Abstract: A process is described for the continuous recovery of substantially pure pentane-1,5-diol from a crude product stream (1) containing pentane-1,5-diol and &dgr;-valerolactone. The feed stream (1) is continuously supplied to a vaporization zone (2) 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 (4). A reflux stream (5) of dimethyl glutarate is fed to an upper section of the distillation zone (4) and an overhead vapor product stream (8) comprising &dgr;-valerolactone and dimethyl glutarate is taken. Also an intermediate stream (11) comprising substantially pure pentane-1,5-diol is taken from the distillation zone (4), while from the bottom section of the distillation zone there is recovered a bottoms product (12).

Abstract: 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.

Abstract: 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 compou

Abstract: 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:(a) providing a hydrogenation zone containing a charge of a granular hydrogenation catalyst which has a total surface area of at least about 15 m.sup.

Abstract: 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:(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 hydrogenarable material comprising a dialkyl cyclohexanedicarboxylate at an inlet temperature which is above its dew point of the mixture;(c) maintaining the hydrogenation zone under temperature and pressure conditions which are conducive to effecting hydrogenation of esters;(d) passing the vaporous feed stream through the hydrogenation zone; and(e) recovering from the hydrogenation zone a product stream containing cyclohexanedimethanol having a trans-:cis-isomer ratio greater than 1:1.

Abstract: 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).

Abstract: 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.

Abstract: A process is described for the production of cyclohexanedimethanol by hydrogenation of a dialkyl cyclohexanedicarboxylate which comprises:(a) providing a hydrogenation zone containing a charge of a granular heterogeneous ester hydrogenation catalyst;(b) forming a vaporous feed stream of a hydrogen-containing gas,and a hydrogenatable material comprising a dialkyl cyclohexanedicarboxylate at a feed temperature which is in the range of from about 150.degree. C. to about 350.degree. C. and which is above the dew point of the feed stream and at a feed pressure in the range of from about 150 psia (about 10.34 bar) to about 2000 psia (about 137.

Abstract: An improved process for the production of fatty alcohols is provided. The fatty alcohols are produced by hydrogenation of lower alkyl esters, especially methyl esters, of fatty acids derived from natural triglycerides, under conditions which minimize formation of by-product alkanes and ethers. The hydrogenation is followed by refining of any resulting ester-containing hydrogenation product to produce a substantially ester free fatty alcohol.

Abstract: An improved process for refining alcohols produced by hydrogenation of esters wherein the crude hydrogenation product still contains a minor amount of unconverted ester starting material. In one embodiment, the process includes a method for recovering fatty alcohol or alcohols from a fatty alcohol fraction containing a major molar amount of at least one fatty alcohol and a minor molar amount of at least one lower alkyl fatty acid ester. In another embodiment, there is provided a process for the production of fatty alcohols which comprises, in addition to other steps, hydrogenating a lower alkyl fatty acid ester to yield a mixture of a lower alkanol, a fatty alcohol fraction and a minor amount of unreacted lower alkyl fatty acid ester.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Butane-1,4-diol is produced by vapor phase hydrogenolysis of an alkyl ester of a C.sub.4 dicarboxylic acid, e.g. diethyl maleate, over a reduced Cu-Cr or Cu-Zn mixed oxide catalyst. Two adiabatic hydrogenolysis zones are used. The mixture exiting the first of these zones is cooled (by, for example, 5.degree. C.) and the resulting cooled mixture is fed to the second zone in which is reequilibriates at a lower temperature to increase the butane-1,4-diol yield at the expense of gamma-butyrolactone. Typical reaction conditions include use of temperatures of 150.degree. C. to 200.degree. C., pressures of 25 to 70 bar, and a H.sub.2 :ester molar ratio of 100:1 to 800:1. When using a maleate ester it is often advantageous to hydrogenate this to the corresponding succinate ester in an upstream hydrogenation zone prior to entry to the first hyrogenolysis zone.

Abstract: Printed circuit manufacture may employ a plated palladium-nickel alloy layer as an etch resist and plating finish. Prior to the use of palladium-nickel, tin-lead was used as the etch resist and plating finish. The palladium-nickel layer is generally superior to the corresponding tin-lead layer except for solderability. To improve the solderability of at least these areas of the palladium-nickel to which elements are to be soldered, a layer of copper is deposited thereon. If desired, the solderability of the copper may be preserved by coating it with, for example, a tin-lead layer.

Abstract: A compression air conditioning system adapted to cool air within the passenger compartment of a motor vehicle can be reversed to function as a heat pump for heating the compartment. The system includes a first heat exchanger located within the compartment wherein the refrigerant is vaporized in the air conditioning mode and condensed during the heating mode. An electrical resistance heater is energized for a short period after starting the engine during which time the various heat sources may be inadequate to heat the passenger compartment air sufficiently. A diverter valve regulates flow through the refrigerant lines so that flow in either the heating or cooling mode is always in the same direction through the lines and the system components. A second heat exchanger located outside the compartment operates as a condenser during the cooling cycle and as an evaporator during the heating cycle. Three sources of heat energy can be used within the second exchanger to heat the refrigerant.

Abstract: A fluid injection system including a flexible bag fluid reservoir acted upon by an elastically deformable compression member for pressurizing the fluid within the reservoir, a combined pump and valve assembly connected to the reservoir, and an injection means consisting of a flexible conduit and needle connected to the output of the combined pump and valve assembly. Also included is a selectively actuable electromagnetic force generator which cooperates with a magnetically polarized pump element and a movable magnetically polarized valve closure element, both of which are located within the combined pump and valve assembly and movable under the action of the electromagnetic force generator for accumulating and pumping a predetermined charge of fluid from the reservoir to the flexible conduit for injection into the body via the needle.

Abstract: 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.

Abstract: 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 containing sodium sulfate and a relatively large amount of sodium bisulfite, e.g. spent absorbing solution, is contacted with a treating gas containing at least a small amount of sulfur dioxide while reducing the amount of water in the medium so that a slurry is obtained having up to about 10, or even up to about 20, weight percent precipitated solids containing sodium sulfate in greater concentration than would otherwise be obtained in the absorption-desorption cycle. Preferably, the sulfur dioxide-containing treating gas is unsaturated with respect to water.

Abstract: Sodium thiosulfate 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. A portion of the liquid from a desorption zone containing a minor amount of sodium thiosulfate and a relatively large amount of sodium bisulfite, is treated to reduce the amount of water in the medium so that solids are precipitated from the liquid phase. The insolubles containing sodium sulfites are removed from the liquid. The liquid separated from the solids can be discarded and thereby purge thiosulfate more selectively with respect to other sodium salts. Also, the sodium values of the sodium thiosulfate-containing purge liquid can be recovered in active form by chemical reduction, and, preferably, carbonation. A sodium sulfate purge material from the absorption-desorption system can also be subjected to the chemical reduction system for further recovery of active sodium values.