Kinetics of novel non-corrosive amino functionalized ionic liquid organic solution for CO2 capture

Abstract

Extensive energy consumption is a challenge for developing industrial carbon capture absorbents. A novel amino functionalized ionic liquid (AFIL) organic solution, tetraethylene pentamine 5-amino-4-imidazolecarboxamide/n-propanol/ethylene glycol ([TEPAH][AICA]/NPA/EG), is considered as a promising absorbent due to its high CO2 absorption capacity and low energy consumption. However, its industry application potential still needs to be further evaluated for carbon capture process. In this work, thermodynamics, kinetics and corrosive behavior of [TEPAH][AICA]/NPA/EG solution were investigated. The regeneration energy consumption was 2.30 GJ⋅t−1 CO2, which was 39.5% lower than the benchmark monoethanolamine (MEA) solution. The mass transfer reaction kinetic model was established, showing that the reaction between CO2 and [TEPAH][AICA]/NPA/EG solution followed fast pseudo-first-order. The enhancement factor and reaction rate constant increased with the increase of absorption temperature, while they showed a decreasing trend with the increase of absorption loading. The relationship between the second-order rate constant and temperature was expressed as k2=7.2075×108exp-3093.5T. The activation energy was 25.72 kJ·mol−1. During absorption process, the dominant mass transfer resistance gradually changed from gas phase to liquid phase. In addition, the absorbent presented non-corrosive behavior after saturated absorption, which was superior than the MEA absorbent for storage and transportation in the carbon capture technology. To be concluded, the above results showed that the [TEPAH][AICA]/NPA/EG solution owned great potential for future industrial application.