In order to reduce the ethanol production cost from lignocellulosic materials, it is imperative to expand or develop the market for the process coproducts, by-products, or derivatives. Unlike the mature corn ethanol industry, the by­product (or coproduct) industry for the lignocellulosic ethanol industry is not very well defined or established yet. Potential coproducts include hemicel — lulose hydrolyzate (xylose), cellulose hydrolyzate (glucose of mixed sugars), cell mass, enzymes, soluble and insoluble lignins, lignin-derived chemicals and fuels, solid residues, and so on. Other valuable products include xylitol, which is a sugar alcohol sweetener and is produced by hydrogenation of xylose (an aldehyde) into a primary alcohol.