ENERGY & FUELS
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2018
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IF 3.024
XiangFeng Tian,LeMeng Wang,Dong Fu,Chao Li
The absorption performance of low-partial-pressure H2S in a monoethanolamine (MEA)-activated N-methyldiethanolamine (MDEA) aqueous solution was investigated. The absorption amount (in mass, g H2S/g solutions) and H2S loadings (mol H2S/(mol MEA + mol MDEA)) were measured, and the apparent absorption rate was determined from the time-dependent absorption capacity. Experimentally, the temperature and partial pressure of H2S (PH2S) ranged from 303.2 to 323.2 K and from 300 to 500 Pa, respectively. The mass fractions of MDEA (wMDEA) and MEA (wMEA) ranged from 0.30 to 0.50 and from 0 to 0.075, respectively. The temperature, wMDEA, wMEA, and PH2S dependencies of the absorption performance were analyzed. It is impressive that the addition of MEA significantly enhanced the absorption amount of H2S yet slightly influenced the apparent absorption rate. In addition, a tray column consisting of six plates was used to verify the removal efficiency of low-partial-pressure H2S (PH2S = 500 Pa) and the results showed that in the case of wMDEA = 0.5, wMEA = 0.075, and T = 313.2 K, the removal efficiency achieved 95% when the ratio of gas to liquid was 40, indicating that MEA-activated MDEA aqueous solutions are promising in the removal process of low-partial-pressure H2S.
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
ENERGY & FUELS
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2019
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IF 3.021
Chongchong Lu,Ming Chen,Xiao Luo,Zhiwu Liang
In order to be able to understand and compensate for the mass transfer effects on the reaction kinetics that typically occur in these studies, the influences of diffusion and gas phase resistance on the measurement of kinetics have been investigated. Carbon dioxide (CO2) absorption into monoethanolamine (MEA) and N-methyldiethanolamine (MDEA) have been taken as the fast and slow reaction cases in this work. The inflection point between diffusion control and reaction control regions was found in the fast reaction case but not in the slow one. Further, there is a low critical value of Pinert, below which its effect can be ignored, in the fast reaction system. Conversely, the critical value of Pinert in the slow reaction system is higher. Additionally, credible intrinsic kinetics of the both systems have been obtained under optimum conditions, expanding the temperature range to lower than what is available in the literature.
研究领域:
化学工程
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环境科学
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高影响因子
AICHE JOURNAL
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2018
·Vol. 64
·期 7
·2515-2525
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IF 3.326
Helei Liu,Moxia Li,Xiao Luo,Zhiwu Liang,Raphael Idem,Paitoon Tontiwachwuthikul
In this work, Diethanolamine (DEA) was considered as an activator to enhance the CO 2 capture performance of Monoethanolamine (MEA). The addition of DEA into MEA system was expected to improve disadvantages of MEA on regeneration heat, degradation, and corrosivity. To understand the reaction mechanism of blended MEA-DEA solvent and CO 2 , 13 C nuclear magnetic resonance (NMR) technique was used to study the ions (MEACOO - , DEACOO – , MEA, DEA, MEAH + , DEAH + , , ) speciation in the blended MEA-DEA-CO 2 -H 2 O systems with CO 2 loading range from 0 to 0.7 mol CO 2 /mol amine at the temperature of 301 K. The different ratios of MEA and DEA (MEA: DEA = 2.0:0, 1.5:0.5, 1.0:1.0, and 0:2.0) were studied to comprehensively investigate the role of DEA in the system of MEA-DEA-CO 2 -H 2 O. The results revealed that DEA performs the coordinative role at the low CO 2 loading and the competitive role at high CO 2 loading. Additionally, the mechanism was also proposed to interpret the reaction process of the blended solvent with CO 2 . © 2018 American Institute of Chemical Engineers AIChE J , 64: 2515–2525, 2018
研究领域:
化学工程
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环境科学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
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IF 6.216
Sini Xiao,Helei Liu,Hongxia Gao,Min Xiao,Xiao Luo,Raphael Idem,Paitoon Tontiwachwuthikul,Zhiwu Liang
The stopped-flow technique was applied on the measurement of the kinetics of carbon dioxide (CO 2 ) absorption into aqueous blends of monoethanolamine (MEA) and diethanolamine (DEA) over the temperature range of 293–313 K. The investigation of blended MEA + DEA with various molar ratios of DEA to MEA revealed that the reaction mechanism between CO 2 and blended absorbents could be different at different ratio of DEA to MEA. Consequently, the kinetic data obtained in this work was split into two groups with respect to the different molar ratios of DEA to MEA in order to study the different mechanisms. In group A, the concentration of MEA was in the range of 5–15 mol/m 3 and the concentration of DEA was low (varied between 5 and 15 mol/m 3 ), while in group B, the DEA concentration was high (varied between 140 and 240 mol/m 3 ) and the concentration of MEA remained in the range of 5–15 mol/m 3 . Modified models based on the termolecular mechanism were developed for each group and used to interpret the experimental kinetic data. Results showed that the models could explain the data well with an AAD of 4.71% for group A at low concentration of DEA and 3.33% for group B at high concentration of DEA. It is interesting to point out that DEA barely reacts with CO 2 at low molar ratios (i.e. group A) whereas at high DEA concentration (i.e. group B), both MEA and DEA reacted with CO 2 .
