275606 Indirect Carbon (CO) PEM Fuel Cell
The advancement of the use of hydrogen fuel cell in many applications has been delayed by the need for safe storage or easy on-site generation of hydrogen fuel. Coal is an abundant source of fuel in the US. However, the use of coal and other fossil fuels in energy generation is inefficient which results in burning high quantities of coal (fuel) and the subsequent release of significant amounts of CO2 into the atmosphere. Hence the need for “Clean Coal Technologies” as an alternative path for future power generation. Direct carbon fuel cells (DCFC) present a good alternative to hydrogen fuel cells in the area of energy density and fuel storage. Also, the efficiency from DCFC is projected to be about 70% which is more than what can be achieved in a hydrogen fuel cell.
Nonetheless, due to the internal operation of a fuel cell, it is difficult to achieve a reasonable three-phase boundary where solid fuel (e.g. coal), electrolyte, and electro-catalyst meet. To avoid this problem, coal can be pre-processed by either gasification or partial oxidation to produce CO and H2. Partial oxidation produces a fuel gas that is high in CO concentration. The product of this process can be used as the inlet fuel for fuel cells. This work utilizes partial oxidation to produce CO fuel for a polyelectrolyte membrane fuel cell (CO-PEMFC). At the anode, carbon monoxide reacts with water in a water gas-shift reaction, generating carbon dioxide, electrons and protons. Protons transport through the membrane and react with oxygen at the cathode to generate water. The generated electrons get transported through an external circuit from anode to cathode thus producing the desired product of the system, electricity. Unfortunately, carbon monoxide cannot be used as fuel in the conventional PEMFC. Traditionally, the electrocatalysts of PEMFC are made of platinum-based material, which is strongly poisoned in the presence of carbon monoxide. However, platinum alloys such as platinum-ruthenium, can be used as the electrocatalyst. In this work, Platinum-Ruthenium based electrocatalysts were made and used in standard PEM fuel cell. Power density from CO-PEMFC will be compared based on composition of electrocatalyst, CO fuel concentration and cell temperature.