Abstract: A vapor recovery system for hydrocarbon storage tanks captures VOCs (volatile organic compounds) which would otherwise escape to the atmosphere, thereby reducing pollutant emissions to the environment. The system includes a wash chamber, where the VOC vapors are sprayed with water at or below ambient temperature to condense the vapors from the air. The liquid hydrocarbons and water then drain downwardly into an accumulator. Due to the immiscibility of water and hydrocarbon fuels, particularly those having high aromatic content such as gasoline, the liquid VOCs are drained off and returned to the storage tank while the water is recycled for further spray cooling of vapors. The spray chamber is also surrounded by a coolant jacket, through which a coolant (water or other suitable liquid) below ambient temperature is circulated. This further reduces the temperature in the spray chamber, to condense additional VOCs and water from the air, as well as cooling the spray water.