Actually vegetable oil is not a power source for all automotive vehicles, only those that operate on diesel fuel. Vegetable oil can be used directly in today's diesel engine with relatively simple modifications. The first application of vegetable oil (termed straight vegetable oil - SVO) was by Rudolph Diesel who used peanut oil to demonstrate his engine at the Exhibition Fair in Paris, France in 1898. This engine was fueled by peanut oil - the "original" biodiesel fuel and Diesel envisioned the utilization of a biomass fuel as the real future of his engine. As a result of Diesel's vision, compression ignited engines were powered by a biomass fuel, vegetable oil, until the 1920's and are being powered again, today, by biodiesel, most frequently with a mixture of biodiesel and fossil diesel rather than biodiesel only.

What is the difference between biodiesel and Straight Vegetable Oil (SVO)?

Both SVO and biodiesel are based on vegetable oil, which leads to some confusion about the two. The difference is that biodiesel fuel has been modified from vegetable oil (either virgin or waste vegetable oil) to meet the fuel standards for the modern diesel engine. The name of biodiesel was introduced by the National Biodiesel Board in 1992. Transesterification, is a common process to convert biodiesel from vegetable oil.

How does one modify a vehicle to run on vegetable oil?

Because viscosity (a measure of "flowability") of vegetable oil is as much as 10-20 times higher than fossil diesel over a range of vehicle operating temperatures, there is a need to heat the vegetable oil to bring viscosity within a satisfactory operating range. One starts the engine with diesel and when the temperature has been adequately increased you can switch to vegetable oil until switching back to diesel at the end of the trip to purge the fuel line and injectors with diesel fuel. This is most simply done by the installation of a second fuel tank for the vegetable oil; adding tubing to create a heat exchanger to heat the vegetable oil in the fuel tank by a line to circulate warm fluid from the radiator; adding a heated vegetable oil fuel line and fuel filter; and adding an electric fuel switch (solenoid) to select between regular diesel and vegetable oil. More details are available from an Ithaca area firm (www.liqiudsolar.org) that does diesel engine conversions or helps interested persons to do conversions with kits that are available.

What are sources of vegetable oil?

The primary sources of waste vegetable oil for fuel are from restaurants after use as a cooking oil, and vegetable oil that is processed from oil crops such as soybeans, peanuts, canola and sunflowers. It is particularly appealing to use waste vegetable oil because it uses a recovered waste product that can be a problem for disposal. Thus, collection and filtering (removal of particles from cooking) of waste vegetable oil is an excellent example of recycling a material and turning it into a useful fuel to cope with our growing liquid fuel issues. However, you may not go unnoticed by persons who follow your vehicle because of a characteristic odor from the tail pipe such as French fries!