Korea Institute of Science and Technology

Howtech Corporation Ltd.

Moon Jo Chung

Kun You Park

Hoon Sik Kim

Byoung Sung Ahn

Byung Gwon Lee

Dong Ju Moon

Young Soo Kwon

Hyun Joo Lee

Sang Deuk Lee

Jong Sung Lim

Honggon Kim

Nak Joong Kim

Seong Joon Cho

Yong Jin Kim

Hong Gon Kim

Kun Yu Park

Method of a simultaneous preparation of hexafluoropropylene and octafluorocyclobutane

A novel refrigerant composition useful as a substitute for HCFC-22, comprising a first constituent of difluoromethane (CH F , HFC-32); a second constituent of pentafluoroethane (CHF CF , HFC-125); a third constituent of 1,1,1-trifluoroethane (CH CF , HFC-143a); a fourth constituent selected from the group consisting of cyclopropane (C H , RC-270), 1,1,1,2,3,3,3-heptafluoropropane (CF CHFCF , HFC-227ea), 1,1,1,2,2-pentafluoropropane (CH CF CF , HFC-245cb), isobutane (CH(CH ) CH , R-600a), octafluorocyclobutane (C F , RC-318), 1,1,1,2,3,3-hexafluoropropane (CHF CHFCF , HFC-236ea), butane (C H , R-600), bis(difluoromethyl)ether (CHF OCHF , HFE-134) and pentafluoroethylmethylether (CF CF OCH , HFE-245).

Refrigerant mixture comprising difluromethane, pentafluroethane and 1,1,1-trifluoroethane

Polyolefin foam bead having a high-density crust and a method for manufacturing the same are disclosed. The novel polyolefin foam bead having an surface layer (crust) which is higher in density than its inner structure can be manufactured by the method comprised of impregnating a polyolefin resin with a forming agent by stirring the mixture of the polyolefin resin particles, water and the foaming agent in a pressure vessel under heat, followed by diffusing out the foaming agent from the surface layer of the resin particle to decrease the concentration of the foaming agent in the surface layer. Thereafter, the polyolefin resin is foamed by discharging the resin particles to low pressure environment.

Polyolefin foam beads having high density crust and method for manufacturing the same

A method for manufacturing polyolefin foam beads by a continuous process is disclosed by which the polyolefin foam beads can be produced with increased efficiency and productivity. The method comprises a step of impregnating foaming agent into polyolefin resin by mixing polyolefin resin particles, water and the foaming agent in a impregnation chamber under heat and pressure, followed by a step of storing the polyolefin resin containing the foaming agent in a storing chamber under heat and pressure. Thereafter, the resin particles are subjected to a foaming step by continuously or intermittently discharging the resin particles from the storing chamber to a low pressure expansion chamber by utilizing a discharging device, in the same time period when a next batch of polyolefin resin is added and mixed in the impregnation chamber after being supplied with the resin particles from a resin supply chamber.

Continuous process for manufacturing polyolefin foam beads

The present invention relates to a process for preparing hexafluoropropylene(CF CF&boxH;CF , HFP) from the pyrolysis of trifluoromethane(CHF , R23) and tetrafluoroethylene(C F , TFE) and more particularly, to the process for preparing hexafluoropropylene from the pyrolysis of an admixture of R23 and TFE mixed in an appropriate molar ratio at below 900 which is lower than the conventional reaction temperature and longer residence time, after investigating the pyrolysis reaction of R23 and TFE by the computer simulation. The process for preparing HFP is performed by carefully controlling reaction temperature with heat balance resulted from an endothermic pyrolysis of R23 and an exothermic dimerization of TFE to prevent from carbon formation, recycling unreacted R23 and TFE in the product separated and purified from distillation column, adding fresh R23 additionally to keep an appropriate molar ratio of R23 and TFE, to improve a total yield of HFP and to minimize heat supply from outside.

Preparation of hexafluoropropylene from the pyrolysis of trifluoromethane and tetrafluoroethylene

The present invention relates to a catalyst characterization apparatus, and in particular to an improved catalyst characterization apparatus which is capable of characterizing the surface of a catalyst more accurately by a volumetric method without requiring a pre-treatment step which may vary the characteristics of the catalyst as well as without exposing the catalyst in air, by combining a dynamic flow type reactor with a volumetric type adsorption apparatus, whereby it is possible to accurately characterize the catalyst during an actual reaction. It is possible to accurately characterize the various catalysts and to characterize the catalyst during the reaction, alternately and/or continuously, by combining a dynamic flow type reactor with a volumetric type characterization apparatus as well as a dynamic flow type characterization apparatus.

Catalyst characterization apparatus

A process is disclosed for preparing N,N'-disubstituted urea by reacting an amine and CO/O.sub.2 mixture gas in the presence of a catalyst system comprising at least one selenium compound selected from SeO.sub.2, (CH.sub.3 O)Se(O)(OH) and (CH.sub.3 CH.sub.2 O)Se(O)(OH), and M.sub.2 CO.sub.3 (M=alkali metal) as a co-catalyst. The process enables less active aromatic amine with a low reactivity as well as an aliphatic amine to be easily transformed into disubstituted urea avoiding the use of expensive precious metal catalysts.

