Volume 4: Innovative Solutions for Energy Transitions: Part III

DMCA-MCA Hybrid With High Absorption Rate and Low Energy Penalty for CO2 Capture Lidong Wang, Shanshan Liu, Rujie Wang, Qiangwei Li, Shihan Zhang

Abstract

The hybrid of amines is regarded as a promising alternative to MEA owing to its good performance on kinetics and thermodynamics for CO2 absorption. The primary/secondary amine can serve as absorption accelerator and the tertiary amine act as CO2 sinker and regeneration promoter. In this study, a novel hybrid comprising of N-methylcyclohexyamine (MCA) and N, Ndimethylcyclohexylamine (DMCA) was put forward. The absorption kinetics using DMCA-MCA for CO2 absorption was investigated in a wetted wall column. The results showed that the total mass transfer coefficient of DMCA-MCA approach 2.02×10-10 mol/cm2 ∙s∙Pa, which was 1.2-folder higher than 5M monoethanolamine (MEA) as the benchmark. Moreover, the CO2 absorption capacity of DMCA-MCA hybrid reached 3.94 mol/L, significantly higher than 2.70 mol/L of 5M MEA. The thermodynamics was evaluated in a high pressure reactor, implying that the total regeneration heat was 2.20 GJ/t CO2, which was much less than MEA (3.99 GJ/t CO2). The results can benefit for developing novel absorption technology with DMCA-MCA solvent with a rapider absorption rate, higher absorption capacity and lower heat duty for CO2 capture.

Keywords CO2 capture; hybrid amine; absorption rate; regeneration heat