Researchers at Oak Ridge National Laboratory, Oak Ridge, Tenn., have developed a series of solid acid nanocatalysts that promise to avoid some post-reaction steps in the production of biodiesel. The catalytic transesterification of vegetable oils or animal fats is central to the production of biodiesel, which is attracting increasing interest (see "Chemical industry sees green").
Conventional processes yield a biodiesel that contains some catalyst, which could corrode engines. Removal of the catalyst adds several steps such as neutralization and washing to the production process, consumes chemicals, water and energy, and invariably leads to some loss of biodiesel.
The new sulfonated mesoporous carbon-based heterogeneous catalysts can be fixed inside a column, retained and reused, notes Oak Ridges Chengdu Liang. They boast pore sizes of five to 10 nanometers to provide improved catalytic performance, and an average surface area of 400 m2/g, which is about 20 times higher than that of other heterogeneous catalysts, he adds.