Integrated Plant Layout for Heat and Power Cogeneration from Diluted Bioethanol

A newly developed kinetic model for the steam reforming of bioethanol has been used to simulate a fully integrated bioethanol-to-power plant. The detailed geometrical model of a tube-bundle reformer has been designed, allowing for a reliable rescaling from a molar-scale hydrogen yield to the selected target of 0.45-0.50 kg/h. This hydrogen output is suitable to grant electrical (up to 5 kW) and thermal (from 5 to 10 kW) power supply for distributed microgeneration. The feedstock cost for this cogeneration plant has been sensibly reduced with respect to other available ethanol reformers proposed in the literature, as the alcohol can be used already mixed with water, i.e., using only partially purified bioethanol. With respect to our previous feasibility studies, the system layout has been further simplified, and a qualitative analysis of the system stability has been performed in relation to a chosen control parameter (i.e., the reformer heat input): the reformer outlet temperature stabilizes at 650 °C and the fuel cell power at 10.0 ± 0.5 kW around a working point that minimizes the oxygen inlet.