Abstract

The article presents and overview of selected physical and chemical issues relating to biomass gasification. It also includes the history of the development of thermal wood treatment technology, with particular attention paid to Polish threads. Basic physical and chemical properties of biomass are discussed, using wood and straw as representative examples. Main types of gravitational gasifying reactors are presented, along with the analysis of basic mechanisms of homogeneous and heterogeneous chemical reactions in the reactor bed. The equation of motion of bed particles is derived based on particle volume changes caused by pyrolysis and surface reactions.