Nanoclay montmorillonite as an adsorbent for CO₂ capture: Experimental and modeling

Abstract

Today, the tendency to use mineral adsorbents has increased due to its low cost for removal of the flue gas of fossil‐fuel power plants. In this research, the optimization of the CO2 adsorption process using the sodium‐montmorillonite adsorbent was investigated. The response surface methodology (RSM), combined with central composite design, was used to assess the effects of process variables and their interaction on the response (CO2 adsorption capacity) to achieve the optimal conditions. According to the analysis of variance, temperature and pressure parameters are the variables that affect the CO2 adsorption capacity. Moreover, one semi‐empirical correlation was established to calculate the optimum operating conditions of the CO2 adsorption process. The optimal variables of the process obtained from numerical optimization are 25°C and 9 bar for temperature and pressure, respectively. Based on the optimal conditions, the adsorption capacity of 100.67 mg/g was achieved. Furthermore, additional experiments were performed to examine the isotherm, kinetic, and thermodynamic models of absorption. Kinetic studies showed that adsorption was in accordance with the second‐order reaction. Equilibrium data were analyzed using Langmuir, Freundlich, Hill, and D‐R isotherm models at different temperatures. The D‐R isotherm provides the best description for the adsorption experimental data.

Triethanolamine‐modified montmorillonite clay as a new adsorbent for CO2 capture: Characterization, adsorption, and RSM modeling

“…A useful method for detecting and optimizing the system conditions is the use of 3D surface plots, contour plots and graphical representations of regression equations. [ 35 ] 3D surface plots are used to understand the interaction effects of parameters on the CO 2 adsorption capacity. Figure 6 presents the results of the interaction between each of the two variables and their effect on the adsorption capacity.…”

“…According to the optimal conditions, the adsorption capacity was obtained at 100.67 mg/g at a temperature of 25°C and pressure of 9 bar. [ 35 ] In another study, Khajeh et al investigated the CO 2 adsorption capacity of modified MMT nano clay with NaOH. CO 2 binding in modified MMT seems to be due to the formation of chemical bonds due to the influence of operating conditions and its structure.…”

Impact of structure, doping and defect-engineering in 2D materials on CO2 capture and conversion

“…Layers of MMT contain an octahedral sheet with an Al cation sandwiched by two tetrahedral sheets with the main silicon cation. 148 The major drawback of clay-based materials for CO 2 adsorption is their low efficiency CO 2 uptake under moist conditions and this was due to the diffused water molecules that prevent the capture of gas molecules. In the absence of water molecules (dry conditions), one can expect high CO 2 uptake due to nano-channels in the clay for the intercalation of CO 2 molecules.…”

“…Under optimum conditions of temperature and pressure of 25 °C and 9 bar, a CO 2 adsorption of 100.67 mg g −1 was achieved and a good agreement between theoretical and predicted (104 mg g −1 ) values of gas adsorption was observed. 148 Like the abovementioned study, an ANOVA treatment was tried on NaOH modified MMT by the same research group. Under optimum conditions of temperature (65 °C), pressure (1 bar), acid concentration (5.99 M) and wt% NaOH (39.76%), a CO 2 This journal is © The Royal Society of Chemistry 2021 adsorption of 105.55 mg g −1 was observed with a desirability index of 0.996, which reveals the good correlation between experimental and predicted gas adsorption values.…”

Hydrocarbon production by addition of Cu‐ZnO on g‐C3N4 for CO2 conversion

“…The use of large quantities of fossil fuels has brought about a substantial increase in greenhouse gas emission and a global energy shortage. The continuing increase of CO 2 being emitted into the atmosphere has gained global attention, [ 1–3 ] and many researchers have attempted to address these issues. Several methods have been studied to reduce the greenhouse gas effect and obtain clean energy resources.…”