Zhao Shujie, Wang Yongqiang, Zhu Kaili, Zhao Dongfeng, Song Qingbin
College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, China.
Macao Environmental Research Institute, Macau University of Science and Technology, Macao, 999078, China.
Environ Sci Pollut Res Int. 2022 Dec;29(56):84903-84915. doi: 10.1007/s11356-022-21822-6. Epub 2022 Jul 5.
Currently, biphasic solvents are receiving more attention for CO capture due to their energy-saving potential. Whereas, most of the current biphasic solvents still suffer from high viscosity and low regeneration efficiency. To solve this problem, a novel tri-solvent biphasic solvent triethylenetetramine (TETA)-2-amino-2-methyl-1-propanol (AMP)-1-dimethylamino-2-propanol (1DMA2P) was proposed in this study, and its absorption properties, viscosity changes, desorption properties, recyclability capacity, and reaction mechanism were explored. The results showed that the CO absorption load showed a trend of firstly increasing and then decreasing with the increase of AMP concentration. Although the volume of the rich phase increased with increasing AMP concentration after the absorption, it also decreases the viscosity growth. The viscosity of the solution decreased from 498 mPa•s to 91 mPa•s. During the desorption process, the maximal desorption rates of AMP-containing solvents is significantly greater than that of 2 mol/L (M) TETA + 2 M 1DMA2P (2T2D). Simultaneously, the recyclability capacity of the AMP-containing solvents were also significantly higher than that of 2T2D. The regeneration efficiency of 1.5 M TETA + 0.5 M AMP + 2 M 1DMA2P (1.5T0.5A2D) was 81.92%. It was concluded by C NMR analysis that amino groups in TETA and AMP can react with CO to form carbamates and carbonates. Since AMP in the biphasic solution can generate free protons through various pathways during the desorption process, it promotes the decomposition of TETA-carbamate. This process achieves the deep stripping of CO in biphasic solvent. Overall, TETA-AMP-1DMA2P solution is a promising energy-saving candidate for industrial CO capture due to its competitive absorption-desorption performance and low viscosity.
目前，由于具有节能潜力，双相溶剂在二氧化碳捕集方面受到了更多关注。然而，当前大多数双相溶剂仍存在高粘度和低再生效率的问题。为解决这一问题，本研究提出了一种新型三溶剂双相溶剂三乙烯四胺（TETA）-2-氨基-2-甲基-1-丙醇（AMP）-1-二甲基氨基-2-丙醇（1DMA2P），并对其吸收性能、粘度变化、解吸性能、循环利用能力及反应机理进行了探索。结果表明，随着AMP浓度的增加，二氧化碳吸收负荷呈现先增加后降低的趋势。吸收后，尽管富相体积随AMP浓度增加而增大，但同时也降低了粘度增长。溶液粘度从498 mPa•s降至91 mPa•s。在解吸过程中，含AMP溶剂的最大解吸速率显著高于2 mol/L（M）TETA + 2 M 1DMA2P（2T2D）。同时，含AMP溶剂的循环利用能力也显著高于2T2D。1.5 M TETA + 0.5 M AMP + 2 M 1DMA2P（1.5T0.5A2D）的再生效率为81.92%。通过碳核磁共振分析得出，TETA和AMP中的氨基可与二氧化碳反应形成氨基甲酸盐和碳酸盐。由于双相溶液中的AMP在解吸过程中可通过多种途径产生游离质子，从而促进TETA-氨基甲酸盐的分解。这一过程实现了双相溶剂中二氧化碳的深度解吸。总体而言，TETA-AMP-1DMA2P溶液因其具有竞争力的吸收-解吸性能和低粘度，是工业二氧化碳捕集领域一种有前景的节能候选溶剂。
