Vapor Controls for Vehicle Tank Refueling at Retail Gasoline Service Stations

摘要

Retail gasoline service stations constitute a large source of uncontrolled VOC emissions. Emission sources include underground storage tank filling and breathing losses, spills, and vehicle tank refueling losses. Current VOC regulations for nonattainment areas require the control of VOC losses from underground storage tank filling, commonly called Stage I controls. In areas where this level of control does not clearly demonstrate attainment will be achieved, additional VOC regulations may be required. The VOC losses from vehicle tank refueling at retail gasoline service stations, can be controlled. Known as Stage II controls, vapor-balance, vapor-aspirator, or vacuum-assisted systems can be used. Field tests demonstrate that efficiencies are 95+% for vapor-balance system, 96% for vapor aspirator, and 97+% for vacuum-assisted system. The vapor recovered is equal to the vapor controlled with the vapor-balance and vapor-aspirator systems, whereas only half of the vapor controlled by a vacuum-assisted system is recovered, as part of this stream is incinerated. Economic analyses of the three systems show the vapor-balance system to be the most affordable. Its addition to retail stations would add an average of 0.2 cent per gallon to the cost of gasoline (in Sept., 1982, dollars.)