Abstract: Methods and apparatus for continuous production of a partially polymerized composition according to the invention comprise those that facilitate continuously providing polymerizable composition comprising one or more monomers to an angled plane at an elevated position thereon; irradiating the polymerizable composition to form the partially polymerized composition; and continuously removing the partially polymerized composition from the angled plane at a lower position thereon, wherein the angle of the angled plane facilitates free flow of polymerizing composition from the elevated position to the lower position.

Abstract: A process for continuously producing water-absorbing polymer particles by polymerizing a monomer solution comprising acrylic acid and/or salts thereof, wherein the acrylic acid supplied has a dimeric acrylic acid content of at least 0.02% by weight and the dimeric acrylic acid content is kept essentially constant.

Abstract: A process for producing an aliphatic polyester includes the steps of: heating a cyclic ester at a melting point or higher to transform the cyclic ester into molten state and convert a moisture contained in the cyclic ester into free carboxylic acid; measuring an amount of the free carboxylic acid in the molten cyclic ester; feeding a proton-source compound in an amount determined based on the measured amount of the free carboxylic acid into the molten cyclic ester; and subjecting the cyclic ester to ring-opening polymerization. The process provides an aliphatic polyester with a desired molecular weight which can be set easily and accurately. An apparatus for the process is also provided.

Abstract: A process unit, having: a) an oligomerization reactor; and b) a control system that enables the reactor to be operated in a distillate mode and in a lubricant mode; and wherein the reactor can switch between modes.

Abstract: Disclosed are systems and methods for producing a polymer dispersion based on polychloroprene, comprising steps of polymerizing chloroprene to polychloroprene, adding the polycholoprene dispersion to a stripper column, and removing chloroprene from the polychloroprene dispersion.

Abstract: A process for polymerizing one or more olefins in a gas-phase polymerization reactor is provided. The gas-phase reactor has a fluidized bed and a fluidizing medium. The fluidizing medium has an operating density and an operating velocity. The process includes determining a critical gas velocity and/or determining a critical gas velocity for the polymerization. The operating gas density and/or the operating gas velocity for the fluidizing medium is then adjusted to be less than or equal to its respective critical value. The process includes increasing the bulk density of the fluidized bed. The increase in the fluidized bed bulk density increases productivity without increasing reactor residence time.

Abstract: The present invention provides an automatic sampling and dilution apparatus for use in a polymer analysis system. The apparatus comprises (a) a primary mixing chamber; (b) a primary pump capable of continuously withdrawing a variable viscosity liquid from a reactor at a selectable, fixed withdrawal rate over a varying viscosity range of about 50 to about 5,000,000 centipoise (cP) for continuously conveying the variable viscosity polymer-containing liquid into the primary mixing chamber; (c) a first dilution pump for continuously delivering a first dilution solvent into the primary mixing chamber at a selectable, fixed flow rate to mix with the variable viscosity liquid in the mixing chamber and thereby form a diluted polymer-containing liquid therein; and (d) a secondary pump for continuously conveying the diluted polymer-containing liquid into a flow-through detector. A polymer analysis system utilizing the automatic sampling and dilution apparatus is also provided.

Abstract: The present invention relates to a process for producing a water-absorbing polymer structure based on acid group-containing monomers, comprising the process steps of: i) providing a monomer solution comprising the optionally partly neutralized, acid group-containing monomer; ii) mixing the monomer solution with fines which consist at least to an extent of 90% by weight, based on the total weight of the fines, of particles having a particle size of less than 850 ?m, to obtain a monomer solution mixed with fines; wherein the mixing in process step ii) is effected in a mixer in which a first stream of the fines and at least one further stream of the monomer solution are passed from different directions simultaneously to a rotating mixing tool.

Abstract: The present invention relates to a reactor (10) and a process for continuous polymerization, where the reactor (10) has an essentially tubular reactor housing (16). The reactor housing (16) has a drive (38) which runs along the geometric central axis (12) in the flow direction (22) and is configured as a central shaft. A rotatably arranged scraper or wiper (36) is provided within the reactor housing (16); the scraper or wiper (36) has at least one scraper or wiper blade (42) to run along an interior side (44) of the reactor housing (16). The rotational movement of the scraper or wiper (36) results in radial mixing of a stream within the reactor housing (16) which dominates gravity effects and, by virtue of shaping of the scrapers or wipers, optionally makes plug flow or backflow within the reactor (10) possible.

