Kinetic and heat duty study of aprotic heterocyclic anion-based dual functionalized ionic liquid solutions for carbon capture

Abstract

Abstract Due to its excellent and reversible CO2 uptake, the novel aprotic heterocyclic anion-based dual functionalized ionic liquid solution ([DETAH][AHA]) presented as an efficient candidate for CO2 capture. The kinetics of CO2 capture into [DETAH][AHA] solutions, e.g., [DETAH][Im] and [DETAH][Tz], was studied by using a double-stirred cell, with concentrations ranging from 0.25 to 1.0 mol/L and temperatures from 303 to 333 K. The overall first-order reaction rate constants (kov) and the secondary-order reaction rate constants (k2, FIL) of CO2 capture into this two [DETAH][AHA] solutions were obtained, and they all increased as the temperature increased. The relationship between k2, FIL and reaction temperature was determined by Arrhenius equation, which expressed as k 2 = 1.0365 × 10 12 exp - 5873.67 T and k 2 = 3.5361 × 10 12 exp - 6380.60 T , respectively. The calculated activation energies of such two solutions were 48.83 kJ/mol and 53.05 kJ/mol, respectively. From the heat duty evaluation, the total CO2 regeneration energy consumption of [DETAH][Im] and [DETAH][Tz] were respectively 2.94 and 2.84 GJ·mol−1 CO2, which were all less than that of traditional MEA solution due to their lower desorption reaction heat. A fast absorbent rate, a lower activation energies and regeneration energy consumption of [DETAH][AHA] solutions indicate greater potential and application prospects.