Abstract:
The invention relates to a method for the continuous production of THF by reacting a reaction mixture containing 1.4-butandiol with a non-predried heteropolyacidic catalyst. The invention is characterised in that the reaction mixture contains 2-(4-hydroxybutoxy)-tetrahydrofuran.
Abstract:
The invention relates to a method for single-step production of polyoxyalkylene glycols by copolymerization of THF and neopentyl glycol in the presence of a heteropoly acid, characterized in that the overall amount of all impurities of general formula (I), wherein R and R represent hydrogen when R is an oxyformyl or isopropionate radical, R represents hydrogen and R represents hydroxy when R is an isopropyl radical and R represents hydrogen when R and R together represent an OCH2-C(CH3)-CH2 radical, in the neopentyl glycol is less than 1000 ppm.
Abstract:
The invention relates to a method for producing optionally akyl-substituted 1,4-butandiol by two-stage catalytic hydration in the gaseous phase of C4 dicarboxylic acids and/or the derivatives thereof with the steps of: a) introducing a gaseous flow of a C4 dicarboxylic acid or a derivative thereof at 200 to 300 °C and 2 to 60 bar in a first reactor and catalytic gas phase hydration to a mainly optionally alkyl-substituted gamma-butyrolactone containing product; b) introducing the product flow so obtained into a second reactor at a temperature of from 150 °C to 240 °C and a pressure of from 15 to 100 bar and catalytic gas phase hydration to optionally alkyl-substituted 1,4-butandiol; c) removing the desired product from the intermediates, byproducts and possibly not reacted educt; d) optionally returning non-reacted intermediates to one or both hydration stages, whereby in both hydration stages one catalyst each is used which comprises = 5 % by weight, preferably 5 to 95 % by weight, especially 20 to 90 % by weight of an oxidic carrier, the pressure prevailing in the second reactor is higher than in the first reactor, and the product mixture removed from the first reactor is introduced into the second reactor without further purifying it.
Abstract:
The invention relates to a method for production of polyvalent alcohols with low acetal content by catalytic hydrogenation of methylolalkanals of general formula (I), where R 1 and R 2 independently = a further methylol or C 1 - 22 alkyl group or C 6 - C 33 aryl or aralkyl group in the liquid phase on a hydrogenation catalyst, characterised in that at least one tertiary amine, inorganic base or inorganic or organic acid is added to the hydrogenation feed to adjust the pH value of the hydrogenation product to 7.0 to 9.0.
Abstract:
The invention relates to a method for producing polytetrahydrofuran, polytetrahydrofuran copolymer, polytetrahydrofuran diester, or polytetrahydrofuran monoester by polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer and an acid heterogeneous catalyst based on activated layered silicates or mixed metal oxides in a fluidized bed.
Abstract:
Carbon monoxide is removed from material streams by adsorption to an adsorption composition containing oxides of copper, zinc and zirconium, the copper-containing fraction of which has a degree of reduction, expressed as weight ratio of metallic copper to the sum of metallic copper and copper oxides, calculated as CuO, of at least 45%, and at most 75%.
Abstract:
The invention relates to a method for variable production of mixtures of optionally alkyl-substituted BDO, GBL and THF by two-stage hydrogenation in the gaseous phase of C4-dicarboxylic acids and/or the derivatives thereof, characterized in that a) a gas flow of C4-dicarboxylic acids and/or the derivatives thereof is hydrogenated in a first stage in the gaseous phase on a catalyst at a pressure of 2-100 bars and at a temperature of 200 DEG C to 300 DEG C in a first reactor in the presence of a catalyst in the form of catalyst moulded bodies with a volume of less than 20 mm3, consisting of 5 - 95 wt. % Cu-oxide and 5 - 95 wt. % of an oxide with acid centres in order to form a flow maintly consisting of optionally aryl-substituted GBL and THF, b) succinic anhydride optionally arising therefrom is separated by partial condensation, c) the products THF, water and GBL which remain predominantly in the gaseous phase during said partial condensation are reacted at the same pressure or at a pressure which is reduced in order to reduce flow losses in the hydrogenation circuit at a temperature of 150 to 240 DEG C in a second reactor on a catalyst of > 95 wt. % CuO and 5 to 95 wt. % of one or several oxides selected from the group consisting of ZnO, Al2O3, SiO2, TiO2, ZrO2, CeO2, MgO, CaO, SrO, BaO, La2O3, and Mn2O3 in order to form a mixture consisting of a flow containing BDO, GBL and THF, d) the hydrogen is separated from the products and returned to the hydrogenation, e) the products THF, BDO, GBL and Wasser are separated in a distillatory manner, a flow rich in GBL is optionally returned to the second reactor or is optionally removed therefrom and BDO, THF and GBL are processed in a distillatory manner, and the ratio of the products THF, GBL and BDO is adjusted in relation to each other in the region of 10 to 100 wt. % THF, 0 to 90 wt. % GBL and 0 to 90 wt. % BDO exclusively by varying the temperatures in the two hydrogenation areas, in addition to that of the GBL return flow.
Abstract:
The invention relates to a method for the production of optionally alkyl-substituted THF. The above is obtained by catalytic hydrogenation of C4-dicarboxylic acids and/or derivatives thereof, in the gas phase, using a catalyst containing 20 wt. %, preferably >30 wt %, in particular 35 to 90 wt. % of an oxidic support with acidic centres, whereby the method is carried out with a hot spot temperature of 240 to 280 DEG C and a catalytic loading of 0.01 to 1.0, preferably 0.02 to 1, in particular 0.05 to 0.5 kg reactant/l catalyst.hour.
Abstract:
A process for catalytically hydrogenating methylolalkanals of the general formula in which R1 and R2 are each independently a further methylol group or an alkyl group having from 1 to 22 carbon atoms or an aryl or aralkyl group having from 6 to 33 carbon atoms, in the liquid phase over a hydrogenation catalyst, which comprises setting a pH of from 7.0 to 9.0 in the hydrogenation effluent by adding at least one tertiary amine, an inorganic base or an inorganic or organic acid to the hydrogenation feed.