CHEMICAL ENGINEERING SCIENCE
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2018
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IF 3.306
Jiamin Hou,Yanying Wei,Sheng Zhou,Yanjie Wang,Haihui Wang
We propose a strategy for rapid in situ fabrication of zeolitic imidazolate framework-8 (ZIF-8) hybrid membrane with assistance of the two dimensional (2D) graphitic carbon nitride (g-C 3 N 4 ) nanosheets at room temperature. The negatively charged g-C 3 N 4 nanosheets with abundant nitrogen coordinating sites are capable to capture and anchor Zn 2+ and thus provide a large number of heterogeneous nucleation sites for the formation of initial ZIF-8 crystals. During the cyclical spin coating of the Zn 2+ /g-C 3 N 4 nanosheets and the ligand (2-methylimidazole), the in situ formed ZIF-8 crystal nucleus on g-C 3 N 4 nanosheets promote the further growth of continues defect-free membranes. The ZIF-8/g-C 3 N 4 membrane with thickness of ∼240 nm can be obtained using this strategy within 30 min at room temperature, which is attractive for fast and facile preparation of molecular sieving membranes. Moreover, it exhibits promising H 2 /CO 2 separation performance with the selectivity up to 42, which is superior to many other ZIF-8 membranes.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
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2018
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IF 3.306
Xunan Hou,Linzhou Zhuang,Beibei Ma,Shuixia Chen,Hui He,Fengqin Yin
In this work, we report a new route to improve the CO 2 adsorption performance of solid amine adsorbents. Platelet mesoporous silicas with abundant surface silanols were prepared by emulsion synthesis followed by simple solvent extraction. These silanol-rich silica particles were then functionalized with branched polyethyleneimine (BPEI) by grafting or impregnation to prepare CO 2 adsorbents. Silanol-rich silicas grafted with BPEI exhibited 70% higher amine density and 47% higher CO 2 adsorption capacity than its calcined counterpart. The adsorbent achieved a maximum CO 2 adsorption efficiency up to 13.82 mmol CO 2 /g-BPEI. Adsorbed species found in the infrared spectra suggested that silanols may contribute to the enhanced CO 2 adsorption efficiency on grafted amines. Silanol-rich silica functionalized with BPEI retained more porosity than its calcined counterparts, which may account for its superior CO 2 adsorption capacity. Silanol-rich silica impregnated with amines achieved the highest CO 2 adsorption efficiency ever reported (5.65 mmol/g, 526.7 mg/g-BPEI). Adsorption kinetic modeling confirmed that silanol-rich adsorbent provides better CO 2 diffusion pathways. These potential benefits of silanol-amine interaction, coupled with platelet mesoporous structure and branched polyamine chains, opens a new pathway to high-performance adsorbents for CO 2 capture.
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高影响因子
ENERGY & FUELS
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2018
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IF 3.024
Hui Guo,Hui Li,Shufeng Shen
Water as a solvent remains the weakest point of CO2 capture systems using aqueous chemical absorbents due to large heat capacity and latent heat of water. Water-lean absorbents including low volatile solvent have been considered as potential use for CO2 capture in terms of reducing energy consumption. In this work, we have examined the capture performance of several water-lean amino acid salts. Ethylene glycol (EG) with high boiling point and low specific heat was used to replace water. The physical properties and the absorption and desorption rate of CO2 were determined and evaluated for potassium lysinate (LysK)/EG/water and potassium prolinate (ProK)/EG/water. Aqueous monoethanolamine (MEA), ProK, and LysK systems were used for comparison. The samples from the absorption test and continuous absorption–desorption cycles were analyzed by NMR spectra to provide insight into the product species and the stability of absorbent. Absorption mechanisms and degradation species were also discussed as well as the main issues such as high viscosity of CO2-free/loaded absorbents and high desorption temperature related to these EG-based water-lean systems.
