(1) At low temperature, the desulfurization rate is high (98%), and the denitrification rate is high (80%);
(2) After treatment, the flue gas does not need to be heated before discharge;
(3) No water, no secondary pollution;
(4) The adsorbent has a wide range of sources, no poisoning problem, and only need to supplement the depleted part;
(5) The advanced treatment of HF, HCl, arsenic, mercury and other pollutants in waste gas by SO2 removal is a deep treatment technology. With dust removal function, the dust concentration at the outlet is less than 10mg / m3. It can recover high-purity sulfur, concentrated sulfuric acid, chemical fertilizer and other by-products with low construction cost, economic operation cost and small floor area.
A new process of desulfurization and denitrification with activated carbon fiber. Fibrous activated carbon with diameter of about 20 μ m was prepared, which greatly increased the adsorption area of activated carbon and improved the adsorption and catalytic performance of activated carbon. After development, the desulfurization and denitrification rate of this technology can reach 90%.
A microwave catalytic reduction desulfurization and denitrification technology was proposed by combining activated carbon adsorption technology with microwave technology. In this process, activated carbon is used as the carrier of nitrogen oxides, and the desulfurization and denitrification rate can reach more than 90% by microwave induction.
The adsorbent is prepared by spraying r-alumina as the carrier, spraying the carrier with alkali or alkali salt solution, then heating and drying the soaked adsorbent to remove the residual water. The adsorbent can be regenerated after adsorption and saturation. The regeneration process is to send the saturated adsorbent to the heater, release NOx by heating at about 600 ℃, and then recycle NOx back to the burner of the boiler. The NOx concentration in the burner reaches a stable state and forms a chemical equilibrium. This will not produce NO x, but only produce N2, thus inhibiting NO x production. When the reducing gas is added into the regenerator, the mixture of SO2 and H2S with high concentration is produced, and Claus process can be used for sulfur recovery.
CuO adsorption desulfurization and denitrification process uses adsorbent for desulfurization and denitrification, the whole reaction is divided into two steps: 1) in the adsorbent, the adsorbent reacts with sulfur dioxide in the temperature range of 300 ~ 450 to produce CuSO4; because CuO and CuSO4 have high catalytic activity for NH3 reduction. Nitrogen oxides, combined with SCR process for denitrification. 2) In regenerator: absorption of CuSO after saturation_ 4 send to regenerator for regeneration. The regeneration process is usually controlled by H_ 2 or CH_ 4. The regenerated sulfur dioxide is recovered by Claus unit to produce acid. In the adsorbent treatment unit, reduced copper or copper is oxidized into copper oxide by flue gas or air, and the generated copper oxide is used for absorption and reduction process. The process can achieve more than 90% sulfur dioxide removal rate and 75% - 80% nitrogen oxide removal rate.
The reaction temperature of adsorption method is high, heating device is needed, and the preparation cost of adsorbent is high. With the development of research, the combination method of activated carbon / carbon (AC) and CuO is gradually developed. By combining the two methods, the catalyst with suitable activity temperature can be prepared, which overcomes the disadvantages of low AC application temperature and high CuO / Al2O3 activity temperature.