Experimental investigation on a novel empirical parameter for simultaneous analysis of the temperature and concentration effects on fuel utilization coefficient of direct ethanol fuel cell

In this study, a DEFC with an anion-exchange membrane is investigated to evaluate fuel utilization both theoretically and experimentally. The effects of variations in the input fuel temperature and fuel concentration on fuel utilization and power density were analyzed through sensitivity analysis. To this end, for different test conditions containing initial conditions, increasing the input fuel temperature and oxygen blowing to the cathode with fuel circulation, ethanol utilization factor and maximum power density were calculated. The findings revealed increasing the fuel temperature and oxygen blowing led to an increase in the ethanol utilization factor from 66.92% to 85.15% and 73.54%. Moreover, maximum power density was increased from 16.2 to 17.5 and 22.5 mWcm−2 for increasing the fuel temperature and oxygen blowing states. According to the results, it was proved that increasing the input fuel temperature and oxygen-blowing conditions had a contradictory impact on the performance analysis. As a solution, a new parameter named δ is introduced to conduct a more accurate performance analysis of DEFC. This parameter indicates the amount of produced power per unit of fuel consumption. The results demonstrated that parameter δ was increased from 0.14 to 0.21 and 0.31 mWcm−2 for increasing the fuel temperature and oxygen blowing states.