System and method for promoting coal fly ash to adsorb and remove pollutants such as mercury in flue gas

Abstract

The invention discloses a system and a method for promoting coal fly ash to adsorb and remove pollutants such as mercury in flue gas. The adsorbing and removing effects of the fly ash on the mercury are effectively improved by taking measures of reducing the temperature of the flue gas, prolonging the adsorption retention time of the fly ash, screening the fly ash with high mercury adsorbing capability, increasing the concentration of the fly ash with high mercury adsorbing capability and the like; on the basis, the method and the system can be further combined with an oxidation mercury removal technology and / or adsorption mercury removal technology, the defects in the prior art are overcome and efficiency mercury removal is realized; in addition, a good effect on control of other pollutants such as SO3 in the flue gas is achieved; and therefore, the method and the system have wide applicability, and the requirements of different coal-fired power plants on the pollutants such as mercury in the flue gas can be met.

Description

technical field [0001] The invention belongs to the technical field of thermal power generating units and environmental protection, and in particular relates to a system and method for promoting the adsorption and removal of mercury and other pollutants in flue gas by coal-burning fly ash. Background technique [0002] Mercury is a highly toxic substance that will cause long-term and serious harm to the environment and human body. As a trace element in coal, mercury is mostly discharged into the atmosphere along with flue gas during coal combustion. Although the mass concentration of mercury in the flue gas of coal-fired power plants is very low, only about 1-20 μg / m 3 , but its total amount is huge, and it is one of the most important sources of anthropogenic mercury emissions in the world. my country is the world's largest coal-burning country, so the problem of mercury emissions caused by coal burning is even more serious. [0003] Under the active promotion of the Uni...

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Problems solved by technology

[0011] In order to meet the requirements of the global Minamata Convention and my country's relevant emission standards, protect the environment and the health and safety of the people, it is imperative to achieve efficient and low-cost mercury pollution control in coal-fired power plants. Among the current major coal-fired power plant-specific mercury removal technologies, Oxidative mercury removal technology has problems such as secondary release of mercury absorbed by the wet desulfurization system into flue gas or the environment. Adsorption mercury removal technology has disadvantages such as high operating costs and possible impact on the comprehensive utilization of fly ash.

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