Method for removing mercury from smoke in coal fired power plant and mercury removing agent used by same

Abstract

The invention discloses a method for removing mercury from smoke in a coal fired power plant and a mercury removing agent used by the same. In the term of the weight percent, the mercury removing agent is prepared from cobalt oxide and copper chloride in a mass ratio of (5-10):1000 through mixing. The mercury removing agent adopted in the invention can be directly used in a limestone- gypsum wet desulphurization system, is simple in use and convenience for use without reconstructing the traditional equipment and is low in cost; and the method for removing mercury by using the mercury removingagent has the advantages of high mercury removing efficiency, difficulty in corrosion to the device, and no generation of secondary pollution, can be used for oxidizing NO in the smoke into NO2 easily dissolved into water, and realizes the effect of removing mercury and NOx simultaneously.

Description

technical field [0001] The invention relates to a method for removing mercury from flue gas of a coal-fired power plant and a mercury removing agent used therefor, and belongs to the technical field of flue gas purification. Background technique [0002] The burning of coal is one of the biggest sources of pollution that causes the deterioration of my country's ecological environment. where SO 2 Pollution has been basically controlled, NO x Emission standards will also be promulgated in the "Twelfth Five-Year Plan", and it is imperative to control Hg emission standards. The current mature mercury removal technology is activated carbon injection. However, the cost of mercury removal by this method is quite expensive. According to the estimate of the US Department of Energy, the operating cost of activated carbon injection is 25,000-70,000 US dollars per ton of mercury, which is unbearable for many power plants. Recently, the U.S. Department of Energy and the National Elec...

AI Technical Summary

Problems solved by technology

However, the process of this method is complicated, and it needs to go through impregnation, drying, activation, calcination and other steps. The process of two or more oxides also includes kneading, drying, activation, drying, etc., resulting in high operating costs.

The other is to add Na to the limestone slurry 2 S solution (patent application CN101850212A), this kind of method is simple to operate, and operating cost is also lower, but needs the elemental Hg in the flue gas and the solid elemental S reaction in the liquid phase in removing elemental Hg reaction, belongs to gas-solid reaction, The reaction is difficult to occur, and a large excess of elemental S is required to achieve high mercury removal efficiency

The unreacted high-concentration elemental S will cause secondary pollution whether it is discharged from the absorption tower with the flue gas or deposited in the gypsum slurry

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