低分壓下二氧化碳吸附劑之吸附動力學探討

Kinetics of CO_2 Adsorption under Low CO_2 Partial Pressures

周豐志(FENG-ZHI JOU) ； 吳淑姿(SHWU-TZY WU) ； 余世宗(SHIH-TSUNG YU)

《科學與工程技術期刊》 13卷2期 (2017/09) Pp. 45-55

摘要

本研究使用吸附劑（活性碳、silica xerogel和amine-grafted silica xerogel），探討三種吸附劑吸附二氧化碳分子的吸附動力學模式（pseudo-first-order kinetic model、pseudo-second-order kinetic model與intraparticle diffusion model）與等溫吸附模式（Freundlich與Langmuir 等溫吸附模式）。活性碳吸附劑吸附二氧化碳氣體分子之實驗結果以pseudo-second-order kinetic model有較好的線性關係。silica xerogel與aminosilane-modified silica吸附劑吸附二氧化碳氣體分子之實驗結果，silica xerogel以pseudo-second-order kinetic model有較好的線性關係，aminosilane-modified silica以intraparticle diffusion model有較好的線性關係。計算之q_e值與實驗q_e值較相近。三種吸附劑之等溫吸附模式，以Langmuir模式有較好的線性關係，且三種吸附劑的R_L值均介於0＜R_L＜1時，為有利性吸附。

關鍵字

活性碳 ； silica xerogel ； amine-grafted silica xerogel ； 二氧化碳

並列摘要

We investigated the adsorption kinetic models （pseudo-first-order kinetic, pseudo-second-order kinetic, and intraparticle diffusion models） of carbon dioxide adsorbed on three adsorbents （activated carbon, silica xerogel, and amine-grafted silica xerogel） and evaluated isothermal adsorption models （Freundlich and Langmuir models）. The experimental results for the adsorption of carbon dioxide gas on the active carbon adsorbents revealed that this model showed a strong linear relationship with the pseudo-second-order kinetic model. The silica xerogel and aminosilane-modified silica showed strong linear relationships with the pseudo-second-order kinetic and intraparticle diffusion models, respectively. The calculated qe values were close to the experimental qe values. The isothermal adsorption model of the three adsorbents showed a strong linear relationship with the Langmuir model, and the RL values of the three adsorbents were in the range of 0 ＜RL ＜1, indicating favorable adsorption.

並列關鍵字

active carbon ； silica xerogel ； amine-grafted silica xerogel ； carbon dioxide