Enefit280 Oil Shale Processing Plant

1. Wet oil shale is fed to a Venturi dryer and the hot flue gas from the waste heat boiler is used to evaporate the moisture in direct contact with the particles.    
2. Downstream of the Venturi dryer, the dried oil shale is separated from the gas stream and the remaining solids particles in the gas are discharged using an electrostatic precipitator (ESP). The cleaned flue gas is discharged to the atmosphere via a stack.    
3. The dried oil shale is combined with a solid heat carrier, which is essentially ash from a semicoke combustion process.    
4. The oil shale is heated in the retort (essentially a rotary kiln) to the reaction temperature via direct contact with the heat carrier solids. The organic material in the oil shale decomposes and hydrocarbon gas and oil fumes are released.    
5. The gas is transferred to a condensation unit for oil and fuel gas production.    
6. Semicoke from the pyrolysis process is fed to a CFB for complete combustion. The excess heat is extracted over fluidized bed coolers to produce steam. The hot flue gas from the CFB is cooled in a waste heat boiler to superheat the steam for use in a turbine for power production.

As oil shale composition and processing capability is highly dependent on the resource, Metso, together with our joint venture Enefit Metso Technology, offers two small-size test facilities. These two units, with 10 and 300 kg/h throughputs, allow testing of the oil shale resource to gain the necessary information for the design of a customized plant.