Ternary deep eutectic solvents: Evaluations based on how their physical properties affect energy consumption during post-combustion CO2 capture

In this work, an inverse design method for absorbent development was proposed to reduce the energy requirement of post-combustion CO2 capture (PCC) with 4 steps. 1. Four physical solvents were modeled for PCC and the artificial neural network (ANN)-simulated annealing (SA) models were developed for fast and accurate multi-objective optimization. 2. The optimization results show that the physical properties of absorbents are important for energy savings. Further analysis on liquid pump energy demand and optimal operating parameters of each absorbent identified absorbents with low viscosity, small average molecular weight, and high CO2 capture ability from flue gas are desirable for PCC. 3. A new strategy was proposed to adjust the physical properties of deep eutectic solvents (DESs) and overcome the disadvantages of aqueous DESs—low thermal stability—by using two ingredients as hydrogen bond donors. 4. Through experimental tests and computer modeling, a DES (TEAC/2Gly/PDO) consisting of tetraethylammonium chloride, glycerol, and 1,3-propanediol in a mole ratio of 1:2:1 was identified as a promising CO2 absorbent with energy demand of 1.06 MJ/kg CO2.