Modeling of the electrochemical transformation of chemical energy of biofuel to electricity

A thermodynamic model is proposed for the electrochemical process of the conversion of the chemical energy of biofuels into electricity in a fuel cell of direct carbon oxidation. It is shown that, with the use of polarization resistance from the experiment, a current density of $0.1$–$0.5$ A/cm$^2$ provides a power-plant efficiency in the range of $87$–$55\%$. At an operating temperature of $1073$ K, carbon is oxidized mainly to monoxide, which is why the initial portion of the fuel cell is actually a gasifier, and the rest is a conventional solid oxide synthesis gas fuel cell. In the gasification section, the electrochemical process proceeds with heat absorption and has an ideal thermal efficiency above unity. It is advisable to separate these two sections constructively to optimize the heat transfer between them.