TWO-STAGE METHOD FOR PRODUCING BUTANDIOL IN TWO REACTORS

摘要

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 <= 95 % by weight, preferably 5 to 95 % by weight, especially 10 to 80 % by weight CuO and >= 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.