Abstract: The present disclosure is directed to an apparatus and process for producing a catalyst composition and a low-fines catalyst composition in particular. A crossflow classification device is used to separate large catalyst particles from catalyst fines. A slurry of a catalyst composition is introduced into the crossflow classification device. A classified catalyst composition is retrieved from a retentate produced as a result of subjecting the catalyst slurry to a crossflow classification process. The solids content of the pre-classified and/or post-classified catalyst slurry is determined by way of NMR spectroscopy. The solids content determination accounts for migration of wash liquid from the catalyst composition and into the slurry liquid phase. The classified catalyst composition has a low-fines content and produces a polyolefin composition with a low polymer fines content.

Abstract: The present invention relates to an apparatus and a process for polymerization, and, in particular, provides an apparatus for gas phase fluidised bed polymerization of olefins, which apparatus comprises: A) a first section which is an upright cylindrical section having a diameter, D1, and cross-sectional area, A1, and B) a second section, provided vertically above the first section and centered about a common vertical axis to the upright cylindrical first section, the base of the second section having a cylindrical cross-section of diameter D1 and being joined to the top of the first section, and the horizontal cross-sectional area of the second section above its base being greater than the cross-sectional area of the first section, characterized in that: i) D1 is greater than 4.5 meters, and ii) the second section has a maximum horizontal cross-sectional area, A2, which is between 3.2 and 6 times the cross-sectional area, A1, of the first section.

Abstract: A spouted bed device according to the present invention includes a vertically extending cylinder; a decreasing diameter member which is formed on the cylinder, has an inside diameter that decreases progressively downward, and has a gas inlet orifice at a bottom end thereof; and a tubular portion which extends downward from an edge of the gas inlet orifice. A spouted bed is formed in a treatment zone enclosed by a top surface of the decreasing diameter member and an inner wall of the cylinder above the decreasing diameter member.

Abstract: A system for processing large quantities of a reaction medium while maintaining the reaction medium in sheets. The system includes a reactor having a plurality of vertically-spaced downwardly-sloped trays over which the reaction medium flows while it is subjected to reaction conditions. The slope of the trays increases downwardly to accommodate for the increased viscosity of the reaction medium while the reaction medium flows downwardly through the reactor. An upper portion of the trays have a uni-directional configuration, while a lower portion of the trays have a bi-directional configuration. Further, the orientation of flow across the uni-directional trays is rotated by 90 degrees in at least one location as the reaction medium flows down the uni-directional trays.

Abstract: The present invention relates generally to polyolefin production and to reducing volatile organic content (VOC) associated with the polyolefin. Techniques include the construction and implementation of a purge column model to calculate or estimate the VOC content in the polyolefin exiting the purge column. The techniques facilitate the design and operation of the polyolefin manufacturing process.

Abstract: Techniques are provided for operating a reactor during a catalyst transition period. The instantaneous reaction rate during a catalyst transition period can be determined using real-time measured process variables, and material balance calculations to provide an instantaneous reaction rate in approximately real time. According to certain embodiments, a material balance can be performed on the reactor system using a continuous ideal stirred tank reactor to determine the fractions of each type of catalyst that are present in the reactor, as well as the overall weight percent of catalyst in the reactor. A controller can then calculate the overall instantaneous reaction rate based on the respective catalyst fractions and the overall weight percent of catalyst in the reactor. The catalyst feed rate can then be adjusted based on the determined instantaneous reaction rate to maintain the instantaneous reaction rate within desired limits during a catalyst transition period.

