A process, for recovery of unreacted olefin monomer(s) from a particulate product of an olefin polymerization reactor, the particulate polymer product is supplied to a degassing vessel, where the particulate product is countercurrently contacted with at least a first gaseous stripping stream, which includes at least 5% by weight unreacted olefin monomer, and then with an inert gas stream under conditions effective to strip hydrocarbon impurities from the polymer product and produce a stripped polymer product, is provided.

A process, for recovery of unreacted olefin monomer(s) from a particulate product of an olefin polymerization reactor, the particulate polymer product is supplied to a degassing vessel, where the particulate product is countercurrently contacted with at least a first gaseous stripping stream, which includes at least 5% by weight unreacted olefin monomer, and then with an inert gas stream under conditions effective to strip hydrocarbon impurities from the polymer product and produce a stripped polymer product, is provided.

An eductor, a process and apparatus for gas phase polymerization of olefins in a polymerization reactor are disclosed. The process and apparatus employ an eductor which has an inlet which makes a bend of less than about 90 toward the outlet after entering the mixing chamber of the eductor.

A process for producing thermally surface postcrosslinked superabsorbent particles, comprising polymerization of a monomer solution or suspension, static drying of the resultant aqueous polymer gel, comminution of the dried polymer gel, classification of the resultant polymer particles, with removal of excessively small polymer particles as undersize, mixing of the removed undersize with an aqueous solution, said aqueous solution comprising a crosslinker, and recycling of the polymer gel obtained from the undersize into the static drying.

A process for the recovery and recycling of unreacted monomer in a one-step process for the production of a carbon-fiber precursor. An integrated and improved single-step process for the production of a carbon-fiber precursor is also described, which starts from the co-monomers and reaches the spinning step obtaining the final precursor fiber, which provides for the recovery of the unreacted monomers at the end of the polymerization step and their recycling to the polymerization process itself.

The present invention relates to a method for producing an ethylene-based copolymer, and more particularly, to a method for producing an ethylene-based copolymer capable of increasing process efficiency by preventing plugging and corrosion of a facility. The method for producing an ethylene-based copolymer includes a producing mode and a washing mode of which one is selectively performed. The producing mode includes: a) hyper-compressing primary compressed ethylene, and a mixture including a carboxylic acid-containing comonomer and a polar solvent to produce a compressed material; b) reacting the compressed material to produce a reaction product including an ethylene-based copolymer; and c) separating and recovering unreacted residues from the reaction product and introducing the unreacted residues into the mixture of step a). The washing mode includes: re-supplying the compressed material produced in step a) to step a) as a mixture, without performing step b).

A process can be used for manufacturing an acrylic copolymer having increased heat resistance, high transparency, and improved adhesion to metal surfaces. The process involves polymerizing a monomer mixture, optional heating of the copolymer mixture, and removing volatile components from the copolymer mixture by degassing. Moulding compositions containing this copolymer are highly suitable for manufacturing optical elements for optoelectronic devices containing acrylic and metallic or ceramic parts.

A method for producing a chloroprene-based polymer latex which can efficiently remove a residual volatile organic substance from the chloroprene-based polymer latex while suppressing the deposition of agglomerates is provided. In the method for producing a chloroprene-based polymer latex of the present invention, when the residual volatile organic substance comprised in the latex is volatilized and removed, a mixed fluid of one or more gases selected from the group consisting of inert gases and air, and water is contacted with the latex at a gas pressure higher than the saturated water vapor pressure, and a temperature of the mixed fluid is a temperature lower than a boiling point of water at the gas pressure.

The invention provides a method, and apparatus, for determining the degree of separation (DOS) of a polymer solution into a polymer-rich stream and a solvent-rich stream, said method comprising the following: adding to a liquid-liquid separation vessel the polymer solution, which comprises a polymer, a solvent and an anti-solvent; separating the polymer solution into a polymer-rich stream and a solvent-rich stream; removing at least some the polymer-rich stream from at least one outlet P on the vessel, and measuring the actual solution density of this polymer-rich stream using at least one flow meter; removing at least some of the solvent-rich stream from at least one other outlet S on the vessel, and measuring the actual density of the solvent-rich stream using at least one flow meter; and wherein the degree of separation (DOS) is determined by the following equation (Eqn. 1):

DOS=[actual solution density (polymer-rich steam)actual solution density (solvent-rich stream)]/[theoretical solution density (polymer-rich stream)theoretical solution density (solvent-rich stream)](Eqn. 1).

A process comprising polymerizing olefin monomers and optionally comonomers in a first reactor vessel, thereby forming a raw product stream comprising polymerized solids, unreacted monomer and optionally comonomer, the polymerized solids comprising olefin polymer, volatile organic compounds (VOC) and catalyst system. Then the polymerized solids are contacted with a catalyst poison selected from carbon monoxide, carbon dioxide, oxygen, water, alcohols, amines, or mixtures thereof, thereby forming a passivated stream. The passivated stream is maintained in an agitated state within a second reactor. The passivated stream within the second reactor is then contacted with a circulating gas comprising unreacted monomer for a residence time, thereby reducing the concentration of VOC in the polymerized solids by at least 10 wt % compared to the level before entering the second reactor, thereby forming a purified olefin polymer solids stream.