Advanced exergy analysis of an oil shale retorting process

Fushun-type process is the most common method of oil shale retorting used in China. The process is, however, characterized by poor thermodynamic performance. While conventional exergy analysis is able to quantitatively determine exergy destruction in a system, identification of the sources of the exergy destruction, and thus identification of areas with the greatest potential for efficiency improvement, requires advanced exergy analysis. In this paper, an advanced exergy analysis is applied to evaluate the performance of a Fushun-type oil shale retorting process. The results indicate that, the simulation results are consistent with industrial data. The process can produce 21.90 t/h of shale oil from 500 till oil shale. The exergy efficiency of the Fushun-type oil shale retorting process studied in this work is 34.17% and the total exergy destruction is 442.62 MW. The analysis shows that 45.40% of the exergy destruction cannot be reduced. The retort is found to be the element of the Fushun-type oil shale retorting process having the greatest potential for decrease in exergy destruction. Improvement strategies are proposed to minimize exergy destruction in the retort. (C) 2015 Elsevier Ltd. All rights reserved.