摘要:
The present invention relates to a process for preparing unsubstituted or C1-C4-alkyl-substituted gamma-butyrolactone by catalytic hydrogenation of maleic acid and/or its derivatives in the presence of chromium-free catalyst comprising from 10 to 80% by weight of copper oxide and from 10 to 90% by weight of at least one catalyst support selected from the group consisting of silicon dioxide, titanium dioxide, hafnium dioxide, magnesium silicate, activated carbon, silicon carbide, zirconium dioxide and alpha-aluminum oxide.
摘要:
The present invention relates to a process for preparing optionally alkyl-substituted 1,4-butanediol by two-stage catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or of derivatives thereof having the following steps: a) introducing a gas stream of a C4-dicarboxylic acid or of a derivative thereof at from 200 to 300° C. and from 2 to 60 bar into a first reactor and catalytically hydrogenating it in the gas phase to a product which contains mainly optionally alkyl-substituted γ-butyrolactone; b) removing succinic anhydride from the product obtained in step a), preferably to a residual level of from
摘要:
The present invention relates to a process for preparing optionally alkyl-substituted 1,4-butanediol by two-stage catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or of derivatives thereof having the following steps: a) introducing a gas stream of a C4-dicarboxylic acid or of a derivative thereof at from 200 to 300° C. and from 2 to 60 bar into a first reactor and catalytically hydrogenating it to a product which contains mainly optionally alkyl-substituted 7-butyrolactone; b) converting the product stream into the liquid phase; c) introducing the product stream obtained in this way into a second reactor at a temperature of from 100° C. to 240° C. and a pressure of from 20 to 250 bar and catalytically hydrogenating it in the liquid phase to optionally alkyl-substituted 1,4-butanediol; d) removing the desired product from by-products and any unconverted reactants; e) optionally recycling unconverted intermediates into one or both hydrogenation stages, said hydrogenation stages both using a catalyst which comprises ≦95% by weight, preferably from 5 to 95% by weight, in particular from 10 to 80% by weight, of CuO, and ≧5% by weight, preferably from 5 to 95% by weight, in particular from 20 to 90% by weight, of a support, said second reactor having a higher pressure than said first reactor, and the product mixture removed from said first reactor being introduced without further purification into said second reactor.
摘要:
The present invention relates to a process for preparing optionally alkyl-substituted 1,4-butanediol by two-stage catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or of derivatives thereof having the following steps: a) introducing a gas stream of a C4-dicarboxylic acid or of a derivative thereof at from 200 to 300° C. and from 10 to 100 bar into a first reactor or into a first reaction zone of a reactor and catalytically hydrogenating it in the gas phase to a product which contains mainly optionally alkyl-substituted y-butyrolactone; b) introducing the product stream obtained in this way into a second reactor or into a second reaction zone of a reactor at a temperature of from 140° C to 260° C. and catalytically hydrogenating it in the gas phase to optionally alkyl-substituted 1,4-butanediol; steps a) and b) being carried out at the same pressure; c) removing the desired product from intermediates, by-products and any unconverted reactants; d) optionally recycling unconverted intermediates into one or both hydrogenation stages, said hydrogenation stages each using a catalyst which comprises ≦95% by weight, preferably from 5 to 95% by weight, in particular from 10 to 80% by weight, of CuO, and ≧5% by weight, preferably from 5 to 95% by weight, in particular from 20 to 90% by weight, of an oxidic support, and the product mixture removed from the first hydrogenation stage being introduced without further purification into the second hydrogenation stage.
摘要:
Optionally alkyl-substituted 1,4-butanediol is prepared from C4-dicarboxylic acids and/or of derivatives thereof by: a) a gas stream of the C4-dicarboxylic acid or the derivative thereof in a first reactor in the gas phase to obtain a product which contains mainly optionally alkyl-substituted γ-butyro-lactone; b) removing succinic anhydride from the product of step a); c) catalytically hydrogenating the product of step b) in a second reactor in the gas phase to obtain optionally alkyl-substituted 1,4-butanediol; d) removing the desired product from intermediates, by-products and any unconverted reactants; and e) optionally recycling unconverted intermediates into one or both hydrogenation stages. The catalysts employed in each of the hydrogenation stages comprise ≦95% by weight of CuO, and ≦5% by weight of an oxidic support, and the second reactor has a higher pressure than the first reactor.
