Friday, May 25, 2007

Bio-Diesel...A Natural Alternative

In 2002, 15 million gallons of biodiesel was consumed in the United States (The American Soybean Association)

The National Biodiesel Board, a trade association for biodiesel producers, is a good source of additional information

The primary advantages of biodiesel are:

1) It has natural lubricating properties and thus eliminates the need for synthetic lubricating additives in ultra low sulfur diesel fuels

2) It is essentially sulfur free and has a very high cetane number (a measure of diesel fuel quality).

The other process for producing biodiesel is through a conventional petroleum refining process known as hydroprocessing. In Europe, the largest producer and user of biodiesel, the fuel is usually made from rapeseed (canola) oil.

Recent environmental and economic concerns (Kyoto Protocol) have prompted resurgence in the use of biodiesel throughout the world. In 1991, the European Community, (EC) Proposed a 90% tax reduction for the use of biofuels, including biodiesel.

There have been reports that a diesel-biodiesel mix results in lower emissions than either can achieve alone. Biodiesel can be obtained from vegetable oil (vegidiesel / vegifuel), or animal fats (bio-lipids, using transesterification).

Biodiesel has a higher gel point than petrodiesel, but is comparable to diesel and is made by transforming animal fat or vegetable oil with alcohol and can be directly substituted for diesel either as neat fuel (B100) or as an oxygenate additive (typically 20%-B20).

Biodiesel produced by this method is sulfur free and has a high cetane number but it lacks the lubricating properties of FAME.

*What Is FAME?
(Fatty-Acid Methyl Ester). Fatty-acid alkyl esters are actually long chains of carbon molecules (12 to 22 carbons long) with an alcohol molecule attached to one end of the chain. In a process called transesterification, organically derived oils (vegetable oils, animal fats and recycled restaurant greases) are combined with alcohol (usually methanol) and chemically altered to form fatty esters such as methyl ester. The biomass-derived esters can be blended with conventional diesel fuel or used as a neat fuel (100% biodiesel).*

Biodiesel is the best greenhouse gas mitigation strategy for today’s medium and heavyduty vehicles, is completely renewable and burns much cleaner than petroleum diesel (plus the exhaust smells like french fries).

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