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高影响因子
Journal of CO2 Utilization
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2018
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IF 5.503
Hui-Bo Qin,Xiao-Chao Sun,Chang-Yu Sun,Guang-Jin Chen,Zheng-Fu Ning,Ke-Le Yan,Lan-Ying Yang
The essential characteristic of CO 2 makes most surfactants futile to form stable CO 2 emulsion. In this work, a green surfactant named alkyl polyglucoside (APG) was applied to prepare liquid CO 2 emulsion. The performance of surfactant on CO 2 emulsion stability was assessed in a sapphire cell by delamination time of emulsion under the operating conditions about 284.5 K and 5.2 MPa. The results demonstrate that APG has a potential to be used in CO 2 emulsion preparation and the suitable dosage of APG is about 3.0 wt% water quality. The phase-inversion point of water-in-CO 2 and CO 2 -in-water was determined as ranging from 15 vol% to 17.5 vol% (water cut) after examining the systems at different water cuts with 3.0 wt% APG. Two surfactants, fatty alcohol polyoxyethylene ether (AEO) and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) were also tested. To consider the applicability of CO 2 emulsion in fields such as submarine hydrate exploitation and CO 2 sequestration, the performance of surfactants in saline solution was examined. The experimental results show that APG can be used as surfactant in preparing liquid CO 2 emulsion with or without NaCl. The adding of 1.0 wt% NaCl for CO 2 emulsion with 3.0 wt% APG was proved to change the phase-inversion point to higher water cut. In comparison, anion surfactant AOT was futile in saline solution.
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高影响因子
Journal of CO2 Utilization
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2018
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IF 5.503
Xianting Cao,Haizhen A. Zhong,Pengfei Zhang,Hui Zheng
A simple chemical fixation of CO 2 at atmospheric pressure to make valuable benzimidazolones derivates via the o -phenylene-diamines carbonylation reaction catalyzed by DBU/S was developed. Different reaction conditions were examined and optimized. A series of benzimidazolones derivatives were synthesized using NMP as solvent at 413K with excellent yields (80–94%). Various substrates were employed and the results suggested the wide application of our method. The quantum mechanics calculations demonstrated that the complexation of DBU with sulfur significantly enhanced the reaction. This protocol rovides a novel approach of fixing CO 2 at atmospheric pressure into a series of 2-benzimidazolones derivates.
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高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2018
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IF 2.631
Min Xiao,Helei Liu,Hongxia Gao,Zhiwu Liang
In this work, the equilibrium CO 2 solubilities of five tertiary amines, namely Triethanolamine (TEA), N-methylethanolamine (MDEA), 2-(Dimethylamino)ethanol (DMEA), 3-dimethyl-amino-1-propanol (3DMA1P), and Diethylethanolamine (DEEA) were measured over the temperature range of 298.15–313.15 K, and at CO 2 partial pressures up to 60.8 kPa. The activity-structure relationship was studied on the molecular level to account for the differences in equilibrium CO 2 solubility. The M-KE model was applied to correlate the vapor-liquid-equilibrium data of the five tertiary amine-H 2 O-CO 2 systems. Results show that the model is able to correlate experimental data very well and gives reasonable prediction results with average absolute deviation (AAD) of 2.5% for TEA, 3.3% for MDEA, 1.3% for DMEA, 1.0% for 3DMA1P and 0.8% for DEEA. In addition, the CO 2 absorption heat was calculated using the Clausius-Clapeyron equation. The potential for the five amines to be considered as alternative solvents for CO 2 capture was evaluated in terms of equilibrium CO 2 solubility, second order reaction rate constant and CO 2 absorption heat.
