摘要:
A process for producing, from PCR polyolefin feedstock, pellets which are suitable for molding into useful articles suitable for food contact and other applications wherein feedstock fragrances are not desirable.
摘要:
The present invention relates to a method of preparing an ethylene/alpha-olefin/diene-based elastic copolymer having high viscosity and a high molecular weight, in which energy efficiency of the entire process is optimized. The method of preparing the elastic copolymer includes the steps of: copolymerizing an ethylene/alpha-olefin/diene-based elastic copolymer; and separating and removing the solvent and unreacted monomers from the polymer solution and recovering the elastic copolymer, by sequentially using a gas-liquid separator and a stripper in the purification of the solvent and unreacted monomers.
摘要:
Process for separating polymeric and gaseous components of a reaction mixture obtained by high-pressure polymerization of ethylenically unsaturated monomers in the presence of free-radical polymerization initiators, the process comprising the steps of entering the reaction mixture into a separation vessel; separating the reaction mixture into in a gaseous fraction and a liquid fraction; and withdrawing the gaseous fraction from the top of the separation vessel and withdrawing the liquid fraction from the bottom of the separation vessel, wherein the separation is carried out at a pressure of from 15 MPa to 50 MPa and a temperature of from 120°C to 300°C; the separation vessel has a vertically arranged cylindrical shape with a ratio of length to diameter L/D of from 4 to 10 and is equipped with an inlet pipe for introducing the reaction mixture into the separation vessel; the inlet pipe extends vertically from the top into the separation vessel; and the ratio of the inner diameter of the inlet pipe at its lower end and the inner diameter of the separating vessel in its cylindrical part is in the range of from 0.2 to 0.4 and process for preparing ethylene homopolymers or copolymers from ethylenically unsaturated monomers in the presence of free-radical polymerization initiators at temperatures from 100°C to 350°C and pressures in the range of from 110 MPa to 500 MPa in a polymerization reactor comprising a such process for separating polymeric and gaseous components.
摘要翻译:本公开涉及一种用于在一个气体馏分和液体馏分通过在自由基聚合引发剂的存在下烯属不饱和单体的高压聚合得到的反应混合物的聚合和气态组分分离成,worin分离是 在15兆帕至50兆帕的压力和120℃至300℃的在分离容器具有带有长度与直径L的比率的垂直布置的圆筒状的温度下进行从4的出/ D 至10和所有其配备有在从顶到分离容器垂直地延伸进水管; 和在其下端的入口管和分离容器在其筒状部的内径的内径的比率是在0.2至0.4的范围内。
摘要:
Provided is a method of purifying polyolefin, the method including the step of contacting linear low-density polyethylene synthesized by a gas phase polymerization reaction with a purge gas containing an ethylene gas and an inert gas in a purge bin. According to this purification method, residual alkene monomers with high carbon numbers may be removed in a simpler and more efficient manner.
摘要:
A process for recovery of ethylene from a polymerization product stream of a polyethylene production system, comprising 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 the contacting the light gas stream with the absorption solvent system occurs at a temperature in a range of from about 40° F to about 110° F, wherein at least a portion of the unreacted ethylene from the light gas stream is absorbed by the absorption solvent system, and recovering unreacted ethylene from the absorption solvent system to yield recovered ethylene.
摘要:
Provided is a method for manufacturing a modified polymer or hydrogen adduct thereof, the method allowing components that inhibit polymerization to be removed and the remaining part to be reused as a polymerization solvent. The method involves manufacturing a modified polymer having at least one functional group in a main chain or a side chain, obtained by polymerizing with a conjugate diene and/or aromatic vinyl compound as the monomer and an active organic metal as the polymerization initiator, in the presence of a hydrocarbon-based solvent that is used as the polymerization solvent; or manufacturing a hydrogen adduct of the modified polymer. The method comprises, in sequence: (a) a solvent removal step for separating the reaction solution where the modified polymer or hydrogen adduct is dissolved in the polymerization solvent into a solvent fraction containing the hydrocarbon-based solvent and a solid fraction containing the modified polymer, or the like; (b) a low-boiling fraction separating step for distilling the solvent fraction and separating the hydrocarbon-based solvent from the low-boiling fraction containing a silanol compound; and (c) a silanol removing step for removing at least a portion of the silanol compound from the low-boiling fraction by liquid-liquid extraction using the low-boiling fraction and an extraction solvent. Furthermore, at least a portion of the extract solution where the silanol compound has been removed by liquid-liquid extraction is reused as a polymerization solvent.
摘要:
The present invention relates to a process for recycling product streams that have been separated from a hydrocarbon-containing feed stream comprising olefin monomer, olefin co-monomer, hydrocarbon diluent and components such as H 2 , N 2 , O 2 , CO, CO 2 , and formaldehyde. In accordance with the present process a hydrocarbon-containing feed stream is separated into a) a first side stream comprising hydrocarbon diluent and olefin monomer; b) a second side stream which is substantially hydrogen-free and comprises hydrocarbon diluent and olefin monomer, c) a bottom stream comprising substantially olefin-free hydrocarbon diluent, and d) an overhead vapor stream comprising olefin monomer, hydrocarbon diluent and components such as formaldehyde, H 2 , N 2 , O 2 , CO and CO 2 . The present process further includes recycling said first and said second side streams in a polymerization process for preparing bimodal polyolefin.