New SPORL Process Efficiently Converts Biomass to Sugars and Ferment
In general, softwoods are considered the most difficult biomass raw material for a biorefinery to convert to sugars and ferment. A process known as SPORL (sulfite pretreatment to overcome recalcitrance of lignocellulose) is uniquely efficient as a pretreatment for softwoods such as Douglas fir and is vital to the Northwest Advanced Renewables Alliance regional biomass project.
In September 2011, the U.S. Department of Agriculture announced that Washington State University would receive a 5-year, $40-million grant to help develop alternatives to petroleum-based fuels and chemicals. The Forest Products Laboratory received a $1.1-million subcontract to pretreat woody biomass for conversion to aviation fuel. The laboratory's part was to demonstrate the SPORL process for efficient sugar production from Douglas fir forest residue.
In the first year of the project, the scientists developed a fractionation technique to reduce the bark content of forest residues. The goal is to leave the bark in the forest for soil conditioning and nutrients. Improved bark removal also reduces the deadload in transportation and biorefinery processing. Preliminary laboratory evaluation has confirmed the high performance of the SPORL process for pretreatment of the Douglas fir, providing efficient enzyme conversion to sugars and high biofuel yield.
Forest Service Partners