Davy Mckee (london) Limited

Davy Process Technology Limited

Davy Mckee Corporation

Davy Research and Development Limited

Mohammad Sharif

Keith Turner

George E Harrison

John Scarlett

Alan J Dennis

Arthur James Reason

Anthony B Carter

Michael A Wood

Norman Harris

Michael William Marshall Tuck

David John Watson

Stephen William Colley

Colin Rathmell

John W Kippax

Christopher Richard Fawcett

Geoffrey Webb

A process is described for the recovery of substantially pure ethyl acetate from a feedstock including ethyl acetate, ethanol and water. The process includes supplying the feedstock to a first distillation zone maintained under first distillation conditions effective for distilling from the feedstock a first distillate including ethyl acetate, ethanol, and less than about 10 mol % water. The first distillate is recovered from the first distillation zone and is supplied to a second distillation zone maintained under second distillation conditions, which include use of a higher pressure than that of the first distillation zone. The second distillation conditions are effective for distilling from the first distillate a second distillate including ethanol, water, and a minor proportion of ethyl acetate and yielding a substantially pure ethyl acetate bottom product, which is recovered. The second distillate is returned to the first distillation zone.

Process

Aldolisation-dehydration process

A diaryl carbonate is produced by transesterification of a dialkyl carbonate, such as dimethyl carbonate, with an aromatic hydroxy compound, such as phenol, in three successive reaction zones. A transesterification catalyst, such as a titanate ester or ester mixture is used in each zone. Conditions are selected to maximize formation of alkyl aryl carbonate in the first and second reaction zones, while conversion to diaryl carbonate is favored in the third reaction zone. The vaporous mixture from the first two reaction zones is a mixture containing alkyl alcohol, dialkyl carbonate, alkyl aryl carbonate and aromatic hydroxy compound. This mixture is separated in an alkyl alcohol recovery zone by distillation in the distillation columns to produce useful recycle streams. The second of these distillation columns can be operated at a lower pressure than the first, thus enabling the heat of vaporization of this mixture to be used as the source of heat for the reboiler of the second distillation column of the alkyl alcohol recovery zone.

Continuous production process of diarylcarbonates

A copper chromite hydrogenation catalyst of enhanced activity is obtained by an ante-pre-reduction treatment in which a copper chromite catalyst precursor is soaked in a reducing atmosphere at temperatures below a pre-reduction temperature (typically about 140.degree. C.) at which appreciable pre-reduction of the catalyst can be detected. This catalyst is characterized by particles of reduced copper substantially all of which have an average particle size of less than about 300.times.10.sup.-10 m (300.ANG.), which have an average particle size of less than about 100.times.10.sup.-10 m (100.ANG.), and which are substantially uniformly distributed on a chromium-containing support. Typically such catalysts exhibit a copper surface area of about 18.5 m.sup.2 /g as determined by N.sub.2 O decomposition at 20.degree. C., compared to a corresponding copper surface area of 4.5 m.sup.2 /g for a catalyst which has been produced by conventional pre-reduction of the same catalyst precursor.

Process for producing a hydrogenation catalyst of copper chromite

Process for the production of butane-1,4-diol

A process for the production of butane-1,4-diol comprises hydrogenating a di(C.sub.1 to C.sub.3 alkyl) ester of a C.sub.4 dicarboxylic acid, e.g. an ester of a but-2-en-1,4-dioic acid, such as diethyl maleate, in the vapor phase at a temperature of from about 150.degree. C. to about 240.degree. C. and at a pressure in the range of from about 25 bar to about 75 bar in the presence of a reduced copper chromite catalyst, and recovering resulting butane-1,4-diol containing reaction product. The catalyst contains, before reduction, from about 25 to about 45% by weight of copper and from about 20 to about 35% by weight of chromium and preferably has an internal surface area of at least about 30 sq. m. per gram. The process is preferably conducted in two or more reaction zones, which are preferably operated adiabatically, the feed temperature to the first zone being higher than that to at least one subsequent reaction zone.

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Middlesbrough, United Kingdom

Mohammad Sharif