EVALUATING INTEGRATION OF BIOMASS GASIFICATION PROCESS WITH SOLID OXIDE FUEL CELL AND TORREFACTION PROCESS

Alibakhsh Kasaeian
2019 Journal of Thermal Engineering  
In the present study, the integration of a solid oxide fuel cell with the biomass gasification process in which the torrefied biomass produced in a torrefaction process is used as the feedstock has been investigated. This novel design gives the power generation system the advantage of eliminating the filtration of the fuel cell inlet gas. This is because of the absence of sulfur and its derivatives in the synthesized gas owing to the terrified biomass, as the feedstock of the gasification
more » ... gasification process. Moreover, the integration of the processes makes it possible to employ the heat recovery methods. Therefore, by using the high-grade thermal energies for preheating process flows, the presented design considers the maximum available heat recovery and minimum heat and mass losses. The optimum design is determined by the sensitivity analysis and then simulated using the ASPEN PLUS software and its performance has been studied. It was specified that in the optimum operation state, the gasifier outlet temperature and pressure are 950 °C and 5 bar, respectively. Also, the oxygen flow rate in the anode of SOFC and the combustion chamber are 3.03 and 0.81 kmol/h, respectively. Moreover, the results showed that the presented design causes an improvement in the performance of the fuel cell. The electrical efficiency and the overall efficiency of the system are determined to be in the range of 63-69% and 80-85%, respectively. Also, it was revealed that the presented design has the power generation capacity of 100 to 997 kW. CONCLUSION In this paper, an integration of a solid oxide fuel cell with a biomass gasifier (BGFC) is presented and simulated to investigate its performance. The feedstock biomass is taken from the outlet of a torrefaction process and according to the absence of sulfur derivatives, there is no need for any filtration or purification process to be done on the biomass. The results indicated that the upgraded biomass would improve the performance of the whole BGFC system. The integration of the different operation units is based on the maximum achievable heat recovery to reduce the heat losses of the system. With this regard, the optimum system design is determined and is simulated using the ASPEN Plus software. The main findings of this research can be summarized as followings: The optimum design parameters: • The gasifier outlet temperature: 950 °C • The gasifier pressure: 5 bar • The SOFC anode inlet Oxygen flow rate: 3.03 kmol/h • The tar combustion chamber Oxygen flow rate: 0.81 kmol/h
doi:10.18186/thermal.654637 fatcat:mw47bdg67nfzlj4uxxk3uxtd2y