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Methanol Synthesis Kinetics

Andre Chen, Anthony Chiu, Justin Foss, Ryan Ghosh, Joshua Hubbard, Rodrigo Salamanca. Methanol Synthesis Kinetics. Overview. Background Methanol Synthesis Reactions Rate Expression Development Other Kinetic Models Preliminary ASPEN Results. Methanol Background: History. <30 BCE.

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Methanol Synthesis Kinetics

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  1. Andre Chen, Anthony Chiu, Justin Foss, Ryan Ghosh, Joshua Hubbard, Rodrigo Salamanca Methanol Synthesis Kinetics

  2. Overview • Background • Methanol Synthesis Reactions • Rate Expression Development • Other Kinetic Models • Preliminary ASPEN Results

  3. Methanol Background: History <30 BCE Ancient Egyptians use pyrolysis of wood to make methanol 1661 Pure methanol produced Cu used as catalyst 1905 BASF (Germany)produces industrial-scale synthetic methanol 1923 2016 85 million metric tonnes produced globally

  4. Methanol Background: Energy Applications Methanol Energy (Mitsubishi Gas Chemical, 2019) Energy resource • Automotive industry: mixed with gasoline for automobile fuel • Heating source • Fuel cells

  5. Methanol Background: Other Applications Methanol Chemicals (Mitsubishi Gas Chemical, 2019) Chemical Industry • Formaldehyde • Acetic Acid • Alkenes (e.g. ethylene) Other Industries • Construction • Electronics

  6. Methanol Background: Market Trends Methanol global growth (ZEEP, 2019) • Asian Growth • US to begin exporting more than importing in 2019 • Impact of weather

  7. Methanol Background: Catalyst Cu/ZnO catalyst (Xu, 2017) Catalyst Type • Cu/ZnO: high selectivity and activity • Al2O3 and/or ZrO2: optional additions • 4-8 year lifetime

  8. Methanol Background: Catalyst Catalyst Mechanism • Initial proposals • Single-site (CO2, H2, & CO compete) • Dual-site (CO2 & CO compete, H2 other side) • Latest proposals • CO2 & CO on different sites • Active site locations still debated

  9. 2. Methanol Synthesis: Reactions Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat

  10. Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) 2. Methanol Synthesis: Reactions CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat ‘Only Carbon Monoxide’ Natta, 1955; Bakemeier et al., 1970

  11. Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) 2. Methanol Synthesis: Reactions CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat ‘Only Carbon Dioxide’ Dybkjaer, 1985; Chinchen et al., 1984

  12. Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) 2. Methanol Synthesis: Reactions CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat ‘Both CO and CO2 play a role’ Liu et al. 1985 (Carbon labeling); Denise and Sneeden (Kinetic); Klier et al. (Kinetic)

  13. 2. Methanol Synthesis: Reactions Synthesis of Dimethyl Ether (DME) Water-Gas Shift (WGS) Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat CH3OCH3 + H2O (4) 2CH3OH

  14. 2. Methanol Synthesis: Reactions Synthesis of Dimethyl Ether (DME) Water-Gas Shift (WGS) Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Major Theme: Inconsistency CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat CH3OCH3 + H2O (4) 2CH3OH

  15. 2. Methanol Synthesis: Reactions Water-Gas Shift (WGS) Synthesis of Dimethyl Ether (DME) 48 different kinetic models depending on reaction theory Carbon Dioxide Hydrogenation Major Theme: Inconsistency Carbon Monoxide Hydrogenation CO + 2H2 CH3OH (1) CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat CH3OCH3 + H2O (4) 2CH3OH

  16. 3. Rate Expression Development - Graaf

  17. 3. Rate Expression Development - Graaf Experimental Setup: Spinning basket reactor (Tjabel et al. 1966)

  18. 3. Rate Expression Development - Graaf Experimental Setup: Spinning basket reactor (Tjabel et al. 1966) GLC

