Physical and chemical properties of DMXTM solvents

Post combustion Carbon Capture (PCC) and Storage technology is viewed as an efficient solution to reduce CO2 emissions. In PCC, an amine in aqueous solution can be used to selectively capture CO2 from a flue gas to usually achieve a targeted 90% CO2 removal. However, using a 30% wt solution of MonoEthanolAmine (MEA), 3.7 GJ/tCO2 is required to release the carbon dioxide from the solvent, which is not satisfactory either from the economical point of view, or from the environmental point of view. One alternative to improve the process is to tune the chemical properties of the solvent in order to obtain a higher cyclic capacity of absorption than the one of 30% wt MEA solution. This allows to reduce the total liquid flow rate in the CO2 capture plant, and thus the energy requirement for a given CO2 removal. Another alternative, which can be combined with the first alternative, is to tune the physical properties of the solvent in order to obtain a liquidliquid phase separation in the process. In this class of DMXTM solvents, the CO2 captured concentrates in one of the two phases and only a portion of the total flow rate has to be sent to the stripper and thus, the energy requirement for a given amount of CO2 captured is reduced. In this work, we present liquid-vapor and liquid-liquid equilibrium data obtained with different DMXTM solvents along with the corresponding estimations of the potential reduction of the liquid flow rate in the stripper.