| 摘要 |
The invention relates to a process for preparing propene from propane, comprising the steps: A) a feed gas stream a comprising propane is provided; B) the feed gas stream a comprising propane, if appropriate steam and if appropriate and an oxygenous gas stream are fed into a dehydrogenation zone and propane is subjected to a dehydrogenation to propene to obtain a product gas stream b comprising propane, propene, methane, ethane, ethene, nitrogen, carbon monoxide, carbon dioxide, steam, if appropriate hydrogen and if appropriate oxygen; C) the product gas stream b is cooled, if appropriate compressed and steam is removed by condensation to obtain a steam-depleted product gas stream c; D) uncondensable or low-boiling gas constituents are removed by contacting the product gas stream c with an inert absorbent and subsequently desorbing the gases dissolved in the inert absorbent to obtain a C<SUB>3 </SUB>hydrocarbon stream d 1 and an offgas stream d 2 comprising methane, ethane, ethene, nitrogen, carbon monoxide, carbon dioxide, if appropriate hydrogen and if appropriate oxygen; E) the Ca hydrocarbon stream d 1 is cooled and if appropriate compressed to obtain a gaseous or liquid Ca hydrocarbon stream e 1; F) the C<SUB>3 </SUB>hydrocarbon stream e 1 is if appropriate fed into a first distillation zone and separated distillatively into a stream f 1 composed of propane and propene and a stream f 2 comprising ethane and ethene; G) the stream e 1 or f 1 is fed into a (second) distillation zone and separated distillatively into a product stream g 1 composed of propene and a stream g 2 composed of propane, the stream g 2 being recirculated at least partially into the dehydrogenation zone.
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