A new aqueous solvent based on a blend of N-methyldiethanolamine and triethylene tetramine for CO2 recovery in post-combustion: Kinetics study

AbstractTo struggle against global warming, CO2 emissions should be limited. The improvement in the thermal efficiency of industries and buildings will contribute to reduce the CO2 emissions for each energy unit. But, given the emergency of the situation, it will also be necessary to recover CO2 from more concentrated sources like power plants and store it deep underground. For CO2 recovery in post-combustion, chemical solvents are put forward since they allow a high recovery rate even with a low partial pressure of CO2 in the flue gas. This work focuses on the development of a new solvent based on a blend of N-methyldiethanolamine (MDEA) and triethylene tetramine (TETA), an amine with four amino groups. CO2 absorption has been investigated between 298 and 333 K using a Lewis cell with a constant interfacial area. Several concentrations of MDEA (17.5 and 40 wt.%) and TETA (3 and 6 wt.%) have been assessed. The influence of the CO2 partial pressure on the absorption rate was pointed out. The addition of small amounts of TETA leads to a high increase in the CO2 absorption rates. A numerical model based on the film theory has been used to determine the rate coefficient between CO2 and TETA for each solvent