A system and method for reducing sulfur dioxide-containing gas by a binary method. The system for reducing sulfur dioxide-containing gas by a binary method includes a gasifier, which is used for performing a gasification reaction of a carbon-based solid fuel and a gasifying agent, and is used for reducing SO2 in the sulfur dioxide-containing gas by a binary method using the coal gas and semicoke generated by the gasification reaction. The present invention innovatively uses the gasifier as a reduction reactor for sulfur dioxide-containing gas, and uses the two binary products, namely semicoke and coal gas, generated by gasifying the carbon-based fuel in the gasifier to perform binary reduction of SO2 in the sulfur dioxide-containing gas, strengthening the reduction effect and improving the SO2 conversion rate.
A fluidized bed gasification system for high-moisture lignite is disclosed. The outlet of the drying and pulverizing unit is connected to the inlet of the fluidized bed gasification unit. The outlet of the fluidized bed gasification unit is connected to the inlet of the sensible heatrecovery unit. The outlet of the sensible heatrecovery unit is connected to the inlet of the gas-solid separation unit. Part of the superheated steam discharged from the steam outlet of the sensible heatrecovery unit goes downstream, and part of it enters the fluidized bed gasification unit together with oxygen. The outlet of the gas-solid separation unit is connected to the synthesis system. One outlet of the synthesis system discharges synthesis gas, and the other outlet discharges methane. The methane and air enter the hot air device for combustion to produce high-temperature flue gas, which enters the drying and pulverizing unit. The drying heat source of this invention comes from the combustion of methane produced by the system itself, and the steam required for gasification comes from the sensible heat recovery of the system's own synthesis gas. The material and energy coupling between each unit is close. This design reduces the dependence on external utilities and makes the device structure more compact.