Gasoline stations rely on vacuum-assisted dispensing systems to minimize the release of hydrocarbon vapors to the atmosphere. These systems use a small pump to draw air and vapors from the gasoline dispensing nozzle. For every liter of gasoline dispensed from the pump, as much as 2 liters of air and gasoline vapor are returned to the storage tank. Build-up of air in the tank leads to atmospheric releases.
MTR and OPW Fueling Components have developed a membrane vapor recovery system for the fuel storage tanks of retail gasoline stations. The OPW Vaporsaver™ system, fitted with MTR's membranes, recovers gasoline vapors and returns them to the storage tank. Hydrocarbon emissions are reduced by 95% to 99%.
Air from the gas station dispenser is collected and sent to the gasoline storage tank. When the pressure in the tank reaches a preset value, a pressure switch activates a small compressor that draws off excess vapor-laden air. A portion of the hydrocarbon vapors condense and is returned to the tank as a liquid. The remaining hydrocarbons permeate the membrane and are returned to the tank as concentrated vapor. Air, stripped of 95% to 99% of the hydrocarbons, is vented. In addition to eliminating hydrocarbon emissions, the unit pays for itself with the value of the recovered gasoline.
