Direct alcohol fuel cells: Assessment of the fuel's safety and health aspects

Fuel cell (FC) is simply a device that directly converts the chemical energy of fuel into electrical energy through electrochemical oxidation. Hence, FC inherently exhibits a low-temperature and high-energy conversion efficiency. Direct alcohol fuel cells (DAFCs) overcome the storage, handling, and safety challenges typically associated with gaseous fuels such as hydrogen. Most of the research and development work in DAFC is focusing on maximizing its performance by varying fuel concentration, operating conditions, and electrocatalysts used. However, less attention is being given to the health and safety aspects associated with these fuels and operating conditions. Most of these fuels are known to be highly flammable, toxic, and become even more hazardous at elevated temperatures. The present work performs a systematic assessment of the safety and health aspects of the widely used fuels for DAFCs, namely methanol, ethanol, ethylene glycol, and glycerol. The safety assessment is considering the flammability characteristics, along with other safe operation aspects. While the health assessment considers the toxicity of fuel and its reaction byproducts to human and aquatic life. The evaluation has provided an envelope of conditions at which the FC operation would be considered “safer” by applying basic principles of inherent safety, i.e., minimizing, substituting, moderating, and simplifying.