CuO/ZnO/Al2O3改性催化剂上CH3OH重整制氢的研究

王康; 李涛; 张海涛

doi:10.14135/j.cnki.1006-3080.20210308003

CuO/ZnO/Al₂O₃改性催化剂上CH₃OH重整制氢的研究

doi: 10.14135/j.cnki.1006-3080.20210308003

华东理工大学大型工业反应器工程教育部工程研究中心，上海 200237

详细信息

作者简介:
王康：王　康（1992—），男，安徽蚌埠人，硕士生，主要研究方向为碳一化工。E-mail：921924873@qq.com

通讯作者:
李　涛，E-mail：tli@ecust.edu.cn

中图分类号: TQ013.2
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出版历程
- 收稿日期: 2021-03-08
- 网络出版日期: 2021-04-27
- 刊出日期: 2022-06-29

CH₃OH Reforming for Hydrogen over CuO/ZnO/Al₂O₃ Modified Catalyst

Engineering Research Center of Large Scale Reactor Engineering and Technology, Ministry of Education, East China University of Science and Technology, Shanghai 200237, China

摘要

摘要: 采用Langmuir-Hinshelwood型双速率动力学模型方程对CH₃OH水蒸气重整制氢反应本征动力学实验数据进行拟合，同时探讨了反应条件对CH₃OH水蒸气重整制氢反应的影响。结果表明：反应器出口气体中CO和CO₂摩尔流率的计算值与实验值较吻合，说明所采用的双速率动力学模型适用。考察CuO/ZnO/Al₂O₃改性催化剂在200 ℃和300 ℃下的失活现象，表征结果表明，催化剂失活的主要原因有热烧结、催化剂比表面积减小、介孔比例减少、活性组分CuO流失、CuO晶粒变大等，但高温反应产生的高含量CO对催化剂失活没有产生明显影响。
- 甲醇水蒸气重整 /
- 制氢 /
- CuO-ZnO-Al₂O₃催化剂 /
- 反应动力学 /
- 催化剂失活
Abstract: The effects of reaction conditions on hydrogen production from methanol steam reforming were discussed. The experimental results showed that the optimal temperature of the reaction was about 240 ℃. High temperature increased the selectivity of CO, and low temperature decreased the conversion rate of CH₃OH. When the molar ratio of H₂O to CH₃OH increased, the conversion rate of CH₃OH increased and the selectivity of CO decreased. If the molar ratio of H₂O to CH₃OH was too high, more energy would be consumed. To ensure the conversion rate of CH₃OH, the liquid hourly space velocity of feed liquid was appropriately increased. The Langmuir-Hinshelwood two-rate dynamics model equation was used to fit the experimental data of intrinsic dynamics. The calculated values of molar flow rates of CO and CO₂ in the gas products at the reactor outlet were in good agreement with the experimental values, and the two-rate model was applicable. The deactivation of CuO/ZnO/Al₂O₃ modified catalysts at 200 ℃ and 300 ℃ was also investigated. Using BET, XRF, XRD and CO-TPD, it was found that the main reasons for the deactivation of the catalysts were, in addition to hot sintering, the reduction of specific surface area and mesoporous ratio, the CuO loss, and the increase of CuO grain size. The high content of CO produced in the high temperature had no obvious effect on catalyst deactivation.
- methanol steam reforming /
- hydrogen production /
- CuO-ZnO-Al₂O₃ catalyst /
- reaction kinetics /
- catalyst deactivation

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图 1 催化剂粒径对内扩散的影响

Figure 1. Effect of particle size of catalyst on internal diffusion

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图 2 进料液时空速对外扩散的影响

Figure 2. Effect of LHSV on external diffusion

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图 3 温度对反应结果的影响

Figure 3. Effect of the temperature on reaction results

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图 4 水与甲醇物质的量之比对反应结果的影响

Figure 4. Effect of H₂O/CH₃OH molar ratio on reaction results

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图 5 液时空速对反应结果的影响

Figure 5. Effect of LHSV on reaction results

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图 6 反应器出口处CO₂(a)、CO(b)摩尔流率实验值与计算值的比较

Figure 6. Comparison of experimental and calculated molar flow rates of CO₂(a) and CO(b) at reactor outlet

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图 7 催化剂活性与时间关系

Figure 7. Relationship between catalyst activity and time

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图 8 催化剂的等温吸附-脱附曲线

Figure 8. Adsorption-desorption isotherms of catalysts

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图 9 催化剂的孔径分布曲线

Figure 9. Pore size distribution curve of catalysts

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图 10 催化剂的XRD图

Figure 10. XRD diagram of catalysts

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图 11 催化剂的CO-TPD图

Figure 11. CO-TPD diagram of catalysts

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表 1 甲醇水蒸气重整制氢的本征动力学实验数据

Table 1. Experimental data of the intrinsic kinetics of hydrogen production via methanol steam reforming

