Method for producing sulphuric acid with SO2 containing coal-fired boiler flue gas

Abstract

The invention provides a method for producing sulfuric acid by using an SO2-containing coal fired boiler flue gas, and relates to the fields of environmental protection and absorbent recycling. The SO2-containing coal fired boiler flue gas is absorbed by the alkaline solution prepared by adding water to alkali metal oxide, the sulfite and the sulfate solids produced are filtered out; the sulfite and the sulfate solids are mixed with sulfur and delivered to a fluidizing reactor, air is blown into the reactor for calcination, the calcination temperature is controlled at 900-1250 DEG C to decompose the sulfite and most of the sulfate into alkali metal oxide and SO2 gas; the SO2 gas obtained from decomposition is purified, absorbed dry and transformed to produce sulfuric acid. The method can absorb the SO2 gas in the flue gas and leads the gas emission of the coal fired boiler to comply with the requirement for environmental protection, the alkali metal oxide regained for absorbing can berecycled infinitely, the SO2 gas concentrated from the flue gas can be used for producing sulfuric acid at low cost.

Description

technical field The invention relates to the fields of environmental protection and absorbent recycling. Background technique The flue gas of coal-fired boilers in power plants contains a certain amount of SO2. Because its concentration is not very high, generally only 0.03% to 3%, sulfuric acid cannot be directly produced, and the venting will pollute the environment and waste resources. Economically viable solutions are being investigated all over the world. Although there are many methods, some have too much investment, some have too high operating costs, some cannot recycle absorbents, and some cannot make SO2 into products, none of which can fundamentally solve the problem of environmental pollution. Contents of the invention The object of the invention is to use coal as energy to produce SO2-containing boiler flue gas as a raw material, a method for producing sulfuric acid. The present invention comprises the following steps: 1) Absorb SO2 with an alkaline solu...

AI Technical Summary

Problems solved by technology

Although there are many methods, some have too much investment, some have too high operating costs, some cannot recycle absorbents, and some cannot make SO2 into products, none of which can fundamentally solve the problem of environmental pollution