Venting of Underground Storage Tanks Containing Ethanol-Gasoline Blends

Vapors produced during the process of refueling cars are a significant source of Volatile Organic Compounds (VOCs) emissions. Uncontrolled emissions cause economic losses and pollute the environment. This problem is exacerbated when the gasoline contains bioethanol because its presence increases the vapor pressure and volatility of the fuel. These increased fuel emissions from ethanol-gasoline blends may lead to limitations on the use of E10 or E15 or higher ethanol blends. If a successful technology is developed and applied to all U.S. fuel stations for solving the VOC emissions problem, 200 million gallons per year of E10 or E15 fuel (containing 10 or 15% ethanol) can be recovered. This is both an energy savings and an emissions reduction of equal magnitude. Working with industrial partners a novel membrane system has been developed for venting biofuel storage tanks. This system reduces ethanol-gasoline VOC emissions by more than 95% and recovers more than 95% of fuel vapors. Therefore, the technical and economic feasibility of the novel membrane system for venting ethanol-gasoline storage tanks during car refueling was demonstrated. Preliminary analyses show that such a system pays for itself in 2 to 2.4 years when installed in a typical fuel station that dispenses 213,000 gal/month. The proposed work plan for Phase II consists of scaling-up the membrane venting system, optimizing it and running a pilot and long-term tests. While the initial focus of this program is VOC abatement associated with biofuel storage tanks, we believe there are many other applications as well. A market research study by BCC (Business Communications Company) has identified potential VOC reduction opportunities in the pharmaceutical industry, cement industry, the power industry, surface coating industry, waste water industry, and semiconductor industry.