Study on Synthesis of Dimethyl Ether Using Silica Membrane Reactor

Silica막 반응기를 이용한 Dimethyl Ether 합성에 관한 연구

  • Sea Bongkuk (Membranes and Separation Research Center, Korea Research Institute of Chemical Technology) ;
  • Youn Min-Young (Membranes and Separation Research Center, Korea Research Institute of Chemical Technology) ;
  • Lee Kew-Ho (Membranes and Separation Research Center, Korea Research Institute of Chemical Technology)
  • 서봉국 (한국화학연구원 분리막다기능소재연구센터) ;
  • 윤민영 (한국화학연구원 분리막다기능소재연구센터) ;
  • 이규호 (한국화학연구원 분리막다기능소재연구센터)
  • Published : 2005.12.01

Abstract

Water selective silica membranes were prepared fur use as membrane reactor for synthesis of dimethyl ether (DME) by methanol dehydration. Silica membranes formed on a Porous SUS tube by ultrasonic spray Pyrolysis (USP) and chemical vapor deposition (CVD) using tetraethoxysilane (TEOS) as precursor. The CVD-derived membranes formed higher level of trade-off line between water permeance and water/methanol selectivity than that of the USP-derived membranes. The membrane reactor possessing water permeance of $1.2\times10^{-7}\;mol\;{\cdot}\;m^{-2}\;{\cdot}\;S^{-1}\;{\cdot}\;Pa^{-1}$ and water/methanol selectivity of 10 exhibited increase in methanol conversion of about $20\%$ comparing to conventional reactor system. These findings led us to conclude that the dehydration membrane reactor simultaneously separating the water vapour produced in the reaction zone was effective in increasing the reaction conversion.

[ $250^{\circ}C$의 고온에서 수증기 선택 투과 특성을 가지는 silica 막을 메탄을 탈수에 의한 dimethyl ether (DME) 합성 반응에 분리막 반응기로 적용하였다. Silica 전구체로서 tetraethoxysilane (TEOS)을 이용하여 초음파 분무 열분해 및 기상화학 증착법(CVD)법 등에 의해 다공성 스테인레스 스틸(SUS)에 silica 막을 합성하였다. CVD법에 의해 합성한 silica막의 수증기 투과도 및 메탄올에 대한 분리계수 상관관계 trade-off 선이 열분해 silica 막보다 높이 존재하였다. 수증기 투과도가 $1.2\times10^{-7}\;mol\;{\cdot}\;m^{-2}\;{\cdot}\;S^{-1}\;{\cdot}\;Pa^{-1}$ 이상이고, 메탄올에 대한 분리계수가 10 이상의 성능을 가지는 분리막 반응기에 대해서 기존 반응기 대비 $20\%$ 이상 메탄을 전환율이 향상되었다. 고온 수증기 선택성 silica 막이 메탄을 탈수 반응에 의해 생성되는 수증기를 제거함으로서 촉매 활성 저하를 억제하여 반응 전환율을 개선시키는 막 반응기로서의 효과를 확인할 수 있었다.

Keywords

References

  1. J. G. Marcano and T. Tsotsis, 'Catalytic Membranes and Membrane Reactors', pp.15-80, Wiley-VCH, Weinheim, Germany (2002)
  2. H. Weyten, J. Luyten, K. Keizer, L. Willems, and R. Leysen, 'Membrane performance: the key issues for dehydrogenation reactions in a catalytic membrane reactor', Catalysis Today, 56, 3 (2000)
  3. R. Dittmeyer, V. Hollein, and K. Daub, 'Membrane reactors for hydrogenation and dehydrogenation processes based on supported palladiwn', Journal of Molecular Catalysis A: Chemical, 173, 135 (2001) https://doi.org/10.1016/S1381-1169(01)00142-X
  4. G. Barbieri, P. Bernardo, E. Drioli, D.- W. Lee, B. Sea, and K.-H. Lee, 'Hydrogen purification using membrane reactors', Korean Membrane J., 5, 68 (2003)
  5. Z. D. Ziaka, R. G. Minet, and T. T. Tsotsis., 'A high temperature catalytic membrane reactor for pro- pane dehydrogenation', J. Membrane Sci., 77, 221 (1993)
  6. M. Lu, G. Xiong, H. Zhao, W. Cui, J. Gu, and H. Bauser., 'Dehydration of l-butanol over $\gamma$-$Al_2O_3$ catalytic membrane', Catalysis Today, 25, 339 (1995)
  7. M. A. Salomon, J. Coronas, M. Menendez, and J. Santamiria., 'Synthesis of MTBE in zeolite membrane reactors', Applied Catalysis A: General, 200, 201 (2000)
  8. R. P. W. J. Struis, S. Stucki, and M. Wiedom, 'A membrane reactor for methanol synthesis', J. Membrane Sci., 113, 93 (1996)
  9. R. P. W. J. Struis, M. Quintili, and M. Wiedom, 'Feasibility of Li-Nafion hollow fiber membranes in methanol synthesis: mechanical and thermal stability at elevated temperature and pressure', J. membrane Sci., 177, 215 (2002)
  10. H. Ohya, J. Fun, H. Kawamura, K. Itoh, H. Ohashi, M. Aihara, S. Tanisho, and Y. Negishi, 'Methanation of carbon dioxide by using membrane reactor integrated with water vapor permselective membrane and its analysis', J. membrane Sci., 137, 237 (1996)
  11. T. A. Semelsberger, R. L. Borup, and H. L. Greene, 'Dimethyl ether (DME) as an alternative fuel', J. Power Sources, in press (2005)
  12. M. Xu, J. H. Lunsford, D. W. Goodman, and A. Bhattacharyya, 'Synthesis of dimethyl ether (DME) from methanol over solid-acid catalysts', Applied Catalysis A: General, 149, 289 (1997)
  13. B. Sea, D.-W. Lee, and K.-H. Lee, 'Preparation of silica/alumina composite membrane by chemical vapor deposition and sol-gel method', Membrane J., 11, 124 (2001)
  14. M.-Y. Youn, S.-J. Park, B. Sea, and K.-H. Lee, 'Gas permeation characteristics of silica membranes prepared by ultrasonic spray pyrolysis', Membrane J., 15, 105 (2005)
  15. 전기원. 이규완. 최명재. '$Co_2$ 가스로부터 내연기 관용 청정연료의 제조 연구에 관한 최종 보고서'. pp.49-60. 산업자원부 (1999)
  16. E. Piera, M. A. Salomon, J. Coronas, M. Menendez, and J. Santamaria, 'Synthesis, characterization and separation properties of a composite mordenite/ ZSM-5/chabazite hydrophilic membrane', J. Membrane Sci., 149, 99 (1998) https://doi.org/10.1016/S0376-7388(98)00184-7
  17. B. Sea, K. Kusakabe, and S. Morooka, 'Hydrogen recovery from a $H_2$-$H_2O$-HBr mixture utilizing silica-based membranes at elevated temperatures', Ind. Eng. Chem. Res., 37, 2509 (1998)
  18. Y.-G. Lee, D.-W. Lee, B. Sea, S.-G. Kim, K.-H. Lee, and K.-Y. Lee, 'Vapor Permeation Characteristics of $TiO_2$ Composite Membranes Prepared on Porous Stainless Steel Support by Sol-Gel Method', Bull. Kar. Chem. Soc., 25, 687 (2004)