Breaking down lignin from plant materials called biomass, such as the non-edible parts of the corn plant, is a tough process; however, it needs to be extracted to obtain energy-rich cellulose that is used to make biofuels.
Lignin can be used to manufacture polymers or other chemical products.
NC State chemical and biomolecular engineering student and lead of the study said Ezinne Achinivu, "Finding inexpensive ways to remove lignin is one of the largest barriers to producing cost-effective biofuels."
Researchers prepared liquid salts called ‘protic ionic liquids,’ one of whihc is mixed with biomass and then heated and stirred. The lignin dissolves into the PIL and the cellulose remains as a solid.
The cellulose is then filtered from the mixture for use in the next biofuel production steps, while remaining PIL-lignin liquid mixture can then be heated to distill the PIL and leaving the lignin as a black powder.
Achinivu said, "This PIL-based technique can be easily scaled up and is likely to be both more energy efficient and less expensive than existing biomass pretreatment techniques for removing lignin."
Currently, the researchers are working to apply the technique to wood and other biomass feedstock materials as well as interactions between the PILs and lignin.
"If we can better understand how the PIL dissolves the lignin, we can make the process even more efficient by using less energy while extracting more lignin," Achinivu added