Abstract: The invention relates to a method for thermally treating polyester pellets to obtain partial crystallization, whereby the polyester melt is supplied to an underwater granulating system and granulated; the thus obtained granulate are fed from the underwater granulating system into a water-solids separator. The dried granulate is then fed into a treatment device at a granulate temperature higher than 100 degrees C., without external energy or heat being supplied. The intrinsic heat of the granulate is used as the heat treatment leading to partial crystallization. The crystallization device is embodied as an at least lightly inclined reactor, into which granulate is fed at a temperature higher than 100 degrees C. The granulate passes through the reactor from the loading point to the discharge point under its own weight and exits the reactor with a temperature higher than 130 degrees C.

Abstract: Systems and methods for separating particles from fluids are provided. The system comprises a vessel with a fluid inlet and a fluid outlet and a baffle assembly located within the vessel. The baffle assembly has a plurality of baffles that can provide a change in direction to fluid entering the vessel thereby separating particles. During shut-down of a polymerization reactor, reaction mixture is discharged to a separation system where polymer particles are removed from the mixture prior to being released into the atmosphere.

Abstract: A method for producing a molded product consisting of a resin polymerized by a melt polycondensation reaction, comprising continuous feeding of a prepolymer in molten state from a prepolymer feeding port to a polymerization reactor, discharging from holes of a porous plate, followed by polymerization while dropping along a supporting substrate under reduced pressure, and molding by transferring to at least one molding machine in molten state without solidification, wherein transfer pressure to said molding machine is controlled so as to maintain at an arbitrary pressure from 0.1 to 100 MPa (absolute pressure).

Abstract: An olefin polymerization reactor is provided with a first cylinder extending vertically; a first tapered cylindrical member placed in the first cylinder, having the inner diameter decreasing progressively downward, and having a gas inlet orifice at a bottom end thereof; a first liquid supplying part supplying a liquid so that the liquid may come into contact with an outer surface of the first tapered cylindrical member; and a gas supplying part supplying an olefin-containing gas through the gas inlet orifice into a first reaction region surrounded by an inner surface of the first tapered cylindrical member and an inner surface of the first cylinder above the first tapered cylindrical member, to form a spouted bed in the first reaction region.

Abstract: Disclosed is a method for manufacturing D-lactide from liquid D-lactic acid and a method for manufacturing D-polylactic acid with a weight-average molecular weight 50,000-20,000 g/mol from the prepared D-lactide. The disclosed method is advantageous in that D-lactide can be prepared in high yield through a relatively simple process as compared to the existing method. Thus, the cost for producing D-polylactic acid from the D-lactide can be reduced.

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 vaporise 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 vaporised 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: The present systems and methods utilize a polyamic acid solution as a precursor to form a polyimide bead having desired properties. The polyamic acid solution may be formed into a polyamic acid droplet. The polyamic acid droplet is then processed to form a polyamic acid bead, such as by extraction of solvent to concentrate the polyamic acid or by partial chemical imidization of the polyamic acid. The polyamic acid bead is then better able to retain its shape during subsequent processing steps, such as drying and pressurizing, before final thermal imidization.

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: The present invention relates to a method for the continuous production of high-molecular polyesters by esterification of dicarboxylic acids and/or transesterification of dicarboxylic acid esters with diols and/or mixtures thereof in the presence of catalysts with formation of a prepolymer in a tower reactor and polycondensation thereof to form a high-molecular polyester in a polycondensation reactor, a prepolymer with >40 to 70 repeat units (DP) being produced in the tower reactor and this prepolymer being polycondensed in only one further reactor to form a polyester with >150 to 205 DP.

Abstract: The present invention relates generally to polyolefin production and to reducing volatile organic content (VOC) associated with the polyolefin. Techniques include the construction and implementation of a purge column model to calculate or estimate the VOC content in the polyolefin exiting the purge column. The techniques facilitate the design and operation of the polyolefin manufacturing process.

Abstract: Treating a synthesis gas includes generating a plasma jet from a non-transferred arc torch having a main axis, the jet having a propagation axis substantially collinear with the torch main axis. The plasma torch is mounted on a feed enclosure. The syngas is received at an inlet port of the feed enclosure, downstream from the plasma torch and feeding the syngas so the flow encounters the plasma jet to mix the syngas and plasma jet in a distribution chamber. The mixture is propagated in a reactor downstream from the feed enclosure to convert the syngas into an outlet gas. The reactor is in communication in its upstream portion with the feed enclosure through a flared segment, and has a longitudinal axis that is substantially collinear with the propagation axis of the plasma jet. The outlet gas is extracted via an outlet port and particles are captured by a submerged conveyor.

