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

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

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

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

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

6. Methanol Background: Market Trends Methanol global growth (ZEEP, 2019)
Asian Growth
US to begin exporting more than importing in 2019
Impact of weather
In 2015, market for methanol was USD 29.6 Billion. By 2021, it is projected to swell to USD 54.2 Billion; this represents a 45% market growth.
Methanol global growth (ZEEP, 2019)

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
Cu/ZnO catalyst (Xu, 2017)

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
CO + 2H2
CH3OH
(1)
Carbon Dioxide Hydrogenation
CO2 + 3H2
CH3OH + H2O
(2)
Water-Gas Shift (WGS)
CO2 + H2 + Heat
CO + H2O
(3)

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

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

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

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

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

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

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: GLC
Spinning basket reactor
(Tjabel et al. 1966)

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

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

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

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

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

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

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

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

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

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

29. 4. Other Kinetic Models Carbon Monoxide Hydrogenation
CO + 2H2
CH3OH
(1)
4 Intermediate Steps
4 x 6 x 2 = 48
Different Combinations
Carbon Dioxide Hydrogenation
CO2 + 3H2
CH3OH + H2O
(2)
2 Intermediate Steps
Water-Gas Shift (WGS)
CO2 + H2 + Heat
CO + H2O
(3)
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
Collected experimental data of conversion for each of CO and CO2 for each of 28 experimental conditions
Determined error between calculated and experimental for each of 28 conditions
Averaged error among all 28 conditions and multiplied by 100 to give a percentage

37. Varied parameters, again, included reactor temperature, space velocity, and feed composition
Collected experimental data of conversion for each of CO and CO2 for each of 28 experimental conditions
Determined error between calculated and experimental for each of 28 conditions
Averaged error among all 28 conditions and multiplied by 100 to give a percentage

38. Averaged error across all 28 conditions contributes to robustness of the developed model to varying conditions
Collected experimental data of conversion for each of CO and CO2 for each of 28 experimental conditions
Determined error between calculated and experimental for each of 28 conditions
Averaged error among all 28 conditions and multiplied by 100 to give a percentage

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
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
CO Hydrogenation - Step 4
CO2 Hydrogenation - Step 2
Water-Gas Shift (WGS) - Step 1

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

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

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

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

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

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

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

48. 5. Preliminary ASPEN Optimal Operating Temperatures and Pressures
PFR
CSTR
Temperature (℃)
278
280
Pressure (bar)
100
Methanol Flow Rate (kmol/hr)
374.26
Conversion
62.38%
50.48%

49. Questions? PFR CSTR Temperature (℃) 278 280 Pressure (bar) 100
Methanol Flow Rate (kmol/hr)
374.26
Conversion
62.38%
50.48%

50. Sources
D Sheldon, 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: [Accessed February 6, 2019].
Anon, ZEEP Market Opportunities. ZEEP Fuels & Chemicals. Available at: [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 /catal
Tajbl, D.G., Simons, J.B. and Carberry, J.J., Heterogeneous Catalysis in Continuous Stirred Tank Reactor. Industrial & Engineering Chemistry Fundamentals, 5(2), pp
Graaf, G.H., Sijtsema, P.J.J.M., Stamhuis, E.J. and Joosten, G.E.H., Chemical equilibria in methanol synthesis. Chemical Engineering Science, 41(11), pp
Graaf, G.H., Stamhuis, E.J. and Beenackers, A.A.C.M., Kinetics of low-pressure methanol synthesis. Chemical Engineering Science, 43(12), pp
Graaf, G.H., Scholtens, H., Stamhuis, E.J. and Beenackers, A.A.C.M., Intra-particle diffusion limitations in low-pressure methanol synthesis. Chemical Engineering Science, 45(4), pp
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),

51. Final kinetic models - Graaf