| 摘要 |
An alkane, e.g. propane, is converted to an alkene in a catalytic dehydrogenator. The resulting stream is introduced into an ammoxidation or oxidation reactor. The product formed therein is recovered in a conventional quench tower. The pressure of the gaseous effluent from the quench tower is raised and it is introduced into an absorber/stripper unit employing a liquid hydrocarbon to form a recycle stream containing unreacted alkane and alkene as well as a minor amount of oxygen, typically 1% percent by volume, and a waste stream comprising the remainder of the quench tower gaseous phase. The recycle stream is introduced into a selective oxidation unit to remover the oxygen therefrom and then recycled to the dehydrogenator. Flammability of the waste stream from the absorber/stripper is minimised by appropriately selecting the operating parameters of the process, and if necessary, by the addition thereto of a gaseous flame suppressor. The gaseous flame suppressor is removed with the absorber/stripper unit waste stream which may advantageously be combusted to provide energy for the process. A PSA unit may be utilised to remove excess hydrogen from the dehydrogenator effluent. The dehydrogenator may be a multistage dehydrogenator making it possible to do without the selective oxidation unit. |
