Celanese International Corporation

Hoechst Celanese Corporation

Celanese Gmbh

Leon B Levy

Edward F Dougherty

Mark O Scates

Charles C Hobbs, Jr

Madan Singh

Jerome F Perez

A process for inhibiting free-radical polymerization of an alpha,beta-unsaturated (&agr;,&bgr;-unsaturated) carboxylic acid, and for providing desired grade &agr;,&bgr;-unsaturated carboxylic acid for use following storage and transport is described herein. In particular, bulk storage and shipment such as with overseas transport is described. The process comprises combining the &agr;,&bgr;-unsaturated carboxylic acid with a phenolic inhibitor and a coinhibitor to form an inhibited mixture, storing the inhibited mixture, transporting the inhibited mixture, and removing the coinhibitor to provide the desired grade &agr;,&bgr;-unsaturated carboxylic acid for use. In preferred embodiments, the &agr;,&bgr;-unsaturated carboxylic acid is acrylic acid, the phenolic inhibitor is p-methoxyphenol, the coinhibitor is manganese cation, and removal of the coinhibitor is carried out using an ion exchange resin.

Stabilization and transport of &agr;, &bgr;-unsaturated carboxylic acid and removal of stabilizer

A process for inhibiting free-radical polymerization of an alpha,beta-unsaturated (.alpha.,.beta.-unsaturated) carboxylic acid, and for providing desired grade .alpha.,.beta.-unsaturated carboxylic acid for use following storage and transport is described herein. In particular, bulk storage and shipment such as with overseas transport is described. The process comprises combining the .alpha.,.beta.-unsaturated carboxylic acid with a phenolic inhibitor and a coinhibitor to form an inhibited mixture, storing the inhibited mixture, transporting the inhibited mixture, and removing the coinhibitor to provide the desired grade .alpha.,.beta.-unsaturated carboxylic acid for use. In preferred embodiments, the .alpha.,.beta.-unsaturated carboxylic acid is acrylic acid, the phenolic inhibitor is .rho.-methoxyphenol, the coinhibitor is manganese cation, and removal of the coinhibitor is carried out using an ion exchange resin.

Stabilization and transport of .alpha.,.beta.-unsaturated carboxylic

Polymer formation is inhibited during the distillation of ethyl acrylate and acrylic acid produced from the reaction of ethylene and acrylic acid with sulfuric acid. In the presence of sulfur dioxide formed during the reaction, nitrogen oxide (NO) is highly effective for inhibition of polymerization fouling.

Inhibition of polymerization fouling during distillation of monomers in

Process for the oxidation of olefins to the corresponding unsaturated aldehydes and acids, e.g. propylene to acrolein and acrylic acid, by reacting the olefin with oxygen in the presence of a catalyst of the empirical formula Mo.sub.x Cr.sub.y Te.sub.z O.sub.n. When x is 100, y is 10-50, z is 0.1-10, and n is 300-500.

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Corpus Christi, TX, United States of America

Leon B Levy