Experimental and modeling studies of bicarbonate forming amines for CO2 capture by NMR spectroscopy and VLE
Experimental and modeling studies of bicarbonate forming amines for CO2 capture by NMR spectroscopy and VLE
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通过 NMR 波谱和 VLE 捕获碳酸氢盐形成胺的实验和模型研究
DOI：
10.1016/j.seppur.2019.116097
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发表时间：
2020
影响因子：
8.6
通讯作者：
Liang Zhiwu
中科院分区：
文献类型：
--
作者：
Xiao Min;Cui Ding;Zou Liangyu;Yang Qi;Gao Hongxia;Liang Zhiwu
研究了N，N，N '，N'-四甲基-1，2-乙二胺、N，N，N '，N'-四甲基-1，3-丙二胺和N，N，N '，N'-四甲基-1，4-丁二胺三种叔二胺在燃烧后CO2捕集中的应用。通过测定酸化胺溶液的pH值，研究了二胺的酸碱性质，得到了反应常数和反应熵。竞争形成的单质子化和双质子化的二胺进行了观察。通过连续流动法进行使用这些二胺溶液的CO2吸收。NMR光谱用于检测本体溶液的形态。然后在平衡CO2溶解度和pKa方面与单胺进行比较，对二胺进行了一般评价。结果表明，结构修饰的二胺是有前途的碳酸氢根形成吸收剂在CO2吸收的潜力。最后，在较宽的温度、CO2分压和胺初始浓度范围内，测定了N，N，N '，N'-四甲基-1，2-乙二胺水溶液的CO2平衡溶解度，建立了热力学模型。该模型提供了合理的预测平衡CO2溶解度和物种浓度分布。
Three tertiary diamines,N,N,N',N'-tetramethyl-1,2-ethanediamine,N,N,N',N'- tetramethyl-1,3-propanediamine andN,N,N',N'-tetramethyl-1,4-butanediamine, were investigated for application in post-combustion CO2capture. The acid-base properties of the diamines were studied through measuring pH values of the acidified amine solutions to obtain reaction constants and corresponding enthalpies/entropies of the reactions. Competitive formation of monoprotonated and diprotonated diamines was observed. CO2absorption using these diamine solutions was carried out through a continuous flow method. NMR spectroscopy was used to detect speciation of the bulk solution. Then a general evaluation of the diamines was made in comparison with the monoamines in terms of equilibrium CO2solubility and pKa. The results demonstrated the potential of the structurally modified diamines to be promising bicarbonate forming absorbents in CO2absorption. Finally, the equilibrium CO2solubility of aqueousN,N,N',N'-tetramethyl-1,2-ethanediamine solution was measured at a wider range of temperatures, CO2partial pressures and initial amine concentrations to establish a thermodynamic model. The model provided reasonable prediction of equilibrium CO2solubility and species concentration profiles.