Clean Technology (청정기술)

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

DOI QR Code

Effects of Hexaaluminate Manufacturing on the Synthetic Time of Hydrothermal Synthesis Using Urea

요소를 이용한 수열합성의 합성시간에 따른 Hexaaluminate 제조의 영향

  • Kim, Seo Young (Graduate School of Energy Science and Technology, Chungnam National University) ;
  • Park, Ji Yun (Graduate School of Energy Science and Technology, Chungnam National University) ;
  • Rhee, Young Woo (Graduate School of Energy Science and Technology, Chungnam National University)
  • 김서영 (충남대학교 에너지과학기술대학원) ;
  • 박지윤 (충남대학교 에너지과학기술대학원) ;
  • 이영우 (충남대학교 에너지과학기술대학원)
  • Received : 2019.08.26
  • Accepted : 2019.09.16
  • Published : 2019.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Interest in environmental pollution is increasing all over the world, and technology development to solve it is actively carried out. In areas where heat is used, especially, combustion is causing countless pollutants in the air environment. Combustion catalyst is a technology that reduces NOx and CO by lowering combustion temperature and enabling complete combustion. Traditional combustion catalysts are expensive and complex in the synthesis process using precious metal catalyst. In this study, hexaaluminate, a high-temperature combustion catalyst, was manufactured using urea, and the properties were investigated according to the synthesis time. The combustion performance and characteristics were evaluated using this catalyst. As the temperature increased, the changing methane conversion rate was shown in two patterns. The conversion rates for 1 hour, 9 hours, and 12 hours were similar, while the conversion rates for 3 hours and 6 hours showed similar patterns. Methane combustion performance increased rapidly as the synthesis time increased from 6 hours to 9 hours, whereas the temperature at T50 was approximately 745 ℃. The performance of the synthesized combustion catalyst for 9 hours was optimum as the NOx emission of this combustion catalyst was not present and the maximum emission of CO was 72 ppm.

전 세계적으로 환경오염에 대한 관심이 높아지고 있으며, 이를 해결하기 위한 기술개발 또한 활발하게 이루어지고 있다. 특히 열을 사용하는 분야에서는 연소로 인해 대기환경 오염물질이 많이 발생하고 있는 상황이다. 연소 촉매는 완전 연소와 연소온도를 낮춰 NOx와 CO를 줄이는 기술이다. 기존 연소 촉매는 귀금속 촉매를 사용하여 값이 비싸고 합성공정이 복잡하다. 본 연구는 요소를 이용하여 고온 연소촉매인 헥사알루미네이트를 제조하였으며, 합성시간에 따른 물성을 조사하였다. 그리고 이 촉매를 이용하여 연소 성능 및 특성을 평가하였다. 온도가 증가하면서 변화하는 메탄 전환율은 두 가지 패턴으로 나타났다. 1 h, 9 h, 12 h의 전환율이 비슷하게 나타났고, 3 h, 6 h의 전환율이 유사한 패턴을 나타내었다. 합성시간이 6 h에서 9 h으로 증가하면서 메탄 연소 성능이 급격하게 증가하였으며, T50이 되는 온도는 약 745 ℃로 나타났다. 9 h 합성된 연소촉매의 성능이 가장 우수하게 나타났으며, 이 연소촉매의 NOx 배출은 없었고, CO의 최대 배출량은 72 ppm으로 나타났다.

