Exergetic life cycle assessment of Fushun-type shale oil production process

Currently, the conventional Fushun-type retorting process is the most main way of shale oil production in China. However, it has many disadvantages, such as low resource utilization efficiency and severe environmental pollution inevitably. In this paper, the framework of exergetic life cycle assessment (ELCA) is applied to the shale oil production process, and the indicator of resource utilization efficiency (gamma) and the indicator of environmental sustainability (zeta) were defined to evaluate the performance of the resource utilization efficiency and environmental sustainability. The results indicate that the Aspen Plus simulation results are reasonably consistent with industrial data. The yield of shale oil is 4.52 kg/s by the pyrolysis of 100 kg/s oil shale. The framework of ELCA is applicable for the Fushun-type shale oil production process. During the whole life cycle, the cumulative exergy consumption (CExC) and the Abatement exergy (AbatEx) of pollutants (per kg shale oil produced) are 225.65 MJ and 61.69 MJ, respectively. The retorting stage has the lowest exergy efficiency, 62.49%, followed by the semi coke gasification stage 63.15%. The gamma and zeta values in shale oil production stage are very poor, 42.64% and 32.64%, respectively. When the retorting temperature is set to 500 degrees C and the saturation of feeding air is controlled to 80 degrees C, the gamma and zeta values of the whole life cycle achieve the greatest potential, 35.85% and 28.05%, respectively.