Biodiesel was not available from local distributors—and hauling blended fuel over 200 miles was not cost effective. With the help of a petroleum equipment contractor, a system was designed to store petroleum diesel and 100% biodiesel in separate tanks capable of receiving transport loads, thus enabling sourcing each commodity from the most economical source. Diesel is available from nearby pipelines, while the nearest biodiesel producers are both 200 miles away (biodiesel cannot be transported by pipeline). The biodiesel storage tank is insulated and equipped with an electric heater to prevent gelling in winter. Once blended with petroleum diesel and winter additives, flow properties are consistent with petroleum diesel.
late matter (smoke). Higher blends improve results, though not proportionally. B100 produced from animal fats has been less expensive than soy-based products in recent months and warm weather results have been good. Cold flow problems have been experienced with fat-based products. It is recommended that all fat-based biodiesel be consumed and replaced with soybased products prior to onset of cold weather. Biodiesel is a solvent that quickly cleans sludge deposits from tanks and lines. Starting with new, clean storage tanks and piping eliminated the need for cleaning. Fayetteville instituted a very proactive vehicle fuel filter change regimen and has had no fuel- or filter-related downtime. Following two months of biodiesel operation, the normal filter change interval was resumed.
Project cost Total project cost was only $47,000 for biodiesel storage and related dispensing equipment. Funds were advanced from the Fleet Fund and will be recovered in approximately seven years from fuel markup charges.
Fuel is blended inside the dispenser to the ratio programmed by management. Blend dispensers for multiple gasoline grades are common, but GPM capacity is not adequate for fueling large trucks. A gasoline dispenser was specially modified by the manufacturer to handle increased volume and withstand solvent properties of diesel and biodiesel. To our knowledge, this is the first biodiesel dispenser in the U.S. capable of blend-at-the-dispenser. Ratio can be changed by management at any time independent of tank inventory. Audit data shows 20% blend ratio with less than one-half percent variation.
Accounting and billing is controlled by an automated fuel management system that uses a magnetic key system with approximately 100 on-road vehicles currently equipped with automatic fuel filler interface that totally eliminates operator data input to the fuel The fuel island biodiesel blending and maintenance manage- dispenser ment systems. All on-road fleet acquisitions are equipped with the automatic fuel interface when introduced to the fleet.
Implementation
Why use biodiesel (benefits)
Fayetteville opened their new fuel facility in June 2007 and began pumping a B-20 blend into all diesel-powered equipment—280 units, slightly over half of the fleet, and representing two-thirds of the total fuel use. Seventy thousand gallons of petroleum fuel annually are replaced with renewable biodiesel, initially saving 2.5 cents per gallon of B-20 vs. petroleum diesel. Current pricing as of June 2009 was fluctuating around break-even. If biodiesel pricing is lower or does not exceed petroleum diesel in the summer, the ratio can easily be increased to a B-50 blend to further reduce petroleum consumption. Twenty percent ASTM certified biodiesel provides substantial emission reductions—20% unburned hydrocarbons, 12% carbon monoxide, and 12% in particu-
Substantial Emissions Reduction Unburned Hydrocarbons -20% Carbon Monoxide -12% -12% Particulate Matter
The main City of Fayetteville fuel island
Blend dispenser
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APWA Reporter
August 2009
Reduced Petroleum Dependence Annual petroleum reduction using B-20 70,000 gallons Annual reduction using B-20 winter, B-50 Summer 105,000 gallons Reduced Fuel Cost Annual savings using B-20 Return on investment
$8,400 5.6 years