by Bradley Wilson

Created on: July 30, 2009   Last Updated: August 01, 2009

What is biodiesel fuel and where can you buy it?

Diesel fuel is one of the most widely used fuels. It is in use worldwide to power a broad range of vehicles from private cars to industrial machinery and heavy transport. Commercial and military aircraft use a close cousin to diesel fuel to fuel their engines. Biodiesel is diesel, particularly to a diesel engine. There are some minor differences but it flows through and burns the same. The fundamental difference for humans is that biodiesel originates from a renewable resource, whereas petroleum diesel as we have known it is made from a scarce resource.

Made from vegetable oil or recycled cooking oil, biodiesel is the end product of a process called transesterification. Big word, simple process. A catalyst and alcohol are added to the oil and thoroughly mixed. The fats and impurities are chemically changed and drained off, leaving a combustible fuel usable in diesel engines. The original diesel engine was actually designed to run on peanut oil, so we really are coming full circle on the fuel for these engines.

The biodiesel resulting from this process performs very well. Minor differences in the energy content and ignition characteristics exist because the fuel is chemically different from regular diesel. On a molecular level, a slight gain in ignition offsets the lower energy content. On a practical level, the engines are more efficient in burning the fuel and produce much cleaner emissions due to higher oxygen content.

Because of the troublesome nature of diesel in cold climates, additives are usually blended with the fuel to reduce sensitivity to cold. Biodiesel is even more sensitive than regular diesel requiring either chemical additives or fuel heating systems to make the fuel continue to flow when the air is cold. The most effective way to use biodiesel in cold climates is to blend the biodiesel with regular petroleum diesel during the cold weather months in ratios of 5 to 20 percent.

Biodiesel can be hard on rubber components in the fuel delivery systems of older diesel engines, so rubber components require upgrading to newer biodiesel compatible materials. These modifications are minor, limited to replacement of rubber seals and hoses, making the transition to biodiesel for an older diesel engine simple.

In America, industrial scale production of biodiesel has mainly been from soybean oil. The soybean industry has been instrumental in its widespread use as feedstock. The biodiesel "feedstock of the future", the superstar of the renewable biofuel industry is algae. The great thing about algae-people don't generally eat algae, so its use as a fuel source won't adversely affect food markets, in America or worldwide.

Since biodiesel is a fairly recent player in the fuel market, distribution is less widespread than traditional diesel but it is available in almost every state in America. A simple to use tool is available at biodiesel.org to aid locating a biodiesel retailer near you or along your planned route. Visit www.biodiesel.org/buyingbiodiesel/retailfuelingsites / for specific locations.

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