Gas Science and Engineering
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2023
·
IF 0
Rui Zhang,Haonan Liu,Ruixi Liu,Yingjie Niu,Luning Yang,Francesco Barzagli,Chao'en Li,Min Xiao
The blending of primary amines, with fast reaction kinetic, together with tertiary amines, with a large loading capacity, is an increasingly popular approach to develop high-performance CO 2 capture sorbents with low energy requirements for regeneration. In this study, we investigated the CO 2 absorption performance of several aqueous solutions obtained by mixing ethanolamine (MEA) and diethylethanolamine (DEEA) and compared them with that of individual MEA and DEEA. CO 2 loadings at equilibrium were measured experimentally under a wide range of operating conditions, at temperatures between 298 and 323 K, CO 2 partial pressures in the range 5–60 kPa, and different amine mixing ratios. In addition, 13 C NMR spectroscopy was employed to elucidate the reaction mechanisms and identify the species formed during CO 2 capture. The results of the study reveal the intricate interplay of MEA and DEEA in CO 2 capture, where MEA carbamate formation predominates in the early stages, gradually shifting to bicarbonate formation as the amine concentration decreases. Moreover, excess properties, which reflect non-ideal behaviors in amine blends, were introduced as a key parameter in the study. An excess property model, based on excess CO 2 loading, was developed to accurately predict the CO 2 equilibrium solubility without constant experimental measurement. As a result, good agreement was found between the experimental data and those calculated with the model (excess CO 2 loading) under the same operating conditions, with a average relative deviation of 1.1%.
研究领域:
化学工程
·
环境科学
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DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Daofan Ma,Chunying Zhu,Taotao Fu,Xigang Yuan,Youguang Ma
The gas-liquid two-phase flow and the mass transfer characteristics for CO 2 absorption into the binary amine mixture of monoethanolamine (MEA) and N,N-diethylethanolamine (DEEA) aqueous solution were investigated in T-junction microchannel reactor with a square cross-section. The effects of gas-liquid flow rate and absorbent concentration on bubble length, velocity and mass transfer coefficient were studied. Three flow regimes including slug-bubbly flow, slug flow and slug-annular flow were observed under experimental condition, and the gas-liquid two-phase flow pattern map was depicted. It is found that the transitions between three flow regimes depend primarily on the competition of forces exerted on bubble in the T-junction. The kinetics of CO 2 absorption into blended amine aqueous solutions was analyzed to understand the mass transfer enhancement mechanism of new hybrid solvent. Furthermore, the liquid-side overall mass transfer coefficient k L and the liquid-side overall volumetric mass transfer coefficient k L a were determined through processing experimental images recorded by a high-speed camera. The results show that k L a is in the range of (3.04–20.07) s −1 in this work, which is 2–3 orders of magnitude higher than that in the conventional equipment. The dimensionless Damköhler number ( Da ) and Peclet number ( Pe ) are introduced to correlate the liquid-side volumetric mass transfer coefficient, new correlation shows good prediction accuracy with the average deviation of 3.64%.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Huajun Zhao,Hongmei Wang,Zixuan Wang,Mengfan Wang,Rujie Wang,Qiangwei Li,Lidong Wang
Tertiary amine-based biphasic solvents exhibit desorption properties, which is beneficial for reducing energy consumption. A DEEA/AMP/2-Me/H 2 O biphasic solvent was proposed. DEEA, a tertiary amine, was used as the main absorbent, 2-Me served as a phase splitter, and AMP functioned as an activator. The introduction of AMP (4 %) raised the CO 2 loading from 3.83 to 4.10 mol/L, constituting 95.7 % of captured CO 2 . Moreover, the absorbent demonstrated robust cyclic stability and exceptional desorption ability at low temperatures, attributable to its deprotonation regeneration mechanism. Notably, it achieved a remarkably high desorption capacity of 3.61 mol/L at 363.15 K, accompanied by a desorption efficiency of up to 88.0 %. These values surpassed those of 30 wt% MEA, which exhibited a desorption capacity of 1.73 mol/L and an efficiency of 58.8 % at 393.15 K, by 209 % and 150 %. Given that 363.15 K was beneath the boiling point of H 2 O, the Q latent was exceptionally minimal (0.034 GJ/t CO 2 ), leading to a remarkably decreased regeneration heat (1.51 GJ/t CO 2 ). A combination of NMR analysis, DFT and MD simulations was utilized to elucidate the phase separation mechanism. The primary factor contributing to phase separation was identified as the formation of a robust hydrogen bonding network among the absorption products.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Longyun Zheng,Zhangyu Guo,Hui Liu,Kai Guo,Chunjiang Liu