No.	n(H₂O)∶n(CH₃OH)	T/K	LHSV/h⁻¹	$F_{ {{\rm{CH}}_3}{\rm{OH}}}$/(mol·h⁻¹)	$F_{ {{\rm{CO}}_2} }$/(mol·h⁻¹)	F_CO/(mol·h⁻¹)
1	1.0	473.85	0.6	0.0205	0.0154	9.8448×10⁻⁵
2	1.0	494.25	3.0	0.1015	0.0671	4.9177×10⁻⁴
3	1.0	513.65	5.4	0.1696	0.1344	2.2848×10⁻³
4	1.0	534.25	7.8	0.2659	0.2527	1.3254×10⁻²
5	1.0	552.75	10.2	0.3780	0.3381	3.9876×10⁻²
6	1.2	473.75	3.0	0.0957	0.0362	9.6495×10⁻⁵
7	1.2	492.15	5.4	0.1723	0.1025	4.5281×10⁻⁴
8	1.2	512.25	7.8	0.2539	0.2052	1.8352×10⁻³
9	1.2	532.15	10.2	0.3296	0.3185	6.4057×10⁻³
10	1.2	552.25	0.6	0.0215	0.0180	3.5035×10⁻³
11	1.4	473.45	5.4	0.1623	0.0409	1.1377×10⁻⁴
12	1.4	493.85	7.8	0.2399	0.1033	4.2425×10⁻⁴
13	1.4	513.45	10.2	0.3129	0.2290	1.6716×10⁻³
14	1.4	532.35	0.6	0.0215	0.0191	2.4027×10⁻³
15	1.4	553.15	3.0	0.0957	0.0864	9.2942×10⁻³
16	1.6	473.65	7.8	0.2200	0.0515	1.2969×10⁻⁴
17	1.6	492.85	10.2	0.2881	0.1463	5.4197×10⁻⁴
18	1.6	513.45	0.6	0.0161	0.0154	7.1376×10⁻⁴
19	1.6	533.25	3.0	0.0836	0.0756	3.1437×10⁻³
20	1.6	552.75	5.4	0.1659	0.1546	1.1266×10⁻²
21	1.8	474.25	10.2	0.2760	0.0567	1.1231×10⁻⁴
22	1.8	494.15	0.6	0.0184	0.0181	3.3210×10⁻⁴
23	1.8	513.45	3.0	0.1025	0.1008	1.6955×10⁻³
24	1.8	532.75	5.4	0.1471	0.1436	3.4834×10⁻³
25	1.8	552.65	7.8	0.1883	0.1765	7.0671×10⁻³

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表 2 运用ISTOpt软件得到的动力学模型参数

Table 2. Estimated parameters for the kinetic model by ISTOpt software

Parameter	${k}_{\rm SR}^{0}$	${k}_{\rm RWGS}^{0}$	${E}_{\rm SR}$/(kJ·mol⁻¹)	${E}_{\rm RWGS}$/(kJ·mol⁻¹)	${K}_{ {\rm CH}_{3}{\rm O}^{\left(1\right)} }^{0}$	${K}_{ {\rm HCOO}^{\left(1\right)} }^{0}$	${K}_{ {\rm OH}^{\left(1\right)} }^{0}$	${K}_{ {\rm H}^{\left(1{\rm{a}}\right)} }^{0}$
Estimated value	8.7×10⁹	3.2×10⁸	100.3	79.5	−32.1	231.9	−54.6	−127.2
LL¹⁾	6.8×10⁹	2.5×10⁸	80.7	67.6	−37.3	204.1	−61.8	−145.3
UL²⁾	10.6×10⁹	3.9×10⁸	119.9	91.4	−26.9	259.7	−47.4	−109.1
¹⁾Lower limit of the 95% confidence interval; ²⁾Upper limit of the 95% confidence interval

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表 3 催化剂的结构参数

Table 3. Structure parameters of catalysts

Catalyst	S_BET/(m²·g⁻¹)	Pore volume/(cm³·g⁻¹)	Pore size/nm	Crystallite size/nm
Catalyst	S_BET/(m²·g⁻¹)	Pore volume/(cm³·g⁻¹)	Pore size/nm	CuO	Cu
Sample 1#	101.08	0.19	7.17	5.8	–
Sample 2#	57.38	0.23	10.89	8.5	16.3
Sample 3#	84.69	0.20	13.74	7.9	11.0

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表 4 催化剂中主要元素质量分数

Table 4. Mass fraction of main elements in catalysts

Elements	w/%
Elements	Sample 1#	Sample 2#	Sample 3#
Cu	42.32	41.15	40.23
O	28.91	20.71	21.44
Zn	14.44	13.62	13.85
C	9.07	7.57	8.09
Al	5.07	3.69	4.04

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