颗粒内部毛细凝聚对气体有效扩散系数的影响

doi:10.11949/j.issn.0438-1157.20141309

化工学报 ›› 2015, Vol. 66 ›› Issue (4): 1363-1369.DOI: 10.11949/j.issn.0438-1157.20141309

颗粒内部毛细凝聚对气体有效扩散系数的影响

罗文, 吴思操, 刘鹏, 程振民, 周志明, 方云进

华东理工大学化学工程联合国家重点实验室, 上海 200237

收稿日期:2014-08-27 修回日期:2015-01-19 出版日期:2015-04-05 发布日期:2015-04-05
通讯作者: 程振民
作者简介:罗文(1988-),男,硕士研究生。
基金资助:
国家自然科学基金项目(20876043,21076072);华东理工大学交叉学科与重大项目培育基金(WA1113008)。

Effect of capillary condensation on effective diffusivity of gases in porous pellet

LUO Wen, WU Sicao, LIU Peng, CHENG Zhenmin, ZHOU Zhiming, FANG Yunjin

State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China

Received:2014-08-27 Revised:2015-01-19 Online:2015-04-05 Published:2015-04-05
Supported by:
supported by the National Natural Science Foundation of China (20876043, 21076072) and the Fundamental Research Funds for East China University of Science and Technology (WA1113008).

摘要/Abstract

摘要：

采用改进型Wicke-Kallenbath稳态扩散池,在373～413 K及0.4～1.0 MPa条件下测定了氢气在某工业催化剂CuO/ZnO/γ-Al₂O₃内部的有效扩散系数。实验采用逐步增加环己烷流量至某最大值而后逐步降低回到初始点的方法,测定了催化剂孔内发生毛细凝聚时氢气有效扩散系数随环己烷蒸气相对压力的变化。实验结果表明:在 373 K下环己烷蒸气相对压力为0.42时开始发生毛细凝聚,而在413 K下则延迟到0.6才开始出现这一现象。此外,滞后环宽度随着温度的升高而变窄,并且氢气的有效扩散系数随环己烷蒸气相对压力变化出现多重滞后环。建立了催化剂部分润湿时氢气的有效扩散系数与内部润湿分率的关联式,与实验测量值符合较好。

关键词: 毛细凝聚, 有效扩散系数, 多孔介质, 内扩散, 滞后环

Abstract:

The effective diffusivity of hydrogen in an industrial catalyst CuO/ZnO/γ-Al₂O₃ pellet was measured with a modified Wicke-Kallenbath steady-state diffusion cell at 373 to 413 K and 0.4 to 1.0 MPa. Through changing the flow rate of cyclohexane in a sequence from low to high to a maximum and then vice versa, the effect of relative vapor pressure of cyclohexane on the effective diffusivity of hydrogen was investigated in the presence of capillary condensation within the catalyst pores. Condensation started at the relative vapor pressure of cyclohexane of 0.42 at 373 K, while it was delayed to the relative vapor pressure of 0.6 at 413 K. Besides, shrinking of hysteresis loops was observed with the increase of temperature, and the effective diffusivity of hydrogen also displayed multiple hysteresis loops with respect to the relative vapor pressure of cyclohexane. A correlation between the effective diffusivity of hydrogen and catalyst internal wetting fraction was proposed, and it showed good agreement between calculation and experimental data.

Key words: capillary condensation, effective diffusivity, porous media, internal diffusion, hysteresis loop

中图分类号:

TQ021.4

罗文, 吴思操, 刘鹏, 程振民, 周志明, 方云进. 颗粒内部毛细凝聚对气体有效扩散系数的影响[J]. 化工学报, 2015, 66(4): 1363-1369.

LUO Wen, WU Sicao, LIU Peng, CHENG Zhenmin, ZHOU Zhiming, FANG Yunjin. Effect of capillary condensation on effective diffusivity of gases in porous pellet[J]. CIESC Journal, 2015, 66(4): 1363-1369.

