Method for the production of defined mixtures of THF, BDO and GBL by gas phase hydrogenation

摘要

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 °C to 300 °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 °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.