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

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

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

摘要

摘要: 探讨了反应条件对甲醇水蒸气重整制氢反应的响，进行甲醇水蒸气重整制氢反应本征动力学研究。采用Langmuir-Hinshelwood型双速率动力学模型方程对本征动力学实验数据进行拟合，反应器出口产物气体中CO和CO₂摩尔流率的模型计算值与实验值比较吻合，双速率模型能够适用。考察CuO/ZnO/Al₂O₃改性催化剂在200 ℃和300 ℃下的失活现象，催化剂表征结果表明，催失活的主要原因除热烧结外，催化剂比表面积减小、介孔比例减少、活性组分CuO的流失、CuO晶粒变大也是催化剂失活的具体原因，高温反应中产生的高含量CO没有对催化剂的失活产生明显影响。
- 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 optimum temperature of the reaction was about 240 ℃. The high temperature would make the CO selectivity higher, and the low temperature would make the conversion of CH₃OH lower.When H₂O/CH₃OH molar ratio increases, the conversion of CH₃OH increases and the selectivity of CO decreases. However, if H₂O/CH₃OH molar ratio is too high, more energy will be consumed.Under the premise of ensuring the conversion rate of CH₃OH, the reaction efficiency can be improved by appropriately increasing the liquid hourly space velocity of feed liquid.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 could be applied.The deactivation of CuO/ZnO/Al₂O₃ modified catalysts at 200 ℃ and 300 ℃ was investigated. The catalysts were characterized by BET, XRF, XRD and CO-TPD, the results showed that the main reasons for the deactivation of the catalysts were besides hot sintering. The reduction of specific surface area, the reduction of mesoporous ratio, CuO loss and the increase of CuO grain size are also the specific reasons for catalyst deactivation. The high content of CO produced in the high temperature has 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(a)和液时空速对外扩散的影响(b)

Figure 1. Effect of particle size of catalyst on internal diffusion(a) and Effect of LHSV on external diffusion (b)

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图 2 温度对反应结果的影响

Figure 2. Effect of temperature on reaction results

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图 3 水醇物质的量之比对反应结果的影响

Figure 3. Effect of H₂O/CH₃OH molar ratio on reaction results

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图 4 液时空速对反应结果的影响

Figure 4. Effect of LHSV on reaction results

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图 5 反应器出口CO₂(a)、CO(b)摩尔流率实验值与计算值的比较

Figure 5. Comparison of experimental and calculated molar flow rates of CO₂(a) and CO(b) at reactor outlet

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图 6 催化剂活性与时间关系

Figure 6. Relationship between catalyst activity and time

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图 7 样品催化剂的等温吸附脱附曲线

Figure 7. N₂ adsorption and desorption isotherms of catalyst

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图 8 样品催化剂的孔径分布曲线

Figure 8. The pore size distribution curve of sample catalyst

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图 9 样品催化剂的XRD图

Figure 9. XRD diagram of sample catalyst

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图 10 样品催化剂的CO-TPD图

Figure 10. CO-TPD diagram of sample catalyst

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表 1 甲醇水蒸气重整制氢本征动力学实验数据

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

No.	n(H₂O)∶n(CH₃OH)	T/K	LHSV/h⁻¹	F_CH₃OH/(mol·h⁻¹)	F_CO₂/(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 动力学参数估值

Table 2. Estimated parameters for the kinetic model

Parameter	${k}_{\rm SR}^{0}$	${k}_{\rm RWGS}^{0}$	${E}_{\rm SR}$	${E}_{\rm RWGS}$	${K}_{ {\rm CH}_{3}{\rm O}^{\left(1\right)} }^{0}$	${K}_{ {\rm HCOO}^{\left(1\right)} }^{0}$	${K}_{ {\rm OH}^{\left(1\right)} }^{0}$	${K}_{ {\rm H}^{\left(1a\right)} }^{0}$
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⁾LL为95%置信区间的下限值；²⁾UL为95%置信区间的上限值

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表 3 样品催化剂的结构参数

Table 3. Structure parameters of sample catalyst

Project	S_BET/(m²·g⁻¹)	Pore volume/(cm³·g⁻¹)	Pore size/nm	Crystallite size of CuO/nm	Crystallite size of Cu/nm
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 catalyst

Element	w/%
Element	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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