Thermal degradation of primary amines blended with N,N-dimethylethanolamine in post-combustion carbon capture

Blending is a common method to improve the performance of amine solution for CO 2 capture. While the amine will degrade at elevated temperatures or so-called thermal degradation, the mixing of multiple amines could change the thermal degradation behavior and it is critical to reveal them before implementing the CO 2 capture at large scale. Herein, the thermal degradation performance of blended amines was studied via experimental and computational methods. In comparison with single amine solution, the effect of an additional tertiary amine N,N -dimethylethanolamine (DMEA) was analyzed. The thermal degradation experiments were carried out at multiple temperatures. The temperature threshold was identified for the blended solution after which the degradation rate increases dramatically. Based on the obtained degradation products, the degradation mechanism of the blended amine is proposed. The energy barrier of key reactions in thermal degradation was obtained and the interaction of primary amine and tertiary amine is clarified.