Technique aims to reduce the cost of biofuel production

Lignin, which protects plant cell walls, is difficult to break down or remove from plant materials called biomass, such as the non-edible parts of the corn plant. However, lignin needs to be extracted in order to reach the energy-rich cellulose that is used to make biofuels.

‘Finding inexpensive ways to remove lignin is one of the largest barriers to producing cost-effective biofuels… And our approach is very promising’ said Ezinne Achinivu, a Ph.D. student in chemical and biomolecular engineering at NC State and lead author of a study describing the new technique.

According to NCSU, the researchers began by making a number of liquid salts called protic ionic liquids (PILs). PILs are fairly inexpensive to prepare, because they are made by mixing together an acid, such as acetic acid, and a base. As part of the pre-treatment process, one of the PILs is mixed with biomass and then heated and stirred. The lignin dissolves into the PIL, leaving the cellulose behind as a solid. The cellulose, which is now much easier to process, is then easily filtered from the mixture for use in the next biofuel production steps.