BIOREFINING
In addition to the fuel potential of biofuels, the natural development of the constituents of plant structure has yielded a rich variety of complex organic molecules that can serve as feedstocks for bulk chemicals. The 5- and 6-carbon carbohydrate backbone of hemicelluloses and cellulose can be gasified or pyrolyzed to yield syngas. Alternatively, the cellulosic materials can be pretreated to liberate the individual sugars, which can then be chemically or biologically transformed into commodities or building blocks for other value-added chemicals. 
Lignin presents a special case as a complex aromatic polymer. While empirically this material has been burned for its heat value, or transformed to lignosulfonate in commercial operations, capturing additional value in the form of coproducts has been and remains a distinct possibility. Hazen runs a number of analytical methods to determine the potential value of the lignin component of biomass. The ability to develop coproducts through the utilization of the lignin-derived phenylpropenyl units in plant feedstocks has a great impact on the economics of biofuel and biochemical production.