Development of a Coupling Oil Shale Retorting Process of Gas and Solid Heat Carrier Technologies

Oil shale is one of the most potential alternative resources for crude oil. Its exploration and exploitation are of increasing interest. In China, oil shale is mainly used by retorting technology. Fushun-type retorting technology, a typical gas heat carrier retorting technology, accounts for the largest proportion in China. However, this retorting technology is only applicable of coarse oil shale particles bigger than 10 mm in diameter. A lot of fine oil shale particles are discarded, resulting in waste of resources. Besides, this technology is criticized by low economic benefit. The main objective of this paper is to develop a coupling oil shale retorting process. The novel process can use fine oil shale particles as the raw materials of solid heat carrier retort to produce more shale oil. The novel process is modeled, and next, the simulation is carried out to build its mass and energy balance. From the techno-economic point of view, the advantages of the novel process are demonstrated by comparison to the traditional Fushun-type oil shale retorting process. Results indicate that the novel process is promising because coupling the two retorting process can increase the shale oil production from 13.86 to 17.34 t/h, the exergy efficiency from 32.46 to 38.01%, and the return on investment from 11.04 to 18.23%.