Performance of a solid oxide fuel cell fueled by the exhaust gases of a diesel engine operating fuel-rich

Abstract

In pursuit of more efficient power generation, this study explores a novel hybrid system with a solid oxide fuel cell (SOFC) electrochemically generating electricity from the exhaust gases of a diesel engine operating fuel-rich. The investigation delves into the composition of exhaust gases using a chemical kinetics model, particularly focusing on H₂ and CO generated in the diesel engine at equivalence ratios ranging from 1.0 to 5.0. A model of the SOFC system predicts the highest electrical efficiency of 36.1 % occurs at an equivalence ratio of 2.8, considering 90 % fuel utilization and operating voltage of 0.7 V per SOFC. Notably the combined system’s efficiency exhibits a marked increase as equivalence ratio increases until 2.6, subsequently decreasing primarily due to the reduced concentration of H₂ at higher equivalence ratios. A comprehensive sensitivity analysis is conducted, emphasizing that higher fuel utilization in the SOFC results in higher combined efficiency of the hybrid system. This study also explores the potential of dual fuel combustion within the combined system, showcasing consistent efficiency improvements, especially near an equivalence ratio of 3.2 when utilizing H₂/diesel fuel blends.