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The CO2 absorption–desorption performances of nonaqueous trisolvent blended amines, monoethanolamine (MEA), 2‐amino‐2‐methyl‐1‐propanol (AMP), methyl diethanol amine (MDEA), 1‐dimethyl amino‐2‐propanol (1DMA2P), diethyl ethanol amine (DEEA), and piperazine (PZ), are investigated in terms of desorption parameters. Two trisolvent amine combinations, primary amine (MEA)/sterically hindered amine (AMP) and tertiary amine (MDEA/1DMA2P/DEEA)‐polyamine (PZ), are prepared at 5 m total amine concentrations with different molarities. Response surface methodology based on a central composite design is used to obtain the optimal condition. This study aims to determine the molarity ratios of solvent systems and investigate their effects on objective functions: heat duty, desorption rate, and desorption factor. Surface analysis suggests optimum conditions as 3 m MEA–1.375 m MDEA–0.625 m PZ for the lowest energy consumption. The experimental results of the proposed system are compared with the 5 m MEA solution. The extensive energy penalty of the CO2 desorption of amine absorbents is reduced with the newly developed solution. [ABSTRACT FROM AUTHOR]

Summary: Chemical absorption of CO2 into aqueous amine‐based solvents is known as the most mature technology featuring high separation efficiencies and applicability of retrofitting. The high regeneration energy requirement of the process is a major drawback, and improvements in solvent design are required. This study investigated the CO2 absorption and desorption performance of the nonaqueous monoethanolamine (MEA)/methyl diethanolamine (MDEA) blend experimentally using a stirred cell reactor. CO2 loading, cyclic capacity loss, and initial absorption rate were measured for different solvent formulations and compared to single amines (MEA or MDEA). A mixture‐process design and response surface methodology were employed to model and optimize the solvent formulation at different temperatures and pressures. The single‐response optimization yielded 0.83molCO2/molamine (at 0% MEA and 303 K/0.5 barg) and 3.17e‐5 kmol/m2·s (at 40% MEA and 310.67 K/0.5 barg) as optimal absorption capacity and rate of absorption, respectively. The multiresponse optimization was conducted using the composite desirability function yielding 0.653molCO2/molamine and 2.987e‐5 kmol/m2·s (D = 0.903). The multiresponse optimization was also extended to include the impact of different initial settings and importance ratios between the absorption capacity and rate of absorption, in which the latter needed at least 1.6 higher importance level to influence the multiresponse optimization. [ABSTRACT FROM AUTHOR]