Abstract: A method for predicting physical properties of a polyethylene resin is provided, which can reliably predict a proper charging ratio of a crosslinking agent in the production process of a low density crosslinked polyethylene resin, and the physical properties of the polyethylene resin achieved therefrom. A method for producing a polyethylene resin by applying the same method is also provided.

Abstract: Provided is a method of predicting fouling during a process of preparing polyolefin. According to the present invention, occurrence of fouling may be predicted in real-time with high reliability during a copolymerization process of preparing polyolefin. Therefore, productivity of the polyolefin preparation process may be further increased.

Abstract: The present disclosure relates to a purification method of a polymerization solvent used in and recovered from the preparation of a polyolefin resin, which can effectively remove impurities, in particular polyolefin wax, from the polymerization solvent to obtain a purified polymerization solvent with high purity, and can improve energy efficiency.

Abstract: The present invention relates to a high-vacuum serial condenser system that can minimize a pressure drop of fluid in condensers by disposing straight pipes between the condensers and installing baffles at predetermined angles in the condensers.

Abstract: An ethylene vinyl acetate copolymer with a high degree of cross-linking and a method of preparing the same are provided, by controlling a temperature and polymerization heat in an autoclave reactor during polymerization, even when a reduced amount of a cross-linking agent is used.

Abstract: The present invention relates to a method for preparing ethylene vinylacetate copolymer that can improve the mechanical strength of copolymer by controlling the polymerization conditions using an autoclave reactor.

Abstract: The present invention relates to a method of preparing an aromatic vinyl compound-vinyl cyanide compound polymer including a step of separating volatile components from a polymerization product containing an aromatic vinyl compound-vinyl cyanide compound polymer, a residual aromatic vinyl monomer, a residual vinyl cyanide monomer, and an organic solvent using a volatilization tank, and a step of condensing the separated volatile components using a condenser, wherein an organic solvent or an aromatic vinyl monomer is sprayed onto the volatile components being transferred to the condenser. Volatile components may be fully condensed in a condenser, thereby significantly reducing the amount of volatile components discharged to the outside without being condensed. Therefore, wastewater treatment costs consumed in treating the volatile components may be reduced, and the amount of vinyl cyanide monomers harmful to the human body discharged into the atmosphere may be significantly reduced.

Abstract: A method of preparing an aromatic vinyl compound-vinyl cyanide compound polymer includes polymerizing a reaction mixture containing an aromatic vinyl compound, a vinyl cyanide compound, and an organic solvent in a reactor and transferring the vaporized reaction mixture present in the upper space of the reactor to a heat exchanger via a pipe and condensing the vaporized reaction mixture. The condensed reaction mixture is transferred to one side of the pipe and sprayed into the pipe, the flow velocity of the reaction mixture vaporized in the reactor is reduced, and temperature is lowered. Accordingly, a phenomenon wherein polymer particles in a reactor are sucked into a heat exchanger is prevented, and occurrence of polymerization in the heat exchanger is suppressed. Therefore, productivity and quality may be improved.

Abstract: The present invention relates to a gas/liquid separator. According to an aspect of the present invention, provided is a gas/liquid separator, including a housing including a first supply part and a second supply part; a rotary shaft rotatably provided to the housing; a drive unit configured to rotate the rotary shaft; fixed cones disposed in an interior of the housing and each including a tilted area, diameters of which are decreased in a direction from the first supply part to the second supply part, a first through-hole, which passes the rotary shaft, and at least one second through-hole, through which a second fluid introduced via the second supply part passes; and rotary cones disposed in an interior of the housing so as to be spaced apart from the fixed cones and installed at the rotary shaft so as to rotate about the rotary shaft.

Abstract: An ethylene vinyl acetate copolymer with a high degree of cross-linking and a method of preparing the same are provided, by controlling a temperature and polymerization heat in an autoclave reactor during polymerization, even when a reduced amount of a cross-linking agent is used.

Abstract: Provided is a method for purifying a waste solvent by removing carbon dioxide contained in a waste solvent derived from supercritical waste liquid generated after supercritical drying by a decompression process, and removing ammonia by a multi-stage distillation process to obtain a solvent of high purity, which can be reused in producing silica aerogel or a silica aerogel blanket.

Abstract: A separation method and a separation apparatus for a solvent extracted by supercritical extraction. The separation method increases a solvent recovery rate by minimizing the amount of a solvent to be evaporated and lost since the pressure of a solvent is reduced by arranging two or more separators in series. The method includes: introducing a fluid having passed through a supercritical extractor into a first flash vessel; introducing the fluid which has passed through the first flash vessel into a second flash vessel; and discharging and recovering the carbon dioxide and the solvent which have passed through the second flash vessel, respectively. The pressure of the first flash vessel is 40-100 bar, and the pressure of the second flash vessel is 1-30 bar. The fluid includes carbon dioxide and a solvent.

