低分壓下二氧化碳吸附劑之吸附動力學探討

Kinetics of CO2 Adsorption under Low CO2 Partial Pressures

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 qe值與實 驗qe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 RL 值均介於 0＜RL＜1 時，為有利性吸附。

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