Abstract: An aldolisation-dehydration process is disclosed for converting an aldehyde, e.g. n-valeraldehyde, to a substituted acrolein, e.g. propyl butyl acrolein (2-propylhept-2-enal). Aldolisation and dehydration are effected in a stirred tank reactor (16; 111) using an alkali catalyst, such as sodium hydroxide. A reaction product stream (23; 113) containing both organic and aqueous phases is distilled (in column 25; 123) to yield a heterogeneous azeotrope containing water and aldehyde. On condensation and phase separation the lower water layer (34; 150) can be discharged from the plant without the need for neutralisation. From the bottom of the distillation zone a mixture (36;157) of substituted acrolein and alkali catalyst solution is obtained. The substituted acrolein is recovered as product (45;173), while the catalyst solution (47;175) is recycled to the aldolisation reactor. Part (49; 181) of the catalyst solution is purged to control the level of Cannizzaro reaction products.

Abstract: Separation of tetrahydrofuran (THF) from a mixture containing water, THF and a lower alkanol such as ethanol or methanol, is achieved by distillation in two zones, the vaporous mixture from the first zone being condensed and redistilled at a higher pressure in the second zone. Substantially pure THF is recovered from a lower part of the second zone, while the vapor from the top of the second zone is combined with the vapor from the first zone prior to condensation and the resulting condensate forms the liquid feed to the second zone. The process is suitable for recovering THF from complex reaction mixtures, containing also butane-1,4-diol and gamma-butyrolactone, obtained by hydrogenation of a dialkyl maleate.

Abstract: In a hydrogenation process, an organic feedstock, such as an unsaturated organic compound containing at least one unsaturated linkage selected from >C.dbd.C<, >C.dbd.O, --C.tbd.C--, and --C.tbd.

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 gas mixer and distributor has an array of parallel gas mixing and distributing tubes which extend from a first chamber through successive second and third chambers. Respective coaxial tubular sections surround the tubes and communicate between the second and third chambers. Openings in the walls of the tubes communicate from the third chamber into the tubes. The first gas is fed into the first chamber for distribution into the first ends of the tube. The second gas is fed into the second chamber and passes through the annular passages formed by tubular sections over the tubes into the third chamber. The annular passages provide indirect heat exchange between the first and second gases to produce uniform temperature and density of the second gas in the third chamber before passing into the tubes through the tube wall openings.

Abstract: A liquid phase catalytic hydrogenation process is described in which an organic feedstock, such as an aldehyde containing from 2 to about 20 carbon atoms, is contracted with hydrogen in the presence of a solid hydrogenation catalyst under hydrogenation conditions to produce a hydrogenation product, such as the corresponding alcohol containing from 2 to about 20 carbon atoms, which process comprises passing a feed solution of the organic feedstock in an inert diluent therefor downwardly in co-current with a hydrogen-containing gas through a hydrogenation zone containing a bed of a particulate hydrogenation catalyst whose particles substantially all lie in the range of from about 1.

Abstract: Continuous process for hydroformylation of olefins containing, typically, from 6 to 20 carbon atoms to produce the corresponding aldehydes. The rate of formation of high boiling aldehyde condensation products is minimized by use of a high boiling inert solvent whose boiling point, at the pressure prevailing in the product recovery zone, lies intermediate between that of the highest boiling aldehyde product produced in the hydroformylation reaction and that of the ligand, as well as by maintaining the concentration of product aldehyde at or below a predetermined minor amount. In this way the length of a production run can be significantly extended before it becomes necessary to shut down the plant due to accumulation of high boiling aldehyde condensation products.

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: Aliphatic aldehydes are hydrogenated to alcohols containing by product ester which ester is removed and separately hydrogenated to provide additional product.

Abstract: Hydrogen is supplied first to a last hydrogenation zone, and gases recovered from the last hydrogenation zone are passed to the first hydrogenation zone of a continuous multi-zone liquid phase process for hydrogenating an organic compound to a corresponding hydrogenation product. The organic compound, with a suitable diluent or recycle hydrogenation product, flows successively through the zones beginning with the first and ending with the last hydrogenation zone to undergo hydrogenation with the hydrogenation product being recovered from the last hydrogenation zone.

