Production method of sodium pyrosulfite with low nitrogen oxide emission

Abstract

The invention discloses a production method of sodium pyrosulfite with low nitrogen oxide emission, which comprises the following steps of S1, feeding sulfur powder into a low-nitrogen combustion furnace, and carrying out spontaneous combustion at 600-1100 DEG C to obtain sulfur dioxide gas, S2, enabling the sulfur dioxide gas to subjected to dust removal treatment and then introduced into a third-stage reactor to be subjected to a neutralization reaction with a sodium carbonate solution, and generating a sodium metabisulfite suspension through the reaction, S3, enabling the sodium metabisulfite suspension obtained in the step S2 to pass through a secondary reactor and a primary reactor to generate sodium metabisulfite crystals, and drying the sodium metabisulfite crystals at the temperature of 150-180 DEG C to obtain a finished product, and S4, treating the tail gas generated in the step S2 by using an alkali liquor absorption tower to remove sulfur dioxide, compressing by using a pressurizing device, introducing into a conversion tower, performing nitrogen oxide absorption treatment, and discharging from an exhaust port. The discharge amount of nitrogen oxide in the production process of sodium pyrosulfite is reduced, the environmental pollution is reduced, the consumption of sulfur is reduced, and the raw material cost is saved.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a production method of sodium metabisulfite with low nitrogen oxide discharge. Background technique [0002] Sodium metabisulfite, also known as sodium metabisulfite, is a white or yellow crystalline powder or small crystal, and is an important sulfite. It is used as bleaching agent, preservative, loosening agent, antioxidant, color-protecting agent and preservative in the food industry; in the pharmaceutical industry to produce chloroform, phenylpropyl sulfone and benzaldehyde; in the printing and dyeing industry as a dechlorinating agent after bleaching of cotton cloth, Cotton scouring aid. In the tanning industry, it is used for leather treatment, which can make the leather soft, plump, tough, waterproof, anti-folding, and wear-resistant. In the chemical industry, it is used to produce hydroxyvanillin, hydroxylamine hydrochloride, etc. The photosensitive industry...

AI Technical Summary

Problems solved by technology

The SCR method uses ammonia or urea as the absorbing liquid, and converts nitrogen oxides into nitrogen under the action of a catalyst with components V, W, and Ti. This method has a good denitrification effect, but there is a problem of ammonia escape, which is very easy to The environment produces secondary pollution; the SNCR method also uses ammonia or urea as the absorption liquid, and converts nitrogen oxides into nitrogen without a catalyst. The denitrification efficiency of this method is low and the effective reaction window temperature is narrow. control

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