Lipophilic Amine Aqueous Solutions for CO2 Capture: Comparison of Absorption Rates For Hexylamine (Hxa), Dimethylcyclohexylamine (DMCA) and Hxa-DMCA Mixtures

Abstract

The low attractiveness and competitiveness of carbon dioxide capture processes play against their deployment. Besides considerable investment costs for capture units and potential leakage of amines into the environment, conventional amine-aqueous solvents commonly used consume steam at temperatures ranging from 120 °C till 140 °C for the regeneration of solvent. A series of novel lipophilic amine solvents with low regeneration temperature are here studied with the aim to improve CO₂ capture processes. This paper presents a comparison of the performance of single HexylAmine 3 M solvent and the mixture of DiMethylCyclohexylAmine/HexylAmine, at different compositions and temperatures. The absorption of CO₂ was performed at 20 °C, 30 °C and 40 °C, in order to define the respective kinetic law. Experimental results obtained in a Lewis cell apparatus show the impact of amines composition on the kinetics of absorption. Besides, both absorption and regeneration rates are studied. Results show outstanding outcomes compared to the conventional aqueous solvent containing MonoEthanolAmine (MEA) and enable novel lipophilic solvents to be suggested for low energy carbon capture processes.