Clean Technology (청정기술)

The Korean Society of Clean Technology (한국청정기술학회)
권호 표지
DOI QR코드

DOI QR Code

A Study on the Oxy-Combustion of the Coal in Drop Tube Furnace

Drop Tube Furnace에서 석탄의 순산소 연소 특성

  • Roh, Seon Ah (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Yun, Jin Han (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Lee, Jung Kyu (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Keel, Sang In (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Min, Tai Jin (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Kim, Sang-Bok (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Park, In-Yong (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Han, Bangwoo (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM)) ;
  • Kim, Jin-Tae (Environment System Research Division, Korea Institute of Machinery and Materials (KIMM))
  • 노선아 (한국기계연구원 환경시스템 연구본부) ;
  • 윤진한 (한국기계연구원 환경시스템 연구본부) ;
  • 이정규 (한국기계연구원 환경시스템 연구본부) ;
  • 길상인 (한국기계연구원 환경시스템 연구본부) ;
  • 민태진 (한국기계연구원 환경시스템 연구본부) ;
  • 김상복 (한국기계연구원 환경시스템 연구본부) ;
  • 박인용 (한국기계연구원 환경시스템 연구본부) ;
  • 한방우 (한국기계연구원 환경시스템 연구본부) ;
  • 김진태 (한국기계연구원 환경시스템 연구본부)
  • Received : 2021.10.21
  • Accepted : 2021.11.23
  • Published : 2021.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

The oxy-combustion system is one of the carbon recovery and storage technologies (CCS: Carbon capture & storage) that performs coal combustion using pure oxygen and recirculated flue gas. This is a technology that facilitates storage of carbon dioxide by generating an exhaust gas consisting of only carbon dioxide without a process of separating carbon dioxide and nitrogen when coal is burned using pure oxygen and recirculated flue gas mixture instead of a conventional air combustion system that produces carbon dioxide and nitrogen mixed exhaust gas. In this study, the characteristics of generated NO and SO2 as atmospheric pollutants during oxy-combustion were examined using O2/CO2 mixed simulation gas. The reaction temperature was varied from 900 ℃ to 1200 ℃ and oxygen partial pressure was varied from 30% to 50%. The results showed that NO and SO2 concentrations in flue gas increased as the oxygen concentration and the reaction temperature in the furnace increased. The partial pressure of CO2 in flue gas also increased as the oxygen concentration and the reaction temperature in the furnace increased. As a results of comparing NO production of 30% O2/CO2 oxy-combustion with air combustion, NO in flue gas increased with reaction temperature in both experiments and NO of oxy-combustion was 40 ~ 80 ppm lower than that of air combustion.

순산소 석탄 화력 발전 시스템은 CO2 가스 회수 및 저장 기술(CCS: carbon capture & storage)의 하나로 순산소와 재순환된 연소가스를 이용하여 석탄 연소를 수행하는 기술이다. 이는 이산화탄소와 질소가 혼합된 배출 가스를 생산하는 기존의 공기 연소 시스템과 달리 공기 중의 산소를 먼저 분리하여 생산된 순산소와 재순환된 연소 가스를 이용하여 석탄을 연소하면 이산화탄소와 질소를 분리하는 후처리 공정 없이 이산화탄소만으로 이루어진 배출 가스를 생성하여 이의 저장을 용이하게 하는 기술이다. 본 연구에서는 O2/CO2 혼합 모의 가스를 이용하여 순산소 연소 시 발생되는 대기오염물질인 NO, SO2의 생성 특성을 살펴보았다. 반응 온도를 900 ℃ ~ 1200 ℃, 산소 분율을 30% ~ 50%로 변화시키면서 실험한 결과 생성 가스 내 NO 및 SO2의 농도는 반응 온도와 산소 분율이 증가할수록 증가하는 현상을 나타내었으며 CO2의 분율도 증가하는 현상을 나타내었다. 순산소 연소에서 30% O2/CO2를 이용한 연소와 air 조건인 21% O2/N2 연소에서 NO 발생을 비교한 결과 양쪽 모두 반응 온도에 따라서 NO 발생이 증가하게 되며 순산소 연소 조건에서 air 연소에 비하여 약 40 ~ 80 ppm까지 NO 발생이 낮아지는 현상을 나타내었다.

