Electrically Heated Alumite Catalyst
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Numerical Investigations on the Development of Plate Reformers: Comparison of Different Assignments of the Chambers • Electrically Heated Alumite Catalyst Introduction Model Figuter Reference Result Model verification Reaactor Calcination Alum inum clad plate Pretreatment Anodization Hydration treatm ent Impregnation 20% H 2 reduction N i/Al 2 O 3 /alloy catalyst Pore widening treatm ent Calcination NaOH 3 m in, H NO 3 1 m in 298K 2h 773K 3h in air 923K 6h 4 wt% oxalic acid solution 60A ∙m -2 303K 5h 4 wt% oxalic acid solution 303K 2h 353K 1h 623K 1h in air Calcination Alum inum clad plate Pretreatment Anodization Hydration treatm ent Impregnation 20% H 2 reduction N i/Al 2 O 3 /alloy catalyst Pore widening treatm ent Calcination NaOH 3 m in, H NO 3 1 m in 298K 2h 773K 3h in air 923K 6h 4 wt% oxalic acid solution 60A ∙m -2 303K 5h 4 wt% oxalic acid solution 303K 2h 353K 1h 623K 1h in air is Combined with three layers i.e. two alumite layers (as the catalyst carrier ) and an alloy layer (high efficiency of the heat transfer, and can be heated by electricity) Fig.1 electrically heating profile of EHAC (endurance temperature : 1273 K) Fig.4Temperature distribution in the reactor bed by different heat-up methods (a) heat-up by heater (b) electrical heat- up through the catalyst Model Equations (a) (b) Fig. 2 the scheme of the reactor( for a clarity, the scheme is not drawn in real scale) (1)catalyst bed (2) pre-heating part (3)heater (4) thermal insulation material (5) thermocouples Figure 3. (a) Cross section photo of the EHAC; (b) Heat exchange reformer (HER); (c) Heat exchange reformer coupled with preheating chamber (PHER). (For clarity, the schemes are not drawn in a real scale). Figure 6. (a) Velocity field surface and stream line profiles in the PHER for (a-1) reforming chamber and (a-2) combustion 1 preheating chambers; (b) temperature distribution and contour profiles in the (b-1) reforming chamber and (b-2) combustion 1 preheating chambers. Figure 7. Transient profiles of the temperature distributio n (a) in the reforming chamber and (b) in the combustion and preheating chamber with 3-min electricall y heating. Figure 8. (a) Ordinary heat exchange system of the fuel processor26; (b) simplified heat exchange system of the fuel processor. AIChE Journal 2. Start-up performance of the reformer Figure 5. Effects of the fuel ratio on the reforming performance and heat point temperature for thePHER As Fig7(a) shows that the temperatures are greatly higher at the locations near the heater while the temperature shows rather even distributions at different radius locations when by electrical heat-up through EHAC (Fig 7 (b)). Since it is obvious that even temperature distribution can improve the reaction performance, the inside heat-up is preferred in the catalytic reactor. [1] Zhang Q, Zhu X, KAMEYAMA H. Numerical investigations on the development of compact plate Reformers: comparison of different assignments of reformers’ chambers[J]. AIChE J., 2008, 54(10): 2707- 2716. [2] Zhang Q, Guo Y, Zhou L. et al. Dynamics simulations of a novel heat-exchange methane reformer using a electrically heated alumite catalyst [J]. 化化化化化化化 , 2008, 34(1): 113-118. [3] Zhou L, Guo Y, Zhang Q, et al. A plate-type anodic alumina supported nickel catalyst for methane steam reforming [J]. J. Chem. Eng. Japan, 2008, 41(2): 90-99. [4] Zhang Q, Takahashi H., Nagaya M, et al. Simulation and experimental analysis on the development of the co-axial cylinder methane steam reformer using the electrically heated alumite catalyst [J]. Int. J. Hydrogen Energy, 2007, 32(16):3870-3879. [5] Zhang Q, Guo Y, Zhou L, et al. Development of the methane steam reformer using an electrically heated alumite catalyst: Start-up performance investigated by the numerical and experimental analysis [J]. J. Chem. Eng. Japan, 2007, 40(6):487- 496. [6] Zhang Q, Sakurai M, Kameyama H. Performance simulations of a compact plate methane steam reformer using electrically heated alumite catalyst [J]. J. Chem. Eng. Japan, 2007, 40(4):319-328 . [7] Guo Y, Tran T, Q. Zhang et al. Steam methane reforming using an anodic alumina supported nickel catalyst (Ni/Al2O3/Alloy): analysis of catalyst deactivation [J]. J. Chem. Eng. Japan, 2007, 40(13): 1121-1128.
