Rapid Increase in China’s Industrial Ammonia Emissions: Evidence from Unit-Based Mapping

Abstract

Ammonia (NH3) is an important precursor of secondary inorganic aerosols and greatly impacts nitrogen deposition and acid rain. Previous studies have mainly focused on the agricultural NH3 emissions, while recent research has noted that industrial sources could be significant in China. However, detailed estimates of NH3 emitted from industrial sectors in China are lacking. Here, we established an unprecedented high-spatial-resolution data set of China’s industrial NH3 emissions using up-to-date measurements of NH3 and point source-level information covering eight major industries and 27 subdivided process categories. We found that China emitted 798 (90% confidence interval: 668–933) gigagrams of industrial NH3 into the atmosphere in 2019, equivalent to 44 ± 20% of the industrial emissions worldwide; this flux is 3-fold larger than that in 1998 and has fluctuated since 2014. Furthermore, although fertilizer production is responsible for approximately half of the emissions in China, the emissions from cement production and coal-fired power plants increased dramatically from near zero to 164 and 41 gigagrams, respectively, in the past two decades, primarily due to the NH3 escape caused by the large-scale application of the denitration process. Our results reveal that, unlike other major air pollutants, China’s industrial NH3 emission control is still in a critical period, and stricter NH3 emission standards and innovation in pollution control technologies are highly desirable.

NH3 Weakens the Enhancing Effect of SO2 on Biogenic Secondary Organic Aerosol Formation

“…The ozonolysis of β-caryophyllene accounts for up to a 70% loss of this compound and 50% of the sesquiterpene–O 3 reactivity. , Effects of SO 2 on SOA formation from β-caryophyllene ozonolysis remains largely unknown. Meanwhile, coexisting anthropogenic pollutants may alter the role of SO 2 according to studies focusing primarily on photooxidation processes. , For example, it was recently revealed that NH 3 , the principal alkaline anthropogenic pollutant that has increased in emissions from agricultural and industrial activities over the past century, , exhibits synergetic effects with SO 2 in promoting SOA formation from anthropogenic VOC photooxidation. , However, the existence of these interactions regarding SOA formation from β-caryophyllene ozonolysis remains unclear and deserves more attention.…”

Room-Temperature NH3 Sensors Based on Polyaniline-Assembled Graphitic Carbon Nitride Nanosheets

“…Ammonia (NH 3 ), as one of the toxic and harmful gases, is mainly generated by emissions from industry, agriculture, and animal husbandry . Emitted NH 3 combines with acid gas to form secondary inorganic aerosols, which are closely related to the level of atmospheric PM2.5 (particles with air-equivalent diameter ≤2.5 μm) .…”

Ammonia Abatement via Selective Oxidation over Electron-Deficient Copper Catalysts

“…1−5 In China, NH 3 emissions from coal-fired power plants and industrial sectors increased rapidly in the last years, mainly due to NH 3 slip from the NH 3 -assisted selective catalytic reduction (NH 3 -SCR) process that is widely applied to abate nitrogen oxides (NO x ) in flue gases. 1 Mitigating the slipped NH 3 from the NH 3 -SCR process has thus become an urgent task and received increasing attention. 6−10 Among different abatement technologies, selective catalytic oxidation of NH 3 (NH 3 -SCO) to N 2 is considered to be highly promising because of its great potential to efficiently eliminate NH 3 slip under mild conditions with minimized secondary pollution.…”

“…Ammonia (NH 3 ) is an important precursor of fine particles (PM 2.5 ) in the atmosphere and could impose adverse impacts on human health and the environment by causing respiratory diseases, disrupting vegetation, etc . − In China, NH 3 emissions from coal-fired power plants and industrial sectors increased rapidly in the last years, mainly due to NH 3 slip from the NH 3 -assisted selective catalytic reduction (NH 3 -SCR) process that is widely applied to abate nitrogen oxides (NO x ) in flue gases . Mitigating the slipped NH 3 from the NH 3 -SCR process has thus become an urgent task and received increasing attention. − Among different abatement technologies, selective catalytic oxidation of NH 3 (NH 3 -SCO) to N 2 is considered to be highly promising because of its great potential to efficiently eliminate NH 3 slip under mild conditions with minimized secondary pollution. − However, it remains a challenge to design and fabricate low-cost NH 3 -SCO catalysts with satisfactory low-temperature activity and water resistance, which are essential for application in the abatement of slip NH 3 from stationary emission sources.…”