Methanol can be used as one possible replacement for conventional gasoline and Diesel fuel. Thermal depolymerization and decomposition of biomass, including cellulose, hemicelluloses and lignin, formed liquid and gaseous products as well as a solid residue of charcoal. A promising route for processing biomass is pyrolytic conversion, which has been conducted under a variety of experimental conditions, resulting in producing charcoal, tarry material, an aqueous fraction and gaseous products. The pyroligneous acid consists of about 50% methanol, acetone, phenols and water. Methanol can be produced by pyrolysis of biomass. Methanol mainly arises from the methoxyl groups of uronic acid and from the breakdown of methyl esters and/or ethers from decomposition of pectin-like plant materials. Acetic acid mainly comes from the acetyl groups of the hemicelluloses. (C) 2001 Elsevier Science Ltd. All rights reserved.