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Transcript of Electrically Heated Alumite Catalyst
Numerical Investigations on the Developmentof Plate Reformers: Comparison of Different
Assignments of the Chambers
• Electrically Heated Alumite Catalyst
Introduction
Model
Figuter
Reference
Result
Model verification
Reaactor
Calcination
Aluminum clad plate
Pretreatment
Anodization
Hydration treatment
Impregnation
20% H2 reduction
Ni/Al2O3/alloy catalyst
Pore widening treatment
Calcination
NaOH 3 min, HNO3 1 min
298K 2h
773K 3h in air
923K 6h
4 wt% oxalic acid solution60A∙m-2 303K 5h
4 wt% oxalic acid solution 303K 2h
353K 1h
623K 1h in air Calcination
Aluminum clad plate
Pretreatment
Anodization
Hydration treatment
Impregnation
20% H2 reduction
Ni/Al2O3/alloy catalyst
Pore widening treatment
Calcination
NaOH 3 min, HNO3 1 min
298K 2h
773K 3h in air
923K 6h
4 wt% oxalic acid solution60A∙m-2 303K 5h
4 wt% oxalic acid solution 303K 2h
353K 1h
623K 1h in air
isCombined with three layers i.e. two alumite layers (as the catalyst carrier ) and an alloy layer (high efficiency of the heat transfer, and can be heated by electricity)
Fig.1 electrically heating profile of EHAC (endurance temperature : 1273 K)
Fig.4Temperature distribution in the reactor bed by different heat-up methods (a) heat-up by heater (b) electrical heat-up through the catalyst
Model Equations
(a) (b)
Fig. 2 the scheme of the reactor( for a clarity, the scheme is not drawn in real scale) (1)catalyst bed (2) pre-heating part (3)heater (4) thermal insulation material (5) thermocouples
Figure 3. (a) Cross section photo of the EHAC; (b) Heatexchange reformer (HER); (c) Heat exchange
reformer coupled with preheating chamber(PHER).
(For clarity, the schemes are not drawn in a real scale).
Figure 6. (a) Velocity field surface and stream line
profilesin the PHER for (a-1) reforming chamber
and (a-2) combustion 1 preheating chambers;
(b) temperature distribution and contour profilesin the (b-1) reforming chamber and (b-2)
combustion 1 preheating chambers.
Figure 7. Transient profiles of the temperature distribution
(a) in the reforming chamber and (b) in
the combustion and preheating chamber with
3-min electrically heating.
Figure 8. (a) Ordinary heat exchange system of the
fuel processor26; (b) simplified heat
exchange system of the fuel processor.
AIChE Journal
2. Start-up performance of the reformer
Figure 5. Effects of the fuel ratio on the reforming performanceand heat point temperature for thePHER
As Fig7(a) shows that the temperatures are greatly higher at the locations near the heater while the temperature shows rather even distributions at different radius locations when by electrical heat-up through EHAC (Fig 7 (b)). Since it is obvious that even temperature distribution can improve the reaction performance, the inside heat-up is preferred in the catalytic reactor.
[1] Zhang Q, Zhu X, KAMEYAMA H. Numerical investigations on the development of compact plate Reformers: comparison of different assignments of reformers’ chambers[J]. AIChE J., 2008, 54(10): 2707-2716.[2] Zhang Q, Guo Y, Zhou L. et al. Dynamics simulations of a novel heat-exchange methane reformer using a electrically heated alumite catalyst [J]. 化学工学論文集 , 2008, 34(1): 113-118. [3] Zhou L, Guo Y, Zhang Q, et al. A plate-type anodic alumina supported nickel catalyst for methane steam reforming [J]. J. Chem. Eng. Japan, 2008, 41(2): 90-99.[4] Zhang Q, Takahashi H., Nagaya M, et al. Simulation and experimental analysis on the development of the co-axial cylinder methane steam reformer using the electrically heated alumite catalyst [J]. Int. J. Hydrogen Energy, 2007, 32(16):3870-3879.[5] Zhang Q, Guo Y, Zhou L, et al. Development of the methane steam reformer using an electrically heated alumite catalyst: Start-up performance investigated by the numerical and experimental analysis [J]. J. Chem. Eng. Japan, 2007, 40(6):487-496. [6] Zhang Q, Sakurai M, Kameyama H. Performance simulations of a compact plate methane steam reformer using electrically heated alumite catalyst [J]. J. Chem. Eng. Japan, 2007, 40(4):319-328 .[7] Guo Y, Tran T, Q. Zhang et al. Steam methane reforming using an anodic alumina supported nickel catalyst (Ni/Al2O3/Alloy): analysis of catalyst deactivation [J]. J. Chem. Eng. Japan, 2007, 40(13): 1121-1128.
