Technologies, standards, practices and philosophical thinking of "Near Zero Emission" of power station air pollutants

The construction of ecological civilization is a revolution involving production methods, lifestyles, ways of thinking, and values. The background and the development of environmental policies and emission standards of "Near Zero Emission" (NZE) of clean coal combustion were summarized. The development status of pollutant emission control technologies regarding particulate matter, sulfur dioxide (SO₂), nitrogen oxides (NO_x) and heavy metals including mercury and the technical route of NZE of coal-fired units were discussed. Typical cases in different zones were analyzed in detail. The results indicated that the emission of particulate matter, SO₂, NO_x from typical units was lower than 5, 35, 50 mg/m³ for a long period, respectively. The emission level of pollutants in Jinjie Power Plant Phase Ⅲ, and Shouguang Power Plant was lower than 1, 10, 20 mg/m³, respectively. Moreover, Zhoushan Unit 4 and Sanhe Unit 4 had been in stable operation for more than seven years after achieving the NZE standard of clean coal combustion. The economy of the NZE was studied, the benefits of NZE of clean coal combustion in the views of economy, environment, and society were analyzed, the philosophical thinking on NZE technologies, standards, and practices were proposed, and the green development direction of clean electricity was projected. The NZE technologies and engineering practices promoted the development of environmental protection standards in China, while the standards promoted the advancement of related technologies. Based on China's national conditions, it was of great significance to continuously promote coal utilization in a clean and efficient way and continuously improve environmental protection standards, to guarantee energy security and sustainable development.