E.i. Dupont De Nemours and Company

Cristobal Bonifaz

Leo E Manzer

Steven Henry Swearingen

William H Manogue

James L Webster

Swiatoslaw Trofimenko

Jan J Lerou

Elrey L McCann

Douglas W Bruhnke

David Richard Corbin

Paul R Resnick

James Arthur Trainham

Frank T Bodurtha, Jr

John B Parise

The present invention relates to multistep syntheses of hexafluoropropylene from hexachloropropylene. In all these syntheses the first step is a fluorination of the starting material; later steps convert the initial products to CF.sub.3 --CFCl--CF.sub.3, which is dehalogenated to the desired product.

Multistep synthesis of hexafluoropropylene

The present invention relates to multistep syntheses of hexafluoropropylene from acyclic three-carbon hydrocarbons or partially halogenated acyclic three-carbon hydrocarbons. In all these syntheses the first step is a vapor-phase chlorofluorination of the starting material to one or more saturated chlorofluorocarbons. Novel catalysts are also provided.

A process for preparing light monoolefins, particularly ethylene and propylene, from a feed stream comprising a reactant consisting of methanol, dimethyl ether or mixtures thereof in the presence of a boron-treated aluminosilicate zeolite catalyst is disclosed.

Boron-treated zeolite catalyst for preparing light monoolefins

An improved laboratory barricade for containment of potentially explosive materials and processes, having a containment chamber provided with a pressure venting port or ports, wherein the improvement comprises said barricade having dimensions such that ratio of total contained volume to total area of the pressure venting port or ports is between about 7620 cm (3000 in) and about 12,700 cm (5000 in), and the total area of the pressure venting port or ports is at least about 6.45 cm.sup.2 (1 in.sup.2) per 100 g TNT equivalent of the potentially explosive materials to be contained.

Laboratory barricade

Process of preparing light monoolefins by: (a) activating a hydrogen-exchanged aluminosilicate catalyst having a silica to alumina ratio of less than 12 and, optionally, containing added metal cations, by treating with steam at a temperature of at least 400.degree. C., preferably 450.degree. to 520.degree. C.; (b) contacting the steam-activated catalyst in a reaction zone, at a temperature of about 350.degree. to about 600.degree. C., preferably 450.degree. to 520.degree. C., with a gas stream consisting essentially of dimethyl ether or a mixture of methanol and dimethyl ether, as reactant, and sufficient water such that the mole ratio of water to ether in the reaction zone is at least 0.3; at a pressure of about 0.2 to about 30 atmospheres (about 20 to about 3000 kPa), preferably atmospheric pressure (100 kPa), and at a weight hourly space velocity (WHSV) of greater than about 0.5 h.sup.-1, preferably 1 to 150 h.sup.-1, to convert at least 85 wt % of the reactant to hydrocarbons comprising at least 50 wt % ethylene and propylene, said 85% conversion being achieved before the contacting has exceeded 1 g of reactant per g of catalyst, preferably before exceeding 0.3 g of reactant per g of catalyst, more preferably before exceeding 0.1 g of reactant per g of catalyst until the catalyst is spent; and (c) regenerating the spent catalyst with a mixture comprising steam and oxygen at a temperature of at least 400.degree. C., preferably 450.degree. to 520.degree. C.

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Conway, MA, United States of America

Cristobal Bonifaz