| 摘要 |
Process for recovering a hydrocarbon (I) from a gas stream which besides various hydrocarbons also contains small amounts of oxygen, using a pressure change adsorption process in a number of adsorbers operating cyclically. During an adsorption phase at elevated press., selective adsorption of the hydrocarbon to be recovered occurs; during the adsorption phase and during at least one equilibrating phase subsequent to the adsorption phase, a gas stream is drawn off the outlet end of an adsorber, which is depleted in the hydrocarbon to be recovered; during at least one subsequent counter flow depressurisation from the inlet end of the adsorber, a desorbate stream enriched in the hydrocarbon to be recovered is drawn off; and after the desorption, the adsorber undergoes a pressure building phase during which it is returned to adsorption press. with a gas low in oxygen. Process allows selective recovery of a hydrocarbon from an O2-contg. gas stream without exceeding the explosive limits of oxygen/hydrocarbon in the system, and is esp. useful for recovering ethylene from a gas stream consisting mainly of methane and ethylene. |