Abstract: A process is described for the production of substantially pure gamma-butyrolactone from a feed mixture containing a major amount of gamma-butyrolactone and a minor amount of diethyl succinate which comprises fractionally distilling the mixture in a fractionation zone in the presence of diethyl ethoxysuccinate and recovering from the fractionation zone an overhead vaporous product comprising gamma-butyrolactone which is substantially free from diethyl succinate and is liquid bottom product comprising diethyl ethoxysuccinate and diethyl succinate in admixture one with another. This procedure can be used to separate a gamma-butyrolactone rich fraction obtained by distillation in one or more stages of a crude reaction product obtained by hydrogenation of a C.sub.

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 process is described for the production of a dialkyl maleate by reaction of maleic anhydride with an alkyl alcohol in a monoesterification zone to form the corresponding monoalkyl maleate, followed by reaction of resulting monoalkyl maleate with further alkyl alcohol to form the corresponding dialkyl maleate, which includes the steps of supplying a first liquid feed comprising said monoalkyl maleate to a secondary esterification zone containing a charge of a solid esterification catalyst, supplying a second feed stream comprising said alkyl alcohol to said secondary esterification zone, maintaining said secondary esterification zone at an elevated temperature sufficient to form or to maintain therein a vaporous stream containing said alkyl alcohol, intimately contacting said first liquid feed in said secondary esterification zone in the presence of said catalyst with said vaporous feed stream, recovering from said secondary esterification zone a vaporous effluent stream containing, in addition to alkyl alco

Abstract: A process is provided for the recovery of an optionally substituted C.sub.7 to C.sub.17 aldehyde from a liquid hydroformylation product medium obtained by rhodium catalyzed hydroformylation of an optionally substituted C.sub.6 to C.sub.16 olefin which contains (i) a rhodium complex hydroformylation catalyst containing rhodium in complex combination with carbon monoxide and with a ligand, (ii) excess ligand, (iii) at least one optionally substituted C.sub.7 to C.sub.17 aldehyde, and (iv) aldehyde condensation products, which process comprises:(a) degassing said liquid hydroformylation medium;(b) passing the degassed liquid hydroformylation medium through an evaporation zone maintained under temperature and pressure conditions conducive to evaporation of said at least one C.sub.7 to C.sub.

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: A method of producing substantially pure dialkyl maleate by separating monoalkyl maleate from dialkyl maleate in a short residence time distillation zone while minimizing reversion of the monoalkyl maleate to alkanol and maleic anhydride and without having to neutralize the monoalkyl maleate.

Abstract: A continuous multi-stage hydrogenation process is described.This is effected in at least three catalytic stages connected in series. All stages up to and including the penultimate stage are operated adiabatically and in the vapor phase. Aldehyde (or other unsaturated organic compound) is fed to all stages up to and including the penultimate stage. The rate of supply of the aldehyde or other unsaturated organic compound to the penultimate stage is controlled in relation to the catalyst volume in the penultimate catalytic stage so that the degree of hydrogenation in that stage is less than 100%. The remaining chemically unsaturated material in the product mixture from the penultimate stage is hydrogenated, after cooling that product mixture, in the final catalytic stage to produce a substantially completely hydrogenated product mixture. In this way the dwell time of the reactants and product(s) at "hot spot" temperatures is minimized, thus reducing byproduct formation.

Abstract: A continuous hydroformylation process for the production of an aldehyde by hydroformylation of an olefin comprises:providing a hydroformylation zone containing a charge of a liquid reaction medium having dissolved therein (a) a complex rhodium hydroformylation catalyst comprising rhodium in complex combination with carbon monoxide and with a cyclic phosphite having a phosphorus atom linked to three oxygen atoms at least two of which form together with the phosphorus atom part of a ring and (b) a ligand stabilizing amount of a tertiary amine;supplying said olefin to the hydroformylation zone;maintaining temperature and pressure conditions in the hydroformylation zone conducive to hydroformylation of the olefin;supplying make-up hydrogen and carbon monoxide to the hydroformylation zone; andrecovering from the liquid hydroformylation medium a hydroformylation product comprising at least one aldehyde.