SYNGAS PROPERTIES FROM GASIFICATION OF BIOMASS AND MUNICIPAL SOLID WASTE BLENDS IN CFB REACTOR

Resumo

This work evaluates the properties of the syngas obtained from simulations of gasification of Brazilian biomass and typical municipal solid waste blends with steam in circulating fluidized bed (CFB) reactor. A gasification model, based on the Gibbs free energy minimization concept and kinetics considerations was used to simulate the effect of the equivalence ratio and the steam/fuel ratio on the yield of CO, CH4 and H2, and the gasification performance. The modified equilibrium model took into account semi-empirical correlations found in literature for correcting both the methane and the carbon conversion during the pyrolysis and gasification processes. The energy balance in the system for equivalence ratios varying between 0.22 and 0.54 was considered to calculate the mean equilibrium temperature inside the reactor. The EES® software was used to solve the equations of the model. Results show that the gasification of the blends with steam injection leads to important changes related to both the syngas properties and the gasification performance. Comparisons with experimental data provided by other authors suggest that a kinetically modified equilibrium model based on the Gibbs free energy minimization can help to find out optimal operating conditions of CFB gasifiers