Technology and equipment for continuously preparing sulfur dioxide from low-concentration fuming sulfuric acid

Abstract

The invention belongs to the technical field of inorganic chemical industry and in particular relates to a technology and equipment for continuously preparing sulfur dioxide from low-concentration fuming sulfuric acid. The technology comprises the following steps: 1) introducing a gaseous phase of a converter at 4 and 5 stages of a sulfuric acid preparation technology into a secondary absorption tower from a gaseous phase input pipeline to be absorbed, enabling the gaseous phase to enter an external absorption system to be continuously absorbed, enabling the fuming sulfuric acid to enter intoa circulating slot, continuously pumping into a primary reaction tower by virtue of a pump A, introducing liquid sulfur at the same time, carrying out reaction, and always keeping a state of lack of the liquid sulfur during reaction, wherein a liquid phase obtained through absorption is fuming sulfuric acid; 2) continuously pumping back reaction liquid produced during reaction in the step 1) intothe circulating slot by virtue of a pump B; and 3) enabling mixed gas produced during the reaction in the step 1) to enter the lower part of a secondary reaction tower, introducing the liquid sulfur at the same time, and carrying out reaction, thus obtaining sulfur dioxide gas, wherein a state of excessive liquid sulfur is always kept in a reaction process. The technology provided by the inventionis simple and practicable, energy consumption is also reduced, production cost is reduced, and product quality is improved; and safety performance is good, and automation degree is high.

Description

Technical field [0001] The invention belongs to the technical field of inorganic chemicals, and specifically relates to a process and equipment for continuously preparing sulfur dioxide with low-concentration fuming sulfuric acid. Background technique [0002] At present, the production process of sulfur dioxide is to first prepare sulfur trioxide, and then the sulfur trioxide reacts with liquid sulfur to form sulfur dioxide. [0003] The production of sulfur trioxide is the production of sulfur dioxide by incineration in the sulfuric acid industry, which is then catalytically converted into sulfur trioxide by the 1, 2, and 3 stage converters. The sulfur trioxide is then absorbed by concentrated sulfuric acid to become fuming sulfuric acid. After evaporation, liquid sulfur trioxide is produced. In the sulfur trioxide conversion part, most of the sulfur dioxide can be converted but some parts have not yet been converted. Therefore, the first conversion part uses the concentrated su...

AI Technical Summary

Problems solved by technology

In the sulfur trioxide conversion part, most of the sulfur dioxide can be converted in the front, but some of them have not been converted, so the previous conversion part uses the concentrated sulfuric acid in the first-level nicotinic acid tower and the second-level nicotinic acid tower to absorb and convert it into high-concentration fuming acid , the gas phase enters the primary absorption tower for absorption, and the unabsorbed sulfur dioxide in the gas phase continues to enter the 4th and 5th stage converters to be converted into sulfur trioxide, and then absorbed into concentrated sulfuric acid through the secondary absorption tower. Concentrated sulfuric acid converts 98% acid, resulting in part of sulfur trioxide not recovered

[0004] The above process has the following problems: the process route is long, and the evaporation and storage of niacin not only brings large investment and high energy consumption, but also brings more potential safety hazards

Images