Joint mercury removing method and device based on SNCR

Abstract

The invention provides a joint mercury removing device based on SNCR. Two kinds of flue gas treatment technologies can be effectively combined, and the purpose of nitrate and mercury removal is achieved while cost is reduced. The device comprises two sets of independent measuring systems, a solution preparing system connected to the output ends of the two sets of measuring systems, a solution conveying system and a solution spraying system, wherein the solution conveying system and the solution spraying system are sequentially connected to the output end of the solution preparing system. The solution spraying system comprises a spraying inlet and a spraying gun. The spraying inlet is formed in a hearth of an SNCR system, and the spraying gun is connected to the spraying inlet and stretches into the hearth. The two sets of measuring systems are used for measuring urea and ammonium chloride solids respectively according to the demanding amount for removing NOx and zero-valent mercury. The mercury removing technology and the SNCR are joined, the advantages of the two technologies are combined, the advanced SNCR technology is developed, additional technological equipment is not added except for the measuring systems based on original facilities, the technology is easier and more convenient to implement and more economical, and capital cost is saved.

Description

Technical field [0001] The invention relates to the technical field of flue gas combined pollutant removal, in particular to a combined mercury removal method and device based on SNCR. Background technique [0002] Because of its high toxicity, high volatility and accumulation in the biological chain, mercury has become a global circulating pollution element, and has received great attention from domestic and foreign scholars in recent years. Hg emissions from coal-fired power plants can account for 70% of man-made emissions. Therefore, the control of mercury emissions from coal-fired power plants has become another focus of environmental protection today. The average mercury content in coal in my country is about 0.22mg / kg, which is much higher than the world average level of 0.13mg / kg. Therefore, the mercury pollution control of coal-fired power plants in my country is facing a more severe test. Zero-valent mercury (Hg0) in Hg emissions from coal-fired power plants is the main...

AI Technical Summary

Problems solved by technology

[0004] The current problem is that although the denitrification efficiency of the SNCR process is difficult to further improve, it has high flexibility and simplicity and can be used in combination with other technologies

In addition, the cost of existing mercury removal technologies is relatively high. For example, the operating cost of activated carbon mercury removal is quite high. To achieve a mercury removal efficiency of 90%, it needs 25,000-70,000 US dollars per pound of mercury treated

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