Patent ID: 7518024

Claim:
A process for preparing 1-butene from 1-butane, which comprises the steps A) provision of an n-butane-containing feed gas stream a; B) introducing of the n-butane-containing feed gas stream a into at least one dehydrogenation zone and nonoxidative catalytic dehydrogenation of n-butane to give a product gas stream b comprising n-butane, 1-butene, 2-butene, butadiene, low-boiling secondary constituents, hydrogen and possibly water vapor; C) removing hydrogen, the low-boiling secondary constituents and optionally water vapor to give a C 4 product gas stream c containing 10-80% by volume of n-butane, 5-40% by volume of 1-butene, 10-50% by volume of 2-butene, 0-40% by volume of butadiene and 0-10% by volume of further gas constituents; D) introducing the C 4 product gas stream c, containing 10-80% by volume of n-butane, 10-60% by volume of 1-butene, 15-60% by volume of 2-butene, 0-5% by volume of butadiene and 0-10% by volume of further gas constituents, into a selective hydrogenation zone and selective hydrogenation of butadiene to 1- and/or 2-butene to give a stream d consisting essentially of n-butane, 1-butene and 2-butene; E) separating of the stream d by distillation into a desired product stream e1 consisting essentially of 1-butene and a recycle stream e2 consisting essentially of 2-butene and n-butane and recirculation of the recycle stream e2 consisting essentially of 2-butene and n-butane to the dehydrogenation zone, wherein the stream e1 contains at least 90% by volume of 1-butene, and the stream e2 contains 10-80% by volume of 2-butene, 20-90% by volume of n-butane and 0-5% by volume of 1-butene.