Abstract: After various sugar nucleotide solutions and glycosyltransferases (or primers) have been mixed, they are introduced into a reaction tank (column) with primers (or glycosyltransferases) immobilized thereon. Then solutions coming out of the reaction tank are led to an ultrafiltration column. The oligosaccharide synthesizer according to the present invention is equipped with a flow path for ensuring that glycosyltransferases or primers separated by the ultrafiltration column are returned into a container for storing each solution in a sample injector.

Abstract: The invention relates to the use of an apparatus for adding at least one solid or viscous liquid additive, or an additive dispersed in solvent, to a reactor interior of a reactor for preparing crosslinked, finely divided polymers by copolymerizing (a) water-soluble, monoethylenically unsaturated monomers and (b) from 0.001 to 5 mol %, based on the monomers (a), of monomers comprising at least two polymerizable groups, (c) from 0 to 20 mol %, based on the monomers (a), of water-insoluble monoethylenically unsaturated monomers, where the apparatus comprises at least one screw for conveying the at least one additive and the at least one screw ends in an addition orifice substantially flush with the inner wall of the reactor interior.

Abstract: Process for the preparation of ethylene homopolymers or copolymers in a high pressure reactor with at least two spatially separated initiator injection points by polymerizing ethylene and optionally further monomers in the presence of at least two different mixtures of free-radical polymerization initiators at from 100° C. to 350° C. and pressures in the range of from 160 MPa to 350 MPa, wherein the process comprises the following steps: a) providing at least two different initiators as solution in a suitable solvent or in liquid state, b) mixing the initiators and optionally additional solvent in at least two static mixers and c) feeding each of the mixtures to a different initiator injection point of the high pressure reactor, and apparatus for feeding initiator mixtures to a high pressure reactor with at least two spatially separated initiator injection points.

Abstract: The present invention provides a polymer synthesizer having a high efficiency production rate. The synthesis of the polymers, and more particularly of DNA and RNA, is done very quickly. Furthermore, it is possible to synthesize a plurality of polymers in the same batch without significantly increasing the time and the complexity of the process.

Abstract: To provide an organic synthesizer that can conduct a pressure reaction and an atmospheric reaction in one organic synthesizer. An organic synthesizer comprising a reaction vessel support part (160), which can support two or more reaction vessels, and pressure regulation means (164) for regulating the pressure within the reaction vessel supported by the reaction vessel support part (160) by supplying/discharging gas. Two or more pressure regulation means (164) are provided for each reaction vessel supported by the reaction vessel support part (160). At least one pressure regulation means (164A) in the two or more pressure regulation means (164) is constructed so as to be detachable from and attachable to the other pressure regulation means (164B). The gas supply/discharge pipes (174a to 174d) are constructed so that a part near the front end can be flexed in a vertical direction and in a lateral direction.

Abstract: A system configured to produce polyvinyl chloride that includes a high shear mixing device comprising at least one rotor/stator set and configured to produce a polymerization mixture by high shear mixing a vinyl chloride solution with an initiator solution, wherein the polymerization mixture comprises an emulsion of droplets; a pump in fluid communication with an inlet of said high shear mixing device; and a vessel in fluid communication with an outlet of said high shear mixing device and configured for to maintain a predetermined pressure and temperature on the polymerization mixture, wherein the vessel comprises an outlet for a product comprising polyvinyl chloride and unconverted vinyl chloride and a vent gas outlet for at least one gas selected from the group consisting of gaseous vinyl chloride, volatile reaction products, and combinations thereof.

Abstract: Process for producing a multimodal polyethylene in at least two loop reactors connected in series. In the process 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. 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: Process for providing a flow of particulate matter to a reactor, by intermittently adding the particulate matter and a diluent to a mixing tank, and continuously withdrawing a slurry of particulate matter in diluent from the mixing tank for introduction into the reactor. Prior to each addition of particulate matter and diluent to the mixing tank, the concentration of particulate matter in the diluent already in the mixing tank is measured or calculated, and the amount of particulate matter and diluent subsequently added is measured so as to achieve the same concentration at the end of the addition as that measured or calculated prior to the addition.

