Principles, advantages and disadvantages of waste gas desulfurization and denitrification process

I believe that many friends are not very clear about the desulfurization and denitrification process. Today, let me introduce the principle, advantages and disadvantages of the waste gas desulfurization and denitrification process?

The first is desulfurization technology. At present, there are dozens of flue gas desulfurization technologies. According to whether water is added in the desulfurization process and the dry and wet form of desulfurization products, flue gas desulfurization can be divided into three categories: wet, semi dry and dry. Wet desulfurization technology is relatively mature, with high efficiency and simple operation.

Then there are denitration technologies. According to the formation mechanism of nitrogen oxides, the technical measures for reducing nitrogen and emission can be divided into two categories:

One is to govern from the source. Control NOx generation during calcination. Its technical measures: ① low nitrogen burner; ② Sectional combustion in calciner and pipeline to control combustion temperature; ③ Change the proportioning scheme, adopt mineralizer, and reduce the clinker burning temperature.

The other is from the end. The technical measures for controlling NOx emission in flue gas are as follows: ① "staged combustion+SNCR", which has been piloted in China; ② Selective non catalytic reduction (SNCR) has been piloted in China; ③ At present, there are only three lines of experiments for selective catalytic reduction (SCR) in Europe; ③ SNCR/SCR joint denitration technology, domestic cement denitration has no successful experience; ④ Biological denitration technology (under development).

The second is the application of desulfurization and denitration technology in boiler enterprises. The desulfurization and denitration technology of boiler enterprises mostly uses coal or gas as the combustion medium in the existing domestic boiler manufacturers. For coal-fired boilers, the domestic application of the mature process is FGD (using absorbent or adsorbent to remove sulfur dioxide in the flue gas) desulfurization technology, and the denitration is dominated by SCR technology of selective catalytic reduction.