Researchers Find Economical Way to Remove Lignin from Biomass

Researchers at North Carolina State University have found a simple, effective and cheaper way to remove lignin from the plant biomass used to make biofuels, which may lead to more efficient and commercially viable biofuel production. The work was recently published in the journal Green Chemistry.

The tough lignin polymer needs to be removed from the plant biomass to access the energy-rich cellulose that must be degraded into fermentable sugars used to make bioethanol. The process of removing lignin is costly and represents a major economic barrier in commercial biofuel production.

The NCSU research team used protic ionic liquids (PILs) to dissolve lignin, separating it from cellulose. The PILs are essentially composed of an acid and a base. The resulting PIL-lignin mixture can then be heated to vaporize the PIL, leaving the lignin behind as a black powder. The vapors are collected and cooled to recover the PIL so that it can be re-used. The recovered lignin can be used to make polymers or other chemical products which could supplement the cost of running the biofuel production facility.