Abstract: One exemplary embodiment can be a process for oligomerizing one or more hydrocarbons. The process can include providing a feed including one or more C3 and C4 hydrocarbons to a separation zone, separating at least a portion of C3 olefins, sending the C3 olefins to a first oligomerization zone for producing one or more C9 hydrocarbons, and returning at least a portion of an effluent from the first oligomerization zone to the separation zone.

Abstract: A polyester production system employing a vertically elongated esterification reactor. The esterification reactor of the present invention is an improvement over conventional CSTR esterification reactors because, for example, in one embodiment, the reactor requires little or no mechanical agitation. Further, in one embodiment, the positioning of the inlets and outlets of the reactor provides improved operational performance and flexibility over CSTRs of the prior art.

Abstract: Disclosed is a reactor or sparging vessel suitable for use for reaction mixtures containing vapor and/or gas bubbles. It comprises a mechanical agitation means suitable to redistribute flow radially and at least one perforated plate suitable to provide resistance to axial flow. In desirable embodiments it may include at least one electrically or hydraulically-stimulated rotatable shaft upon which at least one blade impeller is mounted, and at least one perforated plate oriented such that it provides resistance to axial flow. The perforated plate may have channels therethrough whose cross-sectional dimension is smaller than the projected average diameter of the vapor and/or gas bubbles. The reactor or sparging vessel offers improved flow dynamics, including reduced back mixing and narrowed residence time distribution. A method of employing the reactor for a reaction mixture containing vapor and/or gas bubbles is also disclosed. An impeller blade having two curvatures is also disclosed.

Abstract: A method of treating a gas phase fluidized bed reactor and a method of polymerizing olefins in a gas phase fluidized bed reactor in the presence of a catalyst prone to cause sheeting by introducing a chromium-containing compound into the reactor and forming a high molecular weight polymer coating on the walls of the reactor. Furthermore, a device for and method of introducing the chromium-containing compound into the fluidized bed reactor at a plurality of locations in proximity to a lower section of a bed section wall of the fluidized bed reactor, and forming a high molecular weight polymer coating on the bed section wall.

Abstract: The invention relates to a device for taking out and analyzing a sample from a polymerization reactor comprising one or more sample conduits (2), for taking a sample out of said reactor and for conducting said sample to one or more sample flash tanks (3), whereby said conduits each are in communication with said reactor (19) and each are provided with at least two sampling valves (4, 5); comprising one or more sample flash tanks (3), for separating said solid particles and evaporated gas, whereby said sample flash tanks are connected to said conduits (2) and provided with means for analyzing said evaporated gas (7), and comprising one or more sample receivers (6), for purifying said solid particles, whereby said receivers are connected to said sample flash tanks (3) and provided with means (8) for analyzing said solid particles. The invention further relates to a method for improving a polymerization reaction in a polymerization reactor.

Abstract: Techniques are provided to independently control 3D shape and chemistry of rapidly produced colloids. A pre-polymer mixture including a monomer is made to flow into a channel with insular relief in a wall at a known location of the channel. A stimulus that polymerizes the pre-polymer mixture is directed onto the known location to form a structure locked in place at the known location by the insular relief. A pressure is applied to the channel that is sufficient to deflect the wall having the insular relief sufficiently to release a hydrogel particle comprising the structure.

Abstract: The invention relates to a method of operating a high pressure ethylene polymerization unit comprising a tubular reactor, the method characterized 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 polymerization unit comprising a tubular reactor, the unit characterized in that one or more cooling circuits comprise an electrical conductivity meter. The use of such a polymerization unit is also disclosed.