CO 2 absorption into amine solutions is an important method for reducing carbon emissions. The influence mechanism of chemical reactions on the bubble behavior and mass transfer needs to be comprehensively investigated. In this study, firstly, we measure the bubble behavior and mass transfer of single CO 2 bubbles freely rising in monoethanolamine (MEA)/ N , N -diethylethanolamine (DEEA) blended solutions and DEEA solutions by high-speed photography. Moreover, we investigate the effect of amine concentration on the bubble shape, aspect ratio, rising trajectory, rising velocity, and mass transfer coefficient. The results show that CO 2 bubbles in MEA/DEEA blended solutions experience significant shape deformation, oscillation damping, surface contamination, and mass transfer deterioration. In contrast, CO 2 bubbles in DEEA solutions behave similarly to those in ultrapure water, i.e. negligible surface contamination and mass transfer enhancement. Furthermore, we consider the differences in the bubble behavior and mass transfer from the viewpoint of the chemical reaction kinetics and bubble surface contamination degree. The location where a chemical reaction occurs is close to the bubble surface with a fast reaction, and as a result, the bubble surface is likely to be contaminated. Finally, this study provides insights into the intensification of amine-based CO 2 chemical absorption processes.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Lidong Wang,Shanlong An,Qiangwei Li,Songhua Yu,Siyu Wu
Coal-fired flue gas is a major source of greenhouse gas CO 2 . Phase-change absorbents can be used to reduce energy consumption associated with regeneration during CO 2 capture. In this study, N,N-dimethylbutylamine (DMBA) and N,N-dimethylbutylamine (DEEA) were mixed to develop phase-change absorbents, and the reaction kinetics of CO 2 absorption in the absorbents were examined. A bubbling device was used to prepare phase-change absorbents with different CO 2 loading levels. The physico-chemical parameters of the absorbents under different conditions were specified, and the changes in the CO 2 loading of the upper and lower layers of the absorption solutions after a liquid–liquid separation were analyzed. A wetted-wall column was subsequently used to investigate the effects of temperature, CO 2 loading, gas flow rate, and DMBA/DEEA composition ratio on CO 2 absorption rate. This study determined that the flow velocity, reaction temperature, and CO 2 loading affected the CO 2 absorption rates to a certain extent. In addition, comparing the reactive properties of the 4M DMBA + 2M DEEA and 2M DMBA + 4M DEEA absorbents under the same experimental conditions revealed that the 4M DMBA + 2M DEEA absorbent exhibited higher absorption rate and reaction stability. A kinetics model also indicated that the CO 2 absorption of the phase-change absorbents used in this study was mainly affected by the liquid film diffusion process. This study contributes theoretically to the development of CO 2 absorption technologies.
研究领域:
化学工程
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环境科学
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能源技术
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Liju Bai,Shijian Lu,Qizheng Zhao,Linlin Chen,Yingjie Jiang,Chunxiao Jia,Siming Chen
Non-aqueous biphasic solvents, which combine the advantages of a non-aqueous absorbent and biphasic absorbent, have attracted increasing attention for CO 2 capture because of their great potential to reduce the energy consumption. This study proposed a non-aqueous N -ethylethanolamine (EMEA)/ N , N -diethylethanolamine (DEEA)-based liquid–liquid biphasic absorbent with p -xylene (PX) to replace 45–65 % of DEEA. The biphasic absorbent comprising 30 wt% EMEA + 5 wt% DEEA + 65 wt% PX (30E5D65P) had the best phase-change behaviour. In this absorbent, 98.8 % of the absorbed CO 2 was in the lower phase of the solvent, with a volume percentage of 35.1 %. This absorbent also showed the best CO 2 -desorption performance, with almost double the CO 2 -desorption amount and maximum CO 2 -desorption rate compared with those achieved using the 30 wt% EMEA + 70 wt% DEEA (30E70D) non-aqueous absorbent. The regeneration energy of 30E5D65P was 1.71 GJ∙t −1 CO 2 , which was reduced by 31 % and 55 % compared with that of the non-aqueous 30E70D absorbent and the aqueous 30 wt% monoethanolamine absorbent, respectively. 13 C NMR analysis and quantum chemical calculations showed that carbamate and PX have a better separation effect than that of EMEA and DEEA, owing to the presence of both polarity and hydrogen bonding. PX with low polarity was beneficial for the separation of carbamate. The carbamate interacted with (protonated) EMEA, (protonated) DEEA and carbamic acid through hydrogen bonds, resulting in the appearance of these components in the lower phase. The carbamate had no hydrogen bond self-aggregation, which may be the reason why there was no crystal precipitation.
