Crop Biotech Update

Scientists Reveal How to Convert Sugar Directly to Biodiesel

November 21, 2012

Researchers from the University of California-Berkeley were able to produce diesel fuel from products of a bacterial fermentation discovered nearly 100 years ago. The retooled process produces a mix of products that contain more energy per gallon than ethanol that is used today in transportation fuels and could be commercialized within five to ten years. According to the project scientists, the process would drastically reduce greenhouse gas emissions from transportation, one of the major contributors to global climate change.

From the fermentation process that employs the bacterium Clostridium acetobutylicum to ferment sugars into acetone, butanol and ethanol, scientists developed a way of extracting the acetone and butanol from the fermentation mixture while leaving most of the ethanol behind. They also developed a catalyst that converted the ideally-proportioned brew into a mix of long-chain hydrocarbons that resembles the combination of hydrocarbons in diesel fuel. Tests showed that it burned almost as well as normal petroleum-based diesel fuel.

The process is versatile enough to use a broad range of renewable starting materials, from corn sugar (glucose) and cane sugar (sucrose) to starch, and would work with non-food feedstocks such as grass, trees or field waste in cellulosic processes.

View UC Berkeley's news release at