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METHANOL AUTOTHERMAL REFORMING OVER Cu/ZnO/Al2O3 CATALYST FOR PURE HYDROGEN
PRODUCTION
Meriem Banou, Lemnouer Chibane and Brahim Djellouli
Faculty of Technology, University of Setif-1 Laboratory of Chemical Engineering Processes (LGPC), Department of
Chemical Process Engineering
Hydrogen can be produced from a variety of feed stocks. These include
fossil resources, such as natural gas and coal, as well as renewable resources, such
as biomass and water with input from renewable energy sources (e.g. sunlight,
wind, wave or hydro-power). A variety of process technologies can be used,
including chemical, biological, electrolytic, photolytic and thermo-chemical. Each
technology is in a different stage of development, and each offers unique
opportunities, benefits and challenges. Local availability of feedstock, the maturity
of the technology, market applications and demand, policy issues, and costs will all
influence the choice and timing of the various options for hydrogen production.
INTRODUCTION
Figure 1 : Some feedstock and process alternatives
KINETIC MODEL
(1)
(2)
(3)
(4)
The kinetic model established is based on Langmuir-Hinshelwood mechanism and the reaction rate of expressions are:
Mathematical Modeli :{R, W, D}
j:{CH3OH, H2O, CO, CO2, H2,O2}
:
The model we have developed is based on the following simplifying assumptions: Plug flow in the bed, No radial profiles, The axial diffusion in the bed, the losses are negligible, The intra-particle diffusion is negligible, Steady state, Pseudo-homogeneous model, isothermal and isobaric The reactions on the surface of the membrane are ignored.
Initial Conditions
Table of Operating Conditions for simulationParametres Values
Temperature (°C) 200-300
Pressure in the reaction side (bar) 1-5
Pressure in the permeate side
(bar)
1
Reactor length (m) 30x10-2
Radius of the inner tube(m) 1.10x10-2
Membrane thikness (m) 50x10-6
Methanol molar flux (mol/s) 5.13x10-6
H2O/CH3OH 1.0-2.0
N2/ CH3OH 1-4
O2/ CH3OH 0.4-2.0
Catalyst Weight(g) 0.077x10-3
Results and discussion1/ Effet of molar ratio (O/C) and (S/C)
0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,2
0,660
0,662
0,664
0,666
0,668
0,670
0,672
0,674
xCH3OH
YH2
1,60
1,65
1,70
1,75
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Molar ratio (O/C)
Figure 2: Effect of (O/C) on the performance of the reaction
Operating conditions: I = 3, S/C = 1.0, T =
260 ° C, 1 bar = Pp
0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,2
0,710
0,712
0,714
0,716
0,718
0,720
xCH3OH
YH2
1,70
1,75
1,80
1,85
1,90
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Molar ratio (O/C)
Figure 3: Effect of (O/C) on the performance of the reaction
Operating conditions: I = 3, S/C = 1.0, T = 280 ° C, 1
bar = Pp
0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,20,750
0,752
0,754
0,756
0,758
0,760
0,762
xCH3OH
YH2
1,80
1,85
1,90
1,95
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Molar ratio (O/C)
Figure 4: Effect of (O/C) on the performance of the reaction
Operating conditions: I = 3, S/C = 1.5, T = 260 °
C, 1 bar = Pp
0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,20,800
0,805
0,810
0,815
0,820
0,825
0,830
0,835
0,840
2,00
2,05
2,10
2,15
xCH3OH
YH2
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Molar ratio (O/C)
Figure 5: Effect of (O/C) on the performance of the reaction
Operating conditions: I = 3, S/C = 1.5, T = 280 °
C, 1 bar = Pp
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Molar ratio (O/C)
Figure 6: Effect of (O/C) on the performance of the reaction
Operating conditions: I = 3, S/C = 2.0, T = 260 °
C, 1 bar = Pp
0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,20,779
0,780
0,781
0,782
0,783
0,784
0,785
0,786
xCH3OH
YH2
1,8
1,9
2,0
2,1
2/Temperature effect
