RECONCILING KINETIC MODEL WITH REACTION RATE PROFILE FOR BIOMASS CHAR GASIFICATION

摘要

A good understanding of the char gasification kinetics is important in terms of gasifier design and operation. To date, a number of kinetic models have been proposed for describing the reactivity profiles of the char or carbon, i.e., variation in gasification rates with conversion. All of these models can be divided into either theoretical or semi-empirical group. The theoretical models consider the reactions progress based on either the first-order kinetics or the random overlapping of pores' surfaces during reaction, whereas the semi-empirical models describe experimental results in an acceptable way only. Generally, theoretical models can fit the experimental data well for the pure carbon, but fail to precisely describe the change in reaction rate with conversion for the chars containing catalytic metals.