Chemistry Details of Lignin-Hemicellulose Bonds

Lignin and hemicellulose are bound together by a variety of different chemical bonds. Some of these attachments are easy to break. Others are more difficult. The most stubborn attachments between lignin and hemicellulose belong to a type of chemical bonding called ether bonds. Right now, these bonds can only be broken with harsh chemicals at high temperatures and pressures. The need to break ether bonds between lignin and hemicellulose leads to most of the environmental damage and much of the chemical and energy cost of using biomass for biofuels or other processes. An enzymatic method to break ether bonds between lignin and hemicellulose will lead to a smaller environmental footprint by reducing the amount of polluting chemicals currently needed to delignify biomass. Further, an enzymatic method will reduce energy costs by decreasing the severity of the existing pretreatment process.