摘要:
The present invention relates to a continuous process for the fluorination of perchloroethylene (PER) in the gas phase in a single stage with hydrofluoric acid (HF) in the presence of a catalyst to give, as major product, pentafluoroethane. The process is characterized in that it is carried out at a temperature of between 280 and 430° C. and with an HF/PER molar ratio of greater than or equal to 20.
摘要:
The present invention relates to a continuous process for the fluorination of perchloroethylene (PER) in the gas phase in a single stage with hydrofluoric acid (HF) in the presence of a catalyst to give, as major product, pentafluoroethane. The process is characterized in that it is carried out at a temperature of between 280 and 430° C. and with an HF/PER molar ratio of greater than or equal to 20.
摘要:
Use is made, for selectively hydrogenating the olefinic double bonds of block copolymers, at least one block of which comprises olefinic double bonds, using a catalyst based on a metal from Group VIII in a medium comprising an organic solvent for the copolymer and an ionic liquid as solvent for the catalyst, of a water-immiscible ionic liquid, preferably an ionic liquid for which the anion is the hexafluorophosphate anion and the cation is the 1-butyl-3-methylimidazolium (bmim+) or 1-ethyl-3-methylimidazolium (emim+) cation.Applied to poly(styrene)-b-poly(butadiene)-b-poly(methyl methacrylate) block copolymers, the poly(butadiene) block of which predominantly possesses a 1,4-microstructure, this process results in copolymers for which the degree of hydrogenation is at least equal to 50% and which exhibit a melting point of greater than 30 °C.
摘要:
The present invention relates to a method for producing 1,2,3,3,3-pentafluoropropane, involving reacting gaseous phase 1,2,3,3,3-pentafluoropropene with hydrogen in a superstoichimetric amount in the presence of a hydrogenation catalyst in a reactor, and recirculating a part of the gaseous effluent from the reactor.
摘要:
The subject matter of the invention is a process for preparing fluoroolefin compounds. The invention relates more particularly to a process for producing a (hydro)fluoroolefin compound, which comprises (i) bringing at least one compound comprising from three to six carbon atoms, at least two fluorine atoms and at least one hydrogen atom, on the condition that at least one hydrogen atom and one fluorine atom are located on adjacent carbon atoms, into contact with a solid reactant comprising calcium hydroxide.
摘要:
The present invention relates to a method for producing 1,1,1,2,3,3-hexaafluoropropane, involving reacting gaseous phase hexafluoropropene with hydrogen in a superstoichimetric amount in the presence of a hydrogenation catalyst in a reactor, and recirculating a part of the gaseous effluent from the reactor.
摘要:
The subject matter of the invention is a process for preparing fluoroolefin compounds. The invention relates more particularly to a process for producing a (hydro)fluoroolefin compound, which comprises (i) bringing at least one compound comprising from three to six carbon atoms, at least two fluorine atoms and at least one hydrogen atom, on the condition that at least one hydrogen atom and one fluorine atom are located on adjacent carbon atoms, into contact with a solid reactant comprising calcium hydroxide.
摘要:
The subject of the invention is a process for the preparation of 2,3-dichloro-1,1,1-trifluoropropane by chlorination of 3,3,3-trifluoropropene at a pressure greater than 2 bar. Application in the synthesis of 1234yf.
摘要:
A process for the delignification and bleaching of chemical paper pulps comprising one or more stage(s) of treatment with hydrogen peroxide, at a temperature greater than 100° C. and under high pressure, in the presence of a polymer and of a compound A chosen from potassium hydroxide, sodium hydroxide and alkali metal or alkaline-earth metal carbonates.
摘要:
A process for preparing chemithermomechanical pulp comprising subjecting a lignocellulosic substance from which said pulp is to be formed to the simultaneous action of a sulfite and a reducing agent that is more electronegative than the sulfite ion during a nondestructive cooking operation at a temperature of about 100.degree. C. or above under saturated steam pressure; said simultaneous action taking place at an initial pH of between 7 and 12.5.