Study on CO2 Absorption and Regeneration Property of Flue Gas From Methyldiethanolamine-Amine Mixture System

ObjectivesThe absorption and regeneration properties of different formulations of methyldiethanolamine (MDEA) mixed with different diamines were studied.MethodsIn the simulated flue gas environment with 12% CO2 and 88% N2, MDEA was used as the main agent, while ethylenediamine (EDA), 1,3-diaminopropane (DAP), N-methyl-1,3-propanediamine (MAPA), aminoethylethano-lamine (AEEA), N,N-dimethylethylenediamine (DMEDA) and 3-dimethylaminopropylamine (DMPDA) were added as activators, respectively. Under a total amine concentration of 40%, the chemical absorbent was configured with mass ratios of main agent to activator of 1∶1, 2∶1 and 3∶1, respectively. The absorption rate, regeneration rate and circulation capacity of different absorbers were determined by comparing bubble absorption and oil bath regeneration experiments.ResultsMDEA-EDA system has the best absorption property when the mass ratio of MDEA to EDA is 1∶1. The MDEA-DMEDA system has the best regeneration property when the mass ratio of MDEA to DMEDA is 2∶1, with a circulation capacity reaching 1.7 mol/kg. The overall properties of MDEA-AEEA system are optimized when the mass ratio of MDEA to AEEA is 1∶1, with a cycle capacity reaching 1.49 mol/kg.ConclusionsThe research results can provide a theoretical basis for the formulation optimization of mixed amine solutions in industry.