Deprivation technique based on semi-dry process

Abstract

The invention discloses a simultaneously-removing technology based on a semidry method, which has the following steps: (1) pretreatment for removing dust; (2) oxidation reaction between hydrogen peroxide and smoke gas: NO+H2O2=NO2+H2O, and 2NO+O2=2NO2, SO2+H2O2=SO3+H2O; (3) reaction in an absorption tower: Ca(OH)2+SO2=CaSO3.1/2H2O+1/2H2O, CaSO3.1/2H2O+1/2O2=CaSO4.1/2H2O; Ca(OH)2+H2O+NO2=Ca(NO3)2+2H2O, Ca(OH)2+2HCl=CaCl2+2H2O, and Ca(OH)2+2HF=CaF2+2H2O; (4) after the reaction, the smoke gas is discharged after dust removal. The technology has integrated design, and various pollutants, such as SO2, NOx, can be simultaneously removed in one reaction tower; the invention has the advantages of simple technology, simplified system, small area occupation and low investment and running cost; the system adopts a semidry technique, the water consumption is low, and the technology is particularly suitable for water-deficient areas; the market supply of quick lime or white lime used as system removing agents is abundant, and the removing agents are convenient to buy in local; byproducts belong to available resources; and the removing system can almost completely remove sulfur trioxide in smoke gas. Therefore, the whole device does not need corrosion prevention.

Description

technical field [0001] The invention belongs to the flue gas desulfurization and denitrification purification process, and in particular relates to an integrated process for simultaneous desulfurization and denitrification using a semi-dry method. Background technique [0002] my country is a country that uses coal as the main energy source, and coal-fired power generation is one of the most important ways of coal utilization in my country. According to my country's national conditions, coal-fired power generation will dominate in the 21st century. Among the many air pollutants emitted by coal-fired thermal power units, SO 2 , NOx and dust are more harmful to the environment and are also the main pollutants to be controlled. With the progress of society and the development of economy, the pollution of thermal power plants to the atmospheric environment has been widely concerned by people. Therefore, it is a severe challenge for the sustainable development of my country's e...

AI Technical Summary

Problems solved by technology

[0005] Wet flue gas desulfurization technology mainly has the disadvantages of large investment, large power consumption, large floor area, complex equipment, high operating costs and technical requirements.

[0006] Compared with wet desulfurization technology, semi-dry desulfurization technology has the advantages of less investment, small footprint, low operating cost, simple equipment, convenient maintenance, and no need for reheating flue gas, but there are high calcium-sulfur ratios, low desulfurization efficiency, Disadvantages such as by-products cannot be commercialized

[0007] Although the SCR or SNCR method in the flue gas denitrification technology can achieve high denitrification efficiency and meet very strict environmental protection standards, its denitrification system is huge, the equipment is complex, and the investment and operation costs are high.

[0008] At present, the patents related to this topic include: the Chinese invention patent specification with the application number 200710052129.7 proposes a wet flue gas cleaning process and system for simultaneous desulfurization and denitrification. Since the system actually uses a wet method, the water consumption of the entire process is very high. Large, it is very difficult for flue gas desulfurization in water-shortage areas, and the promotion of this technology is not used; and the price of absorbent - ammonia water is relatively high, and the cost of raw materials is high

[0009] The Chinese invention patent specification with the application number 03125332.6 proposes a simultaneous desulfurization and denitrification dry flue gas cleaning process and its system. In fact, the system is equipped with a desulfurization system and a denitrification system respectively. The system composition is still relatively complicated, and the integration goal has not been achieved.

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