Study on the Performance of the Micro Direct Ethanol Fuel Cell (Micro-DEFC) for Applying with the Portable Electronic Devices

摘要

The objective of this research is focus on a micro fuel cell for using ethanol as a fuel for applying with the portable electronic devices. The direct ethanol fuel cell (DEFC) is selected for this research. DEFC uses ethanol in the fuel cell instead of the more toxic methanol. Ethanol is more attractive than methanol by many reasons. Ethanol is a hydrogen-rich liquid and it has a higher specific energy (8.0 kWh/kg) compared to methanol (6.1 kWh/kg). Ethanol can be obtained in great quantity from biomass through a fermentation process from renewable resources like from sugar cane, wheat, corn, or even straw. The use of ethanol would also overcome both the storage and infrastructure challenge of hydrogen for fuel cell applications. The experimental apparatus on the micro direct ethanol fuel cell for measuring the cell performance has been set for this research. The objective is - to study the micro direct ethanol fuel cell performance for applying with the portable electronic devices. The cell performance is specified in the terms of cell voltage, cell current and power of the cell at room operating temperature (around 30 to 32 °C) and 1 atm for the pressure. The steady state time for collecting each data is about 5 to 10 minutes. With the increase of concentrations of ethanol by volume, the reactant concentration at the reaction sites increases so the electrochemical rate also increase but when it reaches the saturated point the performances are gradually drop. From the average experimental data collections that the maximum current production, maximum cell voltage and maximum power of fuel cell are 17.1953 mA, 0.7574 mV and 13.0473 mW, respectively. They are occurred at the ratio of ethanol equal to 7 milliliters in 60 milliliters of water. The effect of operating temperature change on the electrical production performance is also study too. The cell operating temperatures are vary from 30 to 55 °C at the operating pressure of 1 atm. From the average experimental data collections that the maximum current production, maximum cell voltage and maximum power of fuel cell are 18.8 mA, 0.96 mV and 18.2 mW, respectively. They are occurred at the ratio of ethanol equal to 13 milliliters in 60 milliliters of water and at the cell operating temperature of 49 to 50 °C and 1 atm of pressure. For getting more power that we can operate by extending the number of the cells in the fuel cell stack.