Decomposition of HDPE over HZSM-5 Catalyst Modified with Si, P and Mg for Recycle of Waste Plastics

Si, P, Mg로 개질된 HZSM-5 촉매상에서 폐플라스틱(HDPE) 재활용을 위한 분해반응

  • Yu, Eui-Yeon (Research Institute of Catalysis, Chonnam National University) ;
  • Kim, Sang-Chai (Department of Environmental Education, Mokpo National University)
  • 유의연 (전남대학교 촉매연구소) ;
  • 김상채 (목포대학교 환경교육과)
  • Published : 2006.09.30

Abstract

Catalytic decomposition over HZSM-5 was carried out in semi-batch reactor to recover gasoline from waste plastics(HDPE). To enhance the liquid yield with a molecule range of gasoline, the properties of catalytic decomposition were investigated over a commercial Si/ZSM-5 catalyst and HZSM-5 catalysts modified with P and Mg. Optimum loadings of P and Mg on HZSM-5 were 0.5 wt% and 2.0 wt%, respectively, based on conversion and liquid yield. $NH_3-TPD$ profile indicated that strong and weak acid sites totally decreased in P loading on HZSM-5 catalyst, strong acid sites moderately decreased and weak acid sites sharply reduced in Mg loading on HZSM-5 catalyst. In the case of Si/ZSM-5 catalyst, all acid sites almost disappeared, subsequently, catalytic decomposition significantly decreased, and little liquid product was produced. When HZSM-5 catalyst was modified with P and Mg, the carbon distribution of liquid product was shifted to lower carbon number and its all components was within a molecular range of gasoline($C_5-C_{11}$). Especially, over Mg(2.0 wt%)/ZSM-5 catalyst, 55.8% of liquid yield with 100% of a molecular range of gasoline, was obtained at $400^{\circ}C$, suggesting it as a promising catalyst for recycle of waste plastics.

반회분식 반응기를 이용하여, 폐 고밀도 폴리에틸렌(HDPE)으로부터 가솔린을 제조하기 위하여 HZSM-5 촉매상에서 분해반응을 수행하였다. HZSM-5 촉매상에서 가솔린 분자 범위의 액상수율을 증가시키기 위하여 시판용의 Si/ZSM-5 촉매와, 인과 마그네슘을 HZSM-5 촉매에 첨가한 촉매를 사용하여 접촉분해반응 특성을 조사하였다. HZSM-5에 인과 마그네슘을 지지한 경우, 최적 지지량은 각각 0.5 wt%와 2.0 wt%이었다. 암모니아 TPD 실험 결과에서 인을 지지 시켰을 때는 강산점과 약산점이 전체적으로 크게 감소하였으며, 마그네슘을 지지 시켰을 때는 강산점은 완만하게 감소하였고 약산점은 크게 감소하였다. Si/ZSM-5 촉매에서는 산점은 거의 사라졌으며 분해반응도 크게 감소하여 액상생성물이 거의 생성되지 않았다. 액상생성물의 탄소수 분포는 인과 마그네슘이 지지되었을 때 탄소수가 낮은 쪽으로 이동되었고 성분의 100%가 가솔린 범위($C_5-C_{11}$)에 분포되어 있었다. Mg(2.0 wt%)/ZSM-5 촉매는 반응온도 $400^{\circ}C$E에서 액상 수율이 55.8%이었으며, 생성물의 분포가 100% 가솔린 범위에 있어서 유망한 촉매로 나타났다.

