Most chemicals manufactured in the United States fifty years ago were made from lignocellulosic (e.g., biomass) materials. Then, the advent of cheap petroleum encouraged technological developments in chemical production. New feedstocks, processes, and products replaced biomass as the major chemical building block. However, recent increases in petroleum and natural-gas prices justify a reexamination of lignocellulosic materials as potential chemical feedstocks. This report represents a first step in evaluating biomass as a potential substitute in petrochemical feedstock markets • Goldstein 0979; 1980) has identified three possible mechanisms for biomass substitution in petrochemical markets. The first of these alternatives involves the direct use of natural polymers and fibers rather than synthetic varieties. The second method of substitution involves the use of alternative feedstocks to produce the identical chemicals for their current final uses. The third method involves development of natural products to replace some of the intermediate products currently used in petrochemical markets • Intermediate products do not necessarily have to be identical to their potential substitutes. In addition, once the competitiveness of the intermediate product is determined, the relative competitiveness of its derivatives with petroleum products can also be ascertained • Goldstein has also noted that "there is no technical barrier to the production of almost all petrochemicals, whether oxygenated aliphatics, aromatics, hydrocarbons, or chlorinated compounds, from biomass" (1980, p. 26). Given the technical feasibility of deriving most chemicals from biomass, the focus of petrochemical studies at the Solar Energy Research Institute (SERI) has been to identify high potential markets for biomass chemicals given current (albeit ancient for the chemical industry-50 years or more in some cases) technology and average prices for petroleum and natural gas feedstocks • Even if all petrochemicals were obtained from biomass, the total reduction in U.S. energy would be small. Petrochemicals are much more important than their aggregate Btu content suggests, because: