May 14, 2010
By Robert E. Thomas,
University of Missouri

At today’s prices, not taking steps to lessen evaporation can cost a farmer thousands of dollars a year.

With the high cost of biodiesel fuel, every gallon counts. Improper storage of biodiesel could mean thousands of dollars disappearing into thin air, warns a University of Missouri professor of agricultural systems management.

“Biodiesel blends, like petroleum diesel fuels, should be kept in a clean, dry, dark environment,” said Leon Schumacher. “As with any fuel, water must be prevented from entering the tank. Algae can also grow in biodiesel fuels just as it does in petroleum fuels.”

Clean, inspect and repair your tank before filling with biodiesel fuel. Have older tanks cleaned professionally to remove particles and deposits that might contaminate the fuel supply, he said.

A single 300-gallon tank of biodiesel blend can lose up to 120 gallons each year due to evaporation. At today’s prices, not taking steps to lessen evaporation can cost a farmer thousands of dollars a year.

Paint tanks white or aluminum to better reflect the sunlight. Place the tanks in an east-west orientation. Keep tanks shaded, if allowed under local building and fire codes. This is especially important for tanks and containers constructed from polyethylene or polypropylene, which should be protected from sunlight.

Pressure-relief vacuum caps rather than conventional gas caps also will help reduce evaporation.

Inspect tanks regularly for material decomposition. Some materials, including aluminum, tin and zinc, reduce the shelf life of biodiesel. Biodiesel will break down concrete, varnish and PVC tank linings, Schumacher said.

Pure biodiesel will readily dissolve rubber components in your tank’s plumbing. Low-biodiesel blends reduce degradation of rubber, but there has been little research on the long-term effects of low-biodiesel blends on rubber components, he said.

During inspections, tighten components between the storage tank outlet and the pump. Check valve packings and look for nozzle seepage.

Be especially careful about inspecting underground storage tanks. Leaks can contaminate groundwater.

http://extension.missouri.edu/news/DisplayStory.aspx?N=753