System and method for treating acidic tail gas and producing ammonium salt

Abstract

The invention discloses a system and a method for treating acidic tail gas and producing ammonium salt. The system and the method solves the problems that effective treatment means for tail gas containing hydrogen chloride, chlorine and sulfur dioxide and other harmful gas is lack in the prior art, and at the same time the tail gas cannot be changed from waste into valuables according to the present method. The system and the method can substantially improve acid removing efficiency without inducing system fault. When the acidic gas is treated, solid ammonium salt is also prepared in order to change waste into valuables. A structure of a piece of reactor equipment in the system is divided into three segments, including a micropore aeration section, a gas-liquid reaction section, and a counter current washing section from bottom to up in order; air passes a piece of micropore aeration equipment and enters the gas-liquid reaction section, dissolved oxygen in the liquid phase is improved, and conversion rate from sulfite to sulfate is improved; the gas-liquid reaction section is provided with a circulating water pump, and the circulating water pump improves absorption of ammonia gas when the liquid phase passes through the counter current washing section and washing for removing generated particular ammonium salt.

Description

technical field [0001] The invention belongs to the field of environmental protection, and in particular relates to a system and method for treating acid tail gas to produce ammonium salt. Background technique [0002] At present, some chemical enterprises will produce toxic and harmful mixed tail gas containing hydrogen chloride, chlorine gas, sulfur dioxide, etc. during the production process. There are dry method, semi-dry method and wet method to deal with acid gas. Among them, the dry method is to spray calcium hydroxide powder into the reaction tower to adsorb and react the acidic substances in the acid tail gas to generate harmless central salt. Particles will enter the downstream dust collector for dust removal. The method has the advantages of simple process, low investment, no waste water, and little equipment corrosion. The disadvantage is that the dosage of chemicals is large, and the acid removal efficiency is only 50-80%. The representative technologies of we...

AI Technical Summary

Problems solved by technology

The by-product deacidification ash produced by this process is in the form of dry powder, and its main components are calcium sulfite, calcium sulfate and calcium chloride. On the one hand, the dry powder product is likely to cause secondary dust pollution to the environment. On the other hand, the The economic value of some products is small, and they are generally used as waste mine backfill and road foundation, etc.

However, due to the need to spray and atomize the slaked lime, the particle size of the slaked lime is required to be relatively high. At the same time, the nozzles in this method are used to spray solid particles, which can easily lead to blockage of the nozzles and affect the efficiency of tail gas treatment.

[0003] In addition, the acid-base neutralization reaction is an exothermic reaction. During the tail gas treatment process, a large amount of heat will be generated. If the heat is accumulated in the reactor and cannot be discharged in time, on the one hand, the temperature in the reactor will be too high, causing safety hazards. On the other hand, if the temperature in the reactor is too high, it will hinder the acid-base neutralization reaction and reduce the removal efficiency of acid gas in the tail gas.

[0004] To sum up, in the prior art, there is still no effective treatment method for the tail gas containing harmful gases such as hydrogen chloride, chlorine and sulfur dioxide, and at the same time, according to the current method, it is still impossible to turn this kind of tail gas into treasure

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