CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2018
·
IF 1.712
Yangyang Bian,Shufeng Shen
Phase change solvents are attractive energy-efficient absorbents for carbon dioxide (CO 2 ) capture due to CO 2 -rich phase formation. Potassium prolinate + water + ethanol (ProK/W/Eth) solution has shown good capture characteristics as a promising one in our previous work. In this work, absorption rate of CO 2 , solubility of N 2 O, and heat of absorption for ProK/W/Eth solution were investigated using a stirred cell reactor and a CPA201 reaction calorimeter and these results were also compared with the aqueous ProK and 30 mass% MEA solutions. Using ethanol as a solvent can substantially increase the CO 2 physical solubility and the absorption rate of CO 2 in ProK/W/Eth solutions is far higher than that in aqueous 30 mass% MEA solutions especially at a low CO 2 loading range. Solid precipitation, obtained from the liquid-to-solid phase change absorption, was analyzed by 13 C NMR and DSC-TGA. The enthalpy change for ProK/W/Eth solutions at various CO 2 loading was also discussed.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Jingai Shao,Junjie Zhang,Xiong Zhang,Ye Feng,Han Zhang,Shihong Zhang,Hanping Chen
To enhance the SO 2 adsorption of biochar, CO 2 activation and impregnation with methyldiethanolamine (MDEA) was simultaneously employed to improve its physicochemical characteristics. Furthermore, the effects of the pore structure and nitrogen functionality on SO 2 adsorption were also explored. The results show that after CO 2 activation, the specific surface area of biochar increased from 56.91 m 2 /g to 755.35 m 2 /g, while this figure dropped to 25.54 m 2 /g or even lower after impregnation with MDEA. Although the pore structure of activated biochar was destroyed, the surface nitrogen content of the nitrogen-enriched biochar (with 10% MDEA impregnation) increased from 1.46% to its highest level (7.20%); moreover, as indicated by Fourier Transform Infrared (FTIR) spectroscopy, the nitrogen functional groups introduced on the surface of the nitrogen-enriched biochar were mainly C-N. After 10% MDEA impregnation, the maximum SO 2 adsorption capacity increased from 57.8 mg/g to 156.2 mg/g. Changes to physical and chemical properties in the nitrogen-enriched biochar indicate that the nitrogen functional groups on the surface are more important than the pore structure for SO 2 adsorption at 393 K, and that the dominant nitrogen species are quaternary nitrogen.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2018
·
IF 5.091
Yahui Sun,Kaixi Li,Jianghong Zhao,Jianlong Wang,Nan Tang,Dongdong Zhang,Taotao Guan,Zuer Jin
Millimeter-sized nitrogen and sulfur co-doped microporous activated carbon spheres (NSCSs) were first synthesized from poly(styrene-vinylimidazole-divinylbenzene) resin spheres through concentrated H 2 SO 4 sulfonation, carbonization and KOH activation. Styrene (ST) and N-vinylimidazole (VIM) were carbon and nitrogen sources, while the sulfonic acid functional groups introduced by the simple concentrated sulfuric acid sulfonation worked simultaneously as cross-linking agent and sulfur source during the following thermal treatments. It was found that the surface chemistries, textural structures, and CO 2 adsorption performances of the NSCSs were significantly affected by the addition of VIM. The NSCS-4-700 sample with a molar ratio of ST: VIM = 1: 0.75 showed the best CO 2 uptake at different temperatures and pressures. An exhaustive adsorption evaluation indicated that CO 2 sorption at low pressures originated from the synergistic effect of surface chemistry and micropores below 8.04 Å, while at the moderate pressure of 8.0 bar, CO 2 uptake was dominated by the volume of micropores. The thermodynamics suggested the exothermic and orderly nature of the adsorption process , which was dominated by a physisorption mechanism. The high CO 2 adsorption capacity, fast kinetic adsorption rate, and great regeneration stability of the nitrogen and sulfur co-doped activated carbon spheres indicated that the as-prepared carbon adsorbents were good candidates for large-scale CO 2 capture.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2018
·Vol. 8
·期 5
·275
·
IF 3.504
Jingting Lu,Chengli Jiao,Zeeshan Majeed,Heqing Jiang
Mesoporous carbons (MC) have attracted a tremendous amount of interest due to their efficient molecular transport properties. However, the limited number of active sites and low microporosity generally impede their use for practical applications. Herein, we have fabricated Mg and N co-doped mesoporous carbon (Mg-NMC) with high microporosity via one-pot synthetic route followed by further steam activation. In comparison with the parent N-doped mesoporous carbon, Mg-NMC shows partially ordered mesostructure and improved CO2adsorption capacity attributed to the introduction of basic site after Mg doping. Upon further steam activation, the microporosity is enhanced to 37.3%, while the CO2adsorption capacity is also increased by 70.4% at 273 K and 1.0 bar.Keywords:mesoporous carbon;Mg doping;steam activation;basic site;microporosity;CO2adsorption
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Min Zhou,Sibo Wang,Pengju Yang,Caijin Huang,Xinchen Wang
Ternary boron carbon nitride (BCN) semiconductors have been developed as emerging metal-free photocatalysts for visible-light reduction of CO2, but the achieved efficiency is still not satisfying. Herein, we report that the CO2 photoreduction performance of a bulk BCN semiconductor can be substantially improved by surface engineering with CdS nanoparticles. The CdS/BCN photocatalysts are characterized completely by diverse tests (e.g., XRD, FTIR, XPS, DRS, SEM, TEM, N2 sorption, PL, and transient photocurrent spectroscopy). Performance of the CdS/BCN heterostructures is evaluated by reductive CO2 conversion reactions with visible light under benign reaction conditions. Compared with bare BCN material, the optimized CdS/BCN photocatalyst exhibits a 10-fold-enhanced CO2 reduction activity and high stability, delivering a considerable CO production rate of 12.5 μmol h–1 (250 μmol h–1 g–1) with triethanolamine (TEOA) as the reducing agent. The reinforced photocatalytic CO2 reduction activity is mainly assigned to the obviously improved visible-light harvesting and the greatly accelerated separation/transport kinetics of light-triggered electron–hole pairs. Furthermore, a possible visible-light-induced CO2 reduction mechanism is proposed on the basis of photocatalytic and photo(electro)chemical results.
