CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2019
·
IF 3.073
Suresh Mutyala,Madhavi Jonnalagadda,Harisekhar Mitta,Raveendra Gundeboyina
MIL-101 (Cr) was synthesized by a hydrothermal method and used as support to prepare a series of polyethylenimine (PEI) incorporated MIL-101 (Cr) by wet impregnation method. All characterization results revealed that the structure of MIL-101 (Cr) was well-maintained by the incorporation of polyethylenimine and confirmed the presence of PEI within MIL-101 (Cr). The CO 2 adsorption studies were carried out in a fixed bed reactor from 30 to 90 °C, 1 bar. The adsorption of CO 2 has been increased by the incorporation of PEI. It was due to the chemical interaction between the NH 2 and CO 2 groups to form a carbamate. The high CO 2 adsorption capacity 3.81 mmol g −1 was shown by 70 wt% PEI loaded MIL-101 (Cr) at 75 °C, 1 bar, because of more number of NH 2 groups and a high number of CO 2 molecules diffusion. Its adsorption capacity was 4.7 times higher than the adsorption capacity of MIL-101 (Cr) (0.80 mmol g −1 ). Moreover, in moisture condition, CO 2 adsorption capacity was increased to 4.4 mmol g −1 by the formation of ammonium bicarbonate and showed good adsorption stability throughout each adsorption-desorption cycle. The Avrami adsorption kinetic model was well fitted with experimental breakthrough CO 2 adsorption data of MIL-101 (Cr)-PEI-70. It suggested that the adsorption of CO 2 on PEI incorporated material was chemical adsorption.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Liying An,Shenfang Liu,Linlin Wang,Jiayi Wu,Zhenzhen Wu,Changdan Ma,Qiankun Yu,Xin Hu
In this work, graphene-derived N-enriched porous carbons were synthesized by urea modification and KOH activation of thermally shocked graphene oxide. The prepared sorbents were characterized by various techniques and investigated as potential CO2 capture materials. The as-prepared sorbents possess high CO2 adsorption capacity of 2.40 mmol/g (25 °C) and 3.24 mmol/g (0 °C) at 1 bar, which is higher than most graphene-based carbons reported previously. The nitrogen incorporation and narrow microporosity are the two major factors that determine CO2 uptake for these graphene-derived carbonaceous adsorbents under ambient conditions. The adsorption kinetic data of the optimized sample were well-described by the classical Fick’s diffusion model with a high CO2 diffusion rate. The fast CO2 adsorption kinetics can be attributed to the short diffusion paths of this sample, which is composed of thin layers of graphene sheets. Moreover, these graphene-derived sorbents also demonstrate excellent stability and recyclability, high selectivity of CO2 over N2, suitable heat of adsorption, and excellent dynamic CO2 capture capacity. As a result, these graphene-derived porous carbons deserve consideration for removal of CO2 from exhausted flue gas.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2019
·
IF 5.162
Jie Du,Wen-Cui Li,Zhan-Xin Ren,Li-Ping Guo,An-Hui Lu
Porous carbon materials with developed porosity, high surface area and good thermal- and chemical-resistance are advantageous for gas adsorption and separation. However, most carbon adsorbents are in powder form which exhibit high pressure drop when deployed in practical separation bed. While monolithic carbons have largely addressed the pulverization problem and preserved kinetics and usually suffer from abrasion during multiple adsorption-desorption cycles. Herein, we proposed the designed synthesis of mechanically robust carbon monoliths with hierarchical pores, solid nitrogen-containing framework. The synthesis started with the polymerization of resorcinol and formaldehyde under weakly acidic conditions generated from cyanuric acid, and then an appropriate amount of hexamethylenetetramine (HMTA) was added as a crosslinker to prompt the formation of three dimensional frameworks. After carbonization process, the as-obtained porous carbon monoliths have a high radial compressive strength of 886 N/cm as well as a BET specific surface area of up to 683 m 2 /g. At approximately 1 bar, the CO 2 equilibrium capacities of the monoliths are in the range of 3.1–4.0 mmol/g at 273 K and of 2.3–3.0 mmol/g at 298 K, exhibiting high selectivity for the capture of CO 2 over N 2 from a stream which consists of 16.7% (v%) CO 2 in N 2 . Meanwhile, they undergo a facile CO 2 release in an argon stream at 298 K, indicating a good regeneration capacity. After cycle testing, sieving and regeneration, the adsorbent has no mass loss, compared to that of its fresh counterpart.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Yafei Guo,Chang Tan,Peng Wang,Jian Sun,Weiling Li,Chuanwen Zhao,Ping Lu
