SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xiaobin Zhou,Dan Wang,Zhuo Wang,Zongqiang Zhu,Yinming Fan,Dunqiu Wang,Bihong Lv,Shengpeng Mo,Yanan Zhang,Yinian Zhu,Guohua Jing
Secondary amines are highly suitable candidates for constructing non-aqueous phase change absorbents (PCAs) that boast low viscosity and regeneration heat. However, the secondary amine-based PCAs often encounter the challenge of inadequate phase separation. This study proposed an innovative strategy of tailoring the polarity of absorption products to facilitate the controllable phase transition of the secondary amine-based PCA. Specifically, using aminoethylethanolamine (AEEA) as a regulator of product polarity to endow the 2-(ethylamino)ethanol (EAE)/pentamethyldiethylenetriamine (PMDETA)/dimethyl sulfoxide (DMSO) non-aqueous absorbent with tunable liquid–liquid phase transition behavior. The AEEA/EAE/PMDETA/DMSO (A/E/P/D) PCA realized a high CO 2 loading of 0.77 mol·mol −1 , with over 92% of the absorbed CO 2 being enriched in the CO 2 -rich phase, which exhibited a low viscosity of 13.83 mPa·s. The A/E/P/D PCA also possessed good reusability, maintaining a cyclic loading of 0.65 mol·mol −1 even after five absorption–desorption cycles. Analysis of the phase change mechanism indicated that AEEA reacted with CO 2 to form highly polar AEEA-derived products, which played a pivotal role in driving the phase transition of the A/E/P/D system. In brief, the AEEA-derived product easily combined with polar DMSO , creating a “polar sink” that continually attracted the medium-polar EAE-derived products. Consequently, these products clustered together to form the CO 2 -rich phase with less polar PMDETA being isolated to form the CO 2 -lean phase. Moreover, estimation of the regeneration heat demonstrated that the combined sensible heat and latent heat of A/E/P/D amounted to 0.32 GJ·ton −1 CO 2 , representing a significant reduction of 84% compared to 30 wt% MEA. This study provided a novel idea to manipulate the phase behavior of PCAs and offered a promising A/E/P/D PCA for energy-efficient CO 2 capture.
研究领域:
化学工程
·
环境科学
·
量子化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ENERGY
·
2024
·
IF 10.1
Bingling Yuan,Zhen Chen,Qianxuan Zhang,Guoxiong Zhan,Lei Xing,Zhoulan Huang,Yuchen Li,Lidong Wang,Junhua Li
Chemisorption with biphasic solvents is a promising low-energy strategy for separating CO 2 from industrial flue gas, however, amine degradation and changes in water content can considerably impede the phase-splitting performance. To the issues, tetramethylene sulfone (TMS) was selected as separating agent to prepare a biphasic solvent with polyamine triethylenetetramine (TETA) with a TETA:TMS:H 2 O ratio of 2:6:2 (denoted as 20 T-60TMS). The CO 2 loading of the blended phase and the volume fraction of the rich phase were 2.56 mol/L and 35.4%, respectively; the total regeneration heat duty was 2.36 GJ/tCO 2 . The proposed biphasic solvent exhibited better resistance to oxidative degradation and thermal degradation than did previously reported solvents, attributed to the beneficial effect of TMS. Additionally, the degradation products did not substantially reduce the phase separation performance after a 360 h thermal degradation test. A dynamic phase-splitting evaluation revealed that the 20 T-60TMS solvent was robust to changes in water content. Theoretical calculations confirmed that the introduction of TMS weakened the hydrogen bond between TETACOO − /TETAH + and H 2 O, engendering enhanced TETACOO − and TETAH + self-aggregation, forming a strong hydrogen bond network, and achieving fast phase separation. This work provides a novel biphasic solvent with excellent tolerance and stability for CO 2 capture from flue gas.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Jiexu Ye,Chenkai Jiang,Han Chen,Yao Shen,Shihan Zhang,Lidong Wang,Jianmeng Chen
