Pseudo-Liquid Phase Catalysis of Heteropoly Compound: Application of the Effectiveness Factor Concept

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

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