Black locust trees evaluated in Illinois for biofuel potential

By Chris Hanson | June 19, 2013

The black locust tree, Robina pseudoacacia, is being evaluated by researchers at the Energy Biosciences Institute at the University of Illinois to determine its potential for biofuel production.

“For now the only thing you can do with it is use it for direct combustion, “said Gary Kling, associate professor of crop sciences at the university, “but if it becomes a major crop, other researchers could start working on the process of how to break it down.” He added the EBI is currently tasked with finding a process to break down woody biomass for alcohol to create a drop-in fuel.

Initial studies of black locust have shown promising results. Kling said the species have yielded more material than the next closest species by nearly three times and has a rapid growth rate compared to other woody biomass. In the spring of 2010, two-year-old seedlings were planted, grown and trimmed during the winters of 2011 and 2012. By trimming the tree, Kling explained, it allows the plant to regrow with multiple stems for frequent harvests.

“After that first coppicing in February 2012, and then after last year’s very early spring, the black locust was growing quite rapidly,” Kling said, “It was already a foot tall when we had a freeze in the middle of April, which froze them back to the ground. They began to regrow and put out new shoots in May. By the end of last season the plants were nearly equivalent to the first two years’ growth.”

Black locust production might have the potential as an energy crop for the Midwest, Kling indicated. He explained that land in northern and southern Illinois is subpar for corn and soybean production, but black locust may be grown in large quantities or as a minor crop.

In addition to studying the biofuel potential of black locust, EBI will also be evaluating other short-rotation woody biomass feedstocks that may grow in the Midwest.