Application of response surface methodology to optimize and investigate the effects of operating conditions on the performance of DMFC

In this study, the response surface methodology (RSM) has been applied to optimize the operating conditions of direct methanol fuel cell (DMFC). A quadratic model was developed through RSM in terms of related independent variable to describe the current as the response. The input data required in this model has been obtained experimentally. For this purpose, an experimental set up for testing of direct methanol fuel cell has been established to investigate the effects of temperature and flow rate parameters on the cell performance. Two different analyses for operating conditions were performed applying the response surface method to obtain the maximum power. These analyses were based on the unlimited and minimum methanol consumptions. Methanol flow rate, oxygen flow rate, methanol temperature, humidification temperature and cell temperature were the main parameters considered that they were varied between 2 and 50 ml/min, 100–1000 ml/min, 30–70 °C, 30 70 °C and 30–80 °C in the analyses respectively. The maximum current under the unlimited and minimum methanol consumptions was found as 1230 mA and 582 mA based on the contour plots and variance analysis.

Research highlights
► For the operating condition under the unlimited methanol consumption, the maximum current was found as 1230 mA
► The excess of water on cathode side results in a reduction in the cell performance
► The high humidification temperatures in the cathode side of the cell which causes a decrease on the cell performance
► An increase in the cell performance is expected by increasing of the methanol flow rate
► The optimum operating conditions has a critical importance for the performance of fuel cell.