Direct methanol fuel cells stack

Fuel cells can run on fuels other than hydrogen. In the direct methanol fuel cell (DMFC), a dilute methanol solution ( 3%) is fed directly into the anode, and a multistep process causes the liberation of protons and electrons together with conversion to water and carbon dioxide. Because no fuel processor is required, the system is conceptually vei"y attractive. However, the multistep process is understandably less rapid than the simpler hydrogen reaction, and this causes the direct methanol fuel cell stack to produce less power and to need more catalyst. 

H. Dohle, H. Schmitz, T. Bewer, J. Mergel, and D. Stolten. Development of a compact 500 W class direct methanol fuel cell stack. Journal of Power Sources 106 (2002) 313-322. 

Watt Direct Methanol Fuel Cell Stack for Portable Power Applieations , X. Ren, J. Davey,... 

Spring National Meeting of American Institute of Chemical Engineers, New Orleans, LA, March 10-14, 2002. Title 80 W Direct Methanol Fuel Cell Stack for Portable Power Applications X. Ren, J. Davey, B. S. Pivovar, ... 

Chan YH, Zhao TS, Chen R, Xu C (2008) A small mono-planar direct methanol fuel cell stack with passive operation. J Power Sources 178 118-124... 

Yuan Z, Zhang Y, Fu W, Li Z, Liu X (2013) Investigation of a small-volume direct methanol fuel cell stack for portable application. Energy 51 462-467... 

Argyropoulos P, Scott K, Taama WM (1999) One-dimensional thermal model for direct methanol fuel cell stacks. Part I. model development. J Power Sources 79 169-183... 

Cremers C, Scholz M, Seliger W, Racz A, Knechtel W, Rittmayr J, Grafwallner F, Peller H, Stimming U (2007) Developments for improved direct methanol fuel cell stacks for portable power. Fuel Cells 7 21-31... 

Sbukla, A.K., Ravikumar, M.K., Neergat, M., Gandhi, K.S. (1999) A 5 W Hquid-feed solid-polymer-electrolyte direct methanol fuel cell stack with stainless steel. Journal of Applied Electrochemistry, 29, 129-132. 

In 1998 a report prepared for the California Air Resources Board (CARB) called Status and Prospects of Fuel Cells as Automotive Engines favored methanol fuel cell stacks in cars over a direct-hydrogen infrastructure. Hydrogen is not as ready for private automobiles because of the difficulties and costs of storing hydrogen on board and the large investments that would be required to make hydrogen more available. 

Other types and aspects of polymer-electrolyte fuel cells have also been modeled. In this section, those models are quickly reviewed. This section is written more to inform than to analyze the various models. The outline of this section in terms of models is stack models, impedance models, direct-methanol fuel-cell models, and miscellaneous models. 

The Polymer Electrolyte and Direct Methanol Fuel Cells Brief Overview of Key Components and Features of Cells and Stacks... 

A serious candidate for transportation application is also the direct methanol fuel cell (DMFC) which has been realized already on a laboratory scale. A catalytic burner is requited to evaporate the methanol/water mixture and to bum the exhaust gas at the anode [43]. Considering the complete energy chain, a PEFC is by 50 % more efficient than a diesel engine which consumes 4 1 per 100 km this is also valid for a natural gas driven engine [37]. Fig. 7-6 presents the processing schematics of both IMFC and DMFC. The DMFC offers a much simpler system than the PEFC. The DMFC is currently at an early development stage. It is perceived to offer improved solutions to the need for a small-scale power supply. A program for the construction of a 30 kW stack has recently started [29]. 

The purified hydrogen needs to be stored as liquid (at -253°C) or compressed gas at around 200 bar—this is due to the low energy density of hydrogen (0.003 kW h/L at 1 bar and ambient temperature and 0.5 kW h/L at 200 bar). When used in the transport sector, thick steel cylinders for the compressed gas are needed, and stacks of the cylinders must be carried under or on the top of the vehicle (bus, truck, ferry). For private cars, the direct-methanol fuel cell (DMFC—see Figure 7.25) is more attractive. For a DMFC,... 

The peripheral equipment needed for direct methanol fuel cells is largely analogous to that of polymer electrolyte membrane fuel cells. The mechanical basis of fuel cells and stacks on the whole consists of bipolar plates between which the sandwiched membrane-electrode assemblies are arranged. For the venting of heat, cooling plates with a circulating heat transfer agent are set up in a particular order between individual fuel cells in the stack. 

Simoglou A, Argyropoulos P, Martin EB, Scott K, Morris AJ, Taama WM (2001) Dynamic modeling of the voltage response of direct methanol fuel cells and stacks. Part II feasibility study of model-based scale-up and scale down. Oiem Eng Sci 56 6761-6772... 

Power AND Energy Efficiency Analysis OF Direct Methanol Fuel Cell (DMFC) FROM Single Cell, Fuel Cell Stack TO DMFC System... 

There has been considerable research on modifying Nafion, so as to improve its properties for use in a direct methanol fuel cell. In this chapter, a review of Nafion-based DMFC membranes is presented, including a literature survey followed by recent results by the present authors on improving Nafion by (1) using thick stacked Nafion membranes, (2) blending Nafion with Teflon-FEP or Teflon-PFA, and (3) doping Nafion with polybenzimidazole. 

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