  19. 3. Rate Expression Development - Graaf Experimental Setup: Spinning basket reactor (Tjabel et al. 1966) GLC Water formation (Graaf et al. 1988) Decreasing Pressure

  20. 3. Rate Expression Development - Graaf Experimental Setup: Spinning basket reactor (Tjabel et al. 1966) GLC Water formation (Graaf et al. 1988) Decreasing Pressure

  21. 3. Rate Expression Development - Graaf Experimental Setup: Spinning basket reactor (Tjabel et al. 1966) GLC Water formation (Graaf et al. 1988) Decreasing Pressure Thermodynamically predicted CO reaction

  22. 3. Rate Expression Development - Graaf Experimental Setup: Spinning basket reactor (Tjabel et al. 1966) GLC Water formation (Graaf et al. 1988) Decreasing Pressure Thermodynamically predicted CO reaction Must result from CO2 reaction

  23. Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) 3. Rate Expression Development - Graaf (1) (2) (3) Graaf, G.H., et al.., 1988. Kinetics of low-pressure methanol synthesis. Chemical Engineering Science

  24. 3. Rate Expression Development - Graaf Graaf, G.H., et al.., 1988. Kinetics of low-pressure methanol synthesis. Chemical Engineering Science

  25. Reduced form can be inputted to ASPEN 3. Rate Expression Development - Graaf Graaf, G.H., et al.., 1988. Kinetics of low-pressure methanol synthesis. Chemical Engineering Science

  26. 4. Other Kinetic Models Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) CO + 2H2 CH3OH (1) 4 Intermediate Steps CO2 + 3H2 CH3OH + H2O (2) (3) CO + H2O CO2 + H2 + Heat

  27. 4. Other Kinetic Models Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) CO + 2H2 CH3OH (1) 4 Intermediate Steps CO2 + 3H2 CH3OH + H2O (2) 6 Intermediate Steps (3) CO + H2O CO2 + H2 + Heat

  28. 4. Other Kinetic Models Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation Water-Gas Shift (WGS) CO + 2H2 CH3OH (1) 4 Intermediate Steps CO2 + 3H2 CH3OH + H2O (2) 6 Intermediate Steps (3) CO + H2O CO2 + H2 + Heat 2 Intermediate Steps

  29. 4. Other Kinetic Models Water-Gas Shift (WGS) Carbon Monoxide Hydrogenation Carbon Dioxide Hydrogenation CO + 2H2 CH3OH (1) 4 Intermediate Steps 4 x 6 x 2 = 48 Different Combinations CO2 + 3H2 CH3OH + H2O (2) 2 Intermediate Steps (3) CO + H2O CO2 + H2 + Heat 6 Intermediate Steps

  30. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Overview of Model Development • Measure CO and CO2 conversion experimentally over a range of conditions • Develop expressions for kinetic parameters • Relate rate expressions to CO and CO2 conversion • Nonlinear regression to obtain kinetic parameters • Test parameters for all 48 kinetic models - identify best performing models

  31. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Experimental Setup Operating Conditions: Catalyst: ??? Reactor system: ??? State variables: ??? Feed: ??? Reactants were input into reactor at variables compositions

  32. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Experimental Setup Operating Conditions: Catalyst: ??? Reactor system: ??? State variables: ??? Feed: ??? Inert gas fed in variable composition with reactants

  33. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Experimental Setup Activity tests were carried out in an isothermal tubular fixed bed reactor (10.2 mm I.D.) with a catalyst weight of 1.0 g. (Cu/ZnO/Al2O3/ZrO2)

  34. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Experimental Setup Reactor temperature and reactant flow rate (in terms of space velocity) were also varied experimentally

  35. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Experimental Setup Operating Conditions: Catalyst: ??? Reactor system: ??? State variables: ??? Feed: ??? Outlet composition was analyzed by gas chromatography

