• 作者： Hwang, Hsin-An; Chiao, Shu-Min; Yu, Wen-Ching
• 中文摘要： 有機反應中使用的異相觸媒,會因活性基被結焦占據而失去催化活性。結焦同時也會阻塞觸媒孔隙,使反應物不易進入。本研究探討單一觸媒顆粒再生時氧氣擴散的影響。我們假設氧氣擴散係數隨結焦量而改變。不同的阻塞形態會產生不同的溫度變化情形。當考慮結焦量對質傳的影響時,最高溫較晚出現,溫度變化亦較緩和。同時溫度下降也比較慢。高溫時此系統是在質傳速率控制之下,上述效果有加強之趨勢。
• 英文摘要： Coke deposited on catalyst lowers activity of the catalyst by both occupying the active sites and also deteriorating mass transfer scheme. Including the effect of coke deposition on the rate of oxygen diffusion was attempted in this study for the regeneration of a single catalyst pellet. The effective diffusivity in the catalyst was assumed to be a function of coke content, and increase during the oxidation reaction. Two different pore blocking mechanisms were studied, namely, the pore and border blocking modes. Including coke-dependency of effective diffusivity would delay the appearance of the maximum temperature, and also smooth out its peak. The same effect would also prevent early decreasing of catalyst temperature. Effects were observed to become more significant at high temperature regeneration cases where diffusion-control kinetics dominates.
• 中文關鍵字： 觸媒再生; 煤焦; 有效擴散係數; 質量傳遞; 溫度變化
• 英文關鍵字： Catalyst Regeneration; Coke; Effective Diffusion Coefficient; Mass Transfer; Temperature Variation