Abstract: An improved process and apparatus are provided for recovering hydrocarbons from an intermittent or continuous inlet air-hydrocarbon vapor mixture. The air-hydrocarbon vapor mixture is caused to flow through a bed of solid adsorbent whereby hydrocarbons are removed therefrom and a residue gas stream of substantially hydrocarbon-free air is produced. The substantially hydrocarbon-free air is vented into the atmosphere and a second bed of solid adsorbent having hydrocarbons previously adsorbed thereon is regenerated by evacuation. As long as the concentration of hydrocarbons contained in the vented air is below a predetermined concentration, the inlet air-hydrocarbon vapor mixture is caused to continue to flow through the first bed of adsorbent. After the second bed of adsorbent is regenerated, the pumping and evacuation of the second bed is shut down and not restarted so long as the monitored concentration of hydrocarbons is below the predetermined concentration.