1. METHANOL SYNTHESIS ON COPPER-BASED CATALYSTS
M.V. Bukhtiyarova
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2. Introduction Methanol production is a large industrial process.
Methanol is produced using synthesis gas at 250°C and 50 – 100 bars
CO + 2H2 = CH3OH
Catalyst: Cu/ZnO/Al2O3
High emission of CO2 resulted in studying methanol synthesis through CO2 hydrogenation.
Methanol can be viewed as a way of hydrogen storage
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3. Methanol synthesis CO2 + 3H2 CH3OH +H2O Methanol synthesis setup
Gas mixture: H2:CO2 = 3:1
Pressure: and 50 bars
Temperature: , 210, 230, 250 and 260°C
GHSV: and 7200 h-1
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Süd-Chemie catalyst : Cu/ZnO/Al2O3 (old generation)

4. Sample obtained at 250°C, 30 bar, 7200 h-1
Gas chromatography of liquid sample
Sample obtained at 250°C, 30 bar, 7200 h-1
Samples are dissolved in acetone to have reproducible results
Reference methylformate solution contains 5% of methanol 1 2 1 2 3
air
Reference methylformate
acetone
Sample
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No.
Ret.Time
Peak Name
Rel.Area
min % 1
1.69
Methyl formate
0.014 2
2.02
n.a.
0.015 3
2.98
Methanol
99.970
No.
Ret.Time
Peak Name
Rel.Area
min % 1
2.50
Methanol
48.277 2
3.31
Wasser
51.723
Traces of methylformate are observed during methanol synthesis

5. Increasing temperature promotes water-gas shift reaction
Methanol synthesis
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Methanol synthesis:
Reverse water gas shift:
CO2 + 3H2
CH3OH +H2O
CO2 + H2
CO +H2O
H = – 49.7 kJ/mol
H = 41.2 kJ/mol
Ratio of CH3OH/H2O (ml/ml) = 2.24
Increasing temperature promotes water-gas shift reaction

6. Methanol synthesis Dependence on pressure MS: RWGS:
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MS:
CO2 + 3H2
CH3OH +H2O
RWGS:
CO2 + H2
CO +H2O
According to Chatelier’s principle increase of pressure results in higher methanol formation

7. Volume of formed methanol and water depends on reaction conditions
Methanol synthesis
Dependence on space velocity
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Volume of formed methanol and water depends on reaction conditions

8. Methanol synthesis Dependence on space velocity at high pressure
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Volume of methanol and water does not practically change at temperature higher than 250°C

9. CO2 conversion Dependence on pressure Dependence on space velocity
GHSV = 4800 h-1
Dependence on space velocity
p = 30 bar
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Conversion of CO2 increase with temperature and decrease with space velocity

10. Methanol selectivity Dependence on space velocity
p = 30 bar
Dependence on pressure
GHSV = 4800 h-1
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At high pressure selectivity practically does not change with temperature

11. Methanol yield Dependence on space velocity p = 30 bar
Dependence on pressure
GHSV = 4800 h-1
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Methanol yield increases with temperature, pressure and decreases with space velocity

12. Activation energy Comparison with literature data
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Obtained activation energy is in the agreement with activation energy presented in literature

13. Methanol synthesis Conditions for stability test: H2:CO2 = 3:1;
30 bar, 230°C; 4800 h-1
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Productivity of methanol decreases during first 100 after that the catalyst works stable for another 300 hours

14. Methanol synthesis Methanol synthesis: CO2 + 3H2 CH3OH +H2O
Gas mixture: H2:CO2 = 3:1
Pressure: bar
Temperature: , 210, 230, 250 and 260°C
GHSV: h-1
Clariant (Süd-Chemie) catalysts
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The “old generation” catalyst works better for CO2 hydrogenation at low pressure

15. Conclusions
Methanol yield depends on reaction conditions: high pressure results in formation of higher amount of methanol
Practically pure methanol with trace amount of methylformate is produced
Clariant (Süd-Chemie) catalyst for methanol synthesis is stable during long-term experiment for 400 hours
Clariant (Süd-Chemie) catalyst of old generation is more suitable for production methanol by CO2 hydrogenation
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16. THANK YOU FOR YOUR KIND ATTENTION
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18. Methanol yield
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19. Gas chromatography of liquid samples
Instrument
Agilent 6890
Detektor
TCD 250°C
Column:
Stabilwax 30 m S-1
Injector
250°C
Programm
TCD 60
Tem.Programm
80°C
Method
Wasser
Gas
He 0,93 bar 1 ml
Report
Rep Wasser
Split
1:20
Injection Volume
0.5 µl
Instrument
6890
Detektor
FID 300°C
Column:
Stabilwax 30m S-69
Injector
240°C
Programm
Stabilwax
Tem.Programm:
50°C
Method
Pyrrol
Gas:
H2 0,86 bar 2,3 ml
Report
Rep normal
Split
1:20
Injection Volume:
0.5 µl
The measurement using FID was done for determination organic impurities in methanol. FID does not detect water