Desulfurization and demercuration method for flue gas

Abstract

The invention provides a novel desulfurization and demercuration method for flue gas. In the method, lime / Ca(OH)2 is adopted as a desulfurizing agent; recycling flue gas desulfurization residue is adopted as an auxiliary desulfurizing agent; water mist is sprayed into a flue in advance; the flue gas is cooled and enters a desulfurizing tower, and simultaneously the lime / Ca(OH)2 desulfurizing agent is fed into the desulfurizing through a steam conveyer to be mixed with the flue gas; the SO2 in the flue gas reacts with the lime / Ca(OH)2; and simultaneously the lime / Ca(OH)2 desulfurizing agent has strong adsorbability on hydrargyrum after steam conveying, so that the desulfurization and demercuration of the flue gas are realized. The flue gas desulfurization residue collected by the desulfurizing tower and a bag type dust collector is conveyed to a desulfurizing agent inlet through the steam conveyer to be mixed with the flue gas, and enters the desulfurizing tower once again; after the flue gas is subjected to the desulfurization and the demercuration, the generated desulfurization residue is collected through the bag type dust collector; and the purified flue gas is discharged from a chimney through an induced draft fan. By utilizing the technology, higher removal rate on SO2 and mercury steam is achieved, Pb and other heavy metals can be removed at the same time, and the operation cost is lower; and the side product flue gas desulfurization residue can be directly recycled, and does not cause secondary pollution.

Description

technical field [0001] The invention relates to a method for flue gas desulfurization and mercury removal, which belongs to the technical field of environmental pollution control. Background technique [0002] Coal is the main primary energy source in China at this stage, and the growth of coal consumption has led to SO 2 Emissions continue to climb rapidly, each year due to acid rain and SO 2 Pollution has caused massive economic losses to the ecological environment and human health, and the problem of emission reduction needs to be solved urgently. The coal burning process not only emits sulfur dioxide and nitrogen oxides, but also emits other pollutants such as mercury. Most of the mercury in the coal combustion process enters the flue gas and is emitted into the atmosphere, becoming an important source of mercury in the atmosphere. Mercury is one of the main harmful heavy metal elements. Although the amount is small, it can accumulate in the environment after burning ...

AI Technical Summary

Problems solved by technology

[0005] At present, there are also methods of using bromine-loaded activated carbon and semi-coke to remove mercury from flue gas, but these methods have no obvious effect on desulfurization, and the regeneration cost of mercury removal by-products is relatively high.

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