A cleaning process and system for the disposal of acetylene waste acid

Abstract

The invention provides a cleaning technology of acetylene waste acid treatment, which comprises the following steps: performing spray decomposition on acetylene waste sulfuric acid at 400-700 DEG C to obtain gas products such as sulfuric acid mist and SO3, performing dust collection, ammonia neutralization and absorption liquid concentration, and reacting the vast majority of acid matters in gas with an ammonia-containing solution to obtain an ammonium sulfate solution at 95-105 DEG C; performing high-temperature filtering on an obtained liquid product, removing inorganic impurities, performing cooling to be 25-35 DEG C, performing centrifugal separation to obtain an ammonium sulfate product, mixing a mother solution with a raw material, namely ammonia water as an absorption liquid of an acid gas absorption tower, and treating the treated gas with the absorption liquid to thoroughly remove the acid matters, and allow tail gas to realize up-to-standard discharge. The invention further provides a system for realizing the technology. A core of a whole technology process is gasification decomposition of acetylene waste sulfuric acid, the dust collection of a venturi dust collector, the neutralization, the concentration and the like; a cooling crystallization technique, a flue gas recovery technique and the like are utilized; and the cleaning technology is typically environment-friendly.

Description

technical field [0001] The invention relates to a cleaning process and system for the disposal of acetylene waste acid, which belongs to the three-waste recycling technology in the PVC industry. Background technique [0002] In the production process of PVC, tens of thousands of tons of directly drinking water are consumed every year, and almost the same amount of industrial wastewater is discharged. Especially for the original acetylene cleaning, chlorine gas and sodium hydroxide are used to generate sodium hypochlorite solution through Venturi flowmeter, and sodium hypochlorite is used to react with hydrogen sulfide and phosphine to remove sulfur and phosphorus in acetylene gas. A large amount of waste sodium water generated in the reaction is directly discharged into the environment through the sewage pipe, which not only wastes a lot of acetylene gas dissolved in the waste sodium liquid, wastes resources, increases the consumption of enterprises, reduces production effic...

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Problems solved by technology

It also contains: phosphoric acid, acetylene carbon black, elemental sulfur, etc., which is a complex mixed solution; organic matter and acetylene carbon black in the solution have limitations in purification treatment by chemical methods, filtration methods, adsorption methods, distillation methods, etc., and cannot be regenerated qualified concentrated sulfuric acid

At present, the common treatment method is to use calcium carbide slag to neutralize to make gypsum of poor quality (the content of organic matter seriously exceeds the standard). This gypsum is also difficult to sell, so it is generally disposed of in landfill. In the foreseeable future, such landfill treatment does not meet the requirements of environmental protection (should meet the requirements of chemical solid waste treatment)

[0004] The ultimate outlet for waste acid is to recycle waste acid or regenerate waste acid into sulfuric acid for reuse. Among them, sulfuric acid pyrolysis and regeneration to prepare sulfuric acid for reuse are competitive processes. However, the pyrolysis regeneration technology consumes a lot of energy, equipment investment, and treatment costs. high, and the problem of corrosion of waste heat boilers and other equipment by phosphorus in acetylene waste sulfuric acid has not been well resolved, which limits the promotion of this technology in China

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