Atochem

Elf Atochem S.a.

Produits Chimiques Pechiney-saint Gobain

Rene Clair

Alain Gallet

Yves Correia

Raymond Commandeur

Roland Bachelard

Elie Ghenassia

Jean-Jacques Masini

Alain Petit

Jean-Louis Guillaumenq

Jean Ollivier

Denise Molines

Bernard Bouche-Pillon

Marc Ferrigno

Jean-Pierre Caujolle

In order to remove the methanesulphonyl chloride entrained by the gaseous HCl by-product, an amount of water ranging from 0.01 to 20%, relative to the mass of HCl to be treated, is injected into the HCl gas flow and the temperature is lowered to a value below or equal to 15&deg; C.

Purification of the hydrochloric acid by-product of the synthesis of methanesulphonic acid

Hydrocarbons, e.g., ethylene, are steady-state catalytically oxychlorinated into chlorocarbons, e.g., 1,2-dichloroethane, by fluidizing a fluidizable charge by directing a gaseous feedstream containing a hydrocarbon therethrough and therein oxychlorinating such hydrocarbon, the gaseous feedstream further comprising an oxygen-containing gas and gaseous hydrochloric acid and the fluidizable charge comprising immixture of a catalytically effective amount of an oxychlorination catalyst and particles of a catalytically and chemically inert solid substance, and which further comprises introducing a solution or suspension of a catalytically active copper compound into such fluidized charge during the oxychlorination reaction.

Catalytic oxychlorination of hydrocarbons to produce chlorocarbons

35% to 45% by weight concentrated aqueous solutions of ferric chloride, directly useful as flocculating agents in a variety of water treatments, are prepared by (a) digesting iron with a dilute aqueous solution of hydrochloric acid until such acid has essentially been consumed and thereby producing an aqueous solution of ferrous chloride; (b) reacting chlorine with such aqueous solution of ferrous chloride, in the presence of a recycled aqueous solution of ferric chloride; (c) decompressing the step (b) reaction product solution to vaporize water therefrom, thereby concentrating same; and (d) recycling a fraction of the decompressed liquid phase to step (b) and recovering remaining fraction as final product aqueous solution of ferric chloride.

Production of concentrated aqueous solutions of ferric chloride

35% to 45% by weight concentrated aqueous solutions of ferric chloride, directly useful as flocculating agents in a variety of water treatments, are prepared by (a) reacting chlorine with an aqueous solution of ferrous chloride, in the presence of a recycled aqueous solution of ferric chloride; (b) decompressing the step (a) reaction product solution to vaporize water therefrom, thereby concentrating same; and (c) recycling a fraction of the decompressed liquid phase to step (a) and recovering remaining fraction as final product aqueous solution of ferric chloride.

Water-containing mixtures of at least one hydrocarbon/halocarbon and hydrochloric acid, e.g., the methyl chloride feedstream in conventional process for the synthesis of chloromethanes, are desiccated by intimately contacting such mixtures with an effective drying amount of an essentially anhydrous drying agent that includes (i) a metal sulfate, chloride or perchlorate, or (ii) phosphorus pentoxide.

Drying of hydrocarbon/hydrochloric acid/water admixtures

Concentrated aqueous solutions of ferric chloride, directly useful as flocculating agents in a variety of water treatments, are prepared by (a) digesting iron with a dilute aqueous solution of hydrochloric acid until such acid has essentially been consumed and thereby producing an aqueous solution of ferrous chloride; (b) reacting chlorine with such aqueous solution of ferrous chloride, in the presence of a recycled aqueous solution of ferric chloride; (c) decompressing the step (b) reaction product solution to vaporize water therefrom, thereby concentrating same; and (d) recycling a fraction of the decompressed liquid phase to step (b) and recovering remaining fraction as final product aqueous solution of ferric chloride.

A reactor provided with a gas-safety device/module therefor comprises (i) a reaction vessel having an open upper end, (ii) demisting means engaging and at least partially closing off the open upper end of such reaction vessel, and situated to traverse the path of direction of a gas stream, e.g., hydrogen, evolving from a reaction conducted within such reaction vessel, and (iii) inlet means intermediate such open upper end of the reaction vessel and the demisting means (ii) for charging a stream of air into the reaction vessel, such inlet means (iii) being adopted to charge an amount of air into the reaction vessel such as to maintain the composition of any air/evolved gas mixture below the ignition/explosive limits thereof.

Safety module for hydrogen generating reactors

Concentrated aqueous solutions of ferric chloride, directly useful as flocculating agents in a variety of water treatments, are prepared by (a) reacting chlorine, advantangeously a stoichiometric amount of chlorine, with an aqueous solution of ferrous chloride in the presence of an aqueous solution of ferric chloride, in an essentially vertical reaction zone, with at least a major amount of the ferrous chloride solution being introduced to the upper section of such reaction zone, at least a major amount of the chlorine being introduced countercurrently to the base of such reaction zone, and the ferric chloride solution being introduced at at least one point intermediate such ferrous chloride solution/chlorine inlets, and (b) recovering final product aqueous solution of ferric chloride from the base of the reaction zone.

An electrolytic cell, e.g., for the electrolysis of NaCl to produce chlorine and sodium hydroxide, has an improved operation control system, such system including a plurality of means for monitoring and controlling the flowstreams of inlet starting materials and/or outlet final products, the temperature of the electrolyte, the various reagent concentrations and the cell current, and such plurality of means being operably connected to a computing function which carries out corrective coherence calculations on certain of the parameters of electrolysis and adjusts the operation of the cell in response thereto.

Corrective controller system for electrolytic cells

The process of preparing trichloroethylene from 1,1,1,2-tetrachloroethane by decomposition of the tetrachloroethane under a pressure within the range of 1.5 to 10 bars and at a temperature within the range of 135.degree. to 250.degree. C and the treatment of the effluent from the reaction zone for recovery of components thereof.

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Martigues, France

Rene Clair