Effect of solid acid-catalysts on desorption performance of mixed amine systems

To reduce the high energy consumption associated with chemical absorption, catalysts are introduced into the regeneration stage. The absorption and desorption performance of mixed amine systems monoethanolamine (MEA)-methyldiethanolamine (MDEA)-2-Amino-2-Methyl-1-Propanol (AMP) and n-butyldiethanolamine (BDEA)-2-(2-aminoethylamino)ethanol (AEEA) is first explored in absorption and desorption experimental apparatus, with MEA as the benchmark for comparison. Four commercially available, low-cost catalysts (HZSM-5, Hβ, HY and γ-Al 2 O 3 ) are tested, and the optimal absorbent-catalyst combination, 20 %BDEA-20 %AEEA + γ-Al 2 O 3 is selected. A relevant study is conducted on a 10 Nm 3 /h bench-scale CO 2 capture plant using feed gas with composition of 12 % CO 2 to validate the industrial feasibility of the catalytic process., where optimal conditions are identified based on absorption efficiency, cyclic capacity, and heat duty. Under the condition of 1.8 kW heating power and 60 L/h flow rate, 20 %BDEA-20 %AEEA + γ-Al 2 O 3 achieves the lowest heat duty of 3.15 GJ/t CO 2 , with a capture efficiency of 92 %. This represents a 29.2 % reduction (4.45 GJ/t CO 2 ) compared to the BA system without catalyst under the same capture efficiency, and a 44.7 % reduction (5.7 GJ/t CO 2 ) compared to the traditional MEA solution. A 15-day cyclic life experiment demonstrates good performance under these optimal conditions, providing important insights for industrial applications.