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2018
·Vol. 64
·期 9
·3400-3409
·
IF 3.326
Weixin Zhang,Dahuan Liu,Xiangyu Guo,Hongliang Huang,Chongli Zhong
Mixed-matrix membranes (MMMs) have shown great advantages but still face some challenges, such as the trade-off between permeability and selectivity, stability, and the lack of efficient ways to enhance them simultaneously. Here, the fabrication of MMMs with metal-organic frameworks derived porous carbons (MOF-PCs) as fillers which exhibit selective-facilitating CO 2 transport passage originating from interactions between fillers and CO 2 is showed. With the aid of the developed multicalcination method, MOF-PCs with variable N-contents were prepared and incorporated into PPO-PEG matrix for the first time to prepare MMMs, which show excellent separation performance for CO 2 /CH 4 mixture with a tunable separation performance by combining different N-contents and surface areas of MOF-PCs. Moreover, the developed MMMs have hydrothermal and chemical stability. This work not only presents a series of MMMs with both good separation properties and stability, it also provides useful information for guiding the fabrication of high performance MMMs for practical application. © 2018 American Institute of Chemical Engineers AIChE J , 64: 3400–3409, 2018
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Yannan Li,Jun Cheng,Leiqing Hu,Jianzhong Liu,Junhu Zhou,Kefa Cen
An ionic liquid (IL) [P66614][Triz] with a low regeneration temperature was loaded on a graphene nanoplatelet (GNP) and reduced graphene oxide (RGO) to accelerate the CO2 absorption rate. High-resolution transmission electron microscopy (HRTEM) patterns showed that GNP was composed of a regular “honeycomb” lattice, but a regular lattice structure was not observed for RGO as a result of the functional group on it. The CO2 absorption capacity (63.6 mg of CO2/g of IL) and absorption peak rate (22.4 mg of CO2 g–1 of IL min–1) of IL loaded on GNP were increased by 8.2 and 72.3%, respectively, compared to those of neat IL. The supported IL performed better because [P66614][Triz] was oriented in a favorable dispersion as a result of the negative ζ potential of the GNP surface. In contrast, the CO2 absorption rate of RGO–20% IL (mass ratio of RGO/IL = 4:1) was lower than that of IL, which could be attributed to the hydrogen bond between surface oxygen functional groups and IL. 13C nuclear magnetic resonance and Mulliken atomic charge calculated by Gaussian were used to support the CO2 absorption mechanism.
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Yafei Guo,Chang Tan,Jian Sun,Weiling Li,Chuanwen Zhao,Jubing Zhang,Ping Lu
Nanostructured MgO sorbents show promise for intermediate-temperature CO2 capture from post-combustion flue gas stream. However, their CO2 capture behaviors can be affected by the magnesium precursors applied for sorbent synthesis. To screen potential precursors for fabricating excellent CO2 trappers, MgO nanoparticles (NPs) were synthesized by calcining several organometallic precursors, including magnesium ethoxide, magnesium acetate tetrahydrate, magnesium oxalate dehydrate, magnesium lactate dihydrate, magnesium citrate nonahydrate, and magnesium gluconate hydrate. The precursors and MgO NPs were characterized by thermogravimetric analysis, X-ray diffraction, N2 adsorption–desorption, field emission scanning electron microscopy, and CO2 temperature-programmed desorption. A fixed-bed reactor was used to evaluate the CO2 capture performances of the MgO NPs in a simulated flue gas stream. The effect of organometallic precursors on CO2 capture behaviors of the sorbents was further demonstrated. Results indicated that the different precursors would yield MgO NPs with distinct textural and surface properties, and these could further affect their CO2 capture behaviors. MgO NPs derived from magnesium oxalate dehydrate exhibited the highest CO2 uptake of 4.41 mmol of CO2/g. The excellent CO2 uptake was mainly attributed to its superlative textural properties, uniform surface morphology, and abundant base sites.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Xiong-Fei Zhang,Yi Feng,Zhongguo Wang,Mingmin Jia,Jianfeng Yao
Incorporating metal-organic frameworks into cellulose matrix to prepare composite membranes is promising in gas-separation applications. In this study, UiO-66-NH 2 (Zr-based MOF) nanoparticles are wrapped into the densely packed cellulose nanofibrils (CNF-COOH) via a facile vacuum filtration process. The existence of acid-base interactions and electrostatic forces between UiO-66-NH 2 and CNF-COOH renders ideal interfacial morphology. Results show that UiO-66-NH 2 is cross-linked by -COOH groups and well-dispersed in the CNF matrix. The porous UiO-66-NH 2 strengthens the diffusion process of CO 2 molecules, thus elevating the permeation flux and separation factor simultaneously. The optimum separation performance is achieved over CM-1 membrane with a CO 2 permeability of 139 Barrer and a CO 2 /N 2 selectivity ratio of 46.
