Abstract: Butane-1,4-diol, gamma-butyrolactone or tetrahydrofuran are prepared by vapor phase hydrogenation of a C4-dicarboxylic acid derivative. A maleic anhydride containing vapor stream is contacted in an absorption zone with a first high boiling solvent. A waste gas stream is passed to a scrubbing zone containing a second, higher boiling solvent. The waste gas is purged and the first and second solvents are recovered and recycled. Maleic anhydride is obtained from the absorption zone and converted to a maleic acid diester, which is stripped from the first solvent with hydrogen. The desired products are obtained by hydrogenation.

Abstract: A process is described for the production of butane-1,4-diol, &ggr;-butyrolactone and/or tetrahydrofuran. A vaporous stream containing maleic anhydride, water, and carbon oxides is contact in an absorption zone with a high boiling ester as solvent to form a solution of maleic anhydride in the high boiling ester which has a boiling point at the atmospheric pressure at least about 30° C. higher than that of maleic anhydride and is selected from di-(C1 to C4 alkyl) esters of alkyl dicarboxylic acids containing up to 3 carbon atoms, mono- and di-(C10 to C18 alkyl) esters of maleic acid, fumaric acid, succinic acid, and mixtures thereof, (C1 to C4 alkyl) esters of naphthalene-monocarboxylic acids, tri-(C1 to C4 alkyl) esters of aromatic tricarboxylic acids, and di-(C1 to C4 alkyl) esters of isophthalic acid.

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 continuous process is described for the production of 1,4-cyclohexanedimethanol (CHDM) having a desired or predetermined trans-:cis- isomer ratio by catalytic hydrogenation of a dialkyl 1,4-cyclohexanedicarboxylate in the presence of an ester hydrogenation catalyst. The process is capable of being operated for an extended period of time during which the hydrogenation catalyst declines in catalytic activity and comprises feeding a vaporous mixture of the dialkyl 1,4-cyclohexanedicarboxylate and hydrogen to a hydrogenation zone containing the hydrogenation catalyst and recovering CHDM product. The degree of conversion of the dialkyl 1,4-cyclohexanedicarboxylate at a particular combination of temperature and pressure is related to the trans-:cis- isomer ratio of the CHDM product and may be varied by adjusting at least one feed condition selected from (i) the dialkyl 1,4-cyclohexanedicarboxylate feed rate and (ii) the hydrogen-containing gas:dialkyl 1,4-cyclohexanedicarboxylate molar ratio.

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: 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.