Mesoporous Catalysis


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Mesoporous Catalysis for petroleum and biofuel production.

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Mesoporous Catalysis

  1. 1. Mesoporous Catalysis<br />Ben Lehtovaara1<br />Andrew Finkle1<br />1Department of Chemical Engineering (Nanotechnology), University of Waterloo, <br />Waterloo, Ontario, Canada<br />
  2. 2. Outline<br />Recap of MesoporousMaterial Synthesis<br />Introduction to Petroleum Refining<br />Introduction to BiofuelRefining<br />Zeolitesvs. MesoporousMaterials<br />Biofuel Refining Using Mesoporous/Zeolite Composites<br />MCM - 41<br />
  3. 3. Introduction to Petroleum Refining<br /><ul><li>Crude Oil Contains
  4. 4. methane, ethane, propane, aromatics, cycloalkanes, alkenes, and alkynes
  5. 5. Crude oil is refined to smaller distillates and/or liquefied petroleum gas (LPG; varying ratios of propane/butane)
  6. 6. Hydrocrackingcreates smaller distillates with high temperatures and partial pressure of H2
  7. 7. Mild Hydrocracking uses lower temperatures and pressures to create smaller distillates
  8. 8. Hydrocracking uses noble metals supported on mesoporous material, aluminosilicates, or zeolites. Each with their own advantages / disadvantages.
  9. 9. Our Focus: Mesoporous Catalysis</li></ul>R=catalyst (i.e. noble metal)<br />
  10. 10. Mesoporous Materials Synthesis<br />Mesoporous (~2-50nm pores) require surfactants as templating material to achieve desired structure<br />Formation of Micelles via Surfactant Self Assembly<br />Controled pore size<br />Surfactant chain length<br />Surfactant to Silica ratio<br />Swelling by organic additives<br />
  11. 11. Effects of Surfactant Parameters<br /><ul><li>Changes micelle dimensions and pore sizes
  12. 12. Surfactant/Si Ratio changes phase (e.g. cubic)</li></ul>Other factors:<br />-Temperature<br />-pH<br />-nature of surfactant<br />Swelling Agent<br />MCM-41 Hex. Structure<br />“Rod-like micelles”<br />
  13. 13. Mesoporous Materials Synthesis<br /><ul><li>Sol-gel chemistry
  14. 14. Hydrolysis to create hydroxymetallates
  15. 15. Acidic catalyst such as NaF effective
  16. 16. Condensation to creation oxolated bridges between an inorganic framework</li></li></ul><li>Cracking of Gas Oil<br /><ul><li>Hydrocracking involves creating smaller distillates under high T,P
  17. 17. Activity is greatest for Zeolite material (USY-1), followed by Mesoporous MCM-41, and Amorphous Silica Aluminosilicates (ASA)
  18. 18. High Activity is a result of the higher SA of the zeolite material (pore=~2-5nm)
  19. 19. Zeolites are currently the industry choice for hydrocracking
  20. 20. At high T, P: most mesoporous materials collapse</li></li></ul><li>Mild Hydrocarbon Cracking<br /><ul><li>Mild conditions (lower T, P) are more advantageous to mesoporous material activity due to a decrease in pore collapse at high T,P (more SA)
  21. 21. This leads to increased MCM-41 desirability due to:
  22. 22. Larger exposed surface area
  23. 23. Increased dispersion of catalytic sites
  24. 24. Removal of heteroatoms to reduce emission of sulfur dioxide nitrous oxides which are detrimental to the environment</li></li></ul><li>Biofuel Refining<br /><ul><li>Biomass Refining: Refine to bio-oil that is catalytically upgraded to standard fuels
  25. 25. Leaves, shoots, fronds of oil palm tree
  26. 26. Palm Oil Refining: Palm oil is converted to methyl/ ethyl esters (biodiesel) by transesterification</li></li></ul><li>Palm Biomass Refining<br /><ul><li>Leaves, Shoots, and Fronds of Oil Palm Tree
  27. 27. Pyrolysis: decomposition in absence of oxygen
  28. 28. produces gaseous hydrocarbons, coke, and bio-oil
  29. 29. Nickel on mesoporous materials improves bio-oil yield
  30. 30. Gasification: temperatures higher than 720 degrees celsius
  31. 31. produces CO, H2, CO2, and methane
  32. 32. Fischer Tropsch Synthesis converts CO and H2 into liquid hydrocarbons such as Liquid Petrolium Gas (LPG)
  33. 33. Catalytic upgrading on mesoporous materials produces transportation fuels from both palm biomass and bio-oil</li></li></ul><li>Palm Oil Refining<br />
  34. 34. Effect of Si/Al ratio on Palm Oil Cracking<br /><ul><li>Incorporation of some Aluminum hetero atoms through exchange with Si atoms results in a stronger Lewis Acid due to interaction with noble metal (NiMo)
  35. 35. Catalyst materials synthesized via sol-gel, hydrothermal, ion-exchange and grafting methods
  36. 36. Optimal Si/Al ratio around 20:1</li></ul>Effects of Pore Size on Palm Oil Cracking<br /><ul><li> Linear hydrocarbon production is proportional to pore size
  37. 37. Catalytic activity is proportional to surface area
  38. 38. Palm kernel oil had a higher conversion rate then palm olein oil</li></ul>Increase pore size<br />
  39. 39. Mesoporous / ZeoliteComposite as Hydrocarbon cracking catalyst<br /><ul><li>MCM-41 / ZSM-5 Composite for biofuel applications
