Four-grade purification system and method for all pollutants of coal-fired flue gas

Abstract

The invention discloses a four-grade purification system and method for all pollutants of coal-fired flue gas. The system comprises a first grade of a tower-type wet process purification system, a second grade of a combined active carbon fiber purification system, a third grade of an ozone purification system and a fourth grade of an ammonia process decarburization system. Each grade of purification system in the system is of the function of removing various pollutants of coal-fired flue gas, the four grades of purification systems are combined to form a system for removing all pollutants of coal-fired flue gas in a step manner, and finally ultralow or near-zero emission of all pollutants of coal-fired flue gas can be realized. The four-grade purification system can be flexibly used according to different environmental protection requirements or specific conditions of using units in various regions. If CO2 does not need to be removed, the four grade can be omitted; and if only up-to-standard emission is needed, the second grade or the third grade can be omitted. The system has the advantages of low energy consumption, low water consumption, low operating cost, no waste water emission, no solid waste, no secondary pollution, high decontamination efficiency, complete decontamination types and the like.

Description

technical field [0001] The invention relates to a coal-fired flue gas pollutant control technology, in particular to a four-stage purification system and method for all pollutants in the coal-fired flue gas, belonging to the field of resources and environment. Background technique [0002] Coal combustion flue gas contains a lot of dust, SO x , NO x , CO 2 , mercury, lead and other toxic heavy metals and volatile organic pollutants are the number one source of pollution causing acid rain, smog, global warming and air pollution. Therefore, controlling the emission of various pollutants in flue gas is the most important task in the field of air pollution control. [0003] At present, the control of flue gas pollutants in coal-fired power plants mainly adopts a single pollutant control technology for different pollutants. It is the most widely used mainstream dust removal technology at present. [0004] for SO x Control, limestone / gypsum wet desulfurization (WFGD) technol...

AI Technical Summary

Problems solved by technology

Its dust removal method not only consumes high power, but also has poor dust removal effect, especially for PM 2.5 The filtration is very small, and sodium hypochlorite is used for denitrification and mercury removal, which has poor oxidation performance and low denitrification and mercury removal efficiency.

For the integrated removal technology of multiple pollutants, although it has the advantages of less equipment consumption, less land occupation, and relatively low investment, due to the excessive compactness and concentration of the process, the removal of pollutants is often done in one pass, making it difficult to carry out in-depth It is also difficult to achieve the lowest operating cost and the highest removal efficiency for the removal of each pollutant

[0011] CO 2 The removal of CO2 is the top priority of flue gas treatment work in the future. Today's coal-fired pollutant treatment technologies, whether single-item, technology-integrated or integrated, do not involve CO 2 The reason is that there is no CO2 with low energy consumption and low operating cost 2 Removal technology can be used for reference and application

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