The biphasic solvent-based absorption process has been regarded as a promising alternative to the monoethanolamine (MEA)-based process because of its high absorption capacity, phase separation behavior, and potential for conserving energy for CO2 capture. A trade-off between the absorption capacity and phase separation ratio is critical for developing an advanced biphasic solvent. Typically, water content in the biphasic solvent can be manipulated to tune the phase separation behavior. To explore the relationship between water content and phase separation behavior, an inert organic solvent, 1-methyl-2-pyrrolidinone, was added as a substitute for water in a biphasic solvent, specifically a triethylenetetramine (TETA) and 2-(diethylamino)ethanol (DEEA) blend. Moreover, the water content−kinetics and thermodynamics relationships were also evaluated. Experimental results revealed that reducing the water content was beneficial for phase separation but adverse for adsorption capacity. Kinetic analysis indicated that the water content did not significantly affect the rate of CO2 absorption at a rich loading. Furthermore, the regeneration heat decreased with the water content. The regeneration heat of TETA–DEEA with a water content of 20 wt % was almost 50% less than that of MEA solution. 13C nuclear magnetic resonance analysis revealed that the water content did not affect the reaction mechanism between CO2 and amines.
研究领域:
化学工程
·
环境科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2019
·
IF 5.128
Yannan Li,Jun Cheng,Leiqing Hu,Niu Liu,Junhu Zhou,Kefa Cen
To study the relationship between crystal structures of amine-carbamates and regeneration energy consumptions, two new solid–liquid phase-changing solutions of ethylenediamine/N,N-dimethylacetamide (EDA/DMA) and ethylenediamine/N,N-dimethylformamide (EDA/DMF) were prepared to capture CO 2 efficiently and regulate the crystal structures of CO 2 absorption products (EDA-carbamates). The CO 2 absorption capacity and peak absorption rate of EDA/DMA and EDA/DMF solutions were both 30% and 67%, respectively, higher than those of EDA/water solution. EDA-carbamates in EDA/DMA and EDA/DMF solutions had the same molecular structures but different molecular arrangements (they belonged to orthorhombic and monoclinic crystals, respectively). The regeneration heat of EDA-carbamates in EDA/DMF solution (181.28 kJ/mol) was higher than orthorhombic EDA-carbamates in EDA/DMA solution (133.76 kJ/mol), which was attributed to the endothermic process (recrystallization process) during the transition from monoclinic EDA-carbamates to orthorhombic EDA-carbamates.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ENERGY
·
2020
·
IF 8.848
Min Xiao,Wenchao Zheng,Helei Liu,Xiao Luo,Hongxia Gao,Zhiwu Liang
Protonation and carbamate formation are critical reactions for CO 2 capture using amine-based absorbents which impact both CO 2 absorption and amine regeneration. In this regard, thermodynamic analysis towards CO 2 absorption in N -methylaminoethanol solution is carried out with specific attention to the corresponding protonation and carbamate formation reactions. The CO 2 absorption mechanism is investigated with the acquisition of reaction equilibrium constant and heat of reaction. CO 2 absorption performance of N -methylaminoethanol solution was evaluated in terms of CO 2 loading and solution pH. A thermodynamic model was then developed to mathematically describe the investigated system and make prediction on equilibrium CO 2 solubility, species profiles, and absorption/regeneration heat. Results show that the average relative deviation of equilibrium CO 2 solubility calculated from the is 4.2%. The predictive species profile and CO 2 absorption heat of N -methylaminoethanol solution indicates less energy cost to desorb CO 2 . This is in line with the relative unstable N -methylaminoethanol carbamate formation and consequential conversion to (bi)carbonate. The position of N -methylaminoethanol as a potential absorbent in amine based carbon capture is shown in terms of chemical reaction constants, equilibrium CO 2 solubility, second order rate constant ( k 2 ), and p Ka .
研究领域:
化学工程
·
环境科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）