"Near Zero Emissions" Calls for Environmental Equipment Upgrades

"Fired power plant emissions of air pollutants can reach the discharge standard gas generator." Since the country proposed in March this year that special emission limits were imposed in areas such as Jing-Jin-Ji and other regions, and that the “near-zero-emission” requirement in the coastal areas was being implemented, “near-zero emissions” had become a new target for thermal power plants almost overnight. However, the "near-zero emissions" to optimize the performance of environmental protection equipment, structural design, system upgrades and other aspects of the new requirements, after a long, large-scale, explosive growth of environmental protection equipment industry began to look to invest in equipment upgrades and real The level of technological innovation.

In fact, there are no clear standards for what are the concepts of “near-zero emissions,” “zero discharge,” and “ultra-low emissions.” However, the industry usually uses the emission level of gas-fired power generation as a reference standard. However, from the new round of policy papers on desulphurization, denitrification, and dust removal issued by local governments in the first half of this year, it can be seen that “near-zero emissions” refers to the emission limits of gas turbine units, that is, smoke emission concentration is not greater than 5 mg/m3 , Sulfur dioxide emission concentration is not greater than 35 mg/m3, and nitrogen oxide emission concentration is not greater than 50 mg/m3.

On June 19 of this year, the Zhejiang Provincial Development and Reform Commission issued the news that the No. 8 generating unit of the Zheneng Jiaxing Power Plant in Zhejiang Province achieved zero emissions. This is the first ultra-low emission device for flue gas generation from coal-fired units with millions of kilowatts put into operation in China. Unit 8 uses the “multi-pollutant high-efficiency collaborative coordinated removal and integration technology”, and the emission level of main pollutants of flue gas is equal to or better than that of gas. The unit emission standards blew up the number of "near-zero emissions" of thermal power units in China.

Immediately afterwards, Shenhua Guohua Zhoushan Power Plant Unit 4 was formally handed over to production. This unit is the first newly built “near-zero-emission” coal-fired generating unit in China. The unit is equipped with a high-efficiency flue gas denitrification device (low-nitrogen burner + SCR catalytic reduction), high-efficiency electrostatic dust removal device (high-frequency power supply, rotating electrode), flue gas seawater desulfurization device.

Through the above cases, it is not difficult to find that “near-zero emissions” will revolutionize the environmental protection equipment and even the equipment of the entire power generation system. "Zero-emissions" not only requires technical innovation and upgrading of desulfurization, denitrification, and dust removal equipment in thermal power plants, but also the optimization and design of the entire power generation system for coal quality, boiler selection, draft fan configuration, and catalyst adaptation. Both have made new demands. In short, “Near Zero Emissions” not only requires the upgrading of environmental protection equipment such as desulfurization and denitrification, but also opens up a new model for the design of the entire power generation system.

The proposal from the desulfurization, denitrification and dust removal reform of thermal power plants to the goal of “near-zero emission” is essentially an inevitable result of the development of coal-fired power plants in China. Since China is a big country in coal-fired power generation, and the structure based on coal-fired power generation is short The time will not change, so if you want to achieve clean and efficient power generation and reduce air pollution emissions, "near zero emissions" may be a good choice. However, the special nature of coal and ash in China has made this work even harder. Near-zero emissions still face greater difficulties in most areas.

In the eastern coastal areas of China, Zhejiang, Shanghai, and Guangdong, it has become possible that the emission of atmospheric pollutants from coal-fired power plants will meet the emission standards for natural gas generators.

With the continuous improvement of the technical level of China's power generation equipment and environmental protection equipment, “near-zero emission” seems to have become an industry consensus and is used for reference. However, the work to be done by the environmental protection industry is to sink the mind and change the past pursuit.” The concept of "Dajianjianshangli" turned to the research and development of high-level, high-efficiency environmental protection equipment and tackled the problems, laying a good foundation for "near-zero emissions" of coal-fired power plants.