研究领域:
化学工程
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环境科学
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能源技术
✓ 已验证
DOI
高影响因子
International Journal of Greenhouse Gas Control
·
2014
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IF 3.821
Zhicheng Xu,Shujuan Wang,Guojie Qi,Anastasia A. Trollebø,Hallvard F. Svendsen,Changhe Chen
The carbon dioxide (CO 2 ) solubility in aqueous 2-(diethylamino)-ethanol (DEEA) solutions were measured at (60 and 80 °C), with the DEEA concentrations of 3 M and 4 M and pressure range of (3 to 192 kPa). The absorption heat of CO 2 with (1, 3, and 4 M) aqueous DEEA solutions at different temperatures is also presented in this work. A thermodynamic model based on the electrolyte non-random two-liquid (eNRTL) theory within Aspen Plus ® has been developed to correlate and predict the vapor liquid equilibrium and heat of absorption of CO 2 in aqueous DEEA solutions. Meanwhile, the speciation of the solution at different loadings was also predicted using the developed eNRTL model.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
ENERGY
·
2023
·
IF 9
Lijian Jin,Xueyan Hou,Lingxiao Zhan,Dawei Hou,Lina Gu,Daguang Zhang,Jianchong Shen,Zhihao Zheng,Chao Lv,Shaoqing Liu,Linjun Yang
In this study, we examined the impacts of complete and partial substitution of DEEA with physical solvents (n-butanol) on the performance of AEEA/H 2 O absorption, regeneration, and phase separation. The higher hydrophobicity (log P) of n-butanol, as a phase splitter , expedites the separation process from the AEEA-CO 2 product. Through additional refinement of the mass ratio between n-butanol and DEEA, it was observed that substituting a small portion of DEEA with n-butanol had negligible impact on the absorption capacity and enrichment of the enriched phase. However, it significantly reduced the phase separation time between the two solvent phases. Furthermore, an increase in n-butanol concentration can enhance cyclic loading. On the other hand, it reduces the production of AEEACOO − /DEEAH + , which is more stable compared with AEEACOO − /AEEAH + . Molecular dynamics simulations revealed that n-butanol can modulate the reduction of water molecules surrounding AEEA, creating a lower water molecule environment, which improves the absorption rate of the absorbent in the pre-absorption phase. The addition of a low concentration of n-butanol improves the initial absorption rate, phase separation performance, circulation capacity, and further reduces the regeneration energy of the absorption solution without compromising the CO 2 loading and regeneration energy.
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DOI
高影响因子
AICHE JOURNAL
·
2026
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IF 4.4
Hong Quan,Yaxing Zhang,Can Lv,Yimin Deng,Helei Liu
A biphasic aqueous solvent of 25% aminoethylethanolamine (AEEA)/50% diethylethanolamine (DEEA) has attracted much attention because of its cheap raw material, fast CO 2 absorption rate and low adsorption/desorption energy consumption. In this work, the mass transfer model of CO 2 absorption into biphasic solvent of DEEA–AEEA in structured packed columns was investigated. The influence of operating parameters on K G a v in a regular packed column is investigated and discussed. Meanwhile, mass transfer mechanism of CO 2 absorption into biphasic solvent of DEEA–AEEA was comprehensively examcned. In addition, the prediction model of K G a v is constructed by introducing the phase separation volume, and the error of the empirical correlation is 7%. On this basis, three machine learning algorithms, that is, backpropagation neural network (BPNN), radial basis function neural network (RBFNN) and random forest (RF) algorithms, were used to construct the K G a v model, and the AAD of the models was less than 3%.
