Device for converting SO2 concentration and SO2 conversion system and method

Abstract

The invention discloses a device for converting SO2 concentration, a SO2 conversion system comprising the device, and a SO2 conversion method. Before entering a converter, gas containing SO2 is pretreated through the device for converting the SO2 concentration. The pretreatment equipment comprises an air inlet, an equipment shell, short-section catalyst layers, a heat exchanger and an air outlet. Therefore, the problem that a reaction cannot be carried out due to damage of the catalyst caused by extremely large heat release amount caused after high-concentration SO2 enters the converter is solved, and the nationally specified SO2 content emission standard is reached while the conversion rate can be improved. Meanwhile, the device can be applied to metallurgy, preparation of H2SO4 and other conversion reactions in which high-concentration SO2 needs to be oxidized to generate SO3 in the production process, and also can be applied to conditions that other reactants are high in concentration and strong in heat release in the reaction process and the catalyst activity is damaged due to extremely high heat.

Description

technical field [0001] The invention relates to the field of flue gas treatment, in particular to a method for converting SO 2 Concentration means and SO including the means 2 Transformation systems and transformation methods. Background technique [0002] SO 2 Oxidation to SO 3 The reaction is widely used in actual chemical production, and is usually used in industrial production links such as the preparation of sulfuric acid, while SO 2 The source can be non-ferrous metal smelting, petrochemical tail gas, coal combustion tail gas, etc. [0003] State-mandated SO 2 The conversion rate standard is above 99.6%, which requires the emission of SO into the atmosphere 2 The content must be extremely low. So SO 2 Oxidation occurs in the converter to produce SO 2 , its conversion rate must be up to standard, and it must operate normally at low cost. [0004] SO 2 Oxidation to SO 3 The usual method is to put SO 2 Pass into the converter and carry out catalytic oxidation...

AI Technical Summary

Problems solved by technology

[0008] The heat released by the oxidation reaction of sulfur dioxide will increase the temperature of the catalyst layer, and at the same time the equilibrium conversion rate of sulfur dioxide will also decrease. When the temperature exceeds 650 ° C, the catalyst will be damaged

When SO passing through the first vanadium catalyst 2 When the concentration is too high, the heat released by the most intense reaction will also be the largest, and the vanadium catalyst may overheat and lose activity, or even burn out

Specifically, the temperature range of the general vanadium catalyst is 410-620°C, and the SO in the flue gas 2 The concentration of the inlet gas can only be between 4% and 8%, and when the concentration of the inlet gas is 13% or above, the heat release is the strongest when it passes through the first stage of the catalyst bed of the converter, and the outlet temperature of the bed will decrease. Reaching above 700°C, this temperature is far beyond the temperature range of the catalyst, which will cause serious damage to the catalyst and make it lose its activity

In order to enable the conversion reaction to proceed normally, only by diluting SO 2 method to react, but this not only increases the production cost, but also increases the complexity of production, and increases the processing capacity of the converter, reducing the SO 2 The conversion speed, SO 2 The converter operates very inefficiently

At the same time, if the dilution is uneven, it will also reduce the SO 2 The conversion rate exceeds the national emission standard

[0010] At present, most of the converters used in China are five-stage conversion processes, that is, the first and second stages of the converter use cold shock gas between the beds, and the rest of the beds use partition heat exchange, although this can save the amount of catalyst , but under the condition of high-concentration intake air, the heat released by the conversion reaction is still very large, and because the cold excitation gas does not pass through the first and second catalyst beds, the thermal zone where the overall catalyst bed is located is still at temperature higher, so SO 2 The conversion rate will be reduced, generally as low as below 97%, which cannot reach the state's SO 2 Emission Standards

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