The alternative fuels that the SEAFTF is helping get into the mainstream are biodiesel, ethanol, natural gas and propane. These fuels have the greatest chance at beginning to make a serious dent in our transportation-based petroleum consumption.
Below is information on each of these alt fuels:
| > ||Biodiesel|
Biodiesel is a renewable fuel that is very similar to petroleum-based #2 diesel fuel. It is commonly made from vegetable oils (virgin and recycled/used) and animal fat, which are transesterified to create methyl esters, or biodiesel. The process to make biodiesel is fairly simple, mixing and heating methanol and the oil in the presence of a catalyst, then performing appropriate finished product cleansing to ensure a high-quality biodiesel.
Using biodiesel reduces most emissions including particulate matter, sulfur, hydrocarbons, carcinogenic compounds and air toxics. A very slight increase in nitrogen oxides is typically seen but "low-NOx" additives exist to reduce or reverse that increase. Biodiesel is less toxic than table salt, nonhazardous and biodegradable.
Biodiesel is typically blended with petro-diesel for use, however it can be used pure (as "B100"). A blend of 20% biodiesel in 80% petro-diesel (called "B20") is the most common blend used today in the United States. Biodiesel can be used in any diesel engine without modification or conversion when used in lower blends, like B20. If used at higher blends, B50 to B100, some work is necessary to "convert" the engine by replacing some materials that biodiesel may react with (i.e., natural rubbers, certain metals). Although notoxic and biodegradable, biodiesel is a solvent, and thus care must be taken when handling the fuel.
| > ||Ethanol|
Ethanol is a renewable fuel that is made from corn in the United States, although research is advancing to produce it from other cellulosic materials. Brought to the public's attention during the 1970's as the additive to make "gasahol" (10% ethanol and 90% gasoline) which would help us begin working toward greater independence from petroleum, ethanol has grown up since then and so have vehicles. Today, roughly 20 vehicles are sold on the market as "flex fuel," meaing that they can burn gasoline, E85 (85% ethanol in 15% gasoline) or any mixture of the two. Ford's Taurus and Explorer are just two examples of such vehicles.
Ethanol reduces all emissions at the tailpipe. And like biodiesel, using it supports the agricultural sector. Although it is not expected that ethanol could replace gasoline in fueling all our demands for it, studies show that there is significant opportunities for growing more fuel. Just one example includes the opportunity to find other crops that tobacco farmers could grow as national subsidies for tobacco begin to expire.
| > ||Natural gas|
Natural gas is considered the cleanest alternative fuel, with reductions across the board for emissions. Volatile organic compounds and sulfur are the emissions where the greatest reductions are seen (showing roughly 80% and 100% reductions respectively). Although a nonrenewable fuel, increasing the use of natural gas in the transportation sector would only make then approximately 5% of total natural gas consumption in the United States (that is, using natural gas in the transporation sector is not a main driver for natural gas demand in the U.S.).
| > ||Propane|
Propane is the most widely used alternative fuel in the world, and has held that title for many years. In some countries in Europe and the Far East, you can go into many automobile dealerships a choose whether you want the gas or propane version.
Propane is almost as clean as natural gas at the tailpipe, also showing its greatest reductions in VOCs and sulfur.