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role in the conversion of biological raw materials into industrial products. Some processes have been proven and used in the past but are not in wide use today. Examples of thermal, mechanical, and chemical processes include liquefaction, destructive distillation to methanol, fast pyrolysis of wood, biomass desiccation, protein fractionation, and chemicals from pentose sugars (e.g., furfural).

Biological processes also show great potential. The fermentation industry currently produces alcohol, organic acids, polymers, antibiotics, enzymes, and amino acids. Advances are occurring in reactor design and the selection and genetic modification of microorganisms. Modern tools of molecular biology are being used to improve yield by increasing product concentration and minimizing undesired byproducts. The major U.S. effort to compete internationally in the amino acid industry provides an example of such advances. Poly(hydroxybutyrate), a biopolymer, is produced by microorganisms and is being introduced into high-value niche markets. Enzymes are being used, for example, in the corn-ethanol industry to convert starch to glucose. Possibly the greatest success to date of enzymatic processing is the use of immobilized glucose isomerase to produce high-fructose corn syrup as a sugar substitute.

The development of lignocellulose treatments will be key to unlocking a major sugar source for biological conversion into industrial products. A number of new potential technologies exist, such as clean fractionation, AFEX, liquid hot water, and perhaps others. For example, the high-fructose corn syrup industry has demonstrated that immobilized enzyme processing and chromatographic separation of biomass can be efficient and economical on a large scale. More research is needed, however, to demonstrate the commercial feasibility of these approaches and to identify new processes.

Other research challenges lie ahead in the development of processing technologies. Advances are needed in the engineering principles for fermentation operations. Biological and engineering approaches should be combined to improve product yield, selectivity, productivity, and product purification. Finally, expansion of our fundamental knowledge of microbial physiology, biochemistry, and genetics will be essential in the development of improved biological processes.

For large-scale biobased products, the dominant factors influencing market share will be the cost of the starting raw material and the cost of processing technology to convert the raw material to the desired biobased products. Further reductions in the price of the biobased raw materials will help process economics but not as much as will reducing the costs of processing technologies. Very low-cost processing technologies must be developed if biobased industrial products are to penetrate commodity markets.