Magnesium-based adsorbents present great potential in separating CO 2 from flue gas stream. To satisfy the requirement of efficient CO 2 capture, it is imperative to select suitable methods for preparing MgO adsorbents with good physicochemical properties. In this study, MgO adsorbents were prepared with different methods using MgCl 2 ·6H 2 O as magnesium precursor, and the effect of synthesis method on their structure-performance relationships were investigated. It is found that MgO adsorbents prepared with different methods exhibited varied physicochemical properties, and these were associated with their diverse CO 2 adsorption capacities. Amongst the different MgO adsorbents, the sample prepared with the solid-state chemical reaction method (MgO-SR) featured good textural properties (high specific surface area and total pore volume of 100.03 m 2 /g and 0.67 cm 3 /g), preferable surface morphology (sheet-like structure with reduced layer diffusion resistance) and excellent CO 2 adsorption capacity (2.39 mmol CO 2 /g). The solid-state chemical reaction method endowed the adsorbent with abundant surface basic active sites, and CO 2 molecules interacted with the weak sites (OH group), medium sites (Mg-O pairs) and strong sites (O 2− ) to form stable bicarbonate, bidentate and unidentate carbonates. The experimental CO 2 uptakes were in good agreement with the values predicted by the Avrami fractional kinetic model. Physical adsorption and chemisorption coexisted in the CO 2 adsorption process and the chemisorption sites played a dominant role. The approach enlightens the facile fabrication of cost-effective MgO adsorbents from waste precursors for large-scale CO 2 capture applications.
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Sachin Mane,Yu-Xia Li,Xiao-Qin Liu,Lin-Bing Sun
The use of porous carbons for selective CO2 separation attracts increasing attention. Owing to low thermostability of porous polymers, low yield is the major concern of porous carbons. To obtain porous carbons with high yield, the development of thermostable porous polymers is highly expected. Herein, high yielded (70% for 700 °C and 64% for 800 °C) Sn-doped porous carbons (SnPCs) have been constructed through KOH-assisted carbonization of Sn-containing polymer. Notably, SnPC-700 (218.5 mg·g–1) demonstrates higher CO2 adsorption capacity than the reference sample prepared without KOH, SnPC-700r (188.3 mg·g–1), indicating the importance of KOH-assisted activation. Carbonization temperature has an effect on the adsorption capacity of resultant materials, and high carbonization temperature leads to better adsorption capacity on CO2. SnPC-800 is able to capture 242.8 mg·g–1 of CO2, which is better than some benchmarks including BILP-7 (193.0 mg·g–1), PAF-1–450 (196.4 mg·g–1), and FCTF-1 (205.5 mg·g–1). More importantly, SnPC-800 demonstrates good selectivity of CO2 over CH4 (31.1). Thus, high yield and good performance upon CO2 adsorption capacity and selectivity over CH4 make SnPCs attractive candidates for the removal of CO2 from natural gas.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Yuning Zhang,Lin Liu,Lei Shi,Tingting Yang,Dongfang Niu,Shuozhen Hu,Xinsheng Zhang
The effects of halide ions (F − , Cl − , Br − , and I − ) on nanoporous Ag electrode for reduction of CO 2 to CO were systematically assessed. The electrochemical measurements indicate that the catalytic performance of nanoporous Ag is closely related to the affinity of halide ions to Ag. The current density and Faradaic efficiency for CO production simultaneously increase with the increase of the radius of halide ions from F − to Cl − and then to Br − , and the disparity between catalytic performance will further widen with the negative shift of potential. While the nanoporous Ag in the presence of I − first exhibits the poorest electrocatalytic performance at low potential (<−0.69 V vs . RHE), then reverses the situation at high potential (>−0.89 V vs . RHE) in comparison to the other halide ions. Tafel plots indicate that the adsorption of halide ions on the surface of nanoporous Ag influences mechanistic pathways for CO 2 reduction reaction. 8 h durability test demonstrates that the nanoporous Ag is catalytically stable in a mixed electrolyte containing bromide with only less than 5% deactivation. The density functional theory calculations enlighten that the weakened interaction between Ag atoms on the surface of electrocatalyst in the presence of halides can significantly enhance the binding energy of the intermediate COOH*, and thus effectively lowers the overpotential of CO 2 reduction reaction.
