Exergetic assessment of a hybrid steam biomass gasification and SOFC system for hydrogen, power, and heat production

Abstract

In this chapter, an integrated process of steam biomass gasification and a solid oxide fuel cell (SOFC) for multi-generation purposes (hydrogen, power, and heat) is thermodynamically studied, and its performance is assessed through exergy efficiency. The scheme combines SOFC at 1,000 K and 1.2 bar and a gasifier which is used to gasify saw dust with a steam–biomass ratio of 0.8 kmol/kmol and a gasification temperature range of 1,023–1,423 K at an atmospheric pressure. A parametric study is performed to assess exergetic efficiency and investigate the effect of various parameters related to the different system components such as airflow rate and preheating temperature on the efficiency. The results show that SOFC is a major source of the system destruction exergy. For the gasification temperature range studied here, the system exergetic efficiency increases with hydrogen yield from about 22 to 32 % and the overall exergy efficiency, which considers electricity production, decreases from 57.5 to 51 %, respectively.