Method for removing sulfur dioxide and recycling sulfur in flue gas

Abstract

The invention relates to a method for removing sulfur dioxide and recycling sulfur in flue gas, and belongs to the technical field of desulfurization of flue gas. The method comprises the following steps of dedusting, desalting and cooling the flue gas containing the sulfur dioxide, so that that the content of TSP (total suspended particulate) in the flue gas is smaller than 10%; leading the pretreated flue gas into an absorbing device, and enabling water to absorb the sulfur dioxide in the water, so as to obtain a sulfur dioxide absorbing liquid and the desulfurized flue gas; leading 40 to 60% of sulfur dioxide absorbing liquid into a sulfate microbial reducing bacteria biochemical reactor, and reducing the sulfite in the sulfur dioxide absorbing liquid into hydrogen sulfide gas by the microbial reducing bacteria under the anaerobic function; leading the remaining sulfur dioxide absorbing liquid into a sulfur recycling reactor; using eluting gas to elute the hydrogen sulfide gas in the sulfate microbial reducing bacteria biochemical reactor, sending the hydrogen sulfide gas into the sulfur recycling reactor together with the eluting gas, and enabling the hydrogen sulfide gas to react with the sulfite in the sulfur dioxide absorbing liquid in the sulfur recycling reactor, so as to obtain the sulfur.

Description

technical field [0001] The invention relates to a method for removing sulfur dioxide in flue gas and recovering sulfur, and belongs to the technical field of flue gas desulfurization. Background technique [0002] Sulfur dioxide is an important air pollutant. Its large-scale emission can form environmental pollution such as acid mist, acid rain, and haze, which poses a serious threat to human health and the ecological environment. [0003] At present, the treatment methods of sulfur dioxide in flue gas mainly include calcium desulfurization and ammonia desulfurization. Among them, the calcium method produces calcium sulfate and calcium sulfite through the reaction of calcium oxide or calcium hydroxide with sulfur dioxide in the flue gas. Due to the high impurity content in desulfurized gypsum, it is difficult to realize resource utilization, and the traditional stacking and landfill method will not only It takes up a lot of land and there is a risk of serious contamination ...

AI Technical Summary

Problems solved by technology

This patent needs to use lye, which is easy to cause secondary pollution, and uses aerobic bacteria, which has high requirements for the living environment and increases the corresponding cost

CN104607029B proposes "a chemical absorption combined with anaerobic and aerobic conversion synchronous flue gas desulfurization and denitrification process", which uses lye to absorb sulfur dioxide from flue gas, uses anaerobic microorganisms to convert the sulfur dioxide absorption liquid into sulfide, and passes the sulfide solution into the well Aerobic microorganisms convert sulfide into elemental sulfur. This patent uses lye to absorb flue gas, which increases the corresponding cost. Improper treatment can easily cause secondary pollution. The two strains used in this patent are relatively complicated, and the aerobic bacteria The amount of nutrients needed is large, the energy consumption is high, the environmental requirements are high, and the sludge output is high, and the hydrogen sulfide produced by sulfate-reducing bacteria is not properly treated in this patent

This patent uses lye to absorb, which increases a certain cost, and there is no corresponding treatment for the hydrogen sulfide produced by microorganisms, which will cause poisoning to microorganisms and reduce the treatment efficiency of microorganisms. This patent uses iron ions to catalyze oxidation to recover sulfur, the system is complex, and the reaction The process also requires the addition of a large amount of iron salt, which is not economical and environmentally friendly.

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