Process for preparing n,n'-disubstituted urea using selenium-based

This invention relates to a method for preparing cycloaliphatic diamines by hydrogenating aromatic diamines in the presence of a supported ruthenium catalyst and a metal nitrite as a catalyst promoter to increase the rate of the hydrogenation reaction and decrease the amount of higher boiler by-products.

Method for preparing cycloaliphatic diamines from aromatic diamines

A method for concurrently producing different hydrofluoro carbons, comprising the reaction of halocarbon or hydrohalocarbon with hydrogen fluoride in a reaction system consisting of a series of at least two discrete reactors, in the presence of catalysts, said reactors each being provided with different reactant materials and differing in reaction conditions including the catalysts and/or reaction temperature, thereby flexibly controlling their production rates in accordance with fluctuations in their demand, and eliminating the risk of constructing large scale plants responsible for individual hydrofluorocarbons.

Method for concurrently producing different hydrofluoro carbons

The present invention relates to a process for manufacturing 1,1,1,2-tetrafluoroethane (HFC-134a) from trichloroethylene (TCE) and hydrogen fluoride (HF) by reacting the HCFC-133a with the HF to produce the HFC-134a and reacting the TCE with the HF to produce 1-choro-2,2,2-trifluoroethane (HCFC-133a), characterized by that a part of said HF is mixed with the mixture containing the HFC-134a and the remaining portion of said HF is fed with said TCE in portions to at least two sections of a reactor for producing said HCFC-133a. According the present process, the temperature change in the reactor for producing HCFC-133a is maintained within a narrow range over the whole reaction procedures, and the catalytic activity is well maintained. Further, the formation of by-products is considerably prevented and thus the productivity is remarkably enhanced.

Process for manufacturing 1,1,1,2-tetrafluoroethane

There is a method for concurrently producing 1,1,1,2-tetrafluoroethane and pentafluoroethane, which comprises (A) reacting 1,1,1-trifluoro-2-chloroethane, hydrogen fluoride and chlorine in a first reactor in the presence of flurorination catalyst at a temperature in the range of from 300.degree. C. to 450.degree. C.; (B) transfering the products of step (A) together with trichloroethylene to a second reactor and reacting them at a temperature in the range of from 200.degree. C. to 400.degree. C.; (C) separating 1,1,1,2-tetrafluoroethane and pentafluoroethane from the resultant products; and (D) feeding the remaining products from step (C) back to the first reactor, wherein the molar ratio of chlorine/1,1,1-trifluoro-2-chloroethanethe in step (A) is in the range of from 0.001 to 0.05

Method for concurrently producing 1,1,1,2-tetrafluoroethane and

A process for producing chlorine by reaction of gaseous hydrogen chloride with oxygen in the presence of a catalyst prepared by reaction of chromium trioxide and cerous chloride with ethanol and calcination of the resulting reaction product, or, alternatively, prepared by reaction of chromium trioxide with ethanol, and calcination and impregnation of the resulting chromic oxide with aqueous solution of cerous chloride.

Cerous chloride-chromic oxide catalyst for producing chlorine, methods

A novel cerous chloride-chromium oxide catalyst useful for oxidizing hydrogen chloride to chlorine. The catalyst is prepared by the reaction of chromium trioxide and cerous chloride with ethanol and calcining the reaction product. The catalyst is also prepared by the reaction of chromium trioxide with ethanol, then calcination and impregnation of the resultant chromic oxide with aqueous solution of cerous chloride. The obtained catalyst exhibits high activity at low reaction temperature.

A process for co-production of 1,1,1,2-tetrafluoroethane (HFC-134a;CF.sub.3 CH.sub.2 F), pentafluoroethane (HFC-125; CF.sub.3 CHF.sub.2) and 1,1,1 -trifluoroethane (HFC-143a; CF.sub.3 CH.sub.3) by a two-step gaseous reaction comprising the steps of a) reacting 1,1,1-trifluoro-2-chloroethane (CFCH.sub.2 Cl, HCFC-133a) with HF in a first reactor to prepare 1,1,1,2-tetrafluoroethane (HFC-134a; CF.sub.3 CH.sub.2 F), pentafluoroethane (HFC-125; CF.sub.3 CHF.sub.2) and 1,1,1-trifluoroethane (HFC-143a; CF.sub.3 CH.sub.3); b) adding trichloroethylene (TCE:CCl.sub.2 CHCl) to the reaction product of step a) in a second reactor to prepare HCFC-133a; separating HCl, HFC-134a, HFC-125 and HFC-143a from the reaction product of step b) and recycling HCFC-133a to the first reactor, and the stages being performed in the presence of fluorization catalyst obtained by calcining a reaction product which is obtained by reacting ethanol with a mixture of calcium fluoride(CaF.sub.2) with an aqueous solution of chromium trioxide, zinc chloride and ferrous chloride is provided.

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Seoul, South Korea

Moon Jo Chung