摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A method of simultaneous and selective prepararation of hexafluoropropylene and octafluorocyclebutane comprising the steps of: (a) thermally decomposing difluorochloromethane to obtain tetrafluoroethylene and then supplying the resulting tetrafluoroethylene into a fluidized bed reactor equipped with a distributor for supplying steam; and (b) supplying steam into a flow of tetrafluoroethylene supplied into the fluidized bed reactor, through a distributor for supplying steam at a certain molar ratio of tetrafluoroethylene/stream, and then performing dimerization of tetrafluoroethylene in the fluidized bed reactor under an atmospheric pressure.
摘要:
The present invention relates to a process for preparing hexafluoropropylene(CF3CF═CF2, HFP) from the pyrolysis of trifluoromethane(CHF3, R23) and tetrafluoroethylene(C2F4, 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.
摘要:
A catalyst of the formula (1) for the synthesis of alkylene carbonate by reacting alkylene oxide and carbon dioxide LmMXn (1) wherein L is selected from a group of pyridines; M is a metal atom selected from Zn, Fe, Mn, Pb and In; X is a halogen atom selected from Cl, Br and I; m is 1 or 2, and n is 2 or 3.
摘要:
The present invention relates to a method for preparing alkylene carbonate by reacting alkylene oxide with carbon dioxide in the presence of a catalyst comprising:a) at least one alkali metal halide selected from the group consisting of MCl, MBr and MI, whrerin M is alkali metal; andb) at least one manganese halide selected from the group consisting of MnCl.sub.2, MnBr.sub.2 and MnI.sub.2.
摘要:
Provided is a method of manufacturing a semiconductor device. In the method, after a thin liner is formed on a substrate on which a lower interconnection is formed, a silicon source is supplied to form a silicide layer under the liner by a reaction between the silicon source and the lower interconnection, and the silicide layer is nitrided and an etch stop layer is formed. Therefore, the lower interconnection is prevented from making contact with the silicon source, variations of the surface resistance of the lower interconnection can be prevented, and thus high-speed devices can be fabricated.
摘要:
Provided is a method of manufacturing a semiconductor device. In the method, after a thin liner is formed on a substrate on which a lower interconnection is formed, a silicon source is supplied to form a silicide layer under the liner by a reaction between the silicon source and the lower interconnection, and the silicide layer is nitrided and an etch stop layer is formed. Therefore, the lower interconnection is prevented from making contact with the silicon source, variations of the surface resistance of the lower interconnection can be prevented, and thus high-speed devices can be fabricated.