Eastman Chemical Company

Davy Mckee (London) Limited

Davy Powergas Gmbh

Davy Process Technology Limited

Kvaerner Process Technology, Ltd.

John Scarlett

Michael A Wood

George E Harrison

Norman E Nicholson

Donald H McKinley

Michael W Tuck

Colin Rathmell

Keith Turner

Norman Harris

Mohammad Sharif

John F Flintoff

Anthony B Carter

Martyn Wilmott

Paul Willett

Arthur James Reason

John W Kippax

Edgar E Bailey

Geoffrey Webb

Peter R Wilkes

Philip H Eastland

A process is described for the continuous recovery of substantially pure pentane-1,5-diol from a crude product stream (,) containing pentane-1,5-diol and &dgr;-valerolactone. The feed stream (,) is continuously supplied to a vaporization zone (,) maintained under temperature and pressure conditions effective for the vaporization of pentane-1,5-diol and conducive to the thermal decomposition of reaction products of &dgr;-valerolactone thereby to form a vaporous stream. The resulting vaporous stream is continuously supplied to an intermediate section of a distillation zone (,). A reflux stream (,) of dimethyl glutarate is fed to an upper section of the distillation zone (,) and an overhead vapor product stream (,) comprising &dgr;-valerolactone and dimethyl glutarate is taken. Also an intermediate stream (,) comprising substantially pure pentane-1,5-diol is taken from the distillation zone (,), while from the bottom section of the distillation zone there is recovered a bottoms product (,).

Process for preparing pentane-1,5-diol

Esterification is carried out in a column reactor (14) in which there is a plurality of esterification trays (15) each having predetermined liquid hold-up and containing a charge of a solid esterification catalyst thereon. e.g. an ion exchange resin containing a --SO.sub.3 H and/or --COOH groups. A liquid phase containing the carboxylic acid component, e.g. a fatty acid mixture, flows down the column reactor from one esterification tray to the next downward one against an upflowing alcohol vapour stream, e.g. methanol vapour. Relatively dry alcohol vapour is injected (21) into the bottom of the column reactor. Water of esterification is removed from the top of the column reactor in the vapour stream (26), whilst ester product is recovered (23) from the sump of the reactor. As the liquid flows down the trays it encounters progressively drier alocohol and the esterification equilibrium reaction is driven further and further towards 100% ester formation. A polishing reactor (304) operated under liquid phase conditions may follow the column reactor, the ester-containing product from which is mixed with further alcohol before admission to the polishing reactor.

Production of carboxylic acid ester by esterification and apparatus

A process is described for the production of a hydroxylic compound selected from alcohols and diols by hydrogenation of a corresponding hydrogenatable material selected from monoesters of carboxylic acids, monoesters of dicarboxylic acids, diesters of dicarboxylic acids, lactones, and mixtures of two or more thereof which comprises: (a) providing a hydrogenation zone containing a charge of a granular heterogeneous ester hydrogenation catalyst; (b) supplying to the hydrogenation zone a vaporous feed stream containing hydrogen and a hydrogenatable material selected from monoesters of carboxylic acids, monoesters of dicarboxylic acids, diesters of dicarboxylic acids, lactones, and mixtures of two or more thereof, at an inlet temperature which is above the dew point of the mixture; (c) maintaining the hydrogenation zone under temperature and pressure conditions which are conducive to effecting hydrogenation of esters; (d) recovering from the hydrogenation zone a two phase product stream containing a hydroxylic compound selected from alcohols and diols at an exit temperature which is below its dew point. In a preferred process the hydrogenatable material comprises dimethyl cyclohexanedicarboxylate.

Hydrogenation process for the preparation of alcohols and diols

A process is described for the production of a hydroxylic compound selected from alcohols and diols by hydrogenation of a hydrogenatable material selected from monoesters of carboxylic acids, monoesters of dicarboxylic acids, diesters of dicarboxylic acids, aldehydes, olefinically unsaturated aldehydes, and mixtures of two or more thereof, which process comprises the steps of:

Process for the production of alcohols and diols

A hydrogenation process is described for the production of a hydroxylic compound selected from alcohols and diols by hydrogenation of a corresponding unsaturated organic compound selected from esters, diesters and lactones which involves use of two hydrogenation zones (11, 36), each containing a charge of a hydrogenation catalyst (12, 37). In a first phase of operation one of the hydrogenation zones (36 or 11) is in standby condition and a stream of hot hydrogen-containing gas is passed therethrough. Meanwhile a vaporous feed stream comprising a hydrogen-containing gas and the unsaturated organic compound to be hydrogenated, e.g. dimethyl 1,4-cyclohexanedicarboxylate, is fed to the active zone (11 or 36). This feed stream can include the gas stream from the first mentioned hydrogenation zone (36 or 11). In a second phase of operation the roles of the reactors (11, 36) are switched so that the zone (36 or 11) previously in reactivation condition becomes the active zone whilst the zone that was formerly active (11 or 36) goes into reactivation condition and its partially deactivated catalyst charge is reactivated by the hot hydrogen-containing gas stream.

