Abstract:
The present invention relates to the method for obtaining vinylidene fluoride and the subject matter thereof is more particularly the production of vinylidene fluoride by pyrolysis of 1,2-dichloro-2,2-difluoroethane in the presence of hydrogen at a temperature of greater than or equal to 400° C.
Abstract:
The process of the present invention consists in bringing into contact, on the one hand, (A) gaseous phosphorus pentafluoride or a gaseous mixture comprising phosphorus pentafluoride and hydrochloric acid, and, on the other hand, (B) a solution of lithium fluoride in hydrofluoric acid, in a column (10) having a sufficient number of transfer units to carry out the reaction of PF.sub.5 with LiF under the chosen conditions of temperature, of pressure and of molar ratio of the two contrasting reactants and with complete or substantially complete absorption of the PF.sub.5 in the column. This process makes it possible to solve the problems of blockage by preventing recrystallizations of salts; to discharge the heat given off by the reaction by the evaporation of a portion of the HF; and to separate the HCl which may be contained in the starting PF.sub.5, without loss of PF.sub.5, thus allowing subsequent recovery/value enhancement of this HCl. Moreover, this process is very simple, with a very small number of stages, which makes it possible to avoid any entry of air or moisture capable of contaminating the final LiPF.sub.6.
Abstract:
The present invention relates to a process for producing pentafluoroethane. More particularly, the subject of the invention is a continuous process for producing pentafluoroethane comprising (i) a step of fluorinating perchloroethylene (PER) with hydrofluoric acid, in the gas phase, in the presence of a catalyst, (ii) a step of separating the products issuing from step (i) in order to give a fraction of light products and a fraction of heavy products, comprising hydrofluoric acid, unreacted perchloroethylene and under-fluorinated products, and (iii) a step of pretreating the fraction of heavy products before recycling to step (i).
Abstract:
The subject of the invention is the manufacture of 1,1,1-trifluoroethane by fluorination or 1-chloro-1,1-difluoroethane with anhydrous hydrofluoric acid. The reaction is carried out in the liquid phase and in the presence of a fluorination catalyst.
Abstract:
The present invention relates to a process for producing pentafluoroethane. More particularly, the subject of the invention is a continuous process for producing pentafluoroethane comprising (i) a step of fluorinating perchloroethylene (PER) with hydrofluoric acid, in the gas phase, in the presence of a catalyst, (ii) a step of separating the products issuing from step (i) in order to give a fraction of light products and a fraction of heavy products, comprising hydrofluoric acid, unreacted perchloroethylene and under-fluorinated products, and (iii) a step of pretreating the fraction of heavy products before recycling to step (i).
Abstract:
The invention relates to the synthesis of difluoromethane by gas-phase catalytic fluorination of methylene chloride. To lengthen the lifetime of the catalyst the operation is carried out in the presence of chlorine.
Abstract:
This invention relates to a process for the purification of 1,1-dichloro-1-fluorethane.To remove unsaturated impurities such as 1,1-dichloroethylene and dichloracetylene the crude 1,1-dichloro-1-fluoroethane is subjected to the action of chlorine and/or of a hydracid. This treatment is carried out in the presence of a Lewis acid, or, only in the case of chlorine, by photochemical catalysis.
Abstract:
The present invention relates to the method for obtaining vinylidene fluoride and the subject matter thereof is more particularly the production of vinylidene fluoride by pyrolysis of 1,2-dichloro-2,2-difluoroethane in the presence of hydrogen at a temperature of greater than or equal to 400° C.
Abstract:
The present invention relates to a process for preparing (hydro)(chloro)fluoroolefins comprising at least one step of fluorination in the liquid phase of a (hydro)haloalkane or of a (hydro)haloalkene in the presence of at least one ionic liquid as a catalyst. The ionic liquids are derivatives of Lewis acids based on aluminum, titanium, niobium, tantalum, tin, antimony, nickel, zinc or iron.
Abstract:
The invention relates to the synthesis of difluoromethane by gas-phase catalytic fluorination of methylene chloride. To lengthen the lifetime of the catalyst the operation is carried out in the presence of chlorine.