Kinetic Parameters and Reactivity for the Steam Gasification of Coal Chars Obtained under Different Pyrolysis Temperatures and Pressures

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Energy and Fuels, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/ef200411jThe effect of devolatilization conditions (pressure and temperature) on the steam gasification kinetics and reactivity of coal chars was investigated. For this purpose, five different rank coals were selected: a lignite (LT), two high-volatile bituminous coals (DT and SA), a low-volatile bituminous coal (DI), and a semianthracite (HV). The coal chars were obtained by devolatilization in a novel pressurized fixed-bed reactor at temperatures of 800, 900, and 1000 °C and pressures of 1, 5, 10, and 20 atm. The reactivity of the chars was studied by isothermal thermogravimetric analysis in a kinetically controlled regime at different temperatures under a steam atmosphere. The reactive behavior of the chars was evaluated by means of the random pore model (RPM), which satisfactorily described the steam gasification of the coal chars. The gasification apparent reaction rate increased as the devolatilization pressure increased, whereas this parameter decreased as the devolatilization temperature increased.M.V. Gil acknowledges funding from the CSIC JAE Program co-financed by the European Social Fund.Peer reviewe