Keywords

Acknowledgement

This research was supported by KIMM Institutional program(NK231A and NK231F).

References

  1. Sher, F., Pans, M. A., Sun, C., Snape, C., and Liu, H., "Oxy-fuel Combustion Study of Biomass Fuels in a 20 kWth Fluidized Bed Combustor," Fuel, 215, 778-786 (2018). https://doi.org/10.1016/j.fuel.2017.11.039
  2. Gao, S., Zhang, Z., Zhu, M., Cheng, F., and Zhang, D., "An Experimental Study of the Ignition and Combustion Characteristics of Single Coal Gangue Particles Under Oxy-fuel Conditions," Fuel, 306, 121741 (2021). https://doi.org/10.1016/j.fuel.2021.121741
  3. Rokni, E., Panahi, A., Ren, X., and Levendis, Y. A., "Curtailing the Generation of Sulfur Dioxide and Nitrogen Oxide Emissions by Blending and Oxy-combustion of Coals," Fuel, 181, 772-784 (2016). https://doi.org/10.1016/j.fuel.2016.05.023
  4. Chen, L., and Bhattacharya, S., "Sulfur Emission from Victorian Brown Coal Under Pyrolysis, Oxy-fuel Combustion and Gasification Conditions," Environ. Sci. Technol. 47(3), 1729-1734 (2013). https://doi.org/10.1021/es303364g
  5. Hu, X., Li, X., Luo, G., and Yao, H., "Homogeneous and Heterogeneous Contributions of CO2 and Recycled NO to NO Emission Difference Between Air and Oxy-coal Combustion," Fuel, 163, 1-7 (2016). https://doi.org/10.1016/j.fuel.2015.09.030
  6. Duan, L., Zhou, W., Li, H., Chen, X., and Zhao, C., "Sulfur Fate During Bituminous Coal Combustion in an Oxy-fired Circulating Fluidized bed Combustor," Korean J. Chem. Eng., 28(9), 1952-1955 (2011). https://doi.org/10.1007/s11814-011-0057-x
  7. Stanger, R., and Wall, T., "Sulphur Impacts During Pulverised Coal Combustion in Oxy-Fuel Technology for Carbon Capture and Storage," Prog. Energy Combust. Sci. 37(1), 69-88 (2011). https://doi.org/10.1016/j.pecs.2010.04.001
  8. Min, T. J., Keel, S. I., Yun, J. H., Roh, S. A., Han, B. W., Lee, H. K., Seo, S. I., and Kim, Y. J., "Research on Desulfurization and Dust Removal Characteristics in Oxy-PC Combustion system," Korean Chem. Eng. Res., 48(1), 116-120 (2010).
  9. Cho, Y. W., Ahn, J. H., and Kim, T. S., "Analysis of Efficiency Enhancement of the Integrated Gasification Combined Cycle with Oxy-Combustion Carbon Capture by Changing the Oxygen Supply System," Trans. of Korean Hydrogen and New Energy Society, 30(4), 347-355 (2019). https://doi.org/10.7316/KHNES.2019.30.4.347
  10. Liu, H., Zailani, R., and Gibbs, B. M., "Comparisons of Pulverized Coal Combustion in air and in Mixtures of O2/CO2," Fuel, 84(7-8), 833-840 (2005). https://doi.org/10.1016/j.fuel.2004.11.018
  11. Kazanc, F., Khatami, R., Manoel Crnkovic, P., and Levendis, Y. A., "Emissions of NOx and SO2 from Coals of Various Ranks, Bagasse, and Coal-bagasse Blends Burning in O2/N2 and O2/CO2 Environments," Energy and Fuels, 25(7), 2850-2861 (2011). https://doi.org/10.1021/ef200413u
  12. Zhu, T., Hu, Y., Tang, C., Wang, L., Liu, X., Deng, L., and Che, D. "Experimental Study on NOx Formation and Burnout Characteristics of Pulverized Coal in Oxygen Enriched and Deep-staging Combustion," Fuel, 272, 117639 (2020). https://doi.org/10.1016/j.fuel.2020.117639