Korea Institute of Science and Technology

Honggon Kim

Hoon Sik Kim

Byung Gwon Lee

Hyunjoo Lee

Kun You Park

Moon Jo Chung

Young Soo Kwon

Dong Ju Moon

Sang Deuk Lee

Jong Sung Lim

Sang-deuk Lee

Dong Joo Mun

Sang Hyun Seo

A refrigerant composition useful as a substitute for chlorodifluoromethane (CHClF,, HCFC-22). The refrigerant composition has a first constituent of difluoromethane (CH,F,, HFC-32); a second constituent of 1,1,1-trifluoroethane (CH,CF,; namely, HFC-143a); and a third constituent selected from 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), 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 difluoromethane and 1,1,1-trifluoroethane

This invention relates to a method for preparing cycloaliphatic diamines by hydrogenating an aromatic diamines in the presence of a supported ruthenium catalyst. The catalyst is pre-treated with oxygen or air to increase the rate of the reaction and decrease the amount of higher boiler by-products.

Hydrogenation of aromatic diamines

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

There is a process for removing moisture from chlorodifluoromethane (CHClF.sub.2) containing moisture in excess in the preparation of chlorodifluoromethane comprising lowering the partial pressure of water in the chlorodifluoromethane gas by contacting the chlorodifluoromethane gas with an aqueous solution of calcium chloride of more than 5% by weight.

Method for removing moisture from chlorodifluoro-methane

A catalyst for fluorination of 1,1-dichloro-1-fluoroethane which is obtained by mixing chromic hydroxide and an aqueous solution of magnesium chloride, reacting the mixture with an aqueous solution of HF and then calcining the resulting product and a process for preparing 1,1,1,-trifluoroethane by reacting 1,1-dichloro-1-fluoroethane with HF in the presence of the above catalyst are provided.

Catalyst for fluorination of 1,1-dichloro-1-fluoroethane and process for

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.

Process for co-producing 1,1,1,2-tetrafluoroethane pentafluoroethane and

There are a catalyst for producing 1,1,1,2-tetrafluoroethane represented as Cr.sub.a L.sub.b M.sub.c O.sub.x F.sub.y wherein L is Mg or Ca; M is one element selected from a group consisting of Ce, Ni, Zn, and Al; and each value of a, b, c, x and y are all between 0 and 2, and a method for preparing the same comprising the steps of: producing an admixture of a composition comprising chromium hydroxide hydrate and magnesium chloride or calcium chloride in a weight ratio of Cr to Mg or Ca ranging from 1:0.3 to 1:10 with an aqueous metal salt solution; reacting the admixture with an aqueous HF solution to give a paste; and sintering the paste.

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Seoul, South Korea

Honggon Kim