Adsorption And Separation Of CO₂ On Kureha Carbon And NaY

In recent years, CO2 as one of the main greenhouse gases, its concentration has been increaseing coutinually in the atmosphere. Excessive emissions of this gas can cause carbon imbalance in the nature world, leading to a series of environmental problems such as global warming, resulting in adverse effects on the survival and development of human society. The adsorption-based separation is one of the most promising methods to capture CO2 and gains researchers’s attention greatly. In the adsorption-based technology, the key point for capturing CO2 is to develop adsorbents with high adsorption capacity and high selectivity and stability. Activated carbon as a relatively cheap material is one of the most commonly used adsorbents, widely used in chemical, food, pharmaceutical and nuclear industries and other fields. Zeolites are another type of commonly used adsorbents, which possess good adsorption properties because of their unique molecular-sieving effects. The obtained main resuts of this thesis research are summarized as follows:1. A volumetric method was used to investigate the isotherms of CO2, CH4 and N2 on Kureha carbon at 298 K,310 K, and 323 K. The Langmuir Freundlich model was used to fit the experiment measured isotherms, and the fitted results show that the Langmuir Freundlich model can describe the isotherms. The breakthrough-column technique was then used to investigate the separation performance of CO2/CH4 and CO2/N2 mixtures on Kureha carbon, and the results indicate that the adsotbent can effectively separate the CO2/CH4 and CO2/N2 mixtures under the conditions experimentally applied. In addition, based on the experimentally measured breakthroughs, the component adsorbed amounts and the selectivities for CO2 over CH4 or N2 were calculated. Moreover, the ideal adsorbed solution theory (IAST) was applied to predict the component adsorbed amounts and the selectivities for CO2 over CH4 or N2, and these predicted results are in good agreement with those calculated from the experimental breakthroughs.. At a constant temperature, the selectivity for CO2 increases with increasing pressure while the selectivity for CO2 decreases with increasing temperature at a constant pressure. Finally, an proper model was used to simulate the breakthroughs, which are in agreement with the experimental ones.2. A volumetric method was used to measure the isotherms of CO2, CH4, and N2 on NaY at 298 K,310 K, and 323 K. The Langmuir model was used to fit the measured isotherms and the adsorption thermodynamic parameters were then derived. The results show that the Langmuir model can describe the measured isotherms well. The breakthrough-column technique was used to investigate the separation performance of CO2/CH4 and CO2/N2 mixtures on NaY. The results show that NaY can effectively separate these mixtures. In addition, the IAST was applied to predict the mixture isotherms and the selectivities for CO2 over CH4 or N2. At a constant temperature, the selectivity for CO2 increases with increasing pressure while the selectivity for CO2 decreases with increasing temperature at a constant pressure.