Engineering aspects of the direct methanol fuel cell system

The direct methanol fuel cell presents several interesting scientific and engineering problems. There are many engineering issues regarding eventual application concerning cell materials, feed and oxidant requirements, fuel utilisation and recovery, scale up, etc. This paper looks at several of these issues starting from the point of current, typical, cell performance. A small-scale flow cell and a large scale cell, both with a parallel channel flow bed design, are used. The structure of the direct methanol fuel cell (DMFC) is a composite of two porous electrocatalytic electrodes; Pt-Ru-C catalyst anode and Pt-C catalyst cathode, on either side of a solid polymer electrolyte (SPE) membrane. Flow visualisation on small scale and intermediate scale (100 cm(2)) cells has been used in the design of a new large-scale cell of 225 cm(2) active area. We discuss several important engineering factors in the successful design of large scale DMFCs including the use of vapour and liquid feeds, thermal management, gas management, methanol fuel management, hydrodynamics and mass transport. (C) 1999 Elsevier Science S.A. All rights reserved.