Method and Plant for Thermal Conversion of Solid Fuels

摘要

The invention relates to thermal conversion of solid fuels with a low organic content and can be used in the fuel-processing industry. Conversion of oil shale or high-ash solid fuels comprises flue-gas drying of feedstock, recovering the solid phase as a heat-carrying agent, feedstock pyrolysis in a reactor, separating a gas-vapour mixture from the coke-ash residue in a dust-settling chamber, discharging ash, cooling flue gases, and combustion of the coke-ash residue. An inert material having an ambient temperature is supplied to the outlet of the coke-ash residue ignition chamber. The plant comprises, arranged in series, a reactor, a dust-settling chamber, a flash-process furnace, a heat-carrier cyclone, an ash cyclone, a waste-heat recovery system, an ash-discharge system and a bin for inert material connected to the outlet of the coke-ash residue ignition chamber. The invention allows for a more complete use of the oil shale energy potential and for obtaining ash with a reduced negative effect on the environment, which makes it possible to use the ash for recultivation of quarries resulting from oil shale mining.