| 摘要 |
The invention relates to a method for producing butadiene from n- butane, comprising the steps of A) providing an input gas flow a containing n-butane; B) feeding said input gas flow a containing n-butane into at least one first dehydrogenation zone and dehydrogenating n-butane in a non-oxidative catalytic manner, whereby a product gas flow b containing n-butane, 1-butene, 2-butene, butadiene, hydrogen, low-boiling secondary components, and optional steam is obtained; C) feeding the product gas flow b resulting from the non-oxidative catalytic dehydrogenation process and an oxygen-containing gas into at least one second dehydrogenation zone and oxidatively dehydrogenating 1-butene and 2-butene, whereby a product gas flow c containing n-butane, 2-butene, butadiene, hydrogen, low-boiling secondary components, and steam is obtained, said second product gas flow c having a higher butadiene content than product gas flow b; D) eliminating hydrogen, the low-boiling secondary components, and steam, whereby a C4 product gas flow d essentially comprising n-butane, 2-butene, and butadiene is obtained; E) separating the C4 product gas flow d into a recirculation flow e1 essentially comprising n-butane and 2-butene and a flow e2 substantially comprising butadiene by means of extractive distillation, and redirecting flow e1 into the first dehydrogenation zone. ® KIPO & WIPO 2007
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