Two-phase ammonifying method of wet ammonia desulfurization process

Abstract

The invention relates to a two-phase ammonifying method of a wet ammonia desulfurization process. The method comprises the following steps: fully mixing liquid ammonia from a liquid ammonia tank with a solution from an absorbent buffer tank in a static mixer at the outlet of the absorbent buffer tank, and adjusting the additive amount of liquid ammonia according to the pH value of the solution at the outlet of the static mixer; directly adding gas-phase ammonia from the liquid ammonia tank into the absorbent buffer tank by pressure difference, and dissolving in absorption liquid. According to the method, gas-phase ammonia and liquid-phase ammonia in the liquid ammonia tank can be added into a desulfurization system simultaneously, so that the gas-liquid balance of the liquid ammonia tank is guaranteed and the knocking of the absorbent buffer tank caused by direct addition of liquid ammonia is avoided; in addition, liquid ammonia and the solution are fully mixed in the static mixer, so that an ammonia absorbent can be fully utilized and ammonia can be effectively prevented from escaping.

Description

technical field [0001] The invention relates to a method for simultaneously adding absorbent in gas and liquid phase ammonia in a wet ammonia desulfurization process. Ammonia in different phases is added to different positions to mix with the absorbent. The invention belongs to the technical field of resources and environment. Background technique [0002] At present, the limestone-gypsum method is basically the main desulfurization device in my country. First, because the desulfurizer limestone is abundant in source and cheap, and the limestone-gypsum method technology is quite mature and open abroad, and it is easy to obtain. However, the equipment of this technology is easy to scale and block, the system is complex, the investment is large, the area is large, the secondary pollution is generated, and the operating cost is high. Wet ammonia desulfurization technology does not produce carbon dioxide when removing sulfur dioxide in flue gas (calcium method produces 0.7 tons ...

AI Technical Summary

Problems solved by technology

[0009] All the ammonia is injected into the absorption tower, so that the absorption liquid in the absorption tower is basically reduced to ammonium sulfite solution, and the solution in the absorption tower is kept at a high pH value, which is easy to cause ammonia escape in the outlet flue gas, resulting in secondary Pollution

Therefore, the method and method of controlling ammonia injection in the ammonia desulfurization process is to ensure the desulfurization efficiency while avoiding excessive ammonia injection, which will cause ammonia escape and form new pollution and waste.

[0010] Because ammonia is toxic, harmful, explosive, volatile, etc., in the ammonia desulfurization process, the selection of ammonia sources, transportation, and ammonia addition methods are very critical. At present, many processes use low-concentration ammonia water, which will bring There are many problems: (1) need a larger dilution site; (2) increase transportation costs; (3) increase water consumption

If the method of adding liquid ammonia is used, since the liquid ammonia dissolves, a large amount of heat will be released, and if it is directly put into the absorption tower or other containers, there will be a knock, which will affect the safety of the absorption tower or storage tank; at the same time, liquid ammonia is very volatile, and the liquid ammonia storage tank will have A part of gas phase ammonia exists, in order to maintain the gas-liquid balance of the liquid ammonia storage tank, it is necessary to consider adding gas phase ammonia to the absorbent

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