Kinetics, thermodynamics and synergistic effects analyses of petroleum coke and biomass wastes during H2O co-gasification

Abstract

In this study, the H2O co-gasification of petroleum coke (PC) with low (sulfur and V2O5 contents) and different five kinds of biomass wastes were conducted using a thermogravimetric analyzer (TGA). The biomass used were the agricultural wastes (rice husk (RH), rice stalk (RS), and cotton straw (CS)) and by-product wastes (sawdust (SD) and sugar cane bagasse (SCB)). Their reactivities, kinetics and thermodynamics parameters were investigated and compared in detail as well as a synergistic effect during co-gasification of the blends. The kinetics and thermodynamics parameters were estimated by using the homogeneous model (HM) or the first-order chemical reaction (O1) and shrinking core models (SCM) or Phase boundary controlled reactions (R2 and R3). It was found that the biomass wastes was significantly improved the blends gasification reactivity. The obvious significant synergistic effect was observed in the char gasification stage of the blends compared with the pyrolysis stage. Compared to other models the phase boundary controlled reaction (R2) was found to be the best model to predict the experimental data of the co-gasification process. For both reaction stages of single fuels, SD showed the lowest values of activation energy and thermodynamics parameters. The blends of PC: SD and PC: CS provided the lowest activation energy and thermodynamics parameters for the pyrolysis stage and the char gasification stage, respectively. The co-gasification of PC and biomass wastes are a promising technique for the efficient utilization of PC and biomass wastes.