Space-Borne Monitoring of NOx Emissions from Cement Kilns in South Korea

Abstract

Nitrogen oxide (NOx) emissions from the South Korean cement industry are investigated with remote-sensing measurements, surface observations, and in situ aircraft measurements. In the Yeongwol, Danyang, and Jecheon regions of central South Korea, six closely located cement factories produce 31 million tons of cement annually. Their impact on the regional environment has been a public-policy issue, but their pollutants have not been continuously monitored nor have emissions inventories been fully verified. Using a newly developed downscaling technique, remote-sensing analyses show that Ozone Monitoring Instrument (OMI) NO2 column densities over the cement kilns have more than twice the modeled concentrations, indicating that the kilns are one of the most dominant NOx emission point sources in South Korea. Observed NOx emissions are stronger in the spring, suggesting that these sources play an important role in the formation of surface ozone and secondary particulate matter. These emissions also slightly increased in recent years, even while most major South Korean cities posted a declining trend in NOx emissions. Photochemical models (during May to July 2015) demonstrate that emissions from the South Korean cement industry have significant environmental impacts, both on surface ozone (up to approximately 4 ppb) and PM2.5 (up to approximately 2 µg/m3).

Airborne observation with a low-cost hyperspectral instrument: Retrieval of NO2 VCD and the satellite sub-grid variability over industrial point sources

“…This can be explained by combined effect of the higher absolute uncertainty level due to low-quality clean pixel used for a SF correction, and generally low NO2 VCD leading to greater relative uncertainty per same absolute uncertainty. Still, both TROPOMI and HIS were able to capture some increased NO2 VCDs right above the cement kiln, which has been pointed as a major industrial point source of NO2 at the area (Kim et al, 2020). The research flight over the Pohang area further demonstrated the significance of NO2 emissions from the steel yards, since one of the world's largest steel yard is located within the city of Pohang (Fig.…”

“…Three regions in Korea were selected as the target domain for the research flight: Chungnam, Jecheon, and Pohang. Each domain has one or more industrial point sources with substantial NO2 emissions (Choo et al, 2023;Kim et al, 2020;Cleansys, 2023), such as power plants, steel yards, petrochemical complexes, and cement kilns. generally displayed relatively low concentrations compared to the year-round average (Park et al, 2022), with the highest concentration observed at the southeastern side of the Seoul Metropolitan Area (SMA; 0.70 DU).…”

Alternative Fuel Substitution Improvements in Low NOx In-Line Calciners

“…It is recommended to use it if the total input of chloride is higher than 0.3-0.4 kg of Cl/t of clinker. Nevertheless, the exact number depends on other factors too-especially sulfur volatility, tower cleaning tools, and the quality of their use-and in some cases, chloride inputs without operation of the bypass can be even higher [100].…”

“…The risk of cyclone blockage is increased in the case that this figure is higher than 3.5. In addition, maintaining high oxygen at the kiln inlet to decrease SO3 in the hot meal can minimize the risk of kiln stoppage due to cyclone blockage [100].…”

Marker Compounds Adsorbed on Dust Particles (PM10) Sampled According to Standard EN 12341 in the Outdoor Air Near the Cement Plant

“…To reduce the severe NO x emission techniques, such as selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) were developed. 7,8 Injection of higher values of urea can improve NO x reduction but may also increase ammonia slip. Reduction chemistry is a relatively simple chemical process.…”