Abstract: Apparatus, systems and methods are provided that utilize microreactor technology to achieve desired mixing and interaction at a micro and/or molecular level between and among feed stream constituents. Feed streams are fed to an intensifier pump at individually controlled rates, e.g., based on operation of individually controlled feed pumps. The time during which first and second feed streams are combined/mixed prior to introduction to the microreactor is generally minimized, thereby avoiding potential reactions and other constituent interactions prior to micro- and/or nano-scale interactions within the microreactor. Various microreactor designs/geometries may be employed, e.g., “Z” type single or multi-slot geometries and “Y” type single or multi-slot geometries. Various applications benefit from the disclosure, including emulsion, crystallization, encapsulation and reaction processes.

Abstract: Method of reducing fouling in an elastomer polymerization process that includes providing a reactor capable of housing an industrial-scale elastomer polymerization reaction, and applying a mechanical force to the reactor so as to create a vibration in at least one wall of the reactor, in which fouling is reduced in the reactor. In one embodiment the reaction is an industrial scale butyl polymerization reaction and the reactor is a butyl polymerization reactor.

Abstract: Process for producing a multimodal polyethylene in at least two 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 in the presence of the HMW polymer, wherein the solids concentration in the second LMW reactor, defined as the mass of polymer divided by the total mass of slurry, is at least 35 wt %, most preferably between 45 wt % and 60 wt %, and/or the ratio of solids concentration in the first reactor to that in the second reactor is maintained at less than 1.0, preferably between 0.6 and 0.8, and further wherein the volume of the second reactor is at least 10%, preferably at least 30% and more preferably at least 50% greater than the volume of the first reactor.

Abstract: Process for producing a multimodal polyethylene in at least two 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. 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). The volume of the second reactor is at least 10% greater than the volume of the first reactor, and the ratio of length to diameter of the first reactor, L/D(1), is greater than that of the second reactor, L/D(2).

Abstract: Disclosed is an optimized process and apparatus for more efficiently and economically carrying out the liquid-phase oxidation of an oxidizable compound. Such liquid-phase oxidation is carried out in a bubble column reactor that provides for a highly efficient reaction at relatively low temperatures. When the oxidized compound is para-xylene and the product from the oxidation reaction is crude terephthalic acid (CTA), such CTA product can be purified and separated by more economical techniques than could be employed if the CTA were formed by a conventional high-temperature oxidation process.

Abstract: A process for introducing a catalyst powder into a polymerization reactor comprising: a) metering the catalyst powder by means of a rotary valve comprising a stator, a rotor and sealing means arranged between said stator and said rotor; b) transferring a metered amount of catalyst powder from said rotary valve to a polymerization reactor; the process further comprising the steps of: c) feeding a flushing compound in one or more internal conduits arranged in the rotor of said rotary valve; d) flushing the catalyst powder away from said sealing means.

Abstract: The conversion and run length for oligomerisation of olefins over a molecular sieve catalyst in a tubular reactor is improved by controlling the peak temperature to not exceed 50 degrees C. above the temperature of the temperature control fluid exiting the shell side outlet of the reactor. A tubular reactor containing molecular sieve catalyst is provided with a multipoint thermocouple in at least one tube, and optionally with a bottom design adapted for fast unloading of the molecular sieve catalyst from the tubular reactor.

Abstract: An olefin polymerization reactor according to the present invention comprises: a vertically extending cylinder; a decreasing diameter portion on the cylinder, having an inside diameter that decreases progressively downward, and having a gas inlet orifice at a bottom end thereof; and a plurality of through holes passing through from an outside surface towards an inside surface of the decreasing diameter portion. Inside a reaction zone enclosed by an inside surface of the decreasing diameter portion and an inside surface above the decreasing diameter portion of the cylinder, a spouted-fluidized bed or a spouted bed is formed.

Abstract: A polyethylene production process, comprising contacting ethylene and a polymerization catalyst under suitable reaction conditions to yield a polymerization product stream, separating a light gas stream from the polymerization product stream, wherein the light gas stream comprises ethane and unreacted ethylene, contacting the light gas stream with an absorption solvent system, wherein at least a portion of the ethylene from the light gas stream is absorbed by the absorption solvent system, removing unabsorbed gases of the light gas stream from contact with the absorption solvent system to form a waste gas stream, and recovering ethylene from the absorption solvent system.