relates to a free radical initiation polymerization process for the preparation of ethylene polymers or copolymers, comprising reacting ethylene and optionally one or more comonomers at a high pressure, conveniently between 13,000 psig and 100,000 psig, and at reactor temperatures of 115° C. to 400° C., preferably 125-400° C., more preferably 140-350° C., especially 165-320° C.

Abstract: The present invention relates to a process which comprises preparing polymers. The process uses an appropriate installation, and may comprise determining at least one parameter of a physical and/or chemical conversion. The invention also relates to a corresponding screening process. According to this process, a polymerization reaction medium is made to flow in a tubular flow member (12).

Abstract: An olefin polymerization process and apparatus wherein a fluid slurry comprising monomer, diluent and catalyst is circulated in a continuous loop reactor by two or more pumps. The process and apparatus allow operating the reaction at significantly higher solids content in the circulating fluid slurry. In a preferred embodiment, the fluid slurry is circulated by two impellers arranged so that the downstream impeller benefits from the rotational energy imparted by the upstream impeller. An olefin polymerization process operating at higher reactor solids by virtue of more aggressive circulation has improved efficiencies, particularly in larger-volume reactors.

Abstract: One exemplary method for message suppression comprises: providing first and second rules, each having one or more preconditions and a conclusion, wherein the first rule also has a suppressed-by attribute and at least one of the second preconditions is suppressing; evaluating the one or more first and second preconditions; identifying the first rule as true or false; displaying the message of the second rule if all of the second preconditions are met; identifying the first rule as suppressed if the second rule is named in the suppressed-by attribute; and inhibiting the message display of the suppressed rule or routing the message to second display. The system can comprise: a database containing knowledge of the production unit; a user interface, and at least one precondition, a suppressed by attribute, and one or more rules each having a conclusion and at least one suppressing precondition; an inference engine; and a display.

Abstract: The invention relates to a process for the continuous preparation of ethylene homopolymers or copolymers in the presence of free-radical polymerization initiators and, if desired, molecular weight regulators at from 120° C. to 350° C. and pressures in the range from 100 to 4000 bar, in which the polymer is separated from unpolymerized ethylene in a high-pressure stage at a pressure of from 100 to 500 bar and at least one low-pressure stage at a pressure of from 1 to 100 bar and the ethylene separated off in the high-pressure stage is separated from remaining monomeric, oligomeric and/or polymeric constituents and recirculated to the inlet of the tube reactor in a high-pressure circuit and the ethylene separated off in the low-pressure stage is separated from remaining monomeric, oligomeric and/or polymeric constituents and recirculated to the inlet of the tube reactor in a low-pressure circuit. The initiator is used as a solution in an isoparaffinic solvent having a boiling point of not more than 160° C.

Abstract: Catalyst systems for producing olefin polymers, methods of making such catalyst systems, and processes for producing olefin polymers using such catalyst systems are provided. The catalyst system comprises a first component and a second component, where the first component comprises chromium on a support, where the support comprises phosphated alumina, and the second component comprises: (1) a metal halide compound, a transition metal compound, and a precipitating agent, or (2) a substituted or unsubstituted dicyclopentadienyl chromium compound deposited onto a calcined oxide carrier, where the carrier includes silica, alumina, aluminophosphate, or any mixed oxide thereof.

Abstract: Process comprising polymerising in a loop reactor of a continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent, wherein the average internal diameter of at least 50% of the total length of the continuous tubular loop reactor is at least 700 mm wherein the HMW polymer is produced in a reactor upstream of the LMW polymer reactor and the ratio of the average internal diameter of the HMW reactor to the average internal diameter of the LMW reactor is between 0.8 and 1.4.

Abstract: A process comprising polymerising in a loop reactor of a continuous tubular construction an olefin monomer optionally together with an olefin comonomer in the presence of a polymerisation catalyst in a diluent to produce a slurry comprising solid particulate olefin polymer and the diluent wherein the average internal diameter of at least 50% of the total length of the reactor is at least 650 millimeters, the solids concentration in the reactor is at least 15 volume % and having a particle size distribution such that (D90?D10)/D50 is less than 2.

Abstract: Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages: Stage 1: into and through a reactor, polycondensing a liquid stream which contain the polyamide monomer(s) at a pressure P1 greater than atmospheric pressure, the stream of material at the outlet of the reactor including a vapor phase which contains steam and a liquid phase which at least contains the product of polycondensation; Stage 2: feeding the outlet stream of material into a chamber, evacuating at least a portion of the vapor phase therefrom and recovering at least the liquid phase which at least contains the product of polycondensation, the pressure P2 in the chamber being regulated at a set value such that it is greater than atmospheric pressure and the residence time of said liquid phase in the chamber being less than 5 minutes; and Stage 3: pressure reducing at least the liquid phase which at least contains the stream of polycondensation product recovered during Stage 2.