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Biomass and Conversion Technologies Hydrolysis |
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Hydrolysis is a chemical decomposition process that uses water to split chemical bonds of substances. There are two types of hydrolysis, acid and enzymatic. Feedstocks that may be appropriate for acid or enzymatic hydrolysis typically are plant-based materials containing cellulose. These include forest material and sawmill residue, agricultural residue, urban waste, and waste paper. All plants have structural components composed of lignocellulosic fibers, which in turn are comprised of three major fractions: cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are chains of sugar molecules that can be broken down chemically or biologically into the component sugars. The sugars are then fermented using yeast or bacteria to produce ethanol, which is then distilled to a higher concentration for final use. Sugars can also be converted to levulinic acid and citric acid. Levulinic acid is a versatile chemical that is a precursor to other specialty chemicals, fuels and fuels additives, herbicides, and pesticides. The largest application for citric acid is in the beverage industry, which accounts for about 45 percent of the market for this product. Citric acid is also used in a wide variety of candies, frozen foods, and processed cheeses and as a preservative in canned goods, meats, jellies, and preserves. Lignin binds cellulose and hemicellulose together and cannot be broken down to form sugars. At this point, the most cost-effective use for lignins is as a fuel for biomass-to-energy facilities. |
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Last updated: April 01, 2008 Conversion Technologies http://www.ciwmb.ca.gov/Organics/Conversion/ Jacques Franco: JFranco@ciwmb.ca.gov (916) 341-6608 |