A kinetic approach to catalytic pyrolysis of tars

A kinetic model to describe the catalytic pyrolysis of tars is proposed and validated through the experimental pyrolysis of three tars of different ch aracteristics and origin; calcined limestone (11 m(2)/g) was used as cataly st. Experiments were carried out in a catalytic fixed bed reactor. The mode l assumes that tars are composed of two pseudo-components, described as hea vy and light tars, which can be experimentally determined by a split temper ature. Tar pyrolysis is described by two simultaneous chemical reactions; c atalyst deactivation due to carbon deposition is also considered. Expressio ns for product concentrations as functions of residence time, selectivity a nd deactivation were obtained and the kinetic parameters evaluated. (C) 200 1 Elsevier Science B.V. All rights reserved.