New technology for the comprehensive utilization of Chinese oil shale resources

In China, the conventional utilization of oil shale is concentrated mainly on retorting oil shale to produce shale oil and fuel gas, and burning oil shale to generate electricity. The growth of petroleum price, and the development in heavy industry, make these conventional utilization facilities become unavailable on the energy market. In this paper, a new comprehensive utilization system is recommended for the future use of Huadian oil shale, based on the current status of energy and the characteristics of oil shale. The system involves three subsystems: retort subsystem, where coarse oil shale (8–80 mm) is retorted to shale oil, hydrocarbon gases and oil shale semicoke; combustion subsystem, where the mixture fuel of oil-shale semicoke and fine oil shale (0–8 mm) is fed to a circulating fluidized bed (CFB) furnace to burn, in order to generate high-pressure steam which is used to supply heat and generate electricity via a traditional steam-electric power mode; and ash processing subsystem, where oil shale ash from the CFB furnace is utilized to produce building materials. A comprehensive utilization system with handling capacity of 2.6×106 t/a Huadian oil shale is economically analyzed, showing that it can advantage oil shale utilization in the economic efficiency and the product type.