Statistical optimization of carbon dioxide capture performance by tri-solvent system of MEA-DEA-PZ from the stored gas reservoir



Optimize the process parameters for low concentration blended tri-solvent



This experimental work has studied the effect of various operating factors (such as MEA/DEA/PZ concentration, temperature, operating pressure, agitation speed, and time) on absorption capacity from stored gas reservoir. As the current approach has a significant application to the bio-gas reservoirs to enhance the purity of CH4 and elimination of CO2 from the gas. The RSM has been used to model and optimize the CO2 capture process relating to low-pressure operating conditions.



Maximize rapid CO2 absorption



The CO2 absorption was performed for the total solvent (5, 10, and 15 %v/v) under the temperature range of (20, 25, and 30 °C) having reservoir pressure (1.5, 2, and 2.5 bar). The fraction of DEA: MEA was restricted to (0.2, 0.5, and 0.8) with simultaneous loading of anhydrous PZ range from 0 to 2 gms; and agitation speed for step intervals of (300, 600, and 900 rpm).



The relative error was found to be within ±1.93% and ± 2.25% for the initial absorption rate and CO2 absorption (at t=15 min.) respectively. According to this evidence, the process statistical model suits to be appropriate and accomplishes the goal of optimization.



The findings of the analysis of variance (ANOVA) illustrates good agreement between the experimental and statistical model confirming the potential of blended tri-solvent by aggressive initial rate of absorption and rapid CO2 absorption of 3.415 gm. CO2/min. & 17.779 gm. CO2 respectively.



RSM has successfully optimised the CO2 absorption by blended tri-solvent (MEA/DEA/PZ) for stored gas reservoir. For the initial absorption rate and CO2 absorption (at t=15 min.), the experimental design, quadratic models, and regression analysis developed for these variables were found to be reasonably accurate and efficient in forecasting response values in a range of the variables, with a relative error of ±1.93% and ± 2.25%, respectively. The potential of blended tri-solvent to attain a very high degree of absorption in a relatively short amount of time was proved by the optimum value of initial absorption rate, which was calculated to be 3.415 gm. CO2/min. and rapid CO2 absorption, which was calculated to be 17.779 gm. CO2. The 3D surface plots have shed light on the interactive effects that the process parameters have on the CO2 absorption while the synergistic effects of MEA/DEA/PZ have been taken into consideration.