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Ke Wang,Youwei Zhao,Peter T. Clough,Pengfei Zhao,Edward J. Anthony
Structurally modified and improved NaBr-co-doped Li 4 SiO 4 ceramics were developed for CO 2 absorption in low-CO 2 -concentration atmospheres. Pure and NaCl-doped Li 4 SiO 4 ceramics were also prepared for comparison. The samples were analyzed by X-ray diffraction, Scanning Electron Microscopy, N 2 adsorption, X-ray photoelectron spectroscopy, differential scanning calorimetry , and thermogravimetric analyses (dynamic and isothermal). The sorption kinetics were obtained using a double exponential model. The results showed that both Na and Br can be introduced into the Li 4 SiO 4 structure and doped on Li and oxygen sites, respectively. The doped sample presented a Li 2 O-enriched surface, guaranteeing abundant Li O sites and are significantly different from previous anionic (CO 3 , F and Cl) doping of Li 4 SiO 4 , Br doping also generated macroporous features with small particle size, these favorable characteristics promoted the surface chemisorption kinetics. Moreover, DSC analysis confirmed the formation of the molten phases during CO 2 absorption, which helps improve the lithium diffusion kinetics . Here, 0.1 mol NaBr doping was used to reach a maximum absorption capacity (>30.0 wt%) in 15 vol% CO 2, suggesting that NaBr-doped Li 4 SiO 4 ceramics have great potential for CO 2 capture at high temperature.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Ge Gao,Zhi Zhu,Jia Zheng,Zhi Liu,Qiu Wang,Yongsheng Yan
The two-dimensional (2D) ultrathin Mg-Al layered double hydroxide modified by magnetic Fe 3 O 4 (Fe 3 O 4 /Mg-Al LDH) was successfully synthesized via the co-precipitation method. The Fe 3 O 4 /Mg-Al LDH not only exhibits superior separation efficiency of charge carriers but also possesses signally enhanced photocatalytic activity for CO 2 reduction than Mg-Al LDH. The as-prepared Fe 3 O 4 /Mg-Al LDH affords the CO and CH 4 generation rate of 442.2 µmol g −1 h −1 and 223.9 µmol g −1 h −1 . The enhanced reduction CO 2 activity mainly comes from synergetic effect of Fe 3 O 4 and ultrathin Mg-Al LDH. And Fe 3 O 4 can increase the separation efficiency of photogenerated electron-hole pairs, and ultrathin Mg-Al LDH can reduce the transmission resistance of charge carriers. Moreover, a detailed mechanism insight of Fe 3 O 4 /Mg-Al LDH for CO 2 reduction is also investigated by a series of characterization methods and activity experiments. This work offers a simple and environment-friendly approach to develop recycled photocatalysts in CO 2 reduction treatment.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
METABOLIC ENGINEERING
·
2019
·
IF 7.808
Ting Shi,Shan Liu,Yi-Heng P. Job Zhang
Carbon dioxide (CO 2 ) is an appealing carbon feedstock for the sustainable production of biocommodities. Here we designed three in vitro artificial enzymatic pathways featuring the ATP-excess, ATP-deficit, and ATP-balanced pathways for the biotransformation of starch and CO 2 to malate. This ATP-balanced pathway without exogenous ATP donors can auto-regulate its carbon fluxes from glyceraldehyde 3-phosphate to 3-phosphoglycerate via either the ATP-generating pathway (a part of glycolysis) or no-ATP-generating pathway from a hyperthermophilic archaeon Thermococcus kodakarensis . The ATP-balanced pathway enabled to produce up to 52.4 mM malate with 95.3% of the theoretical yield, that is, 2 mol of malate synthesized from 1 mol of glucose of starch and 2 mol of CO 2 . This pathway also enabled to produce high-yield malate regardless of ATP/ADP ratios. Anaerobic reaction conditions and/or the addition of a reducing agent dithiothreitol were of importance for creating an anoxic environment for biocatalysis of enzyme cocktails and for mitigating the deactivation of enzymes and degradation of intermediates. This new pathway could provide a green route for direct conversion of CO2 to many building blocks, a promising alternative of petrochemical-based production of biocommodities.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）