It has been estimated that over 8 billion US gallons (30.3 billion liters) of used motor oil are produced every year by the world's cars and trucks. While some of that is re-refined into new oil or burned in furnaces for heat, neither of those processes are entirely environmentally-innocuous. In other cases, it is simply discarded. Today, however, researchers from the University of Cambridge announced the development of a process that uses microwaves to convert waste oil into vehicle fuel.
Scientists have already been using a process known as pyrolysis for recycling oil. It involves heating the oil to a high temperature in the absence of oxygen, and causes the oil to break down into a mixture of gases, liquids, and solids. While the gases and liquids can be converted to fuel, the Cambridge scientists state that traditional pyrolysis doesn't heat the oil very evenly, making the fuel conversion process difficult and impractical.
What they did, however, was to add a microwave-absorbent material to samples of waste oil, before subjecting it to pyrolysis by heating it with microwaves. The addition of the material caused the oil to heat more evenly, allowing almost 90 percent of it to easily be converted into a mixture of conventional gasoline and diesel.
Study leader Howard Chase, a professor of Biochemical Engineering, believes that their unique brand of pyrolysis shows great potential for being scaled up to the commercial level.
The research was presented today in Anaheim, California, at the 241st National Meeting & Exposition of the American Chemical Society.