Fuel cells have attracted a great deal of attention in recent years. Their high theoretical efficiency, silence and low contribution to atmospheric pollution are all factors which encourage their development.
The petroleum industry is particularly concerned with the possible impact of any new energy conversion equipment on fuel demand. In this paper the various forms of low temperature fuel cells are considered. It is suggested that natural gas, L.P.G. and pentane are likely to be the most attractive hydrocarbon fuels for commercial fuel cells.
On s'occupe beaucoup récemment des piles à combustible. Le rendement théorique élevé, le silence et la propreté d'opération sont des facteurs qui favorisent leur développement.
L'industrie du pétrole s'intéresse en particuliér à l'effet possible de n'importe quel système nouveau de transformation d'énergie sur la consommation des combustibles. Dans cet article, on examine les types de piles à combustible à basse température. On propose que le gaz nature1, le gaz de pétrole liquéfié et le pentane semblent être les combustibles hydrocarbures les plus attrayants pour les piles à combustible industrielles.
Low temperature fuel cells are a tantalizing subject for both research and speculation. In principle, such cells can convert the chemical energy of a fuel directly into electricity; they are not subject to the Carnot limitation of thermal efficiency; they are inherently noiseless in operation, with no moving parts; they can operate with little or no contribution to atmospheric pollution. Small wonder that sizeable research teams in all continents are trying to produce commercially viable low temperature fuel cells.
The petroleum industry is naturally concerned with these developments. In particular it wishes to know the types of fuel that fuel cells are likely to require and the probable demand for such fuels in the foreseeable future.
Before the various problems associated with the construction of fuel cells are considered it may be helpful to describe the underlying principles of the fuel cell.
BASIC PRINCIPLES A fuel cell may be defined as a primary cell in which a conventional fuel is supplied to one electrode and an oxidant, usually oxygen or air, to the other. Both electrodes should be unaffected by the reactants as should the electrolyte that separates them. At the fuel electrode (anode), the fuel is oxidized and electrons by K. R. WILLIAMS, Shell Research Limited, Thornton Research Centre, Chester, U.K. released to the external circuit. Correspondingly at the oxygen electrode (cathode), oxygen is reduced and electrons accepted from the external circuit. The term "conventional fuel" is interpreted fairly liberally and is normally taken to include hydrogen.
The operation of low temperature fuel cells can best be illustrated by the hydrogen-oxygen cell (Fig. 1).
EXTERNAL CIRCUIT ELECTRON FLOW HYDROGEN ELECTRODE