JOURNAL OF CHEMICAL ENGINEERING OF JAPAN | |
Pseudo-Liquid Phase Catalysis of Heteropoly Compound: Application of the Effectiveness Factor Concept | |
Hiroo Niiyama1  Somchai Akaratiwa1  | |
[1] Department of Chemical Engineering and International Cooperation Center for Science and Technology, Tokyo Institute of Technology | |
关键词: Heteropoly Acids; 12-Tungstophosphoric Acid; Effectiveness Factor; Thiele Modulus; Diffusion; Catalysis; Pseudo-Liquid Phase; | |
DOI : 10.1252/jcej.23.143 | |
来源: Maruzen Company Ltd | |
【 摘 要 】
References(15)Cited-By(2)The “pseudo-liquid phase” catalytic behavior of 12-tungstophosphoric acid was confirmed by studying the effect of catalyst particle size on the apparent rate of t-BuOH dehydration. The apparent rate of reaction strongly depended on the particle size, indicating strong diffusional effects in the pseudo-liquid phase. Based on the theory of Thiele with some modification and extension to pseudo-liquid phase catalysis, along with a knowledge of intrinsic reaction rate, diffusivity values were evaluated. The effective dilfusivity was found to lie in a range of 10–11–10–10 m2/s, which are very small values for diffusivity in gas phase, but close to that in liquid-filled pores. Due to the large temperature dependency of diffusivity, the effectiveness factor is smaller in the lower-temperature region—a sharp contrast to the usual diffusion-restricted gas–solid catalytic reaction in a microporous solid.
【 授权许可】
Unknown
【 预 览 】
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RO201912080693124ZK.pdf | 1352KB | download |