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 dataset 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 to the atmosphere in 2019, equivalent to 44±20% of the industrial emissions worldwide; this flux is three-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.

Please refer to the article for a detailed description of the methods.

The dataset includes unit-based geographical locations (longitudes and latitudes) and ammonia emissions covering nitrogen fertilizer production, catalytic cracking, coke, iron and steel production, wastewater treatment, and soda ash production for years 2013, 2008, 2003, and 1998. Data of cement production, solid waste treatment (incineration), and coal-fired power plants are also included for the year 2013.