Mitsubishi Chemical Industries Limited

Ken Shiraga

Jun Toriya

Yasuo Tanabe

Masato Sato

Takeru Onoda

Ikuo Kasahara

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

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

Ken Shiraga