WEST LAFAYETTE, Ind. - Tiny pores within plant cells may hold promise for green fuels.
Researchers have discovered that particles from cornstalks undergo previously unknown structural changes when processed to produce ethanol, an insight they said will help establish a viable method for large-scale production of ethanol from plant matter.
Their research demonstrates that pretreating corn plant tissue with hot water - an accepted practice that increases ethanol yields 3 to 4 times - works by exposing minute pores of the plant's cell walls, thus increasing surface area for additional reactions that help break down the cell wall.
"This brings together the tools that link the processing technology to the plant tissue physiology," said Nathan Mosier, an assistant professor of agricultural and biological engineering at Purdue University. "It helps us understand, on a fundamental level, what the processing is doing and how we can improve it."
Mosier said that research, further described in a study published Thursday (April 26) in the journal Biotechnology and Bioengineering, applies to cellulosic ethanol, or ethanol produced from cellulose, which is a key component of plant's cell walls.
Using high-resolution imaging and chemical analyses, the researchers determined that pretreatment opens reactive areas within the cells of the corn stover - another name for postharvest corn remnants, like leaves and stalks - that were previously overlooked. In the next step of processing, these enlarged pores are more easily attacked by enzymes that convert cellulose into glucose, which is in turn fermented into ethanol by yeast, Mosier said.
Producing ethanol from cellulose would be advantageous over existing industrial processes in several ways, said Michael Ladisch, the study's co-author and a professor of agricultural and biological engineering.