摘要:
The present invention relates to a process for preparing optionally alkyl-substituted 1,4-butanediol by two-stage catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or of derivatives thereof having the following steps: a) introducing a gas stream of a C4-dicarboxylic acid or of a derivative thereof at from 200 to 300° C. and from 2 to 60 bar into a first reactor and catalytically hydrogenating it to a product which contains mainly optionally alkyl-substituted γ-butyrolactone; b) converting the product stream into the liquid phase; c) introducing the product stream obtained in this way into a second reactor at a temperature of from 100° C. to 240° C. and a pressure of from 20 to 250 bar and catalytically hydrogenating it in the liquid phase to optionally alkyl-substituted 1,4-butanediol; d) removing the desired product from by-products and any unconverted reactants; e) optionally recycling unconverted intermediates into one or both hydrogenation stages, said hydrogenation stages both using a catalyst which comprises ≦95% by weight, preferably from 5 to 95% by weight, in particular from 10 to 80% by weight, of CuO, and ≧5% by weight, preferably from 5 to 95% by weight, in particular from 20 to 90% by weight, of a support, said second reactor having a higher pressure than said first reactor, and the product mixture removed from said first reactor being introduced without further purification into said second reactor.
摘要:
The present invention relates to a process for preparing optionally alkyl-substituted 1,4-butanediol by two-stage catalytic hydrogenation in the gas phase of C4-dicarboxylic acids and/or of derivatives thereof having the following steps: a) introducing a gas stream of a C4-dicarboxylic acid or of a derivative thereof at from 200 to 300° C. and from 10 to 100 bar into a first reactor or into a first reaction zone of a reactor and catalytically hydrogenating it in the gas phase to a product which contains mainly optionally alkyl-substituted γ-butyrolactone; b) introducing the product stream obtained in this way into a second reactor or into a second reaction zone of a reactor at a temperature of from 140° C. to 260° C. and catalytically hydrogenating it in the gas phase to optionally alkyl-substituted 1,4-butanediol; steps a) and b) being carried out at the same pressure; c) removing the desired product from intermediates, by-products and any unconverted reactants; d) optionally recycling unconverted intermediates into one or both hydrogenation stages, said hydrogenation stages each using a catalyst which comprises ≦95% by weight, preferably from 5 to 95% by weight, in particular from 10 to 80% by weight, of CuO, and ≧5% by weight, preferably from 5 to 95% by weight, in particular from 20 to 90% by weight, of an oxidic support, and the product mixture removed from the first hydrogenation stage being introduced without further purification into the second hydrogenation stage.
摘要:
The invention relates to a catalyst containing from 0.1 to 20 mass % rhenium and 0.05 to 10 mass % platinum in relation to the total mass thereof. The inventive method for producing a support for said catalyst consists in a) treating a support which can be eventually pre-treated with the aid of a solution of rhenium compound, b) drying and annealing said support at a temperature ranging from 80 to 600° C., and c) impregnating the support with a solution of platinum compound and in drying it. The inventive method for producing alcohol by catalytic hydrogenation of carbonyl compound on said catalyst is also disclosed.
摘要:
A multi-zone jacketed pipe reactor (2; 60; 90; 130) for carrying out exothermic gaseous phase reactions and with at least one reaction zone (I) working with vaporisation cooling, at least one reaction zone (II) working with circulation cooling and, possibly, with additional zones (III, IV) is characterised in that one reaction zone (I) working with vaporisation cooling forms the first reaction zone to which is connected an additional reaction zone (II) working with circulation cooling. In this way there occurs at the beginning of the reaction, when the latter is most violent, very intensive cooling at a precisely controllable temperature and especially as well a temperature that is constant across the entire cross-section of the reactor while subsequently in a subsequent reaction zone working with circulating cooling by means of global counter-flow guidance of the heat transfer agent a constant cooling of the reaction gas is achieved.
摘要:
The present invention provides a process for distillatively purifying crude water-containing tetrahydrofuran by passing the crude tetrahydrofuran through three distillation columns, withdrawing water from the bottom of the first column, recycling water-containing tetrahydrofuran from the top of the second column into the first column, passing a sidestream of the first column into the second column, recycling the bottom product of the third column into the first column, and withdrawing a distillate at the top of the first column, which comprises passing a sidestream of the second column into the third column and recovering the pure tetrahydrofuran as the top product of the third column.