چكيده به لاتين
In this study, we successfully utilized a green chemistry approach to prepare an adsorbent by functionalizing Montmorillonite with Choline Chlroride: Urea (a Deep Eutectic Solvent) to compare CO2, O2, and N2 adsorption. We conducted studies on the adsorption mechanism using a volumetric system at temperatures ranging from 25-55ºC under pressures of up to 9 bar. We assessed the effects of acid activation concentration, solvent concentration, and adsorbent mass on the CO2/O2 and CO2/N2 adsorption ratios (mg/mg). Characterization analyses confirmed that modification of interlayer spaces, ion exchange content, and Al/Si occurred through acid treatment and solvent impregnation. The CO2 adsorption mechanism demonstrated a heterogeneous multilayer and chemophysical sorption nature, which was in agreement with the Hill isotherm and Ellovich kinetic model. In contrast, the O2 and N2 mechanisms were in agreement with a monolayer nature, which matched the Langmuir isotherm and first-order kinetic model. We achieved the optimum adsorption ratio of CO2/O2 and CO2/N2 at 35ºC, while the highest individual adsorption for all three gases was obtained at 25ºC. At 35ºC, 5 bar, and 0.5 g, the highest uptake adsorption was 208.6 mg/g for CO2, 72.6 mg/g for O2, and 39.3 mg/g for N2. Thermodynamic parameters showed that the adsorption nature of CO2, O2, and N2 was exothermic (ΔH<0) with values of -14.49 Kj/mol, -7.74 Kj/mol, and -4.09Kj/mol, respectively. The study's experimental and modeling results showed a corresponding interpretation, which was remarkable. The adsorbent exhibited desirable renewability at adsorption/desorption cycles with remarkable uptake capacity, making it a highly potential adsorbent for CO2 capture from flue gases. The selectivity of CO2 towards O2 and N2 was almost 2.1 and 3.9, respectively.
The research focuses on the development of a green and sustainable adsorbent using deep eutectic solvents (DES) for cost-effective and biocompatible CO2 sequestration. The study investigates the breakthrough curve, adsorption capacity, regenerability, and CO2/N2 selectivity of the developed adsorbent under various conditions, such as gas flow rate, CO2 concentration, and solvent loading concentration. The ANOVA analysis revealed the high significancy effect of gas flow rate and CO2 vol. % on break-time and adsorption capacity with F-value of 147.2 , 112.1 and, respectively. The lower flow rate and higher CO2 vol.% obtained the higher CO2 uptake. The highest CO2 uptake of 96.1 mg/g attained at 30 ºC, 20 mL/min, 15% CO2 and with MMT100 acivated with 3 M HCl thereby inoculated by 25 wt.% ChCl:2U. The mathematical models used for breakthrough curve analysis having the best fit with the Clark, and Yoon-Nelson models confirming the characterization of Hill isotherm and Ellovich sinetic models. A negligible reduction in adsorption quality after 8 cycles and proper selectivity of 93.1% indicate the high potential of the adsorbent in real flue gas separation. The study highlights the potential of nanoclay-based adsorbents in CO2 capture and their alignment with green chemistry principles, offering a promising avenue for further research and development in this field.
Keywords: CO2 capture, Montmorillonite, Mesoporous Nano-clay, DES impregnation, Adsorption kinetics, Adsorption Thermodynamics