研究领域:
化学工程
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环境科学
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2018
·
IF 3.412
Huipei Liang,Xiaoli Qin,Chin Ping Tan,Daoming Li,Yonghua Wang
Docosahexaenoyl and eicosapentaenoyl ethanolamides (DHEA and EPEA) have physiological functions, including immunomodulation, brain development, and anti-inflammation, but their efficient production is still unresolved. In this study, choline-chloride-based natural deep eutectic solvents are used as media to improve the production of DHEA and EPEA. The water content showed a key effect on the reactant conversion. Adding water to choline chloride–glucose (CG, molar ratio of 5:2) led to a significant increase (13.03% for EPEA and 27.95% for DHEA) in the yields after 1 h. The high yields of EPEA (96.84%) and DHEA (90.06%) were obtained under the optimized conditions [fish oil ethyl esters/ethanolamine molar ratio of 1:2, temperature of 60 °C, 1 h, enzyme loading of 2195 units, and CG containing 8.50% water of 43.30% (w/w, relative to total reactants)]. The products could be easily separated using centrifugation. In summary, the research has the potential to produce fatty acyl ethanolamides.
研究领域:
化学工程
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生物化学
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生物技术
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PubMed
高影响因子
FLUID PHASE EQUILIBRIA
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2024
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IF 2.8
Nan He,Yukun Zhang,Fenhong Song,Jing Fan,Xiwu Zhang
Deep eutectic solvents (DESs) have appealed increasing research interest across various scientific and industrial applications, notably in relation to efforts in CO 2 capture. This study presents a novel series of DESs were synthesized on the basis of monoethanolamine (MEA) and N-methyldiethanolamine (MDEA) as hydrogen bond donors with tetrabutylammonium bromide (TBAB) and tetrabutylphosphine bromide (TBPB) salt as hydrogen bond acceptors. A gas solubility measurement experimental system based on pressure drop method has been established to evaluate the solubility of CO 2 in amine-based deep eutectic solvents. The evaluation was performed over a temperature range of 303.15 to 323.15 K and a pressure range of 100 to 1000 kPa. The results indicated that as the molar ratio of hydrogen bond donors increases, the solubility of CO 2 in DESs increases, while it was found to be less affected by the hydrogen bond acceptor. Of these, the solubility of CO 2 is strongest at a 1:10 molar ratio of TBAB and MEA. The nuclear magnetic resonance spectroscopy spectra (NMR) and FTIR spectroscopy revealed that the MEA-based DES mixture primarily exhibited chemical absorption of CO 2 , while the MDEA-based DES predominantly showed physical dissolution of CO 2 . In addition, it was observed that both temperature and pressure significantly influenced the CO 2 solubility, and a successful correlation was developed using different semi-empirical models.
研究领域:
化学工程
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环境科学
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高影响因子
ENERGY & FUELS
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2019
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IF 3.021
Hao Ling,Sen Liu,Tianyu Wang,Hongxia Gao,Zhiwu Liang
To get a more accurate mass transfer coefficient model of CO2 into aqueous monoethanolamine (MEA)/N,N-dimethylethanolamine (DMEA) solution in a packed column, the Henry’s law constant, equilibrium CO2 solubility, volumetric overall mass transfer coefficient (KGav), overall gas-phase mass transfer coefficient (KG), and effective gas–liquid interfacial area (av) were comprehensively studied. The Henry’s law constant was obtained using a jacketed stirred glass reactor, and the equilibrium CO2 solubility was investigated using a bubbling absorption reactor. Additionally, the mass transfer performance was measured and evaluated experimentally in a packed column with DX-Type structured packing in terms of KGav, KG, and av. These experiments were conducted under the MEA/DMEA concentration of 6 kmol·m–3 with ratio of 5:1. The dynamic changes of solubility, species concentration, and absorption heat of solution were analyzed under different CO2 loadings. The experimental results showed that the relationship of successive absorption without synergistic effect from the perspective of equilibrium state for the MEA/DMEA solution and the blended MEA/DMEA solution can reduce the CO2 absorption heat compared to that of MEA solution. Furthermore, a predicted model of KGav, which should be suitable for different solution systems with DX-Type structured packings in a packed column, was also proposed and developed based on the KG model and av model in this work.
