Limestone/lime-gypsum desulfurization process

Technical principle:

The flue gas enters the wet absorption tower of the desulfurization device, and is in countercurrent contact with the spray of the alkaline limestone slurry sprayed from the top to the bottom, wherein the acidic oxide SO2 is

And other pollutants such as HCL and HF are absorbed, and the flue gas is fully purified; the slurry after absorbing SO2 reacts to form CaSO3, which is forcedly oxidized and knotted locally.

The crystal forms CaSO4•2H2O, and after dehydration, the commercial grade desulfurization by-product, gypsum, is obtained, and finally the comprehensive treatment of sulfur-containing flue gas is realized.

flow chart:

Technical features:

1. Wide range of absorbents: Various absorbents can be used in FGD equipment, including limestone, lime, magnesite, waste soda solution, etc.

2. Wide application range of fuel: It is suitable for tail gas treatment of boilers burning coal, heavy oil, Orimulsion, and petroleum coke;

3. The range of fuel sulfur content is adaptable: it can treat flue gas with fuel sulfur content up to 8%;

4. The adaptability of the unit load change is strong: it can meet the stable operation of the unit within the range of 15~100% load change;

5, high desulfurization efficiency: generally greater than 95%, the highest reached 98%;

6. Patented tray technology: Effectively reduce the liquid/gas ratio, which is conducive to uniform airflow in the tower, saving material consumption and energy consumption, and facilitating the maintenance of the internal parts of the absorption tower;

7. High utilization rate of absorbent: the ratio of calcium to sulfur is as low as 1.02~1.03;

8, the purity of by-products is high: it can produce commercial grade gypsum with a purity of more than 95%;

9. The dust removal efficiency of coal-fired boiler flue gas is high: 80%~90%;

10. Cross-spray tube layout technology: It is beneficial to reduce the height of the absorption tower.

Recommended scope of application:

1. Medium and large-scale new or modified units;

2. The sulfur content of coal combustion is 0.5-5% and above;

3. The required desulfurization efficiency is above 95%;

4. The area where limestone is rich and the gypsum is widely used.