Pressure Fluctuation Analysis of the Defluidization Caused by a Reaction Involving Gas-Volume Reduction in a Fluidized Catalyst Bed

JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

Mitsuyuki Nakajima²  Norihiro Tanaka¹  Kei Mizuta¹  Takami Kai¹  Tsutomu Nakazato¹ 

[1] Department of Chemical Engineering, Kagoshima University;IHI Plant Engineering & Construction Co., Ltd.

关键词: Fluidized Bed;    Defluidization;    Pressure Fluctuations;    Wavelet Analysis;    Autocorrelation;   

DOI  :  10.1252/jcej.14we334

来源: Maruzen Company Ltd

【 摘 要 】

References(36)Severe defluidization occurs when a reaction that is accompanied by a decrease in gas volume is performed in a fluidized catalyst bed. Defluidization occurs because the gas velocity in the emulsion phase decreases to less than the minimum fluidization velocity. Because numerous useful industrial reactions involve a decrease in gas volume, the development of a method for rapid detection of defluidization is important for maintaining good fluidization. In this study, the inside of a column was visually observed during CO2 hydrogenation in a fluidized bed. When the reaction rate was low, good fluidization was always observed. However, defluidization, such as channeling, occurred occasionally when the reaction rate was increased. These reaction conditions were classified as the defluidization region in this study. The time-change characteristics for the frequency of pressure drop fluctuations were studied using continuous wavelet transfer (CWT). Additionally, the autocorrelation function was used to determine the dominant frequency. Using these functions, the decrease in the dominant frequency and the periodicity of the pressure fluctuations were detected in the defluidization region, even when the bed was observed to be satisfactorily fluidized. On the other hand, the prediction of defluidization itself several seconds before it occurred proved difficult.

【 授权许可】

Unknown