The pyrolysis products divided into a volatile fraction, consisting of gases, vapors and tar components and a carbon rich solid residue. The pyrolysis process consists of a very complex set of reactions involving the formation of radicals. The gasification of biomass is a thermal treatment, which results in a high production of gaseous products and small quantities or char and ash. Hydrogen is produced from solid wastes by pyrolysis. In this study, three different biomass samples were subjected to direct and catalytic pyrolysis to obtain hydrogen rich gaseous products at desired temperatures. The samples, both untreated and impregnated with catalyst, were pyrolysed at 775 K, 925 K, 975 K and 1025 K temperatures. The total volume and the yield of gas from both pyrolyses increase with increasing temperature. (C) 2002 Elsevier Science Ltd. All rights reserved.