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DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 12
·2140
·
IF 2.847
Bin Liu,Zhe Cui,Wende Tian
Tertiary amines have been used as alternative absorbents for traditional primary and secondary amines in the process of carbon capture. However, the carbon dioxide (CO2) absorption rates in these kinds of amine are relatively slow, which implies greater investment and construction costs and limits the large-scale application of carbon capture. Carbonic anhydrase (CA) is considered to be an ideal homogeneous catalyst for accelerating the rate of CO2into aqueous amine solution. In this work, CO2absorption combining CA with two single aqueous tertiary amines, namely triethanolamine (TEA) and 2-(diethylamino)ethanol (DEEA), was studied by use of the stopped-flow apparatus over temperature ranging from 293 to 313 K. The concentrations of selected aqueous amine solution and CA used in the experiment were ranging among 0.1–0.5 kmol/m3and 0–50 g/m3, respectively. Compared to the solution without the addition of CA, the pseudo first-order reaction rate in the presence of CA (k0,withCA) is significantly increased. The values ofk0,withCAhave been calculated by a new kinetics model. The results of experimental and calculatedk0,amineandk0,withCAin CO2-amine-H2O solutions were also investigated, respectively.Keywords:carbon capture;CO2absorption;carbonic anhydrase;reaction kinetics
研究领域:
化学工程
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环境科学
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生物催化
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 13.2
Yutong Wang,Zili Fan,Menghan Yuan,Chenlin Zhang,Zihan Hu,Xinlin Cao,Xinming Zhou,Hui Fu
Biphasic absorbents are regarded as highly promising absorbents for carbon dioxide (CO 2 ) capture, owing to their potential energy savings and facile separation. This study introduces a novel piperazine (PZ)/2-(diethylamino)-ethanol (DEEA)/n-propanol (NPA) biphasic absorbent, in which the addition of NPA to the PZ/DEEA binary system results in a doubling of absorption rate, a reduction of the lower phase volume by over 50% to just 28.77% of the total volume, and a CO 2 enrichment level of up to 95.59%, achieving rich phase concentration. Furthermore, the PZ/DEEA/NPA absorbent exhibited excellent absorption-desorption stability and a high desorption efficiency (~ 90%), with a regeneration heat approximately 31% lower than that of benchmark monoethanolamine (MEA). NMR and molecular simulation analyses indicate that NPA's weak competitive solvation effect reduces dispersive interactions with CO 2 absorption products, thereby indirectly strengthening hydrogen bonding of products. This facilitates dense aggregation, resulting in a volumetrically contracted, high-concentration solid product during the final absorption stages. Additionally, corrosion assessments indicate that both fresh and CO 2 -saturated absorbents demonstrate extremely low corrosion rates, favoring industrial implementation. In conclusion, the PZ/DEEA/NPA biphasic absorbent proves to be a potential alternative to the conventional MEA for sustainable CO 2 capture.
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DOI
高影响因子
Green Chemical Engineering
·
2025
·
IF 7.6
Can Lv,Yimin Deng,Dongfang Zhao,Miyi Li,Helei Liu
Revealing the reaction mechanism of CO 2 absorption by mixed amine solutions can provide theoretical guidance for establishing complex kinetic models. This study investigates the CO 2 capture mechanisms of blended amine systems, specifically 1,6-hexamethyl diamine (HMDA)-N,N-diethylethanolamine (DEEA) and 2-(ethylamino)ethanol(EAE)-1-dimethylamino-2-propanol (1DMA2P), utilizing 13 C nuclear magnetic resonance (NMR) spectroscopy and quantum mechanical calculations. The 13 C NMR analysis identified the formation and conversion of species during CO 2 absorption, while quantum calculations elucidated the reaction energetics. The results indicate that tertiary amines (DEEA or 1DMA2P) facilitate CO 2 absorption by promoting the desorption of protonated primary amines (HMDA or EAE), thereby enhancing the absorption rate. This research provides insights into the role of tertiary amines in blended systems, guiding the development of efficient and low-energy amine solvents for CO 2 capture.
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高影响因子
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