Technique for preparing sulfuric acid from SO2 by non-equilibrium state high-concentration twice conversion

Abstract

The invention discloses a technique for preparing sulfuric acid from SO2 by non-equilibrium state high-concentration twice conversion. SO2 flue gas is subjected to heat exchange twice through a heat exchanger and enters a first section of a converter to be subjected to conversion reaction; the filling amount of the catalyst for the first section of the converter is reduced so that the flue gas can leave the catalyst layer before reaching the SO2 equilibrium conversion rate; a waste heat boiler is arranged before the flue gas entering a second section of the converter to keep the temperature of the second section of the converter stable; the flue gas flows through the waste heat boiler and the heat exchanger to be cooled, and enters the second section catalyst layer of the converter, and at this time, the flue gas SO2 concentration is lower than 12%; the subsequent technique is equivalent to a conventional 3+1 twice conversion technique; and in the process, the temperatures of the first and second sections of the converter are lower than 640 DEG C. The technique can treat flue gas of which the SO2 concentration reaches 18% so as to lower the gross project investment and operating cost and enhance the steam output of the sulfuric acid waste heat boiler, thereby being an energy-saving consumption-reduction conversion technique.

Description

[0001] technical field [0002] The invention relates to a process for producing sulfuric acid by a contact method, in particular to a non-equilibrium high-concentration double conversion technology. Background technique [0003] The main raw materials for sulfuric acid production are pyrite, sulfur, and non-ferrous metal smelting flue gas. In the field of non-ferrous smelting flue gas acid production, with the development of non-ferrous metal oxygen-enriched smelting technology, especially the development of copper oxygen-enriched smelting technology, it has become a reality that the concentration of sulfur dioxide in the flue gas entering the flue gas acid production system reaches more than 20%. SO 2 converted to SO 3 is an exothermic reaction, SO 2 The higher the concentration, the greater the heat of reaction and the higher the temperature after conversion. Currently, for SO 2 converted to SO 3 For catalysts, the temperature resistance limit of foreign production ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a non-equilibrium high-concentration twice-conversion sulfuric acid production technology of SO2, which can handle SO2 Flue gas with sub>2 concentration less than 18% solves the problem that the temperature limit temperature of the catalyst cannot meet the high-concentration conversion requirements of more than 14% SO2, so as to reduce operating costs and total project investment , improve the steam output of the waste heat boiler, and better adapt to the change of copper-sulfur ratio in copper concentrate, which is an energy-saving and consumption-reducing conversion technology

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