Oxygen-enriched air gasification of biomass materials for high-quality syngas production

The oxygen-enriched gasification of five biomasses (pine sawdust, rice husk, corn core, legume straw and wood chips) for high-quality gas production was studied using Aspen Plus software. At first, in order to ensure the model accuracy, the simulation results performed at different temperatures were compared with the experimental data, and a good agreement was obtained. The performance of the process was evaluated based on the yield of producer gas, lower heating value of the fuel gas (LHVFG) and the tar yield. The simulation results indicated that temperature was the most important parameter in the process; higher temperature contributed to higher gas production and lower tar yield. The gas yield also increased with the increase of equivalence ratio (ER), while the LHVFG and tar yield significantly reduced. Results also showed that the use of oxygen-enriched air was more favorable for gas quality and tar cracking; however, it lowered the gas yield. As ER increased from 0.19 to 0.27, the tar yields decreased markedly which is attributed to the thermal conversion of volatiles with the rise of oxidant. As a result, gasification of all the biomasses was feasible; however, gasification of pine sawdust showed the highest gas yield and gas heating value. The lowest tar yield was obtained from gasification of rice husk.