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 15
·4152-4158
·
IF 9.405
Bernard Baffour Asare Bediako,Qingli Qian,Jingjing Zhang,Ying Wang,Xiaojun Shen,Jinbiao Shi,Meng Cui,Guanying Yang,Zhen Wang,Shengrui Tong,Buxing Han
Synthesis of ethanol from cheap and renewable CO2 is of great importance, but is still a challenge. Because it involves CO2 hydrogenation with simultaneous C–C bond formation, and the synergy of two or more transition metals is usually required for catalyzing the reaction effectively. Moreover, higher temperature is needed to drive the reaction. In this work, we found that the monometallic Ru3(CO)12 catalyst could efficiently catalyze the synthesis of ethanol from CO2, methanol and H2 in the ionic liquid, 1-butyl-3-methylimidazolium chloride ([bmim]Cl), using LiCl and LiI as promoters. Ethanol could form at 120 °C, which is among the lowest temperatures reported to date. A detailed study indicated that ionic liquids play an important role in monometallic catalysis. High ethanol selectivity and activity were obtained under optimized conditions. In addition, the catalyst could be easily recycled and the TON of ethanol reached 180 after five cycles. To our knowledge, this is the first time that an ionic liquid has been used as a reaction medium to produce ethanol using CO2 and H2.
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Li Wang,Jihe Zhao,Hongsheng Lu,Zhiyu Huang,Baogang Wang
In many practical processes, it is necessary to separate the aliphatic amine from the aromatic amine from water to obtain the desired product. A simple and effective strategy was proposed for selective separation of aliphatic amines from aromatic amines by using CO 2 . With the introduction of CO 2 into the aqueous solution, aliphatic amines can be switched from hydrophobicity to hydrophilicity but aromatic amines cannot due to their different p K a . The separation performance associated with product purity cannot be explained by p K a or log K ow . Thus, solubility parameter was employed to explain the separation performance of these amines. The relationship between solubility parameter and separation performance was investigated by gas chromatography and ultraviolet spectrophotometry , which established the concentration of each aliphatic amine in aromatic amine and that of aromatic amine in water. This relationship can guide the selection of appropriate switchable-hydrophilicity solvents (SHSs) to acquire better quality products. In addition, aliphatic amines dissolved in water could be regenerated by removing CO 2 and the recovery of aliphatic tertiary amines was up to 93.4%.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 94
·期 12
·3780-3786
·
IF 2.659
Yujiang Wang,Yang Xu,Qiankun Liu,Jinwei Sun,Shengfu Ji,Zhou-jun Wang
Background Carbon dioxide (CO 2 ) methanation is an important reaction in energy and environmental fields, which aims to convert CO 2 into natural gas with hydrogen (H 2 ) from renewable sources. One of the technical bottlenecks for CO 2 methanation is the lack of feasible catalysts, especially the ones with satisfactory low-temperature activity. Results The NiMgAl/SiC composite catalyst that was derived from hydrotalcite precursor on the SiC substrate possessed enhanced low-temperature activity and excellent long-term stability in CO 2 methanation. For the low-temperature activity, CO 2 conversion reached 63.8% and 74.5% at 300 and 325 °C respectively. For the long-term stability, CO 2 conversion merely decreased from 78.4% to 76.9% after 50 h of reaction at 400 °C. Conclusion The NiMgAl/SiC composite catalyst was successfully synthesized by the co-precipitation method, which exhibited enhanced low-temperature methanation activity compared with the NiMgAl and Ni/SiC catalysts. The superior low-temperature activity was mainly ascribed to two structural parameters. One was the small nickel (Ni) nanoparticle size, which was endowed by the unique structure of the hydrotalcite precursor. The other one was the high reducibility of Ni species, which was rendered by the appropriate metal-support interactions. The present work provides guidelines for the synthesis of highly efficient composite catalysts for energy and environmental applications. © 2019 Society of Chemical Industry
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2018
·
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.
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 3
·589-596
·
IF 9.405
Ying Wang,Jingjing Zhang,Qingli Qian,Bernard Baffour Asare Bediako,Meng Cui,Guanying Yang,Jiang Yan,Buxing Han
CO2 transformation is an important topic in green chemistry, and methanol homologation using CO2 is a promising route to produce ethanol. In this work, we studied this reaction using different homogeneous catalytic systems. It was found that a [RuCl2(CO)3]2/Co4(CO)12 bimetallic catalyst using LiI as a promoter and N-ethyl-2-pyrrolidone (NEP) as the solvent was very effective under mild conditions. The reaction could proceed efficiently at 160 °C, which is much lower than that reported before. The turnover frequency (TOF) of ethanol based on Ru was as high as 7.5 h−1 and the selectivity of ethanol in total products could reach 65.0 C-mol%, which are obviously higher than those reported in the literature. Ethanol was synthesized through cascade catalysis of a reverse water gas shift (RWGS) reaction and methanol homologation with syngas (CO/H2). The outstanding performance of the catalytic system originated from the excellent cooperation of the components. The catalyst could be reused at least five times without any obvious decrease of the catalytic performance. The effect of the solvent on this reaction was studied systematically. The mechanism was also discussed based on isotope labeling tests.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
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.
✓ 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）