UCR develops high-yield, one-step cellulosic Fractionation process
In California, researchers from the University of California, Riverside’s Bourns College of Engineering have developed a versatile, relatively non-toxic, and efficient way to convert raw agricultural and forestry residues and other plant matter, known as lignocellulosic biomass, into biofuels and chemicals.
The patent-pending method, called Co-solvent Enhanced Lignocellulosic Fractionation (CELF), brings researchers closer to solving the long elusive goal of producing fuels and chemicals from biomass at high enough yields and low enough costs to become a viable alternative or replacement for petroleum-based fuels and chemicals.
CELF is unique in that it can consolidate multiple processing steps – such as pretreatment, sugar hydrolysis, and sugar catalysis – into one step. This reduces the water content of the reaction to maximize the amount of actual solids that can be loaded and also conserve heat and energy.
The key to the UC Riverside technology is using tetrahydrofuran (THF) as a co-solvent to aid in the breakdown of raw biomass feedstocks to produce valuable primary and secondary fuel precursors at high yields at moderate temperatures. Those fuel precursors can then be converted into ethanol, chemicals or drop-in fuels. Drop-in fuels have similar properties to conventional gasoline, jet, and diesel fuels and can be used without significant changes to vehicles or current transportation infrastructure.
Compared to other available biomass solvents, THF is well-suited for this application because it mixes homogenously with water, has a low boiling point (66 degrees Celsius) to allow for easy recovery, and can be regenerated as an end product of the process. The process is also tunable so that different end products can be made by changing the configurations.
In a recently published paper in the journal Green Chemistry, the UC Riverside researchers showed that using CELF with highly selective acid catalysts called metal halides was particularly effective at simultaneously producing the fuel precursors furfural and 5-hydroxymethylfurfural (5-HMF) directly from raw maple wood. Furfural and 5-HMF are widely recognized renewable chemicals for their conversion into gasoline, jet, and diesel range liquid fuels. Furfural and 5-HMF further can be further chemo-catalytically upgraded to drop-in fuels including 2-methylfuran (MF) and 2,5- dimethylfuran (DMF).
Using the combination of CELF with iron chloride, a type of metal halide, to break down the maple wood, Cai and the research team obtained yields of 95 percent of the theoretical maximum for and 51 percent for 5-HMF in a single pot reaction. This presents an improvement in yield rates of almost 50 percent over current commercial technologies and can thereby potentially reduce the cost of furfural production to within the range of current price of crude oil.
Category: Fuels