Keywords

References

  1. Kim, K. K., Chun, S. C., and Ryu, K. O., 'Resources Recovery from Pyrolysis of Waste Plastics,' Journal of Korea Solid Wastes Engineering Society, 13(4), 504-513( 1996)
  2. Moskolczi, N., Bartha, L., and Deak, Gy., 'Thermal Degradation of Polyethylene and Polystyrene from the Packaging Industry over Different Catalysts into Fuellike Feed Stocks,' Polymer Degradation and stability, 91, 517 - 526(2006) https://doi.org/10.1016/j.polymdegradstab.2005.01.056
  3. Kim, J. R., Yoon, J. H., and Park, D. W., 'Catalytic Recycling of the Mixture of Polypropylene and Polystylene,' Polymer Degradation and stability, 76, 61-67( 2002) https://doi.org/10.1016/S0141-3910(01)00266-X
  4. Songip, A. R., Masuda, T., Kuwahara, H., and Hashimoto, K., 'Test to Screen Catalysts for Reforming Heavy Oil from Waste Plastics,' Applied Catalysis B: Environmental, 2, 153 -164(1993) https://doi.org/10.1016/0926-3373(93)80045-F
  5. Songip, A. R., Masuda, T., Kuwahara, H., and Hashimoto, K., 'Kinetics Studies for Catalytic Cracking of Heavy Oil from Waste Plastics over REY Zeolites,' Energy & Fuels, 8, 136-140(1994) https://doi.org/10.1021/ef00043a023
  6. Uddin, M. A., Koizumi, K., Murata, K., and Sakata, Y., 'Thermal and catalytic degradation of structurally different types of polyethylene into fuel,' Polymer Degradation and stability, 56, 37-44(1997) https://doi.org/10.1016/S0141-3910(96)00191-7
  7. 김희영, 전종열, 김형천, '환경 오염 방지 소재 및 재활용 기술 개발,' 한국화학연구소(1994)
  8. 선도원, 한근희, 손재익, '일본의 폐플라스틱 열분해 기술동향,' 화학공업과기술, 14(4), 371-378(1998)
  9. 전학제, '촉매개론', 한림원, 380-381(1992)
  10. 손종락, 최상준, '제올라이트의 탈알루미늄과 촉매성질,' 경북대 논문집, 34-41(1988)
  11. 정민웅, 김상채, 유의연, '플라스틱 폐기물 재활용을 위한 열분해반응과 HZSM-5상에서의 촉매분해반응,' 대한환경공학회지, 23(9), 1537-1545(2001)
  12. Zhao, X. and Roberie, T. G., 'ZSM-5 Additive in Fluid Catalytic Cracking. 1. Effect of Additive Level and Temperature on Light Olefins and Gasoline Olefins,' Ind. Eng. Chem. Res., 38(10), 3847-3853(1999) https://doi.org/10.1021/ie990179q
  13. Erdogan, K. and Gillham, J. K., 'Pyrolysis-Molecular Weight Chromato-graphy: A New On-line System for Analysis of Polymer. II. Thermal Decomposition of Polyolefins: Polyethylene, Polypropylene, Polyisobutylene,' J. Applied Polymer Science, 20, 2045 -2068(1976) https://doi.org/10.1002/app.1976.070200803
  14. 심종섭, 김기백, 김종호, 서곤, 'H-beta 제올라이트에서 폴리에틸렌 왁스의 액상 촉매분해반응,' 화학공학회지, 36(3), 447-452(1998)
  15. Tynjala, P. and Pakkanen, T. T., 'Modification of ZSM-5 zeolite with trimethylphosphite part 1. structure and acidity,' Microporous and Mesoporous Materials, 20, 363 - 369 (1998) https://doi.org/10.1016/S1387-1811(97)00050-4
  16. 심종섭, '제올라이트 촉매에서 고분자 물질의 액상 분해 반응,' 박사학위논문, 전남대학교(1999)
  17. Ueno, A., Suzuki, H., and Kotera, Y., 'Particle-size Distribution of Nickel Dispersed on Silica and its Effects on hydrogenation of Proplonaldehyde,' J. Chem. Soc., Faraday Trans, I, 79, 127-131(1983) https://doi.org/10.1039/f19837900127
  18. Hu, Z., Wei, L., Dong, J., Wang, Y., Chen, S., and Peng, S., 'Modification of the external surface of ZSM-5 by a metal surfactant,' Microporous and Mesoporous Materials, 28(1), 49-55(1999) https://doi.org/10.1016/S1387-1811(98)00218-2
  19. Raphael, C. M., Roy, F., and John, D., 'Thermolysis of low density polyethylene catalysed by zeolites,' Journal of Analytical and Applied Pyrolysis, 29, 45 - 55(1994) https://doi.org/10.1016/0165-2370(93)00789-P