| 1. |
- Liu, Yanrong, et al.
(författare)
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Cascade utilization of lignocellulosic biomass to high-value products
- 2019
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Ingår i: Green Chemistry. - : Royal Society of Chemistry. - 1463-9262 .- 1463-9270. ; 21:13, s. 3499-3535
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Tidskriftsartikel (refereegranskat)abstract
- Lignocellulosic biomass is a potential sustainable feedstock to replace fossil fuels. However, the complex structure of biomass makes it difficult to convert into high-value products. Utilization of lignocellulosic biomass in a green and effective way is of great significance for sustainable development. Based on the analysis of different options, we proposed that cascade utilization according to its composition, characteristics, and nature is the best way to utilize the lignocellulosic biomass. To promote the cascade utilization of lignocellulosic biomass, this article provides a review of the latest research results from the aspect of cascade utilization of lignocellulosic biomass covering the whole chain from pretreatment to high-value products, and the research on the non-conventional pretreatments including microwave irradiation, supercritical fluids, ultrasonic irradiation, electric field, hydrodynamic cavitation, and ionic liquids are presented in detail and evaluated by 4 proposed levels, and the newly developed high-value applications were further overviewed for lignin (carbon/graphene/carbon nano-tubes, dye dispersants, bioplastics, and aerogels), cellulose (cellulose-based ionic liquids, functional composites, adsorbent materials, carbon, and aerogels), and hemicellulose (films and pharmaceutical carriers), respectively. Finally, perspectives on the future research on the cascade utilization of lignocellulosic biomass are highlighted.
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| 2. |
- Liu, Yanrong, et al.
(författare)
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Preparation of MWCNTs-Graphene-Cellulose Fiber with Ionic Liquids
- 2019
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 7:24, s. 20013-20021
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Tidskriftsartikel (refereegranskat)abstract
- The conductive multiwalled carbon nanotubes (MWCNTs)-graphene sheets (rGOs)-cellulose fiber was prepared with an eco-friendly wet-spinning method in which ionic liquid (IL) was used as both green solvent and dispersant. It was found that the selected IL 1-ethyl-3-methylimidazolium diethyl phosphate (EmimDep) shows remarkable capacities for dissolving cellulose and dispersing MWCNTs, and the synergistic effect of MWCNTs, rGOs, and cellulose results in a high electrical conductivity of 1195 S/m of MWCNTs-rGOs-cellulose fibers. Macropores and the double-layer structure of MWCNTs and rGOs can be observed by SEM in the studied fibers, and the number of macropores decreased with increasing rGOs amount, which is consistent with the result of the specific surface area. In addition, the prepared MWCNTs-rGOs-cellulose fibers present a nearly perfect electrical double-layer structure. The MWCNTs-rGOs-cellulose fiber with a mass ratio of 2:3:1 shows the best performance as the electrode candidate, with an electrical conductivity of 1195 S/m, specific capacitance of 597 mF/cm2, and specific surface area of 91 m2/g. Furthermore, the results from the molecular dynamics (MD) simulation evidenced that EmimDep can disperse CNTs effectively at 363.15 K, 1 atm compared to rGOs; the synergy effect of CNT and rGO exhibit great potential to enhance the dispersion than each individual component.
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| 3. |
- Liu, Yanrong, et al.
(författare)
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Study on ionic liquid/cellulose/coagulator phase diagram and its application in green spinning process
- 2019
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Ingår i: Journal of Molecular Liquids. - : Elsevier. - 0167-7322 .- 1873-3166. ; 289
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the cellulose phase separation behavior was investigated by using ionic liquids (ILs) as novel solvents to acquire a green process for cellulose fiber spinning. The cloud point titration method combined with the turbidity correlation equation was used to obtain the ternary diagram of IL/cellulose/coagulator throughout the whole compositional range. The effects of the type of ILs, the cellulose materials, the kind of coagulators and the regeneration temperatures for cellulose fiber manufacturing process on the phase separation behavior were studied systematically. It was found that the linearized cloud point (LCP) curve correlation fits to experimental data well and can be used to quantify the optimized coagulator, and among the studied cases, the system of [EMIM]DEP, cotton pulp and water with the regeneration temperature at 298.15 K is the best. Meanwhile, COSMO-RS was used to predict the interaction between solvent, cellulose and coagulator, and the comparison with the LCP correlation shows good agreement. The crystal structure of the regenerated cotton pulp was determined with XRD, and the result evidences that the crystal structure of the regenerated cellulose transforms from cellulose I to cellulose II. The crystallinity decreases from 96.0% (raw cotton pulp) to 85.6% after 24 h dissolution in [EMIM]DEP at 363.15 K, and it has a slight deviation from 24 h to 72 h, which illustrates that the spinning process can run continuously at 363.15 K when using [EMIM]DEP as the solvent.