  36. Combinations of varied parameters form 28 experimental conditions for which conversion data was collected

  37. Varied parameters, again, included reactor temperature, space velocity, and feed composition

  38. Averaged error across all 28 conditions contributes to robustness of the developed model to varying conditions

  39. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 Parameter Estimation • Express theoretical CO and CO2 conversion (XCO, calc and XCO2, calc) from rate equations • Use nonlinear regression in MATLAB to get estimated kinetic parameters Kinetic Parameters Objective Function for Nonlinear Regression

  40. 4. Lim et al. 2009: Proposed Kinetic Model Based on Influence of CO2 CO Hydrogenation - Step 4 Water-Gas Shift (WGS) - Step 1 CO2 Hydrogenation - Step 2 Choosing Kinetic Model Choosing a kinetic model: • Calculate total average errors • Calculate standard deviation of error • Select kinetic models which give errors/std deviations within threshold values • 17% XCO error • 60% XCO2 error • 10% XCO STD • 30% XCO2 STD

  41. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst

  42. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst PFR 1 Analysis:

  43. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst PFR 1 Analysis: Temperature: 100 - 1000℃

  44. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst PFR 1 Analysis: Temperature: 100 - 1000℃ Pressure: 1 - 101 bar

  45. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst PFR 1 Analysis: Temperature: 100 - 1000℃ Pressure: 1 - 101 bar Max Methanol Flow Rate 303.36 kmol/hr = when T = 300℃; P = 101 bar

  46. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst PFR 2 Analysis: Temperature: 270 - 310℃ Pressure: 80 - 100 bar

  47. 5. Preliminary ASPEN Feed: CO = 500 kmol/hr CO2 = 100 kmol/hr H2 = 2000 kmol/hr = 141.37m3 Reactor: Volume = 3000 kg Catalyst PFR 2 Analysis: Temperature: 270 - 310℃ Pressure: 80 - 100 bar Max Methanol Flow Rate 374.26 kmol/hr = when T = 278℃; P = 100 bar

  48. Optimal Operating Temperatures and Pressures 5. Preliminary ASPEN

  49. Questions?

  50. Sources • D Sheldon, 2017. Catalytic methanol industry production | Last 100 years and the future. Johnson Matthey Technology Review 61. • Anon, The Many Uses of Methanol: From Clothing to Fuel. Mitsubishi Gas Chemical. Available at: https://www.mgc.co.jp/eng/rd/technology/methanol.html [Accessed February 6, 2019]. • Anon, ZEEP Market Opportunities. ZEEP Fuels & Chemicals. Available at: https://zeep.com/market-opportunities/ [Accessed February 7, 2019]. • Xu, Xinhai & Shuai, Kaipeng & Xu, Ben. (2017). Review on Copper and Palladium Based Catalysts for Methanol Steam Reforming to Produce Hydrogen. Catalysts. 7. 183. 10.3390/catal7060183. • Tajbl, D.G., Simons, J.B. and Carberry, J.J., 1966. Heterogeneous Catalysis in Continuous Stirred Tank Reactor. Industrial & Engineering Chemistry Fundamentals, 5(2), pp.171-175. • Graaf, G.H., Sijtsema, P.J.J.M., Stamhuis, E.J. and Joosten, G.E.H., 1986. Chemical equilibria in methanol synthesis. Chemical Engineering Science, 41(11), pp.2883-2890. • Graaf, G.H., Stamhuis, E.J. and Beenackers, A.A.C.M., 1988. Kinetics of low-pressure methanol synthesis. Chemical Engineering Science, 43(12), pp.3185-3195. • Graaf, G.H., Scholtens, H., Stamhuis, E.J. and Beenackers, A.A.C.M., 1990. Intra-particle diffusion limitations in low-pressure methanol synthesis. Chemical Engineering Science, 45(4), pp.773-783. • Lim, H. W., Park, M. J., Kang, S. H., Chae, H. J., Bae, J. W., & Jun, K. W. (2009). Modeling of the kinetics for methanol synthesis using Cu/ZnO/Al2O3/ZrO2 catalyst: influence of carbon dioxide during hydrogenation. Industrial & Engineering Chemistry Research, 48(23), 10448-10455.

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