steam reforming of ethane and ethanol over rh/alumina: a … · steam reforming of ethane and...
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Steam Reforming of Ethane and Ethanol over Rh/Alumina:
a comparative study.Muhammad Bilal1, Claire Gillan1, Sam French2,
Martin Fowles2 and S David Jackson1
1Centre for Catalysis Research, WestCHEM, University of Glasgow, Glasgow G12 8QQ, Scotland, UK2Johnson Matthey plc, Belasis Ave, Billingham TS23 1LB UK
Hydrogen Hydrogen
AmmoniaAmmonia
NaphthaO2/N2
Steam Reforming
Steam Reforming
MethanolMethanol
Syngas Syngas
Hydrogen Hydrogen
AmmoniaAmmonia
O2/N2
Steam Reforming
Steam Reforming
MethanolMethanol
Syngas Syngas
Naturalgas
MethanolMethanol FischerFischerTropschTropsch
Syngas Syngas Hydrogen Hydrogen
AmmoniaAmmonia
NaturalgasO2/N2
Steam Reforming
Steam Reforming
MethanolMethanol FischerFischerTropschTropsch
Syngas Syngas
Biomass
Hydrogen Hydrogen
AmmoniaAmmonia
NaturalgasO2/N2
Steam Reforming
Steam Reforming
Ethane Steam Reforming
CnH2n+2 + nH2O nCO + (2n+1)H2
Steam Reforming
Water Gas Shift
Hydrogenolysis
CO + H2O CO2 + H2
C2H6 + H2 2CH4
Methanation
CO + 3H2 CH4 + H2O
Ethanol Steam Reforming
Ethanol decomposition
C2H5OH CO + CH4 + H2
C2H5OH + H2O 2CO + 4H2
Ethanol steam reforming
Ethanol dehydration
C2H5OH C2H4 + H2O
Ethanol dehydrogenation
C2H5OH CH3CHO + H2
Catalyst: 0.2 % Rh/Al2O3
Temp: 873 K
GHSV: 49,000
H2O:C2H6 /C2H5OH 5:1
Pressure: 20 barg
Experimental
2 7.5 27.5 31.5 55.5 74.5 79.5 100
Time on stream (h)
0
20
40
60
80
100
Con
vers
ion
(%)
Ethanol steamreforming over
alumina support
0
9
18
27
36
45
23.5 47.5 71.5 100
% Y
ield
Time on stream (hrs)
CH4 H2 CO2 CO C2H6 C2H4
Alumina selectivity
Ethanol Steam Reforming
Ethanol decomposition
C2H5OH CO + CH4 + H2
C2H5OH + H2O 2CO + 4H2
Ethanol steam reforming
Ethanol dehydration
C2H5OH C2H4 + H2O
Ethanol dehydrogenation
C2H5OH CH3CHO + H2
Ethanol Steam Reforming, alumina
Ethanol decomposition
C2H5OH CO + CH4 + H2
Water Gas ShiftCO + H2O CO2 + H2
0
9
18
27
36
45
23.5 47.5 71.5 100
% Y
ield
Time on stream (hrs)
CH4 H2 CO2 CO C2H6 C2H4
Alumina selectivity
-0.0055
-0.005
-0.0045
-0.004
-0.0035
-0.003
0
0.05
0.1
0.15
0.2
0.25
0 100 200 300 400 500 600 700 800 900 1000
Ion
curr
ent (
m/e
44)
Der
ivat
ive
wei
ght
Temperature (C)
Derivative weight 44
Alumina
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0
Conversion
(%)
Time on stream (h)
Ethane Ethanol
Rh/alumina, 873 K
Ethanol, 873 K
24 48 72 100
Time on stream (h)
0
2
4
6
8
10
12
Yie
ld (%
)
Acetaldehyde DEE Acetone 1,1-DiethoxyE
2C2H5OH + H2O CH3COCH3 + CO2 + 4H2
2CH3CHO CH3CH(OH)CH2CHO
CH3CH(OH)CH2CHO + O(s) CH3CH(OH)CH2COO(s) + H(s)
CH3CH(OH)CH2COO(s) + H(s) CH3COCH3+ CO2 + H2
‐5.50E‐03
‐5.00E‐03
‐4.50E‐03
‐4.00E‐03
‐3.50E‐03
‐3.00E‐03
‐0.0338
‐0.0336
‐0.0334
‐0.0332
‐0.033
‐0.0328
‐0.0326
‐0.0324
‐0.0322
‐0.032
‐0.0318
0 100 200 300 400 500 600 700 800 900 1000
ion curren
t, m/e 44
ion curren
t. m/e 44
Temperature (C)
Rh/alumina Alumina
1000
2400
3800
5200
6600
8000
100 600 1100 1600 2100 2600 3100 3600 4100
Inte
nsity
(a.u
.)
Raman shift (cm-1)
600C
1344
1594
CONCLUSIONS
Ethane: No significant catalyst deactivation at 873 K No evidence for filaments High methane selectivity O:C ratio in products, ~4:6
Ethanol: No significant deactivation at 873 K Filament formation High hydrogen selectivity O:C ratio in products, ~5:6
CONCLUSIONS
Ethane: Simpler reaction sequence No evidence for synthesis
Ethanol: Complex reaction sequence Synthesis as well as deconstruction
CONCLUSIONS
Ethane: primary reactions, steam reforming & hydrogenolysis secondary reactions, WGS & methanation
Ethanol: primary reactions, ethanol dehydration, ethanol decomposition, steam reforming, ethanol dehydrogenation, acid catalysis secondary reactions, WGS & ethene hydrogenation, synthesis reactions
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