Electric Power Technology and Environmental Protection

The transformation of ultra-low emissions in Chinese coal-fired power plants has been widely completed,leading to a significant improvement in environmental air quality.In order to determine whether further need to tighten the pollutant emission standards and continue to develop new flue gas control technologies for coal-fired power plants,this study presented an outlook on emission standards and flue gas control technologies.This outlook is based on a systematic systematic review of the development history of Chinese coal-fired power plants and the history of atmospheric pollutant control,considering the fact of still high proportion of the atmospheric pollutant emissions in the thermal power industry and urgent need for continuous improvement of air quality.(1) The Chinese power industry has undergone four distinct phases since its inception in 1882:a tentative start,challenging entrepreneurship,vigorous growth,and remarkable achievements.In comparison to the early days of China,national installed capacity and electricity generation have increased by 1383 and 1950 times,respectively.Since 2013,China has consistently ranked first in the world in terms of installed capacity and electricity generation,surpassing the combined total of the G7 countries in 2022.Over the past century,coal-fired power generation,characterized primarily by coal-based facilities,has dominated China's installed capacity and electricity generation.Individual plant capacities have gradually increased,with the construction of the world's largest single-unit,lowest coal consumption coal-fired power generation unit with a capacity of 1.35 million kW completed in 2021.While the installed capacity of thermal power generation continues to grow,its proportion has declined from83.3%in 2006 to 53.0%in 2022.(2) Prior to 1991,Chinese coal-fired power plants had no emission concentration standards for dust,sulfur dioxide (SO₂),or nitrogen oxides (NO_x).Over the past three decades,emission standards for atmospheric pollutants in coal-fired power plants have undergone three revisions,transitioning from the world's most lenient limits to the strictest limits,driving the achievement of ultra-low emissions in Chinese coal-fired power plants.Simultaneously,significant advancements have been made in the technologies for controlling dust,SO₂,and NO_xemissions,setting global benchmarks.In 2007,China began implementing desulfurization electricity pricing policies,followed by denitrification electricity pricing policies in 2011,the addition of dust removal electricity pricing in 2014,and the introduction of ultra-low emission electricity pricing policies in 2016.These policies have played a crucial role in ensuring the efficient operation of flue gas control facilities.Under the guidance of China's environmental protection authorities,a comprehensive technical standard system for flue gas control has been gradually established,covering the entire process from emission standards to technical guidelines,engineering specifications,acceptance testing,and operational management.In comparison to the peak emissions of dust and SO_2in the thermal power industry in 2006,emissions in 2022 decreased by 97.3%and 96.4%,respectively.Furthermore,compared to the peak NO_xemissions in the thermal power industry in 2011,NO_xemissions in 2022 decreased by 93.1%.(3) China's annual average concentration of PM_2.5in environmental air quality standards is seven times higher than the World Health Organization's guideline values and 2.3times higher than the value of U.S.1997 standard.The actual level of PM_2.5in China's environmental air is more than four times that of the U.S.and more than three times that of countries like Russia and Brazil.To align with the goals of creating a"Beautiful China"and a"Healthy China,"China's annual average PM_2.5concentration in environmental air quality standards needs to decrease by at least 50%.In 2020,emissions of SO_2and NO_xfrom the thermal power industry accounted for 30.8%and 20.9%of the total emissions from industrial sources,respectively.Drawing on the experiences of developed countries in improving air quality and considering the continuous growth in China's coal consumption,it is imperative for the thermal power industry to reduce its atmospheric pollutant emissions by at least 70%or more.Achieving this requires breakthroughs in integrated dust,sulfur,and nitrogen control technologies,as well as costeffective,energy-efficient retrofit technologies,to enable coal-fired power plants to achieve ultra-clean emissions.