Abstract: The present invention relates to a method for recovering ethylene and a vinyl-comonomer that is capable of improving the rate of recovery of unreacted monomers remaining after polymerization of ethylene and a vinyl-based comonomer and increasing process efficiency through the reduction of costs. Specifically, the method for recovering ethylene and a vinyl-comonomer includes: a step of polymerizing ethylene and a vinyl-based comonomer at a pressure of 1500 bar or more; a step of depressurizing the product obtained in the polymerization step including an ethylene-vinyl-based comonomer polymer, ethylene, and a vinyl-based comonomer to 0.1 bar to 5 bar; a step of adding ethylene to the product obtained in the polymerization step under the pressure of 0.1 bar to 5 bar; and a step of separating ethylene and a vinyl-based comonomer from the product obtained in the polymerization step to which the ethylene is added.

Abstract: The present application relates to a method for removing an unreacted vinyl chloride monomer (VCM) in polyvinyl chloride (PVC). According to an illustrative stripping apparatus and a stripping method using the stripping apparatus of the present application, in a stripping process using steam, a temperature difference between a raw material including a target substance to be removed and steam is minimized to suppress foam generation in the stripping process, thereby increasing efficiency of removing the target substance to be removed, particularly, an unreacted VCM in PVC. In addition, a cleansing cycle to remove foams generated in the stripping apparatus can be reduced, thereby not only securing economic feasibility of the process, but also preventing degradation in quality of a final product that may occur when an antifoamer to remove the foams is used.

Abstract: The present invention provides a method for producing a polyethylene resin in which gel or fish eye formation is greatly reduced, by controlling various reaction conditions such as the supply flow rate ratio of the monomers to each reactor, the temperature range of each reactor, and the temperature range of the mixing region, in the method for producing a polyethylene resin which is applied to produce a polyethylene resin for a protective film of display.

Abstract: The present invention relates to an olefinic monomer recovery device capable of suppressing fouling and pressure drop in the recovery device in a process of separating and recovering unreacted monomers after production of a polyolefin resin. The olefinic monomer recovery device is used for separating and recovering unreacted olefinic monomers after production of a polyolefin resin, the apparatus comprising a vertical-type heat exchange unit, and a knock-out drum unit.

Abstract: The present invention relates to a method for recovering ethylene and a vinyl-comonomer that is capable of improving the rate of recovery of unreacted monomers remaining after polymerization of ethylene and a vinyl-based comonomer and increasing process efficiency through the reduction of costs. Specifically, the method for recovering ethylene and a vinyl-comonomer includes: a step of polymerizing ethylene and a vinyl-based comonomer at a pressure of 1500 bar or more; a step of depressurizing the product obtained in the polymerization step including an ethylene-vinyl-based comonomer polymer, ethylene, and a vinyl-based comonomer to 0.1 bar to 5 bar; a step of adding ethylene to the product obtained in the polymerization step under the pressure of 0.1 bar to 5 bar; and a step of separating ethylene and a vinyl-based comonomer from the product obtained in the polymerization step to which the ethylene is added.

Abstract: The present invention relates to a high-vacuum serial condenser system that can minimize a pressure drop of fluid in condensers by disposing straight pipes between the condensers and installing baffles at predetermined angles in the condensers.

Abstract: The present invention relates to a gas/liquid separator. According to an aspect of the present invention, provided is a gas/liquid separator, including a housing including a first supply part and a second supply part; a rotary shaft rotatably provided to the housing; a drive unit configured to rotate the rotary shaft; fixed cones disposed in an interior of the housing and each including a tilted area, diameters of which are decreased in a direction from the first supply part to the second supply part, a first through-hole, which passes the rotary shaft, and at least one second through-hole, through which a second fluid introduced via the second supply part passes; and rotary cones disposed in an interior of the housing so as to be spaced apart from the fixed cones and installed at the rotary shaft so as to rotate about the rotary shaft.

Abstract: The present application relates to a method for removing an unreacted vinyl chloride monomer (VCM) in polyvinyl chloride (PVC). According to an illustrative stripping apparatus and a stripping method using the stripping apparatus of the present application, in a stripping process using steam, a temperature difference between a raw material including a target substance to be removed and steam is minimized to suppress foam generation in the stripping process, thereby increasing efficiency of removing the target substance to be removed, particularly, an unreacted VCM in PVC. In addition, a cleansing cycle to remove foams generated in the stripping apparatus can be reduced, thereby not only securing economic feasibility of the process, but also preventing degradation in quality of a final product that may occur when an antifoamer to remove the foams is used.