研究领域:
化学工程
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环境科学
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高影响因子
Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Hao Dong,Bo Wang,Xiandong Hao,Jinyu Wang,Zhiyong Xu,Wenbo Zhao
Seeking top-performing absorbents with excellent structural stability and renewability to realize efficient removal of H 2 S from natural gas is of great importance. Here, the H 2 S absorption thermodynamic and kinetic properties by a non-aqueous liquid binary blend of monoethanolamine (MEA) and ethylene glycol (EG) was systematically studied. The addition of solvent EG not only improves the thermal stability but also reduces the viscosity of the system especially after H 2 S absorption. The absorption mechanism was revealed by the combination of experimental characterization and Density Functional Theory (DFT) calculations, which show that the absorption process is a proton transfer reaction. In addition, a quasi-primary kinetic model was used to describe the absorption kinetic behavior, with rate constants increasing with temperature and pressure. Reaction equilibrium thermodynamic model (RETM) fitting thermodynamic results showed that the enthalpy (ΔH) and entropy (ΔS) of the interaction of the absorbent with H 2 S was −40.72 kJ/mol and −114.71 J/mol/K, respectively. Most importantly, the optimum absorption temperature was calculated to be 287.80 K and the optimum desorption temperature was 386.62 K. Moreover, the desulphurization rate was verified to increase with decreasing temperature and increasing H 2 S partial pressure. Five cycles of absorption-desorption experiments were conducted at 313.15 K for absorption and 373.15 K for desorption in order to verify the good reuse properties of the absorbent. Considering the excellent thermal stability, low viscosity after H 2 S absorption, acceptable absorption capacity as well as good reversibility, it is believed that the MEA/EG blend has a significant potential in the field of desulfurization.
研究领域:
化学工程
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环境科学
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Sihan Ai,Yong Xiang,Xue Chen,Yanlin Zhang,Yufei Zhang,Kangning Lv,Xin Chen,Daoyong Yu,Baosheng Ge,Fang Huang
Carbon dioxide capture, utilization and storage (CCUS) technology is considered an effective solution to achieve carbon neutrality. In CCUS, chemical absorption stands out as an efficient CO 2 capture method suitable for environments with low CO 2 partial pressures. This study aims to enhance the CO 2 capture performance of monoethanolamine (MEA) solution by employing zeolitic imidazolate frameworks ZIF-8 and ZIF-67 as catalysts. The impacts of catalyst concentration and experimental temperature on the quantity, rate of absorption, rate of desorption, and reusability of MEA for CO 2 absorption were investigated. Changes in the volume concentration of CO 2 in the mixed gas were monitored to assess these parameters. The results demonstrated that at a catalyst concentration of 150 mg/mL for ZIF-8 and 125 mg/mL for ZIF-67, MEA achieved CO 2 absorption quantity of 22.22 % and 18.89 %, respectively. This corresponded to substantial increases of 63.39 % and 125.9 % in the CO 2 maximum absorption rate of MEA solution. While the maximum desorption rate of MEA was enhanced by 49.71 % and 83.28 %. In conclusion, the introduction of ZIF-8 and ZIF-67 catalysts effectively catalyzed the CO 2 capture process, significantly enhancing the CO 2 capture quantity of MEA and ensuring energy-efficient regeneration of MEA. This study provides a novel approach for improving the performance of MEA in terms of capturing CO 2 .
