17/11/05 (soyatech.com) - New York Times Full Feed via NewsEdge Corporation : Biodiesel fuel -- soybean or other oil that has been converted for use in diesel engines -- is slowly catching on in the United States. The National Biodiesel Board, an industry group, estimates that some 75 million gallons will be produced this year, triple the production in 2004.
The fuel is most commonly mixed with petroleum-based diesel to make a cleaner-burning blend. Although biodiesel is more environmentally friendly than fossil fuels, its production -- a process called transesterification -- has some drawbacks. Either a strong base or acid is used as a catalyst, and if that acid or base is liquid, it must be separated from the biodiesel at the end, which can be a wasteful process. So chemical engineers have searched for solid, insoluble catalysts that will be far simpler to separate.
Scientists from the Tokyo Institute of Technology and other Japanese institutions have come up with one that is easy and relatively inexpensive to make. It is essentially a solid acid, made by charring sugars, starches or other organic material and treating them with sulfuric acid.
The result, the researchers report in the journal Nature, is a matrix of ringed carbon molecules dotted with active sites where the transesterification reactions take place. The material, a black powder that can be molded into films or pellets, is not as efficient a catalyst as liquid sulfuric acid, but it is more effective than other solid biodiesel catalysts.