Triacetoneamine-derivates (EvAs) for CO2-absorption from process gases

•Comprehensive experimental screening of a new class of solvents for CO2-absorption.•All solvents are aqueous solutions of triacetoneamine-derivates named EvAs.•The EvAs systematically differ in the substituent of the triacetoneamine ring.•Some EvAs show improved performance compared to MEA and MDEA/PZ. New amines for reactive absorption of CO2 from process gases were investigated in a comprehensive experimental screening. All studied amines are derivates of triacetoneamine and differ only in the substituent of the triacetoneamine ring structure. The amines are abbreviated by the acronym EvA with a consecutive number, designating the derivate. About 50 EvAs were considered in this work from which 26 were actually synthesized and investigated in aqueous solution. The mass fraction of the amines in the unloaded solution was either w˜EvA0=0.05 g/g or w˜EvA0=0.4 g/g. The following properties were studied: solubility of CO2, rate of absorption of CO2, liquid–liquid and solid–liquid equilibrium, foaming behavior, dynamic viscosity, and acid constants. The nine most promising EvAs were evaluated with the NoVa short-cut method (Vasiliu et al., 2020). The method yields estimates for the specific energy demand and recirculation rate for a given purification task. Two typical purification tasks were considered: the CO2-removal from natural gas and from synthesis gas, respectively. Some of the EvAs showed significantly improved performance compared to monoethanolamine (MEA) and a solvent-blend of methyl-diethanolamine and piperazine (MDEA/PZ).