Equipment Options for E85 Fueling Systems
The information below provides an overview of equipment options for E85 (85% ethanol, 15% gasoline) fueling systems. Also see a schematic of an E85 dispensing station and an E85 dispenser.
Storage Tanks
The June 2004 National Petroleum News article, "Making the Switch," quotes Charles Frey, Jr. of Highland Tank as stating, "As far as compatibility goes, there's nothing we're putting into a tank that's going to have a problem. An advantage is you're not going to get much water in the tank because ethanol absorbs a certain percentage of the water and provides a little bit of an improvement for fuel quality."
High-blend alcohol fuels, however, can have an impact on metals, namely aluminum, as well as certain grades of plastics and rubber. When purchasing any fueling system component, the project contractor should be made aware that E85 will be used.
Aboveground Storage
A variety of companies manufacture aboveground storage tanks (ASTs), and many indicate their products can be used to store E85. ASTs might be suitable for temporary sites or locations where excavating is costly or impossible owing to subsurface concerns. Local fueling equipment vendors and certified contractors will be aware if local ordinances restrict the use of ASTs.
Before selecting an AST, a fuel site manager will want to consider the fleet's present and future storage capacity. The per-gallon transportation and delivery charges for small fuel loads are more costly. Although larger capacities are available, ASTs are usually smaller than their underground counterparts. ASTs are often installed at capacities of 1,000 to 3,000 gallons. A site manager choosing to operate a smaller-volume AST or underground tank should consult with local fuel suppliers about the feasibility of delivering and off-loading smaller fuel volumes.
ASTs can be constructed of stainless steel, cold-finished steel, or fiberglass. The use of plated metal tanks is generally not recommended for use with high-blend alcohol fuels.
All ASTs must have a secondary containment area that prevents the release of fuel into the environment. State requirements might vary for ASTs of single- or double-wall construction. AST containment areas must be constructed of specific materials of specific permeability and be capable of containing specific volumes. If more than one fuel is stored within a containment area, the fuels must be compatible with each other.
Most AST operators are required to have equipment or procedures in place to prevent overfilling during fuel loading. Generally, tanks filled at more than 55 gallons per transfer must have one of the following overfill protection systems in place:
- High-level alarm
- Automatic shut-off
- Permanently mounted site gauge during fueling
- Manual "sticking" of the tank during fuel loading
Underground Storage
E85 can be used with double-walled, low-carbon, cold-finished steel underground storage tanks (USTs). Welded USTs are preferable, and all tanks should be corrosion protected in accordance with U.S. Environmental Protection Agency requirements. The use of plated metal tanks generally is not recommended for high-blend alcohol fuels.
Double-walled fiberglass USTs are the most common fiberglass variety, representing approximately 70% of all fiberglass tanks in service today. New fiberglass tanks are tested for 100% alcohol (ethanol and methanol) compatibility.
Double-walled and post-1992 single-walled fiberglass USTs can be used with E85 when approved by Underwriters Laboratories. The Fiberglass Tank and Pipe Institute and a paper, Underground Storage Tank Guide, published by Thompson's, might be of further assistance to fuel site managers requiring more detailed information.
Regulated USTs are required to have overfill protection to minimize and eliminate the chances of delivering more product to a tank than the capacity of the tank allows. There are three options for overfill protection to comply with state and federal requirements:
- Automatic shutoff device
- Overfill alarm
- Ball float valve
Overfill protection has been required for regulated USTs since December 22, 1998.
Turn-Key Applications
Vehicle fleet managers might be familiar with fuel providers that supply onsite fueling equipment as part of the contract for supplying fuel. These arrangements have been common with propane vehicle fleets and some fuel suppliers. As of 2008, no similar arrangements are known to be in operation between E85 suppliers and fleets. "Turn-key" E85 fueling systems, however, are now available for fleet applications.
Fleet operations with interest in turn-key aboveground storage and dispensing options are referred to the following companies:
- Clean Fuel USA of Georgetown, Texas
- Modern Welding Company of Owensboro, Kentucky