| 摘要 |
The invention relates to a method for producing butadiene from n-butane, said method comprising the following steps: A) a feed gas flow (a) containing n-butane is prepared; B) the feed gas flow (a) containing n-butane is fed into at least one first dehydrogenating region and the n-butane is subjected to non-oxidative catalytic dehydrogenation, in order to obtain a gas flow (b) containing n-butane, 1-butene, 2-butene, butadiene, hydrogen, optionally carbon dioxide, and optionally water vapour; C) the gas flow (b) and a gas having an oxygen content of at least 75 vol. % are fed into at least one second dehydrogenating region and the 1-butene and 2-butene are subjected to oxidative dehydrogenation, in order to obtain a gas flow (c) containing n-butane, butadiene, hydrogen, and water vapour; D) the gas flow (c) is compressed in at least one first compression step and cooled, in order to obtain at least one condensate flow (d1) containing water and a gas flow (d2) containing n-butane, butadiene, hydrogen, carbon dioxide, and water vapour; E) the gas flow (d2) is compressed in at least one other compression step and cooled, in order to obtain at least one condensate flow (e1) containing n-butane, butadiene and water and a gas flow (e2) containing n-butane, butadiene, hydrogen and carbon dioxide; F) the gas flow (e2) is cooled, in order to obtain a condensate flow (f1) containing n-butane and butadiene and an exhaust gas flow (f2) containing carbon dioxide and hydrogen; G) water is separated from the at least one condensate flow (e1) and optionally the condensate flow (f1) during phase separation, in order to obtain at least one C4-hydrocarbon flow (g1) containing n-butane and butadiene and at least one waste water flow (g2); H) the C4-hydrocarbon flow (g1) is fractionated into a return flow (h1) containing n-butane and a product flow (h2) essentially consisting of butadiene, and the flow (h1) is redirected into the first dehydrogenating region. |