200 220 240 260 280 300
0,2
0,4
0,6
0,8
0,0
0,5
1,0
xCH3OH
YH2
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Temperature (°C)
Figure 7: Effect of the temperature on the performances of the reaction
Operating conditions: I=3, S/C=1.0, O/C=0.4,
P= 1 bar, Pp=1 bar
200 220 240 260 280 300
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
xCH3OH
YH2
0,0
0,5
1,0
1,5
2,0
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Temperature (°C)
Figure 8: Effect of the temperature on the performances of the reaction
Operating conditions: I=3, S/C=1.0, O/C=0.4,
P= 3 bar, Pp=1 bar
200 220 240 260 280 300
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
xCH3OH
YH2
0,0
0,5
1,0
1,5
2,0R
ecovered HydrogenM
eth
anol
Con
vers
ion
Temperature (°C)
Figure 9: Effect of the temperature on the performances of the reaction
Operating conditions: I=3, S/C=1.0, O/C=0.4,
P= 5 bar, Pp=1 bar
3/Pressure effect
1 2 3 4 50,46
0,48
0,50
0,52
0,54
0,56
0,58
0,60
xCH3OH
YH2
0,6
0,8
1,0
1,2
1,4
1,6
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Pressure (bar)
Figure 10: Effect of the pressure on the performances of the reaction
Operating conditions: I=3, S/C=1.0, O/C=0.4,
T=240°C, Pp=1 bar
1 2 3 4 50,62
0,63
0,64
0,65
0,66
0,67
0,68
1,0
1,2
1,4
1,6
1,8
xCH3OH
YH2
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Pressure (bar)
Figure 11: Effect of the Pressure on the performances of the reaction
Operating conditions: I=3, S/C=1.0, O/C=0.4,
T=260°C, Pp=1 bar
4/Sweep gas effect
1 2 3 4
0,42
0,44
0,46
0,48
0,50
xCH3OH
YH2 0,4
0,6
0,8
1,0
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Sweep gas |Factor (I)
Figure 12: Effect of sweep gas on the performances of the reaction
Operating conditions: S/C=1.0, O/C=0.4, T=240°C,
P= 1 bar, Pp=1 bar
1 2 3 40,50
0,52
0,54
0,56
0,58
0,60
0,62
0,64
0,66
0,68
xCH3OH
YH2
0,4
0,6
0,8
1,0
1,2R
ecovered HydrogenM
eth
anol
Con
vers
ion
Sweep gas Factor (I)
Figure 13: Effect of sweep gas on the performances of the reaction
Operating conditions: S/C=1.0, O/C=0.4, T=260°C,
P= 1 bar, Pp=1 bar
1 2 3 40,56
0,58
0,60
0,62
0,64
0,66
0,68
0,70
0,72
0,74
0,4
0,6
0,8
1,0
1,2
1,4
xCH3OH
YH2
Recovered H
ydrogenMet
han
ol C
onve
rsio
n
Sweep gas Factor (I)
Figure 14: Effect of sweep gas on the performances of the reaction
Operating conditions: S/C=1.0, O/C=0.4, T=280°C,
P= 1 bar, Pp=1 bar
CONCLUSION
The study on the autothermal reforming of methanol allows us to highlight
the effect of some operating parameters on the behavior of the process. A
mathematical model is developed by which a various parameters are simulated and
the performances are quantified (methanol conversion and the amount of recovered
hydrogen). The main results show that the performances of the reactor depend
strongly on the pair (S/C and O/C). At O/C=0.4 and S/C=1 good performances in term
of conversion and hydrogen recovered are noted.
BIBLIOGRAPHICAL REFERENCES[1] I.E. Wachs, R.I. Madix (1978) kinetic model of methanol oxidation over Cu/ZnO
catalyst. J Catal, Vol 53, Page 208
[3] T.L Reitz, P.L Lee, K.F Czaplewski, J.C Lang, K.E Popp, H.H Kung (2001) Time
Resolved XANES Investigation of CuO/ZnO in the Oxidative Methanol Reforming
Reaction. J Catal, Vol 199, Pages 193-201.
[2] J. Agrell, H. Birgersson, M. Boutonnet, I. Melián-Cabreara, R. M. Navarro, and
J. L. G. Fierro (2003) Production of hydrogen from methanol over Cu/ZnO catalysts
promoted by ZrO2 and Al2O3. J Catal, Vol 219, Pages 389-403.
[4] B.A. Peppley, J.C. Amphlett, L.M. Kearns, R.F. Mann (1999) Methanol steam
reforming on Cu/ZnO/ Al2O3 catalyst. Part 2: A comprehensive kinetic model, Appl
Catal A: Gen, Vol 179, Pages 31-49.
[5] J. R. Lattner, M. P. Harold (2005) Comparison of methanol-based fuel processors
for PEM fuel cell systems. Appl Catal B: Environ, Vol 56, Pages 149–169.
THANK YOU FOR YOUR TIME