Ethanol derived from biomass holds the potential for reducing demands for oil supplies, but supplies of the grain used in its production are limited and can compete for acreage used for food supplies. Replacing grain-derived ethanol has proven challenging, because of incompatible production processes, extensive capital expenditures, and high operation costs stemming from multistep procedures, complex chemistries, high temperature and pressure processing conditions, and energy-intensive operations. The Pacific Northwest National Laboratory has developed a simple, cost-effective method for developing transportation fuel precursors using lignocellulosic biomass, such as cellulose, hemicellulose, and lignin from plant-based materials including wood, grasses, stovers (e.g., corn), bagasse (e.g., sugarcane), straw, and some species of algae (e.g., filamentous algae).

PNNL’s patented process converts biomass to a transportation fuel precursor in a single step. Levulinic acid and/or gamma-valerolactone (or combinations thereof) is reacted in an aqueous feed containing a reducing agent over a catalyst that includes cerium or zirconia. This reaction takes place at ambient pressure and a temperature from 340 to 450 degrees Celsius. The process generates a diesel-like hydrocarbon mixture that has an organic oil phase with a boiling range similar to diesel fuel. The hydrocarbon mixture can be used to create diesel and aviation fuels.