| 摘要 |
A process and apparatus for recovering hydrocarbons from an air-hydrocarbon vapor mixture such as the mixture of air and vaporized light hydrocarbon compounds expelled as a result of loading gasoline, benzene or the like into storage tanks and tank trucks. The air-hydrocarbon vapor mixture is caused to flow through a bed (12) of solid adsorbent whereby the hydrocarbons are removed from the mixture and a residue gas stream comprised of substantially hydrocarbon-free air is produced. The substantially hydrocarbon-free air is vented to the atmosphere (at 54) and a second bed (14) of solid adsorbent having hydrocarbons adsorbed thereon is subjected to conditions which cause desorption of the hydrocarbons and thereby regeneration of the bed. The regeneration of the bed is accomplished by evacuating the bed by means of a liquid seal vacuum pump (72) whereby a major portion of the hydrocarbons are desorbed therefrom and subsequently subjecting the bed to further evacuation by means of both a positive displacement booster vacuum pump (68) and by the liquid seal pump (72), whereby additional hydrocarbons are desorbed therefrom. <IMAGE> |