研究领域:
化学工程
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环境科学
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材料科学
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高影响因子
CEMENT AND CONCRETE RESEARCH
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2023
·
IF 11.4
Yazhou Zhao,Yang Chen,Xiaoyu Li,Da Chen,Min Wu
Chloride penetration , facilitated by drying-wetting cycles, poses significant threats to reinforced marine concrete structures . In this study, the corrosion inhibition effects of triethanolamine dodecylbenzene sulfonate (TEA·C 18 H 30 O 3 S, TDS) and triethanolamine phosphate (TEA·H 3 PO 4 , TP) were investigated using mortar specimens. Electrochemical tests including electrochemical impedance spectroscopy and potentiodynamic polarization test were performed. The morphology and Vickers hardness of the steel/mortar interface were analyzed. Molecular dynamics and quantum mechanical simulations were conducted to explore the interactions between the inhibitors and the iron surface. The results demonstrated that the inhibition efficiency of TP was high, while TDS only presented some effect within limited drying-wetting cycles. After 24 wetting-drying cycles, the inhibition efficiency of TP reached 59.29 %, TDS exerted a detrimental effect on reinforcement corrosion , and the inhibition efficiency was −410.96 %. At the mortar/steel interface, the irregular defects were curtailed and the Vickers hardness was improved by TP. Meanwhile, TDS entrained large hydration pores. The adsorption of the inhibitors on the iron surface is primarily through the benzene ring , P O and N C bonds, where the TEA-Fe adsorption is the most stable among the studied chemical components.
研究领域:
土木工程
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材料科学
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理论化学
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高影响因子
Foods
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2023
·Vol. 12
·期 15
·2843
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IF 5.2
Siyu Xue,Naihui Dong,Kexin Xiong,Hui Guo,Yiwei Dai,Huipeng Liang,Yingxi Chen,Xinping Lin,Beiwei Zhu,Sufang Zhang
Ethyl carbamate (EC), a 2A carcinogen produced during the fermentation of foods and beverages, primarily occurs in distilled spirits. Currently, most studies focus on strategies for EC mitigation. In the present research, we aimed to screen strains that can degrade EC directly. Here, we report twoCandida ethanolicastrains (J1 and J116), isolated from fermented grains, which can reduce EC concentrations directly. These two yeasts were grown using EC as the sole carbon source, and they grew well on different carbon sources. Notably, after immobilization with chitosan, the two strains degraded EC in Chinese Baijiu by 42.27% and 27.91% in 24 h (from 253.03 ± 9.89 to 146.07 ± 1.67 and 182.42 ± 5.05 μg/L, respectively), which was better than the performance of the non-immobilized strains. Furthermore, the volatile organic compound content, investigated using gas chromatography-mass spectrometry, did not affect the main flavor substances in Chinese Baijiu. Thus, the yeasts J1 and J116 may be potentially used for the treatment and commercialization of Chinese Baijiu.Keywords:ethyl carbamate (EC);Candida ethanolica;Chinese Baijiu;immobilization
研究领域:
微生物学
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食品科学
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PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Bingke Tian,Chaofeng Huang,Yingshuang Zhang,Cong li,Hongru Jiang,Chongqing Wang,Hui Wang,Shangbo Zhang,Liuchuang Zhao
Plastics are extensively used in packaging, automobiles, sanitation, agriculture, and architecture due to their lightweight, malleability, corrosion resistance, and low cost. However, their short lifespan leads to the rapid accumulation of plastic waste. Therefore, recycling waste plastics is crucial to conserve resources and protect the environment from "white pollution." This study developed a flotation process to facilitate the recycling of common polyesters by separating polyamide (PA), polycarbonate (PC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), and polyurethane (PU). The flotation process was based on a hydrophilic gradient induced by modification with methanol, ethanol, and ethanolamine. The floatability sequence of the polyesters was PA < PU < PET < PC < < PMMA in the methanol-based system, PA < PU < PET < < PC ≈ PMMA in the ethanol-based system, and PET < PU < PA < < PC < PMMA in the ethanolamine-based system. The floatability of the polyesters was closely related to the reactivity of ester exchange. Based on the hydrophilic gradients, a cascaded flotation process was designed, following the ester exchange mechanism, to sequentially recover PET, PA, PC, and PMMA. PA, PET, and PU were the sinking plastics after modification with methanol, ethanol, and ethanolamine, respectively, while only PC remained hydrophilic after methanol modification. The purity of PA, PC, PET, and PMMA was 95.10 %, 93.68 %, 89.39 %, and 86.42 %, respectively, with recovery rates of 82.96 %, 83.90 %, 96.08 %, and 100 %. This study presents a promising approach for the flotation separation of waste polyesters.
研究领域:
环境科学
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材料科学
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高影响因子
危险品化学品经营许可证（带存储）