参考文献 20

[1]	Bhatia S K. Steady state multiplicity and partial internal wetting of catalyst particles [J]. AIChE Journal, 1988, 34 (6): 969
[2]	Watson P C. Dynamic effects of vaporization with exothermic reaction in a porous catalytic pellet [J]. AIChE Journal, 1993, 39 (6): 898
[3]	Zheng Q, Yu B M, Wang S F, Luo L. A diffusivity model for gas diffusion through fractal porous media [J]. Chemical Engineering Science, 2012, 68: 650-655
[4]	Zheng Q, Xu J, Yang B, Yu B M. Research on the effective gas diffusion coefficient in dry porous media embedded with a fractal-like tree network [J]. Physical A, 2013, 392: 1557-1566
[5]	Mezedur M M, Kaviany M. Effect of pore structure, randomness and size on effective mass diffusivity [J]. AIChE Journal, 2002, 48: 15-24
[6]	Mu D Q, Liu Z S, Huang C, Djilali N. Determination of the effective diffusion coefficient in porous media including Knudsen effects [J]. Microfluid Nanofluid, 2008 (4): 257-260
[7]	Wang Shuxiong (汪叔雄), Zhang Hong (张虹), Lü Dewei (吕德伟). The determination of the effective diffusion coefficient in porous catalyst [J]. Chemical Reaction Engineering and Technology (化学反应工程与工艺), 1985 (4): 25-32
[8]	Wang Guirong (王桂荣), Wang Fumin (王富民), Xin Feng (辛峰). Measurement of the tortuosity factor of porous solid catalyst using improved diffusion cell [J]. Petrochemical Technology (石油化工), 2002 (1):14-17
[9]	Nguyen P T M, Do D D, Nicholson D. Pore connectivity and hysteresis in gas adsorption: a simple three-pore model [J]. Colloids and Surfaces A:Physicochem.Eng.Aspects, 2013, 437: 56-68
[10]	Alejandro R, Ligia S, Mónica M, Johans R. Simulation of nitrogen adsorption-desorption isotherms. Hysteresis as an effect of pore connectivity [J].Chemical Engineering Science, 2005, 60: 4702-4708
[11]	Wang Y, Do D D, Herrera L F, Nicholson D. On the condensation evaporation pressures and isosteric heats for argon adsorption in pores of different cross-sections [J]. Colloids and Surfaces A:Physicochem.Eng.Aspects, 2013, 420: 96-102
[12]	Zhou Zhiming (周志明), Li Zhuo (李卓), Cheng Zhenmin (程振民). Adsorption on γ-Al2O3 of benzene and cyclohexane at high temperature and pressure [J]. Process in Natural Science (自然科学进展), 2004, 14 (2): 161-165
[13]	Yu Y M, Cheng Z M, Zhou Z M, Wu S C, Liu P, Jin J. Regulation of catalytic reaction via vapor phase condensation (Ⅰ): Experimental study on the reaction rate hysteresis loop [J]. Ind. Eng. Chem. Res., 2012, 51: 8735-8741
[14]	Wu S C, Cheng Z M, Liu P, Yu Y M, Jin J, Zhou Z M. Pore network effects under the reduction of catalyst size at elevated temperatures [J]. Chemical Engineering Science, 2013, 93: 350-361
[15]	Li Zhuo (李卓), Zhou Zhiming (周志明), Cheng Zhenmin (程振民). Study on the reaction characteristics of the internal partial wetted catalyst particles [J]. Process in Natural Science (自然科学进展), 2004, 14 (11): 1325-1328
[16]	Ravikovitch P I, Neimark A V. Experimental confirmation of different mechanisms of evaporation from ink-bottle type pores: equilibrium, pore blocking and cavitations [J].Langmuir, 2002, 18 (25): 9830-9837
[17]	Cheng Z M, Zhou Z M, Yuan W K. Determination of catalyst wetting fraction on the molecular level [J]. AIChE Journal, 2007, 53: 741-745
[18]	Evans R B, Watson G M, Mason E A. Gas diffusion in porous media at uniform pressure [J]. Chem.Phys., 1961, 35: 2076-2083
[19]	Johnson M F L, Stewart W E. Pore structure and gas diffusion in solid catalysts [J]. Journal of Catalysis, 1965, 4: 248-252
[20]	Hessari F A, Bhatia S K. Reaction rate hysteresis in a single partially internally wetted catalyst pellet: experiment and modeling [J]. Chemical Engineering Science, 1996, 51 (8): 1241

