Composite additive for flue gas desulfurization according to limestone method

Abstract

A composite additive for flue gas desulfurization according to a limestone method is composed of the following materials by mass: 85 to 90 percent of nylon acid extracted residue, 1 to 3 percent of salicylic acid, 1 to 3 percent of humic acid, 1 to 5 percent of manganese chloride, and 1 to 5 percent of dimethyl silicone antifoaming agent which are mixed with each other, wherein nylon acid extracted residue is the residue of nylon acid extracted with a large part of glutaric acid. The composite additive has the beneficial effects that the defects of deeper color and unqualified desulfuration drainage chromaticity caused when a nylon acid-type additive is used for flue gas desulfurization are overcome; the pH value buffer zone is wider; sulfur dioxide gas can be dissolved in limestone paste faster; the dissolution of limestone calcium carbonate can be accelerated; the desulfuration efficiency is improved; the cost is greatly reduced; the oxidation efficiency of calcium sulfite is improved; the poisoning problem of limestone paste liquid is solved; foam of a desulfurization tower is eliminated; and the efficient steady operation of the desulfurization tower can be guaranteed.

Description

(1) Technical field [0001] The invention relates to the field of limestone flue gas desulfurization, in particular to a composite additive for limestone flue gas desulfurization. (2) Background technology [0002] At present, limestone flue gas desulfurization is the desulfurization process with the most mature technology and the most engineering application achievements in the world. It is suitable for flue gas desulfurization of any sulfur-containing coal. At present, there are roughly three types of additives used to improve the efficiency of limestone flue gas desulfurization in the market, namely, desulfurization additives mainly composed of benzoic acid or sodium benzoate, desulfurization additives mainly composed of adipic acid and nylon acid. desulfurization synergist. However, each of these three additives has its disadvantages, such as: [0003] Benzoic acid or sodium benzoate type desulfurization additive: the effect of improving desulfurization efficiency is lo...

AI Technical Summary

Problems solved by technology

But there are three disadvantages: firstly, the price is high; secondly, it is difficult to dissolve in water at room temperature, so the reaction process is slow, and the energy consumption is high during the reaction; finally, the pH value buffer zone of a single species of adipic acid is narrow, which is not suitable for The use of desulfurization towers with lower pH values;

However, nylon acid has a darker color, resulting in unqualified chromaticity of desulfurization drainage, so it is difficult to widely promote

[0006] At the same time, if the oxidizing air volume cannot meet the operation requirements during the desulfurization of limestone flue gas, it is very easy to cause poisoning of sulfite in the limestone slurry, resulting in fouling of the system and difficulty in dehydration of gypsum, reducing desulfurization efficiency and causing certain dangers

Moreover, when using limestone flue gas desulfurization, it is necessary to add defoamer to the inside of the desulfurization tower to ...

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