Experimental Modeling and Optimization of CO₂ Absorption into Piperazine Solutions Using RSM-CCD Methodology

Abstract

The present work evaluates and optimizes CO 2 absorption in a bubble column for the Pz-H 2 O−CO 2 system. We analyzed the impact of the different operating conditions on the hydrodynamic and mass-transfer performance. For the optimization of the process, variable conditions were used in the multivariate statistical method of response surface methodology. The central composite design is used to characterize the operating condition to fit the models by the least-squares method. The experimental data were fitted to quadratic equations using multiple regressions and analyzed using analysis of variance (ANOVA). An approved experiment was carried out to analyze the correctness of the optimization method, and a maximum CO 2 removal efficiency of 97.9%, an absorption rate of 3.12 g/min, an N CO 2 of 0.0164 mol/m 2 •s, and a CO 2 loading of 0.258 mol/mol were obtained under the optimized conditions. Our results suggest that Pz concentration, solution flow rate, CO 2 flow rate, and speed of stirrer were obtained to be 0.162 M, 0.502 l/h, 2.199 l/min, and 68.89 rpm, respectively, based on the optimal conditions. The p-value for all dependent variables was less than 0.05, and that points that all three models were remarkable. In addition, the experiment values acquired for the CO 2 capture were found to agree satisfactorily with the model values (R 2 = 0.944−0.999).

An Optimization Study of Carbon Dioxide Absorption into the Aqueous Solution of Monoethanolamine and Tetrabutylphosphonium Methanesulfonate Hybrid Solvent Using RSM-CCD Methodology

“…These results confirmed that the predicted and actual values were in good agreement, with high acceptability of the models [23]. The adequate precision measures the signal to noise ratio, and the ratio value of 33.76 indicated an adequate signal (adeq precision >4) [24].…”

CFD and statistical approach to optimize the average air velocity and air volume fraction in an inert-particles spouted-bed reactor (IPSBR) system

“…A three-dimensional (3-D) graph can also be used to represent the RSM results [ 13 ]. As an example, Figures 13 , 14 , and 15 show the effect of some interactions (feed gas velocity-orifice diameter, orifice diameter-gas head, and mixing particle diameter-mixing particles loading) on the average air velocity in the three different regions of the contact system.…”

“…1 À 23701 x 2 2 À 5:691 x 2 3 À 382:1 x 2 4 À 35:36 x 2 5 þ 52:13 x 1 x 2 À 66:7 x 2 x 3 À 198:1 x 2 x 5 À 29:74 x 3 x 4 þ 4:05 x 3 x 5 À 93:9 x 4 x 5 (13) Time-averaged middle air velocity (m/s) ¼ 0:6581 þ 38:07 x 2 À 22:24 x 4 À 0:0397 x 2 1 À 7642 x 2 2 þ 4:122 x 2 3 þ 320:7 x 2 4 þ 9:33 x 2 5 À 0:4880x 1 x 3 þ 5:523 x 1 x 4 þ 3:442 x 1 x 5 þ 146:1 x 2 x 3 þ 1988 x 2 x 4 À 4:61 x 3 x 5 þ 53:7 x 4 x 5 (15) where x 1 , x 2 , x 3 , x 4 , and x 5 are coded variables.…”

“…Pashaei et al. [ 13 ] used Central Composite Design (CCD) which is a method within RSM to optimize CO 2 absorption in a bubble column for the piperazine–H 2 O–CO 2 system. Their results indicated that, under the optimized conditions, a maximum CO 2 removal efficiency of 97.9% and a CO 2 loading of 0.258 mol/mol were achieved.…”

“…It was concluded that the axial and radial profiles of volume fraction illustrated a coherent behavior for the largest particles when compared with the literature data. Pashaei et al [13] used Central Composite Design (CCD) which is a method within RSM to optimize CO 2 absorption in a bubble column for the piperazine-H 2 O-CO 2 system. Their results indicated that, under the optimized conditions, a maximum CO 2 removal efficiency of 97.9% and a CO 2 loading of 0.258 mol/mol were achieved.…”