Direct Coal Gasification with Simultaneous Production of Electricity in a Novel Fused Metal Anode SOFC: A Theoretical Approach

Abst ract. Coal gasification in molten metal baths is a relatively new process with important technological dvantages. The economics of the process can be made even more attractive if part of the Gibbs energy change of the oxidation reaction is directly converted into electricity through the use of the concept of a solid oxide fuel cell. This combination of fuel cell and fused metal gasifier in a single reactor-cell of the type: C, 02, fused metal / YSZ / perovskite, 02 is the distinguishing feature of the new process analyzed in this work. A mathematical model has been developed which describes the steady-state behaviour of this novel fuel cell and discusses the effect of operating conditions upon cell performance. This theo-retical approach shows that, under best-case estimates, the electrochemical e l gasifier is capable of producing very l~gh current and power densities. 1. In t roduct ion Solid electrolyte galvanic ell applications include so far their use for (i) sensor devices [1,2], (ii) power-producing systems [3] and (iii) in heterogeneous catalysis for study-ing the mechanism of catalytic reactions and enhancing the catalytic properties of metal electrodes via the effect of non-faradaic electrochemical modification of catalytic activity (NEMCA) or electrochemical promotion [4,5]. Yet another important application of solid electrolyte devices is their use for chemical cogeneration [6-15], i.e., the simultaneous production of electricity and useful che-micals. This mode of operation combines the concepts of a fuel cell and a chemical reactor. Electricity and useful chemicals are produced simultaneously the ratio of electric power to heal generated, as well as reactant conversion, can be conveniently controlled by varying the external re-sistive load [15]. A number of important industrial reactions, such as the conversion of NH 3 to NO [6] the oxidation of nE