Study on a Vapor-Feed Air-Breathing Direct Methanol Fuel Cell Assisted by a Catalytic Combustor

Abstract

Feeding vaporized methanol to the direct methanol fuel cell (DMFC) helps reduce the effects of methanol crossover (MCO) and facilitates the use of high-concentration or neat methanol so as to enhance the energy density of the fuel cell system. This paper reports a novel system design coupling a catalytic combustor with a vapor-feed air-breathing DMFC. The combustor functions as an assistant heat provider to help transform the liquid methanol into vapor phase. The feasibility of this method is experimentally validated. Compared with the traditional electric heating mode, the operation based on this catalytic combustor results in a higher cell performance. Results indicate that the values of methanol concentration and methanol vapor chamber (MVC) temperature both have direct effects on the cell performance, which should be well optimized. As for the operation of the catalytic combustor, it is necessary to optimize the number of capillary wicks and also catalyst loading. In order to fast trigger the combustion reaction, an optimal oxygen feed rate (OFR) must be used. The required amount of oxygen to sustain the reaction can be far lower than that for methanol ignition in the starting stage.

Experimental Studies on the Performances of a Direct Methanol Fuel Cell with a Novel Integrated Ultrasonic Atomization Fuel Feeder

“…Traditionally, the vaporizer can be an electric heater or pervaporation membrane. Various designs of using electric heaters are proposed by researchers . Though enhanced cell performance is achieved in these designs, the weakness is that it increases the parasitic power.…”

“…Though enhanced cell performance is achieved in these designs, the weakness is that it increases the parasitic power. Zhang and Yuan , utilized a methanol catalytic combustor to vaporize the fuel. This system can effectively reduce parasitic power and achieve higher cell performance than traditional electric heaters.…”