(715b) Utilization of Chemical Looping Strategy to Minimize Exergy Loss

A given chemical reaction can be decomposed into multiple sub-reactions through the use of chemical intermediates. A reaction scheme of this nature is denoted as chemical looping reactions. An ideal chemical looping scheme is to design these sub-reactions in such a manner that the exergy (availability) loss in their process applications can be minimized while allowing the separation of the products and/or pollutants generated from the reactions to be accomplished with ease, thereby yielding an overall efficient and economical process system. In this paper, several chemical looping process configurations that convert carbonaceous fuels such as coal and biomass into hydrogen, electricity, and/or liquid fuels are analyzed using exergy analysis. The analysis results indicate that, through the utilization of chemical looping strategy, the irreversibility of the fuel conversion process can be minimized, resulting in significantly improved energy and exergy conversion efficiencies. Effective exergy recuperation techniques that improve the overall energy management of the chemical looping systems are also provided.