颗粒内部毛细凝聚对气体有效扩散系数的影响

Effect of capillary condensation on effective diffusivity of gases in porous pellet

PDF (PC)

可视化

被引次数

摘要/Abstract

引用本文

使用本文

参考文献 20

相关文章 15

编辑推荐

Metrics

本文评价

[1]	周继鹏, 何文军, 李涛. 异形催化剂上乙烯催化氧化失活动力学反应工程计算[J]. 化工学报, 2023, 74(6): 2416-2426.
[2]	贾晓宇, 杨剑, 王博, 林梅, 王秋旺. 金属丝网毛细特性的孔隙尺度数值分析[J]. 化工学报, 2023, 74(5): 1928-1938.
[3]	胡香凝, 尹渊博, 袁辰, 是赟, 刘翠伟, 胡其会, 杨文, 李玉星. 成品油在土壤中运移可视化的实验研究[J]. 化工学报, 2023, 74(4): 1827-1835.
[4]	王晓萱, 胡晓红, 陆雨楠, 王士勇, 凡凤仙. 旋转膜过滤器内部流动特性数值模拟[J]. 化工学报, 2023, 74(4): 1489-1498.
[5]	张银宁, 王进卿, 冯致, 詹明秀, 徐旭, 张光学, 池作和. 升温条件下多孔介质内气泡的生长和聚并行为[J]. 化工学报, 2023, 74(4): 1509-1518.
[6]	杨辉著, 兰精灵, 杨月, 梁嘉林, 吕传文, 朱永刚. 高功率平板热管传热性能的实验研究[J]. 化工学报, 2023, 74(4): 1561-1569.
[7]	钱志广, 樊越, 王世学, 岳利可, 王金山, 朱禹. 吹扫条件对PEMFC阻抗弛豫现象和低温启动的影响[J]. 化工学报, 2023, 74(3): 1286-1293.
[8]	马语峻, 刘向军. 多孔陶瓷膜烟气水分回收理论与模型研究[J]. 化工学报, 2022, 73(9): 4103-4112.
[9]	王沛, 魏荣阔. 光热驱动多孔氧化铈热化学循环解水制氢非热质平衡模型[J]. 化工学报, 2022, 73(7): 2885-2894.
[10]	张宇伦, 陈长坤, 雷鹏. 不同可燃液体层高度下浸润多孔介质砂床组合燃烧特性实验研究[J]. 化工学报, 2022, 73(4): 1826-1833.
[11]	王晔, 张婉雨, 汪彬, 耑锐, 任枫, 蔡爱峰, 杨光, 吴静怡. 多孔网幕泡破压力预测模型的建立及实验验证[J]. 化工学报, 2022, 73(3): 1102-1110.
[12]	顾帅威, 张纬, 陈阵, 王海名, 由长福. 低品位石灰石溶解特性及动力学模型[J]. 化工学报, 2022, 73(12): 5547-5554.
[13]	王文松, 杨英英, 陈周林, 杨晴雨, 李帅华, 武卫东. 介观尺度下多孔介质内水结冰相界面演化机制研究[J]. 化工学报, 2022, 73(12): 5343-5354.
[14]	黄笑乐, 杨甫, 韩磊, 宁星, 李瑞宇, 董凌霄, 曹虎生, 邓磊, 车得福. 富油煤（长焰煤）孔隙结构三维表征及渗流模拟[J]. 化工学报, 2022, 73(11): 5078-5087.
[15]	梁恒, 刘益才, 汪谦旭, 赵祥乐, 李政. 开孔泡沫金属复合材料有效热导率的研究进展[J]. 化工学报, 2021, 72(S1): 7-20.