degrade uselessly.
             In the Philippines, one factor limiting the efficient use of this energy resource is the lack of basic data. The thermal properties, nature of heat generation and the kinetics of the thermal decomposition of rice hulls are not yet fully defined and understood. Thus, this limitation has made design of thermochemical conversion equipment empirical and subject to guesswork. There are, however, researches about kinetic properties of rice hulls in other countries (Mansaray & Ghaly,1998; Teng, et al., 1998 &1997; Liou, et al., 1997 & 1996; Milosavljevic & Suuberg,1995).
             Pyrolysis as a processing technique for energy recovery of agricultural wastes has become important worldwide, not only as a source of alternative fuel but also as a means to dispose agricultural wastes in an environmentally accepted manner. The primary products of pyrolysis are solid (char), liquid, and gas. The ratio of the products of pyrolysis varies with the chemical composition of the biomass and the operating conditions at which pyrolysis takes place. These primary products can be used directly, or they may be subjected to further processing to give higher quality fuel. Pyrolyzed rice hulls are also suitable for the production of valuable materials such as Si3N4, SiCl4, SiO and Si.
             Rice hulls, like all biomass are composed of cellulose, hemicellulose and lignin (Antal, et al., 1995; Liou, et al., 1997). However, the actual composition is variable and changes with variety, climate, and geographic location of growth (Liou & Chang, 1997) The chemical complexity of the decomposition of rice hull as well as other biomass materials has made researchers very busy. Earlier studies on the thermal decomposition of the individual components of lignocellulosic materials (cellulose, hemicellulose, lignin) indicated that decomposition of hemicellulose starts first followed by cellulose and finally lignin (Ramiah, 1970; Shafizadeh & de Groot,1976). This tr...