Atochem

Elf Atochem S.a.

Jean-Jacques Masini

Raymond Commandeur

Rene Clair

Elie Ghenassia

Yvan Verot

Jean-Louis Guillaumenq

Bertrand Collier

Yves Correia

Jacques Bousquet

Maurice A Bergougnou

Jean-Marc Le Blevec

Rene Chabidon

Bernard Durand

Vinyl chloride monomer is selectively prepared by intimately contacting, in the absence of steam, a feedstream of 1,2-dichloroethane with a flow of fluid or solid particulates heated to such elevated temperature and for such minim period of time, e.g., 0.010 to 0.5 second, as to flash transfer a dehydrochlorinating amount of thermal energy to the 1,2-dichloroethane and thereby ultrapyrolyzing at least a fraction of same into vinyl chloride and HCl, and recovering the vinyl chloride from the medium of ultrapyrolysis.

Prepartion of vinyl chloride by ultrapyrolysis of 1,2-dichloroethane

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

Apparatus for the production of higher chloromethanes, i.e, CH.sub.2 Cl.sub.2, CHCl.sub.3 and CCl.sub.4, by chlorinating methyl chloride with chlorine in a first reaction zone A, chlorinating at least one of the higher chloromethanes CH.sub.2 Cl.sub.2 and CHCl.sub.3 with chlorine in a parallel second reaction zone B, combining the reaction products from the first and second reaction zones A and B, separating higher chloromethanes from the combined reaction prodcuts, and recycling at least one of the separated higher chloromethanes CH.sub.2 Cl.sub.2 and CHCl.sub.3 as chlorination feed to the second reaction zone B.

Simultaneous producting of higher chloromethanes

Free chlorine values are removed by radical chlorination from uncombined admixtures thereof, notably admixtures of free chlorine and at least one halogenated organic compound that is not completely chloro-substituted.

Free chlorine removal process

A tube extends through a wall of a vessel and is adapted to carry an ultraviolet emitter for use with a photochemical reaction vessel. An end of the tube disposed outside of the vessel is mounted within a support which forms a ball joint for that end of the tube. That joint allows the tube to pivot slightly in response to forces acting on the portion of the tube disposed within the vessel, thereby resisting any breaking or bending of the tube which might otherwise occur. A lip seal is disposed around the tube at a location intermediate the ball joint and the vessel to prevent the escape of fluids from the vessel past the tube.

Device for sealingly mounting tubes which pass through a wall

Residual aqueous phases, emanating from the synthesis of methyl chloride by reacting methanol with hydrochloric acid, are conveniently demethanolized by maintaining same in liquid phase and in the absence of catalyst, at a temperature of from 50.degree. to 150.degree. C. and under a pressure of less than about 8 bars. The methanol recovered is in the form of a crude methyl chloride which is advantageously recycled to the CH.sub.3 OH/HCl reaction zone.

Demethanolization of aqueous CH.sub.3 OH/HCl solutions

The higher chloromethanes, i.e., CH.sub.2 Cl.sub.2, CHCl.sub.3 and CCl.sub.4, are simultaneously produced by chlorinating methyl chloride with chlorine in a first reaction zone A, chlorinating at least one of the higher chloromethanes CH.sub.2 Cl.sub.2 and CHCl.sub.3 with chlorine in a parallel second reaction zone B, combining the reaction products from said first and said second reaction zones A and B, separating higher chloromethanes from said combined reaction products, and recycling at least one of said separated higher chloromethanes CH.sub.2 Cl.sub.2 and CHCl.sub.3 as chlorination feed to said second reaction zone B.

Simultaneous production of higher chloromethanes

The higher chloroalkanes, advantageously the higher chloromethanes, are continuously produced from at least one lesser chloroalkane, by (i) continuously introducing chlorine and said at least one lesser chloroalkane into a stream of reaction medium continuously and essentially autogenously recirculating in a loop circuit which comprises an essentially vertical principal reaction zone, (ii) continuously chlorinating said at least one lesser chloroalkane in said essentially vertical principal reaction zone, and (iii) continuously withdrawing higher chloroalkane product from said stream of essentially autogenously recirculating reaction medium.

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Chaponost, France

Jean-Jacques Masini