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
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