Experimental and Mathematical Modelling of Factors Influencing Carbon Dioxide Absorption into the Aqueous Solution of Monoethanolamine and 1-Butyl-3-methylimidazolium Dibutylphosphate Using Response Surface Methodology (RSM)

Abstract

This paper investigated the solubility of carbon dioxide (CO2) in an aqueous solution of monoethanolamine (MEA) and 1-butyl-3-methylimidazolium dibutylphosphate ((BMIM)(DBP)) ionic liquid (IL) hybrid solvents. Aqueous solutions of MEA-(BMIM)(DBP) hybrid solvents containing different concentrations of (BMIM)(DBP) were prepared to exploit the amine’s reactive nature, combined with the IL’s non-volatile nature for CO2 absorption. Response surface methodology (RSM) based on central composite design (CCD) was used to design the CO2 solubility experiments and to investigate the effects of three independent factors on the solubility of CO2 in the aqueous MEA-(BMIM)(DBP) hybrid solvent. The three independent factors were the concentration of (BMIM)(DBP) (0–20 wt.%), temperature (30 °C–60 °C) and pressure of CO2 (2–30 bar). The experimental data were fitted to a quadratic model with a coefficient of determination (R2) value of 0.9791. The accuracy of the developed model was confirmed through additional experiments where the experimental values were found to be within the 95% confidence interval. From the RSM-generated model, the optimum conditions for CO2 absorption in aqueous 30 wt% MEA-(BMIM)(DBP) were 20 wt% of (BMIM)(DBP), a temperature of 41.1 °C and a pressure of 30 bar.

Velocity Augmentation Model for an Empty Concentrator-Diffuser-Augmented Wind Turbine and Optimisation of Geometrical Parameters Using Surface Response Methodology

“…Additionally, the maximum increasing impact of the dependent factor was 0.0007775, related to the interaction between L c and L d parameters. The coded parameters in the quadratic model were beneficial for predicting the relative significance of the factors by comparing the coefficients of the factors [86]. By default, the factors' low and upper levels were coded as −1 and +1, respectively [66].…”

“…By default, the factors' low and upper levels were coded as −1 and +1, respectively [66]. The coded equations were useful for understanding the relative effects of the parameters by comparing the coefficients of the factors [86]. In contrast, Equation (13) with actual factors specified in original units was used for predictions in the original factor units.…”

“…the coefficients of the factors [86]. By default, the factors' low and upper levels were coded as -1 and +1, respectively [66].…”

“…Model significance and proper variable fitting were affirmed by the Fvalue of 106.67, with only a 0.01% probability that such a high F-value could arise due to noise. The non-significant lack of fit (p-value = 0.0866) can be used to navigate design spaces with a low probability of error [86]. Furthermore, the low coefficient of variation The analysis of model fitness included a lack-of-fit test and analysis of variance (ANOVA).…”

Investigation of Molecular Mechanism of Cobalt Porphyrin Catalyzed CO2 Electrochemical Reduction in Ionic Liquid by In-Situ SERS

“…They suggested that the longer alkyl chain in the dibutylphosphate anion creates a larger free volume to accommodate more CO 2 molecules. Azhar et al investigated the solubility of CO 2 in an aqueous solution of monoehanolamin and 1–butyl–3–methylimidazolium dibutylphosphate (BMIM·DBP) ionic liquid hybrid solvents [ 17 ]. Based on response surface methodology (RSM) and mathematical modelling, they predicted the optimum conditions for CO 2 absorption.…”