A spark plug for an automotive internal combustion engine providing improved ignition even when carbon is deposited on the insulator of the plug. A rich fuel-air ratio causes carbon to be deposited on spark plug insulators, thereby decreasing its effective insulation. By limiting the geometrical dimension of the plug's center electrode, ground electrode, and insulator the problem of carbon build-up is overcome. The sizes of these elements have certain allowable ranges that enhance the igniting effect of the plug.

Spark plug for internal combustion engine

A process for the synthesis of hydrocchlorofluoro olefins (HCFO) and/or hydrofluoroolefins (HFO). The process is based on the steps of fluorination of hydrochloropropenes or hydrochloropropanes to form hydrochlorofluoropropenes and/or hydrofluoropropenes, followed by gas phase, catalytic fluorination of the hydrochlorofluoropropenes to form hydrofluoropropenes. The process produces 1,1, 1,2- tetrafluoropropene (HFO-1234yf) from "feedstock" such as tetrachloropropenes, 1,1,2,3 tetrachloropropene (HCO-1230xa) and/or 1,1,1,2 tetrachloropropene (HCO-1230xf) or pentachloropropanes, HCC-240db, HCC-240aa and/or HCC-240ab which are precursors of the tetrachloropropenes. The process of the present invention comprises the steps of: a) liquid phase or gas phase fluorination of tetrachloropropene (which may be formed via gas phase fluorination of pentachloropropane), in the presence or absence of homogenous or heterogeneous catalyst; to form the intermediate product HCFO- 1233xf and thereafter b) gas phase, catalytic fluorination of the intermediate HCFO-1233xf to form the hydrofluoropropene product 1,1,1,2-tetrafluoropropene (HFO-1234yf).

Process for the manufacture of hydrofluoroolefins

Disclosed is a process for the preparation of cis/trans 1,1,1,3-tetrafluoro-2-propene (1234 ze) which comprises (a) contacting 1,1,1,3,3-pentafluoropropane (245fa) with an alkaline solution, preferably an aqueous or alcoholic solution of a base such as KOH, NaOH, Ca(OH)2 or Mg(OH)2, or with a chromium-based catalyst, such as fluorided Cr2O3 or fluorided Cr/Ni/Alf3, and (b) recovering cis/trans 1,1,1,3-tetrafluoro-2-propene from the reaction mixture.

Preparation of 1,1,1,3-tetrafluoropropene( 1234ze )

The present invention provides a process for preparing 1234yf, comprising: (i) contacting 1233xf with hydrogen fluoride HF in gas phase in the presence of a fluorination catalyst under conditions sufficient to produce a reaction mixture; (ii) separating the reaction mixture into a first stream comprising HCl, 1234yf and a second stream comprising HF, unreacted 1233xf and 245cb; (iii) recycling at least a part of the second stream at least in part back to step (i). The present invention also provides a process for preparing 1234yf, comprising: (i) contacting 1233xf with hydrogen fluoride HF in gas phase in the presence of a fluorination catalyst under conditions sufficient to produce a reaction mixture; (ii) separating the reaction mixture into HCl and a stream containing the fluorinated products; (iii) separating said stream containing the fluorinated products into a first stream comprising 1234yf and a second stream comprising HF, unreacted 1233xf and 245cb; (iv) recycling at least a part of the second stream at least in part back to step (i).

Catalytic gas phase fluorination of 1233xf to 1234yf

This Review chronicles the progress made in the field of small fluorocarbon synthesis since their invention in the early 1930s by Thomas Midgley, Jr., and his coworkers, with special focus on their...

Fluorocarbon Refrigerants and their Syntheses: Past to Present.

Manufacture of 1,1,1,2-tetrafluoroethane (F134a) by catalytic gas-phase fluorination of 1-chloro-2,2,2-trifluoroethane (F133a). A mixed catalyst is employed, consisting of nickel and chromium oxides, halides and/or oxyhalides deposited on a support consisting of aluminium fluoride or of a mixture of aluminium fluoride and alumina. This mixed catalyst makes it possible to obtain an excellent selectivity for F134a with a high production efficiency.

Process for the preparation of 1,1,1,2-tetra fluoroethane

The invention relates to mass catalysts based on chromium and nickel oxides, obtained from a sol of chromium and nickel hydroxides. These catalysts, in which the Ni/Cr atomic ratio is between 0.05 and 5, may be used from the fluorination of halogenated hydrocarbons by HF in the gas phase.

Mass catalysts based on chromium and nickel oxides and their application to the fluorination of halogenated hydrocarbons

The invention relates to the manufacture of 1,1,1,2-tetrafluoroethane (F134a) by gas-phase catalytic fluorination of 1-chloro-2,2,2-trifluoroethane (F133a). A mixed catalyst is employed, composed of nickel and chromium oxides, halides and/or oxyhalides deposited on a support consisting of aluminium fluoride or of a mixture of aluminium fluoride and alumina. This mixed catalyst makes it possible to obtain an excellent selectivity for F134a with a high production efficiency.

Process for the manufacture of 1,1,1,2-Tetrafluoroethane

The invention relates to the catalytic fluorination of perchloroethylene or of pentachloroethane in the gas phase by means of hydrofluoric acid. A mixed catalyst is used composed of oxides, halides and/or oxyhalides of nickel and of chromium deposited on a support consisting of aluminium fluoride or of a mixture of aluminium fluoride and of alumina.

Process for the fluorination of perchloroethylene or pentachloroethane

The invention relates to a process for the manufacture of 1,1,1,2-tetrafluoro-2-chloroethane and of pentafluoroethane. The process, which consists of the gas phase catalytic fluorination of at least one pentahaloethane of formula C2 HX2-n F3+n in which X denotes a chlorine or bromine atom and n the number 0 or 1 by means of hydrofluoric acid, is characterized in that there is used a mixed catalyst composed of oxides, halides and/or oxyhalides of nickel and chromium deposited on a support consisting of aluminium fluoride or a mixture of aluminium fluoride and alumina.

Bernard Cheminal

Papers

Process for the preparation of 1,1,1,2-tetra fluoroethane

Mass catalysts based on chromium and nickel oxides and their application to the fluorination of halogenated hydrocarbons

Process for the manufacture of 1,1,1,2-Tetrafluoroethane

Process for the fluorination of perchloroethylene or pentachloroethane

Process for the manufacture of 1,1,1,2-tetrafluoro-2-chloroethane and of pentafluoroethane