What is biodiesel?

Biodiesel is the name of a clean-burning alternative fuel produced from domestic,
renewable resources. It contains no petroleum but can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression ignition (diesel) engines with no major modifications. The fuel is simple to use, biodegradable, non-toxic, and essentially free of sulfur and aromatics.

Technical definition: Biodiesel, n—a fuel composed of mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats designated B100, and meeting the requirements of ASTM (American Society for Testing & Materials) D 6751.

Is biodiesel used as a pure fuel or is it blended with petroleum diesel?

Biodiesel can be used as a pure fuel or blended with petroleum in any percentage.
B20 (a blend of 20 percent biodiesel with 80 percent petroleum diesel) has demonstrated significant environmental benefits with a minimal increase in cost for fleet operations.

How do biodiesel emissions compare against petroleum diesel?

Biodiesel is the only alternative fuel to have fully completed the health effects testing requirements of the Clean Air Act. The use of biodiesel in a conventional diesel engine results in a substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter compared to emissions from diesel fuel.

In addition, the exhaust emissions of sulfur oxides and sulfates (major components of acid rain) from biodiesel are essentially eliminated compared to diesel.

Of the major exhaust pollutants, both unburned hydrocarbons and nitrogen oxides are ozone or smog forming precursors. The use of biodiesel results in a considerable reduction of unburned hydrocarbons. The emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle of the engine and testing methods used.

Based on engine testing, using the most stringent emissions testing protocols required by EPA for certification of fuels or fuel additives in the U.S., the overall ozone(smog) forming potential of the hydrocarbon exhaust emissions from biodiesel is nearly 50 percent less as compared to diesel fuel.

Can I use biodiesel in my existing diesel engine?

Biodiesel blends of up to 20 percent work in any diesel engine with no modifications to the engine or the fuel system. Biodiesel has a cleansing effect that may release deposits accumulated on tank walls and pipes from previous diesel fuel usage.

The release of deposits may end up in fuel filters initially, so fuel filters should be checked more frequently at first. It is important to ensure that the fuel meets the biodiesel specification (D6751).

Can biodiesel help mitigate ‘global warming’?

Biodiesel is the best greenhouse gas mitigation strategy for today’s medium and heavy-duty vehicles. A 1998 biodiesel lifecycle study, jointly sponsored by the US Department of Energy and the US Department of Agriculture, concluded that biodiesel reduces net carbon dioxide emissions by up to 78 percent as compared to petroleum diesel. This is due to biodiesel’s closed carbon cycle.

The CO2 released into the atmosphere when biodiesel is burned is recycled by growing plants, which are later processed into fuel.

Does biodiesel consume more energy to manufacture than it gives back?

No. Biodiesel has one of the highest “energy balance” of any liquid fuel. For every unit of fossil energy, it takes to make biodiesel, 5.5 units of energy is gained. This takes into account the planting, harvesting, fuel production and fuel transportation to the end-user.

Is biodiesel better for human health than petroleum diesel?

Scientific research confirms that biodiesel exhaust has a less harmful impact on human health than petroleum diesel fuel. Pure biodiesel emissions have decreased levels of polycyclic aromatic hydrocarbons (PAH) and nitrated PAH compounds that have been identified as potential cancer-causing compounds. Also, particulate matter, an emission linked to asthma and other diseases, is reduced by about 47 percent, and carbon monoxide, a poisonous gas, is reduced by about 48 percent.

Do I need special storage facilities?

In general, the standard storage and handling procedures used for petroleum diesel can be used for biodiesel. The fuel should be stored in a clean, dry, dark environment. Acceptable storage tank materials include aluminum, steel, fluorinated polyethylene,

fluorinated polypropylene and teflon. Copper, brass, lead, tin, and zinc should be