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高影响因子
RSC Advances
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2018
·Vol. 8
·期 63
·35989-35997
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IF 2.936
Halidan Maimaiti,Abuduheiremu Awati,Dedong Zhang,Gunisakezi Yisilamu,Bo Xu
To obtain high-efficiency, low-cost, environmentally friendly carbon-based photocatalytic material, we synthesized coal-based carbon dots with sp2 carbon structure and multilayer graphene lattice structure by the hydrogen peroxide (H2O2) oxidation method to strip nano-scale crystalline carbon in the coal structure and link with oxygen-containing groups such as the hydroxyl group. N, S co-doped aminated coal-based carbon nanoparticles (NH2-CNPs) were then obtained by thionyl chloride chlorination and ethylenediamine passivation. The physical properties and chemical structure of the synthesized NH2-CNPs were studied and the photocatalytic CO2 reduction performance was tested. The results show that NH2-CNPs are vesicle-type spherical particles with particle size of 42.16 ± 7.5 nm and have a mesoporous structure that is capable of adsorbing CO2. A defect structure was formed on the surface of the NH2-CNPs due to the doping of N and S elements, thereby significantly improving the ability to photogenerate electrons under visible light along with the ability to efficiently separate the photo-generated carriers. The photocatalytic reduction products of CO2 over NH2-CNPs were CH3OH, CO, C2H5OH, H2 and CH4. After 10 hours of reaction, the total amount of products was 807.56 μmol g−1 cat, the amount of CH3OH was 618.7 μmol g−1 cat, and the calculated selectivity for conversion of CO2 to CH3OH was up to 76.6%.
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PubMed
高影响因子
Journal of CO2 Utilization
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2018
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IF 5.503
Shuai Wang,Dongfang Liu,Jihe Zhao,Xiaojiang Li,Daixue Xu,Yuan Gu,Hongsheng Lu
In this paper, a practical and environmental friendly method was successfully developed by using CO 2 -Triggered switchable water additive to reversibly emulsify and demulsify diesel, aims to provide guidance for recovering oil substances in waste oil-based drill cuttings. In this new method, N, N, N', N'-tetramethyl-1, 6-hexanediamine(TMHDA) was a switchable water additive whose aqueous solution can switch the ionic strength by addition and removal CO 2 . Then it can be used to separate diesel through reversibly emulsification and demulsification. The nuclear magnetic resonance hydrogen spectrum ( 1 H NMR) and conductivity demonstrated TMHDA have better switching performance. Then, diesel/naphthenic acid mixtures have been used for modeling the application of recovering oil substances in waste oil-based drill cuttings. When the acid value≥1.76mgKOH/g (the oil and TMHDA solution were 5 mL), diesel can be emulsified. The material produced by TMHDA and naphthenic acid have a strong surface activity so that the oil/water interfacial tension was less than 0.1 mN·m −1 . The demulsification performance was illustrated by change of the ionic strength, pH and the content of oil in the aqueous phase during the breaking process. Brief provided two optimization strategies of recycling of TMHDA additive. Finally, the possible mechanism of the new method was discussed.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2018
·Vol. 42
·期 12
·10016-10023
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IF 3.201
Fenglei Liu,Yizhu Kuang,Shuoyu Wang,Shuixia Chen,Wenhao Fu
