Kinetics simulation study of biomass partial gasification for producer gas and biochar co-production in the fluidized bed

Producer gas and biochar are the main products of biomass partial gasification in the fluidized bed. In order to reasonably predict the producer gas, biochar and performance indexes of biomass partial gasification process in the fluidized bed, a kinetic model considering tar reaction kinetics and biochar elements distribution of biomass partial gasification for producer gas and biochar co-production in bubbling fluidized bed was established by using Aspen plus, and the model are validated with the relevant experimental data under different air equivalence ratios. At the same time, the energy balance in the pyrolysis stage, oxidation stage and reduction stage of biomass partial gasification process in the bubbling fluidized bed under different air equivalence ratios was evaluated. The results indicate that the prediction data of producer gas components, biochar yield, gasification efficiency and carbon conversion ratio are in good agreement with the experimental data, and the root-mean-square error are less than 0.05. With the increase of air equivalence ratio(from 0.07 to 0.16), the gasification temperature keeps rising(from 602 °C to 716 °C), the volume contents of CO, CO2 and CnHm keep decreasing, the volume contents of H2 and CH4 show an increasing-decreasing trend, and the volume content of N2 keeps increasing; biochar yield continues to decline, the carbon and oxygen content in biochar decrease continuously; gasification efficiency and carbon conversion ratio keep increasing; the heat absorbing from the oxidation stage of the pyrolysis stage and reduction stage are increasing, and the heat releasing in the oxidation stage is also increasing.