Fuel Choices For Fuel Cell Powered Vehicles

Fuel cells offer the potential of ultra-low emissions combined with high efficiency. Recent, rapid advances in the past few years in fuel cell technology have resulted in a vast increase in fuel cell research and development directed towards wide spread application in vehicle and stationary power. The PEM (proton exchange membrane) fuel cell proposed for future vehicles requires hydrogen as a fuel. Supplying hydrogen, as either hydrogen gas or a hydrogen-rich reformate, is a critical issue. A large number of fuel sources can be used to provide the hydrogen, each has advantages and disadvantages. For example, hydrogen provides the simplest and easiest on-board system, but requires the largest infrastructure hurdles. Methanol has some advantages in producing usable reformate, but several other issues ranging from performance on cold-start and transients, to acute toxicity and maintaining purity in transport would need to be addressed. Similarly, gasoline-like liquids present opportunities to capitalize on existing infrastructure and customer familiarity, but may increase system complexity and require longer hardware development time. This paper will explore the fuel choice issue, highlighting the advantages and disadvantages of hydrogen, methanol reformers, and hydrocarbon (gasoline) reformers. Infrastructure, safety & health issues, system complexity and feasibility will also be addressed.