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| 4. |
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| 5. |
- Zhang, Fengjiao, et al.
(författare)
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Passive seismic interferometry imaging : An example from the Ketzin pilot CO2 geological storage site
- 2022
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Ingår i: Journal of Applied Geophysics. - : Elsevier. - 0926-9851 .- 1879-1859. ; 205
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Tidskriftsartikel (refereegranskat)abstract
- Ketzin is a well-known onshore CO2 geological storage test site. Injection started in June 2008 and ended in August 2013. About 67 kt of CO2 was injected into a saline aquifer reservoir. Numerous geophysical surveys have been conducted at the site, including passive seismic ones. Passive seismic interferometry can be applied in many seismic exploration investigations to image the underground structures. This study compares several passive seismic interferometry imaging methods to a data set acquired at Ketzin. The passive data set consist of 5 lines with 20 h of recordings in total. First, we apply the autocorrelation method to obtain zero offset stacked sections directly. Secondly, we test different interferometry methods to generate virtual shot gathers. These virtual shot gathers are then processed to obtain CDP stacked sections. Results from these methods are compared with an active data set recorded at the site. The processed passive sections have relatively less coherent reflections compared with the active stacked sections. However, the passive sections obtained by autocorrelation show good agreement with the active stacked sections. The stacked sections obtained by processing virtual shot gathers using crosscorrelation show similar features to the active stacked sections, but with poorer coherence in the reflections and are noisier than the autocorrelation sections.
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| 6. |
- Zhou, Le, et al.
(författare)
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Ionic liquid assisted fabrication of cellulose‐based conductive films for Li‐ion battery
- 2020
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Ingår i: Journal of Applied Polymer Science. - : John Wiley & Sons. - 0021-8995 .- 1097-4628. ; 137:35
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Tidskriftsartikel (refereegranskat)abstract
- An imidazolium‐based ionic liquid, 1‐ethyl‐3‐methylimidazolium diethyl phosphate ([Emim]DEP) was used to dispense graphene nanoplates (GN) and multiwalled carbon nanotubes (MWCNTs) as well as dissolve cellulose for fabricating composite conductive films. The effects of GN, MWCNTs, and cellulose mass ratios on the electrical conductivity and morphology of the films were investigated. The interaction between GN, MWCNTs, and cellulose was analyzed by SEM, X‐ray diffraction (XRD), TGA, and Raman spectroscopy. The results indicate that [Emim]DEP plays a vital and irreplaceable role in GN and MWCNTs dispersion, cellulose dissolution, and porous formation during the regeneration and drying processes. MWCNTs linked flaky GN and a hybrid structure was constructed elaborately to form a better conductive path and improve the conductivity as well as increase the film stability. For the XRD result, the carbonized GN‐MWCNTs‐cellulose films exhibited the graphitic peaks, showing that the films still retained the structure of carbon atoms or molecules. Besides, the maximum conductivity of carbonized GN‐MWCNTs‐cellulose (7:3:2) composite film was up to 9,009 S m−1, due to the small carbon clusters formation and the high degree of graphitization. Further, the carbonized films were applied as anodes in Li‐ion battery and showed good electrochemical performance. The best cyclic stability (i.e., discharge/charge capacity) of 438/429 mA h g−1 and coulomb efficiency of 50.2% were obtained. This novel and sustainable design is a promising approach to obtain cellulose‐based conductive films and anodes for Li‐ion battery applications.
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| 7. |
- Zhou, Le, et al.
(författare)
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Study on the regularity of cellulose degradation in ionic liquids
- 2020
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Ingår i: Journal of Molecular Liquids. - : Elsevier. - 0167-7322 .- 1873-3166. ; 308
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Tidskriftsartikel (refereegranskat)abstract
- Ionic liquids (ILs) show the superiority in dissolving and spinning of cellulose. In this work, wood pulp and microcrystalline cellulose were dissolved respectively in two ILs, 1-allyl-3-methylimidazolium chloride ([Amim]Cl) and 1-ethyl-3-methylimidazolium diethyl phosphate ([Emim]DEP), to investigate the regularity of cellulose degradation in ILs. A novel method for determining degree of polymerization of cellulose employed ILs was proposed and its accuracy was compared with the traditional method. The results indicated that cellulose depolymerized seriously with the increase of time and temperature in [Amim]Cl than in [Emim]DEP. In addition, after cellulose dissolving for 72 h, none of the reducing sugar remained in the recycled [Emim]DEP, however, more than 2% reducing sugar can be measured in the recycled [Amim]Cl. These results are consistent with FT-IR investigation, i.e., [Amim]Cl shows greater dissolution capability for cellulose than [Emim]DEP. Therefore, [Emim]DEP shows great prospects in the continuous industrial spinning process under the determined temperature of 90–100 °C.
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