Acid gas wet method acid making technology combined with semidry method tail gas desulfurization

Abstract

The invention relates to an acid gas wet method acid making technology combined with semidry method tail gas desulfurization. Acid gas and fuel gas enter an acid gas combustion furnace, the burnt technological gas enters a sulfur dioxide converter after subjected to heat exchanging through an acid gas waste heat boiler, the technological gas coming out from the sulfur dioxide converter enters a sulfuric acid condenser, sulfur acid flowing out from the bottom of the sulfur acid condenser enters a sulfur acid mixing slot after being mixed with recycling cool acid, and then cooled by a sulfur acid water cooler to serve as a sulfur acid product to be sent out of boundary, the tail gas coming out from the top of the sulfur acid condenser is mixed with part of hot air coming out from the sulfuracid condenser to form acid making tail gas which enters a venturi section on the lower part of a circulating fluidized bed desulfurizing tower, the acid making tail gas is in sufficient contact withslaked lime in the tower, the tail gas containing the slaked lime powder enters a bag filter, and the purified tail gas is exhausted into a chimney through a desulfurization induced draft fan. The method firstly combines the semidry method desulfurization with a wet method acid making technology, achieves 97-100% removal rate of SO3 (sulfuric acid mist) while removing SO2 in the tail gas, and up-to-standard emission of the tail gas is achieved.

Description

technical field [0001] The invention relates to the technical field of acid gas acid production process, in particular to an acid gas wet acid production process combined with semi-dry tail gas desulfurization. Background technique [0002] Acid gas wet acid production is a process system widely used in coal chemical industry, coking, oil refining chemical industry, viscose fiber production, non-ferrous metal smelting and other industries to process acid gas and recover high-concentration sulfuric acid. Compared with dry acid production, it has technological advantages The process is simple, the floor area is small, the heat utilization rate is high, and high-quality steam can be produced by-product. However, limited by the performance of the sulfur dioxide catalytic conversion catalyst, the conversion rate of sulfur dioxide is up to 99.0-99.3%, so the tail gas of acid production contains a certain amount of SO 2 , in addition, the tail gas also contains a certain amount of...

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Problems solved by technology

[0004] At present, wet desulfurization is a commonly used method to treat the tail gas of acid plant, but due to the limitation of wet desulfurization process characteristics, the SO entering the wet desulfurization system 3 It is easy to form SO with a diameter of 0.1 μm 3 aerosol, to remove these SO 3 The pressure drop required by the aerosol is much higher than the operating pressure drop of the normally designed wet desulfurization system. 3 The removal rate of the exhaust gas is less than 30%. When the concentration of sulfuric acid aerosol in the tail gas exceeds 5-8ppm, there will be "smoke" in the chimney, resulting in SO in the tail gas 3 (acid mist) content exceeds the standard, and it will also cause corrosion, blockage, scaling and other hazards to the equipment, affecting the normal and stable operation of the desulfurization system

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