Mitsubishi Chemical Industries Limited

Jun Toriya

Yasuo Tanabe

Ken Shiraga

Masato Sato

Ikuo Kasahara

Takeru Onoda

Akihisa Ohno

Diacetoxybutane is prepared by a process for hydrogenating diacetoxybutene in the presence of a supported hydrogenation catalyst comprising catalytically reacting diacetoxybutene with hydrogen continuously in an insulation reaction apparatus utilizing a fixed-bed of said hydrogenation catalyst, withdrawing the reaction effluent continuously from said reaction apparatus, circulating at least a part of said reaction effluent to said reaction apparatus while controlling the temperature of influx of said reaction apparatus at a temperature lower than the temperature of efflux from said reaction apparatus by 5.degree. to 100.degree. C.

Process for hydrogenation of diacetoxybutene

A process is disclosed in which hydrolysis and cyclization of an acetate ester of a 1,4-diol are carried out in separate reaction zones in the pressure of a solid acid catalyst and unreacted acetate ester recovered from each of the reaction zones is supplied to another zone thereby producing a hydrofuran and a 1,4-diol in any proportion.

Process for producing a hydrofuran and a 1,4-diol

Disclosed is a method of recovering butadiene gas from an acetoxylation process which method comprises steps: (a) contacting a butadiene-containing gas with acetic acid to effect the absorption of butadiene in acetic acid, (b) recycling the acetic acid containing butadiene to the acetoxylation process, (c) contacting the waste gas containing acetic acid from step (a) with water to effect the absorption of acetic acid in water and (d) recycling the water containing acetic acid to hydrolysis step of the acetoxylation product.

Method of recovering butadiene gas from an acetoxylation process

A process for producing 1,4-glycol diester from unsaturated glycol diesters prepared by reacting butadiene, acetic acid and oxygen or an oxygen-containing gas in the presence of a palladium catalyst or, from saturated glycol diesters prepared by hydrogenating said unsaturated glycol diesters, wherein, 1,4-glycol diester is separated from the isomer mixture of glycol diesters prepared, the residual glycol diester isomers are decomposed by heating and butadiene and/or acetic acid produced on decomposition are recycled to the process for the production of glycol diesters.

Process for producing 1,4-glycol diester

In the process for preparing tetrahydrofuran by the dehydrocyclization of 1,4-butanediol in the presence of a non-volatile acid catalyst, wherein vapor mixture of water and tetrahydrofuran is continuously taken out from the reaction zone and subjected to the azeotropic distillation in three distillation columns operated under specified conditions thereby obtaining tetrahydrofuran of high quality in a high yield.

Process for preparing tetrahydrofuran

Butanediol and/or butenediol are prepared by hydrolyzing diacetoxybutane and/or diacetoxybutene in the presence of a cation-exchange resin and recovered by fractional distillation. By the treatment of the hydrolyzed product with an anion exchange resin at any stage before the butanediol and/or butenediol are fractionated, butanediol and/or butenediol are recovered in high yield.

Process for preparing butanediol and/or butenediol

There is disclosed a process for producing diacetoxybutane diol by hydrogenating diacetoxybutene in the presence of a hydrogenation catalyst in which the hydrogenation is carried out in two stages within predetermined temperature ranges, the temperature of the second stage is higher than that of first thereby obtaining the product in high selectivity with high conversion, and a process for producing butanediol by hydrolyzing the diacetoxybutane thus obtained in the presence of a solid acid catalyst.

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Kurashiki, Japan

Jun Toriya