Keywords

References

  1. Prefferle, L. D., and Prefferle, W. C., "Catalytically Stabilization Combustion," Catal. Rev. Sci. Eng., 29(2&3), 219-267 (1987). https://doi.org/10.1080/01614948708078071
  2. Arai, H., Yamada, T., and Eguchi, K., "Catalytic Combustion of Methane over Perovskite-Type Oxides," Appl. Catal., 26, 265-276 (1986). https://doi.org/10.1016/S0166-9834(00)82556-7
  3. McCarty, J. G., and Wise, H., "Perovskites Catalyst for Methane Combustion", Catal. Today, 8, 231-248 (1990). https://doi.org/10.1016/0920-5861(90)87020-4
  4. Machida, M., Eughi, K., and Arai, H., "Effect of Additives on the Surface Area of Oxide Supports for Catalytic Combustion," J. Catal., 103, 385-393 (1987). https://doi.org/10.1016/0021-9517(87)90129-1
  5. Beguin, B., Garbowski, E., and Primet, M., "Stabilization of Alumina by Addition of Lanthanum," Appl. Catal., 75(1), 119-132 (1991). https://doi.org/10.1016/S0166-9834(00)83128-0
  6. Machida, M., Eguchi, K., and Arai, H., "Effect of Structural Modification on the Catalytic Property of Mn-Substituted Hexaaluminates," J. Catal., 123(2) 477-485 (1990).
  7. Beguin, B., Garbowski, E., and Primet, M., "Stabilization of Alumina toward Thermal Sintering by Silicon Addition," J. Catal., 127(2), 595-604 (1991). https://doi.org/10.1016/0021-9517(91)90185-7
  8. Groppi, G., Bellotto, M., Cristiam, C., Forzatti, P., and Villa, P. L., "Preparation and Characterization of Hexaaluminate-Based Materials for Catalytic Combustion," Appl. Catal. A: Gen., 104(2), 101-108 (1993). https://doi.org/10.1016/0926-860X(93)85092-4
  9. Mao, C. F., and Vannice, M. A., "High Surface Area a-alumina. I.: Adsorption Properties and Heats of Adsorption of Carbon Monoxide, Carbon Dioxide, and Ethylene," Appl. Catal. A: Gen., 111(2), 151-173 (1994). https://doi.org/10.1016/0926-860X(94)85049-6
  10. Romero, A., Jobbagy, M., Laborde, M., Baronetti, G., and Amadeo, N., "Ni(II)-Mg(II)-Al(III) Catalysts for Hydrogen Production from Ethanol Steam Reforming: Influence of the Mg Content," Appl. Catal. A: Gen., 470(30), 398-404 (2014). https://doi.org/10.1016/j.apcata.2013.10.054
  11. Seo, Y. S., Jung, Y. S., Yoon, W. L., Jang, I. J., and Lee, T. W., "The Effect of Ni Content on a Highly Active Ni-$Al_2O_3$ Catalyst Prepared by the Homogeneous Precipitation Method," Int. J. Hydrogen Energy, 36, 94-102 (2011). https://doi.org/10.1016/j.ijhydene.2010.09.082
  12. Roh, H. S., Jung, Y. S., Koo, K. Y., Jung, U. H., Seo. Y. S., and Yoon, W. L., "Steam Reforming of Methane over Highly Active and KOH-resistant $Ni/{\gamma}-Al_2O_3$ Catalysts for Direct Internal Reforming (DIR) in a Molten Carbonate Fuel Cell (MCFC)," Appl. Catal. A: Gen., 383(1-2), 156-160 (2010). https://doi.org/10.1016/j.apcata.2010.05.037
  13. Cheng, H., Yue, B., Wang, X., Lu, X., and Ding, W, "Hydrogen Production from Simulated Hot Coke oven Gas by Catalytic Reforming over Ni/Mg(Al)O Catalysts," J. Nat. Gas. Chem., 18(2), 225-231 (2009) https://doi.org/10.1016/S1003-9953(08)60104-8
  14. Shishido, T., Yamamoto, Y., Morioka, H., TaKaKi, K., and TaKehira, K., "Active Cu/ZnO and Cu/ZnO/$Al_2O_3$ Catalysts Prepared by Homogeneous Precipitation Method in Steam Reforming of Methanol," Appl. Catal. A: Gen., 263, 249-253 (2004). https://doi.org/10.1016/j.apcata.2003.12.018
  15. Maeda, K., Mizukami, F., Watanabe, M., Arai, N., Toba, M., and Shimizu, K., "Synthesis of Thermostable High-Surface-Area Alumina for Catalyst Support," J. Mater. Sci. Lett., 9(5), 522-523 (1990). https://doi.org/10.1007/BF00725864
  16. Serantoni M., Costa, A. L., Zanelli, C., and Esposito, L., "Crystallization Behaviour of Yb-doped and Undoped YAG Nanoceramics Synthesized by Microwave-Assisted urea Precipitation," Ceram. Int., 40(8), 11837-11844 (2014). https://doi.org/10.1016/j.ceramint.2014.04.018
  17. Bernhard, A. M., Peitz, D., Elsener, M., Wokaun, A., and Krocher, O., "Hydrolysis and Thermolysis of Urea and Its Decomposition Byproducts Biuret Cyanuric Acid and Melamine over Anatase $TiO_2$," Appl. Catal. B: Environ., 115, 129-137 (2012).
  18. Bell T. E., Gonzalez-Carballo J. M., Tooze R. P., and Torrente-Murciano L., "${\gamma}-Al_2O_3$ nanorods with tuneable dimensions - a mechanistic understanding of their hydrothermal synthesis," RSC. Adv., 7, 22369-22377 (2017). https://doi.org/10.1039/C7RA02590D
  19. Chen B.,, Wang J. X., Wang D., Zeng X. F., Clarke S. M., and Chen J. F., "Synthesis of Transparent Dispersions of Aluminium Hydroxide Nanoparticles," J. Nanotechnol, 29(305605), 1-7 (2018).
  20. Mishra, D., Anand, S., Panda, R. K., and Das, R. P., "Preparation of Barium Hexa-Aluminate through a Hydrothermal Precipitation-Calcination Route and Characterization of Intermediate and Final Products," Mater. Lett., 56(6), 873-879 (2002). https://doi.org/10.1016/S0167-577X(02)00630-4
  21. Mishra, D., Anand, S., Panda, R. K., and Das, R. P., "Studies on Characterization, Microstructures and Magnetic Properties of Nano-Size Barium Hexa-Ferrite Prepared through a Hydrothermal Precipitation-Calcination Route," Mater. Chem. Phys., 86(1), 132-136 (2004). https://doi.org/10.1016/j.matchemphys.2004.02.017
  22. Mohapatra, M., Pattanaik, D. M., Anand, S., and Das, R. P., "Effect of Barium to Aluminium Ratio on Phases Leading to Barium Aluminates," Ceram. Int., 33(4), 531-535 (2007). https://doi.org/10.1016/j.ceramint.2005.10.019
  23. Yin, F., Ji, S., Wu, P., Zhao, F., and Li, C., "Preparation, Characterization, and Methane Total Oxidation of $AAl_{12}O_{19}$ and $AMAl_{11}O_{19}$ Hexaaluminate Catalysts Prepared with Urea Combustion Method," J. Mol. Catal. A: Chem., 294, 27-36 (2008). https://doi.org/10.1016/j.molcata.2008.05.015
  24. Park, J. Y., Jung, Y. S., and Rhee, Y. W., "Effects of Concentration of Precipitants and Aging Time on Synthesis of Mn-Substituted Barium Hexaaluminates by Homogeneous Precipitation," Korean Chem. Eng. Res., 56(3), 349-355 (2018). https://doi.org/10.9713/KCER.2018.56.3.349