چكيده به لاتين
Carbon dioxide is the most common greenhouse gas emitted by global warming and climate change. Among the various CO2 capture technologies, solid adsorbents are considered to be the most efficient and cost effective processes. In this study, the halloysite nanotubes were studied as porous adsorbents for CO2 adsorption. The structure of synthesized nanocomposite was evaluated and confirmed by characteristic methods. To optimization of adsorption operational condition, the experimental design with RSM method was used and the adsorption capacity, measured at temperature range of (20~50°C) and at pressures of (1~9 bar) for two different amines. For preparation of the nanotube halloysite adsorbents, initial preparation was carried out with calcination and acid treatment that significantly increased the specific surface area and pore volume of adsorbent than basal support. The next step was loading of amines by wet impregnation with PEI and TEPA amines. In order to improve the efficiency of the adsorption capacity, the applied amines were loaded with different weight percentages. The highest adsorption capacity with optimally prepared adsorbents, IMSiNTs / PEI30 (IMP-30) and EMSNTs / TEPA30 (EM-TE30) were obtained 7.84 mmol.g-1 and 9.3 mmol.g-1, respectively, at 20°C, at pressure of 9 bar and an optimum loding of amine, 30wt %. CO2 capture were done in two stages, first an intense increase in adsorption capacity and then a relatively slow adsorption step. 70% of adsorption occurred within the first 2 to 3 minutes of adsorption, indicating high adsorption potential. All adsorption tests were performed in a fixed bed reactor durin 100 minutes. The experimental results were also compatible with the Freundlich isotherm model and the fractional–order kinetic model. The desorption test results indicated that the prepared halloysite nanoparticles have high thermal and chemical stability and good reversibility during the adsorption / desorption cycles.