  40. 40. MCM-41 selective to C5+ olefin products (diesel gasoline)
  41. 41. MCM-41 lacks in catalytic activity, incorporate ZSM-5
  42. 42. Composite named CMZ
  43. 43. Mesoporous structure synthesized on surface of ZSM-5 particles
  44. 44. Microporousstructure is combined with a mesoporous material.</li></ul>  <br />
  45. 45. Mesostructure:<br />MCM-41<br />Zeolite: ZSM-5<br />Composite Zeo/Meso:<br />CMZ (0.2,0)<br />
  46. 46. CMZ NitrogenIsotherms<br />Catalytic Activity and Selectivity<br /><ul><li>Increased SA of composite
  47. 47. Decreased SA with increased Aluminum
  48. 48. Due to Loss of Crystallinity
  49. 49. CMZ(0.2,0.05) had highest yield and selectivity
  50. 50. More liquid fewer gas products
  51. 51. desirable</li></li></ul><li>Conclusions<br />There are distinct advantages of mesoporous materials over traditional zeolites<br /><ul><li>Larger pores facilitate mass transport and selectivity for C5+ products
  52. 52. More versatile synthesis techniques that require lower T and P and shorter periods of time (Zeolites take weeks, mesoporous take days/hours)
  53. 53. Versatility in the incorporation of other materials (heteroatoms for catalysts) into their active sites (Al3+, Ti4+)
  54. 54. Currently not as effective as zeolites in fuel refining activity
  55. 55. Composite Zeo/Meso materials do improve performance
  56. 56. Mesoporous materials have the most distinct advantages in the realm mild hydrocarbon cracking </li></li></ul><li>References<br />Adam, J., M. Blazso, E. Meszaros, M. Stocker, M. Nilsen, A Bouzga, J. Hustad, M. Gronli, and G. Oye. 2005. Pyrolysis of biomass in the presence of Al-MCM-41 type catalysts. Fuel 84: 1494-1502.<br />Beck, J. S., J. C. Vartuli, W. J. Roth, M. E. Leonowicz, C. T. Kresge, K. D. Schmitt, C. T. W. Chu, D. H. Olson, and E. W. Sheppard. 1992. A new family of mesoporous molecular sieves prepared with liquid crystal templates. Journal of the American Chemical Society 114, no. 27: 10834-10843.<br />Biz, S., and M. Occelli. 1998. Synthesis and Characterization of Mesostructured Materials. Catalysis Reviews 40, no. 3: 329-407<br />Chew, T. L., and S. Bhatia. 2008. Catalytic processes towards the production of biofuels in a palm oil and oil palm biomass-based biorefinery. Bioresource technology 99, no. 17: 7911-22.<br />Corma, A., A. Martinez, V. Martinezsoria, and JB Monton. 1995. Hydrocracking of Vacuum Gasoil on the novel mesoporous mcm-41 aluminosilicate catalyst. Journal of Catalysis 153, no. 1: 25–31.<br />Corma, A. 1996. Cracking Activity and Hydrothermal Stability of MCM-41 and Its Comparison with Amorphous Silica-Alumina and a USY Zeolite. Journal of Catalysis 159, no. 2: 375-382.<br />Corma, A. 1997. From Microporous to Mesoporous Molecular Sieve Materials and Their use in Catalysis. Chem. Rev. 97: 2373-2420.<br />Kresge, C. T., W. J. Leonowicz, W. J. Roth, J. C. Vartuli, and J. S. Beck. 1992. Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism. Nature Letters 39: 710-712.<br />Mokaya, R., W. Jones, Z. Luan, M. D. Alba, and J. Klinowski. 1996. Acidity and catalytic activity of the mesoporousaluminosilicate molecular sieve MCM-41. Catalysis Letters 37, no. 1-2: 113-120.<br />Mokaya, R., and W. Jones. 1996. Acidity and catalytic activity of aluminosilicatemesoporous molecular sieves prepared using primary amines. Chemical Communications, no. 8: 983-984.<br />Mokaya, R., and W. Jones. 1996. Synthesis of acidic aluminosilicatemesoporous molecular sieves using primary amines. Chemical Communications, no. 8: 981-982.<br />Mokaya, R. 1997. Physicochemical Characterisation and Catalytic Activity of Primary Amine TemplatedAluminosilicateMesoporous Catalysts. Journal of Catalysis 172, no. 1: 211-221.<br />Taguchi, A., and F. Schuth. 2005. Ordered mesoporous materials in catalysis. Microporous and Mesoporous Materials 77, no. 1: 1-45.<br />Trong On, D. 2001. Perspectives in catalytic applications of mesostructured materials. Applied Catalysis A: General 222, no. 1-2: 299-357.<br />Twaiq, F. A. A., A. R. Mohamed, and S. Bhatia. 2003. Liquid hydrocarbon fuels from palm oil by catalytic cracking over aluminosilicatemesoporous catalysts with various Si/Al ratios. Microporous and Mesoporous Materials 64, no. 1-3: 95-107.<br />Twaiq, F. A. A., A.R. Mohamad, and S. Bhatia. 2004. Performance of composite catalysts in palm oil cracking for the production of liquid fuels and chemicals. Fuel Process. Technol. 85, no. 11: 1283-1300.<br />Twaiq, F. A. A. 2003. Catalytic conversion of palm oil over mesoporousaluminosilicate MCM-41 for the production of liquid hydrocarbon fuels. Fuel Process. Technol. 84, no. 1-3: 105-120. <br />U.C. Program, Technology Options 2005, Washington D.C.: US Climate Change Technology Program<br />
  57. 57. Characteristics of MCM-41 and CMZ materials<br />