a low concentration so 2 Preparation method of flue gas one-transfer and two-suction sulfuric acid

Abstract

The invention discloses a low-concentration SO2 flue gas one-winding two-sulfuric acid absorption preparation method. The method is characterized in that flue gas containing sulfur dioxide is subjected to purifying and demisting, impurity removal and defoaming, and then is sent to a first absorption unit for absorption, is sent to a gas unit for gas stripping, is sent to a primary conversion unitfor conversion, and is sent to a secondary absorption unit to generate sulfuric acid. Through a one-conversion two-absorption technology, the SO2 flue gas with concentration being 0.5-3% is completelyrecovered, exhaust gas emission can achieve a national strict standard (lower than 35 mg / m<3>), and qualified 98% acid is prepared. The method can be popularized, is cost-effective, reduces steam consumption, and reduces operation cost and reduces total engineering investment, a lot of waste and by-products cannot be generated, and the desulphurization acid-making technology has the advantages ofenergy saving and emission reduction, and environmental protection.

Description

technical field [0001] The invention relates to a high-efficiency SO removal with one rotation and two suctions 2 Then the process of making sulfuric acid. Background technique [0002] Domestic smelting SO 2 When the flue gas concentration is 4.0-6.5%, the one-turn-one-suction technology is adopted, and the second-turn-two-suction mature technology can be used to make acid with a high concentration of 98% acid when the smoke concentration is above 6.5%. SO 2 When the flue gas concentration is 0.1% or below, lime-gypsum method, double-alkali method, hydrogen peroxide method, ammonia method, etc. can be used for desulfurization treatment. Desulfurizers need to be consumed, there are by-products, and by-products are discarded or recycled in small quantities, while SO 2 The smelting flue gas with a concentration between 1.0% and 4.0%, especially between 0.5% and 3%, can neither be used for conventional acid production, nor can it be desulfurized by conventional desulfurizati...

AI Technical Summary

Problems solved by technology

SO 2 When the flue gas concentration is 0.1% or below, lime-gypsum method, double-alkali method, hydrogen peroxide method, ammonia method, etc. can be used for desulfurization treatment. Desulfurizers need to be consumed, there are by-products, and by-products are discarded or recycled in small quantities, while SO 2 The smelting flue gas with a concentration between 1.0% and 4.0%, especially between 0.5% and 3%, can neither be used for conventional acid production, nor can it be desulfurized by conventional desulfurization methods (such operation costs are extremely large, and side effects The product cannot be processed)