Unleashing Biomass Sugars Using Bromine Salt


Background: Methods to produce bioethanol from cornstarch or sugarcane are inadequate to meet the global demand for renewable fuels. To be sustainable biofuel production should rely on abundant cheap inedible lignocellulose – like switchgrass corn stover wheat straw wood chips and waste paper. However lignocellulose is a complex material made of cellulose wrapped by tough hemicellulose and lignin. For this reason lignocellulose is more difficult than starch to break down and convert (hydrolyze) into fermentable sugars. Harsh acids high temperatures or other chemical/mechanical pretreatments may be required before the raw biomass is suitable for hydrolysis with costly enzymes. Researchers have speculated that conversion of lignocellulose material has the potential to yield 25 to 50 billion gallons of ethanol per year. There remains a clear need for a cost-effective single-step hydrolysis process.Technology Description: UW–Madison researchers have developed a process for hydrolyzing lignocellulosic biomass in concentrated aqueous solutions of inorganic bromine salt with a small amount of acid. The process breaks down the lignocellulose material (corn stover saw dust hardwood softwood etc.) into fermentable sugars without pretreatment. The reaction works on the raw lignocellulosic biomass for 5-200 minutes at moderate temperatures hydrolyzing cellulose and hemicellulose and releasing monosaccharides for subsequent biofuel or chemical production. Lignin separates from the product sugars and can be filtered out for use in co-products. The bromine salt like LiBr or CaBr2 also can be recovered and reused. Applications: 1) Breaking down lignocellulosic biomass to sugars 2) Biofuel and chemical production


1) Single-step process 2) Mild conditions 3) Fast reaction 4) No pretreatment or enzymes 5) Easy implementation 6) Overall sugar yield (hexoses and pentoses) may be greater than 90 percent 7) The process results in limited sugar degradation or fermentation inhibitors like furans. 8) Salts can be recycled 9) Lignin can be recovered with high purity to make co-products

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