Technology for preparing sulfuric acid by partially pre-converting original SO2

Abstract

The invention discloses a technology for preparing sulfuric acid by partially pre-converting original SO2, which comprises the following steps of: shunting 0.1-10 percent of gas in original SO2 gas, heating by using a heating furnace or partial high-temperature gas at an outlet of a first section of a conversion section to a catalyst initiation temperature, entering a small-sized pre-converter, after the reaction, the SO3-containing gas is mixed with the rest 90%-99.9% of original SO2 gas which is connected in parallel for heat exchange and then enters a first section for conversion, at the moment, at least 0.0077% of SO3 gas is contained in the SO2 gas entering the first conversion section, the dynamic equilibrium relation of the original SO2 gas is changed, the first conversion section SO2 reaction is controlled within a certain speed, the first conversion reaction is relatively uniform and stable, and the reaction time is shortened; the outlet plane temperature is uniform. According to the technology, the flue gas with the low oxygen-sulfur ratio of 0.6-0.8 and the SO2 concentration of 14%-24% can be treated through the two conversion processes of 3 + 2, 3 + 1, 4 + 1 or 5 + 1, and due to the fact that the pressure drop of equipment on the gas side where the original SO2 part is subjected to pre-conversion is smaller than that of equipment on the other original SO2 gas side where heat exchange is conducted in parallel connection, no power consumption is increased by means of the technology for preparing the sulfuric acid through pre-conversion of the original SO2 part.

Description

technical field [0001] The invention relates to a process for preparing sulfuric acid by a contact method, in particular to original SO 2 Partially pre-converted sulfuric acid technology. Background technique [0002] With the advancement of technology, especially the oxygen-enriched smelting of non-ferrous metals, the smelted SO 2 The concentration is as high as 30% or more, which further promotes the improvement of the production intensity of the conversion equipment, and the SO entering the conversion reaction 2 The concentration is increased to 14%-24%, the oxygen-sulfur ratio is reduced to 0.6-0.8, the gas volume is reduced, and the strength of the production equipment is greatly improved. [0003] At present, it is limited by the temperature resistance limit of the catalyst, and for processing high concentration SO 2 There are various methods of conversion, each with advantages and disadvantages, and the most economical method is to use direct conversion. With SO ...

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Problems solved by technology

[0009] SO 3 The partial pressure is equal to 0, so the initial reaction rate will be infinite under certain temperature conditions, so that as long as there is a small difference in the temperature or catalyst on the reactor inlet plane, the final reaction result will be very different, especially like SO 2 Under the conditions of high concentration (14-24%) and low oxygen-sulfur ratio (0.6-0.8), the outlet temperature of the first stage is extremely uneven

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