A process is described for the production of cyclohexanedimethanol having a trans-:cis-isomer ratio greater than about 1:1 by hydrogenation of a dialkyl (e.g. dimethyl) cyclohexanedicarboxylate having a trans-:cis-isomer ratio less than about 1:1 which comprises:

Process for the production of cyclohexanedimethanol

A process is described for reactivating an at least partially deactivated copper-containing ester hydrogenation catalyst which has undergone deactivation through use in hydrogenation of an unsaturated organic compound selected from esters of C.sub.8 to C.sub.22 monocarboxylic acids, diesters of dicarboxylic acids, and lactones, to yield a corresponding hydroxylic compound selected from alcohols and diols which comprises contacting the at least partially deactivated copper-containing catalyst at an effective reactivation temperature and for an effective period of time with a stream of hydrogen-containing gas which is substantially free from the unsaturated organic compound thereby to reactivate the at least partially deactivated copper-containing catalyst.

Process for the preparation of alcohols and diols

A process is described for the production of cyclohexanedimethanol by hydrogenation of a dialkyl cyclohexanedicarboxylate which comprises:

Process for the production of fatty alcohols

Fatty alcohols

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

Tetrahydrofuran is recovered by a two stage distillation procedure from a crude hydrogenation product resulting from vapor phase hydrogenation of diethyl maleate and containing water, ethanol and a minor amount of n-butanol, and possibly also dissolved hydrogen, in addition to butane-1,4-diol, gamma-butyrolactone and 'heavies' such as diethyl ethoxysuccinate. In the first distillation stage, conveniently operated substantially at atmospheric pressure, ethanol, water, and tetrahydrofuran are recovered as overhead product, are condensed to separate the condensible components from a hydrogen stream which can be vented, and then redistilled in the presence of a molar excess of a hydroxylic solvent containing at least two hydroxyl groups, such as butane-1,4-diol, in a second distillation zone. Pure tetrahydrofuran is recovered as overhead product from the second distillation zone, while the bottom product therefrom is stripped in a third distillation zone of tetrahydrofuran, ethanol and water which are recycled to the first distillation zone and the stripped bottom product is recycled to the second distillation zone.

Process for the purification of tetrahydrofuran

A continuous process is described for the production of a substantially acid free dialkyl maleate, for example diethyl maleate, from a feed stream containing a major amount of dialkyl maleate and a minor amount of the corresponding monoalkyl maleate. This comprises continuously distilling the feed stream in a primary distillation zone, which can comprise a single distillation column or a series of distillation columns connected in series, so as to give (i) a bottom fraction containing monoalkyl maleate and dialkyl maleate in admixture, (ii) a vaporous fraction comprising alkanol, and (iii) an intermediate fraction that is substantially free from alkanol and comprises a major proportion of diethyl maleate and a minor proportion of maleic anhydride. The intermediate fraction (iii) is redistilled in a secondary distillation zone to yield (i) an overhead fraction containing maleic anhydride and (ii) a bottom fraction containing substantially acid free dialkyl maleate. The vaporous stream can be condensed to recover alkanol for recycle to a dialkyl maleate production facility.

Process for the production of a dialkyl maleate

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

Sodium sulfate is purged from a sulfur dioxide removal system involving contact of a sulfur dioxide-containing gas with a solution containing sodium sulfite to absorb sulfur dioxide from the gas. The spent absorbing solution is regenerated by desorbing sulfur dioxide and recycled for further use. To avoid an unduly large build-up of sulfate in the system, at least a portion of the absorbing-desorbing medium, e.g. spent absorbing solution, containing sodium sulfate and a relatively large amount of sodium bisulfite is treated to reduce the amount of water in the medium so that there is precipitated therefrom up to about 10 weight percent undissolved solids containing sodium sulfate in greater concentration than would otherwise be obtained in the absorption-desorption cycle. The insolubles containing sodium sulfate are removed from the liquid, and the liquid can be returned to the sulfur dioxide removal system. In one preferred aspect of the invention, up to about 75 weight percent of the entire stream of spent absorbing solution is treated to precipitate therefrom up to about 10 weight percent undissolved solids which are relatively rich in sodium sulfate content. In the invention the sodium sulfate-containing solids can be separated from the liquid which is then subjected to a desorption operation to produce sulfur dioxide, and the latter operation can be conducted while maintaining at least about 25 weight percent undissolved solids in the desorption zone.

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Spennymoor, United Kingdom

John Scarlett