A molecularly imprinted solid amine adsorbent was successfully synthesized via a facile crosslinking reaction based on polyethyleneimine (PEI) as the skeleton, glycol diglycidyl ether (GDGE) as cross-linker and CO2 molecules as template. FT-IR, FT-Raman, 13C NMR spectroscopy and TGA were employed to characterize the chemical structure and thermal stability of the solid amine adsorbent. The experimental results showed that the amine content of the molecularly imprinted polymer polyethyleneimine spheres (MIP-PEIs) could reach as high as 11.41 mmol g−1, and the material exhibited a lower CO2 diffusion resistance during CO2 adsorption. The CO2 adsorption capacity of MIP-PEIs (6.58 mmol g−1) was higher than that of non-imprinted NIP-PEIs (5.87 mmol g−1). The presence of water markedly increased the CO2 adsorption capacity by promoting the chemical adsorption of CO2 on the solid amine adsorbent. The pseudo-second order model could accurately describe the CO2 adsorption process on the MIP-PEIs from the beginning to the end. Moreover, this adsorbent also exhibited good regeneration performance, retaining almost the same adsorption amount of CO2 as the fresh material after ten adsorption–desorption cycles.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2018
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IF 4.229
Aisheng Huang,Bo Feng
Pristine graphene oxide (GO) sheets were pretreated with polyethyleneimine (PEI) to prepare PEI-modified GO (PEI-GO), which was further inserted with ZIF-8 crystals to form a novel PEI-GO@ZIF-8 nanocomposite for CO 2 capture. The good dispersion of PEI and interlayer growth of ZIF-8 within the GO sheets is helpful for high CO 2 adsorption. Therefore, the PEI-GO@ZIF-8 nanocomposite show high surface area and enhanced CO 2 adsorption capacity . The adsorption capacity of the PEI-GO@ZIF-8 nanocomposite was six times higher than that of the pristine GO and ZIF-8. The CO 2 /N 2 adsorption selectivity was significantly improved due to amine groups loading which provide more sites for CO 2 adsorption. The preferential adsorption of CO 2 over N 2 makes PEI-GO@ZIF-8 nanocomposite be a promising candidate in the field of CO 2 capture.
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2018
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IF 3.649
Mingqiang Liu,Lishu Shao,Jianhan Huang,You-Nian Liu
The O-containing hyper-cross-linked polymers were synthesized from phenol (2-naphthol) and formaldehyde dimethyl acetal by a simple one-step Friedel-Crafts reaction, they were subsequently carbonized using KOH as the activating agent, and their adsorption to CO 2 was carefully tested. The results indicated that these samples had a high Brunauer-Emmett-Teller surface area (up to 2241 m 2 /g), pore volume (up to 1.20 cm 3 /g), CO 2 uptake (up to 6.3 mmol/g at 273 K and 1.0 bar), and CO 2 /N 2 selectivity (up to 96 for the HCPs, and 22.5 for the porous carbon). In particular, the CO 2 adsorption was highly dependent on the ultramicropore volume (pore width<0.7 nm), while the CO 2 /N 2 selectivity mainly relied on the oxygen content and the ultramicropore structure.
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高影响因子
ENERGY
·
2018
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IF 4.968
Pan Zhang,XiangFeng Tian,Dong Fu
A tray tower was designed to verify the absorption performance of CO 2 in 1-butyl-3-methylimidazolium glycinate ([Bmim][Gly]), 1-butyl-3-methylimidazolium lysinate ([Bmim][Lys]) and tetramethylammonium glycinate ([N 1111 ][Gly]) activated MDEA ( N -methyldiethanolamine) aqueous solutions. The simulated flue gas was composed of 15% (mole fraction) CO 2 and 85% N 2 and the experiments were performed at 313.2 K. To find a suitable absorbent composition, the mass fractions of MDEA and amino acid ionic liquids (AAILs) respectively ranged from 0.200 to 0.400 and 0.025 to 0.100. The removal efficiency of CO 2 ( η CO 2 ) and the overall volumetric mass transfer coefficient ( K G a v ) were determined. The effects of absorbent composition ( w ), absorbent flow rate ( L ), gas flow rate ( G ) and plate number ( N p ) on η CO 2 and K G a v were demonstrated. Our results showed that, when activated by AAILs, MDEA aqueous solution was able to absorb CO 2 in tray tower efficiently, and both η CO 2 and K G a v were significantly increased, e.g., in the case of w MDEA = 0.200, η CO 2 and K G a v were increased from 43.48% to 95.55% and from 0.0069 (kmol m −3 h −1 ·kPa −1 ) to 0.0350 (kmol m −3 h −1 ·kPa −1 ), respectively, when w [N1111][Gly] was changed from 0 to 0.100, indicating AAILs activated MDEA aqueous solution is of great potential for industrial application in CO 2 capture process.
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高影响因子
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