摘要
Lower regeneration energy and superior cyclic capacity have enabled biphasic absorbents great potential in the area of flue gas CO 2 capture. The liquid film mass transfer coefficient(k L ) is a vital parameter in the development of absorbents with efficient CO 2 absorption mass transfer performance, while the phase separation behavior of biphasic solutions could be an essential factor for the absorption mass transfer and the stability of absorber. However, systemic kinetic research towards biphasic absorbents, especially the impact of phase separation behavior, is limited. In this study, a typical amide-based biphasic absorbent diethylenetriamine(DETA)/diethanolamine(DEA)/N, N-dimethylacetamide(DMAC) which has achieved great reduction in regeneration energy, was selected as the subject of kinetic investigation in a wetted wall column. The CO 2 overall mass transfer coefficient(K G ) of DETA/DEA/DMAC exceeded other biphasic solvents, blended amine solution, and 40% K 2 CO 3 solution, with 3 times that of 40% K 2 CO 3 solution. Moreover, various operational conditions including absorption temperature, gas flow rate, and water content of solution were taken into account to build a multiple-condition kinetic mechanism to offer guidance for biphasic absorbents. Furthermore, phase separation behavior was revealed as the main blame for the deterioration in the liquid film chemical mass transfer process of biphasic solvents in the CO 2 absorption process, resulting in the k L of DETA/DEA/DMAC before phase separation decreased by 75.3% at the phase separation stage. Therefore, it is crucial to ensure that the CO 2 loading of the solution entering absorber is lower than the phase separation point in applications. After phase separation, DETA/DEA/DMAC split into the organic and aqueous phases, the k L of the aqueous phase gradually exceeded that of the organic phase as CO 2 loading increased for its higher chemical enhancement factor(E).
危险品化学品经营许可证（带存储）