Improved ammonia-method desulfurization process and system

Abstract

The invention relates to an improved ammonia-method desulfurization process and system. The improved ammonia-method desulfurization process is characterized in that ammonia water and calcium hydroxide are used as the absorbing agents and are in countercurrent contact with flue gas in a desulfurization tower, cooling is performed, desulfurization reaction is performed, generated ammonium sulfate and ammonium sulfite enter a regeneration tank and are regenerated by using a calcium hydroxide solution, generated ammonia water flows back to the desulfurization tower, the calcium sulfite at the bottom of the regeneration tank is oxidized and discharged into a calcium sulfate turbid liquid storage tank, and the oxidized calcium sulfite has reaction with ammonia gas generated by the regeneration tank and carbon dioxide in the flue gas to obtain ammonium sulfate fertilizer and calcium carbonate byproducts; ammonia gas escaped from the gas outlet of the desulfurization tower is absorbed by the phosphoric acid of a neutralization reactor to obtain ammonium phosphate compound fertilizer, and clean flue gas is discharged into atmosphere. The improved ammonia-method desulfurization process and system has the advantages that the problems of ammonia escaping, aerosol generation and gas tailing of ammonia-method desulfurization are solved effectively, and the problem that the ammonium sulfite is hard to dissolve is avoided; the system can simultaneously output various high-value byproducts, has considerable economic benefits and can relieve the high cost pressure of the ammonia-method desulfurization.

Description

technical field [0001] The invention relates to the field of flue gas desulfurization, in particular to an improved ammonia desulfurization process and system. Background technique [0002] China is a country where coal is the main energy source. With the rapid development of industry, sulfur dioxide produced by coal combustion has become the main pollutant of air pollution in China. my country's coal resources with less than 0.5% ultra-low sulfur coal are very limited, mainly distributed in Heilongjiang and Jilin in the northeast, Inner Mongolia in North China and some remote provinces in the northwest. Shipping is also expensive. Therefore, it is obviously unrealistic to exploit and widely use ultra-low sulfur coal in large quantities. [0003] Since there are abundant high-sulfur coal resources in our country, and it has caused serious pollution and acid rain, it shows that our country urgently needs a set of countermeasures and measures for the development and utilizati...

AI Technical Summary

Problems solved by technology

The aftermath of this process is a large amount of desulfurized gypsum piled up. The industrial by-product gypsum has high impurity content, complex components, and poor color. Limited by resource utilization technology and economic conditions, the comprehensive utilization rate in my country is currently less than 50%, of which phosphogypsum is only 27%, titanium gypsum is only 30%

Moreover, the ammonia-based desulfurization technology has my country's independent intellectual property rights. At present, the widely used calcium method is basically imported from abroad. Domestic desulfurization companies introduce the same technology, resulting in waste of resources

However, ammonia desulfurization also has some disadvantages, such as ammonia escape, aerosol and gas tailing phenomenon, ammonium sulfite oxidation difficulty, long-term operation to produce waste slurry and other problems. Efforts to solve these problems will be more conducive to the long-term and sustainable use of ammonia desulfurization in my country. Comprehensive promotion

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