| 1. |
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| 2. |
- Beal, Jacob, et al.
(author)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 3. |
- Chen, Yifeng, et al.
(author)
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Thermodynamic Study for Gas Absorption in Choline-2-pyrrolidine-carboxylic Acid + Polyethylene Glycol
- 2016
-
In: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 61:10, s. 3428-3437
-
Journal article (peer-reviewed)abstract
- The solubility of pure CO2, CH4, and N2 in the mixture of choline-2-pyrrolidine carboxylic acid ([Cho][Pro]) and polyethylene glycol (PEG200) (mass ratio = 1:2) was measured experimentally at temperatures from 308.15 to 338.15 K and pressures up to 28 bar, in which [Cho][Pro] is an ionic liquid and PEG200 is a cosolvent with the purpose to decrease the viscosity. It was found that [Cho][Pro]/PEG200 showed a good selectivity for CO2/CH4 and CO2/N2 separation. The measured experimental data points from this work and others were further used to estimate the thermodynamic properties including the Henry's law constants for the gases in [Cho][Pro]/PEG200, the equilibrium constant for the reaction between CO2 and [Cho][Pro], the CO2 absorption enthalpy in [Cho][Pro]/PEG200, and so forth. The consistent results of the CO2 absorption enthalpy at infinite dilution prove the reliability of the thermodynamic properties obtained in this work. The thermodynamic properties of [Cho][Pro]/PEG200 were further compared with other three typical absorbents, and the absorption enthalpy is nearly half of that for 30 wt % MEA aqueous solution. At the same time, the theoretical amount of absorbents needed for [Cho][Pro]/PEG200 is much lower than that of H2O scrubbing. This shows that [Cho][Pro]/PEG200 is a promising absorbent
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| 4. |
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| 5. |
- Jiang, Bin, et al.
(author)
-
Topological structure of urban street networks from the perspective of degree correlations
- 2014
-
In: Environment and Planning, B. - : SAGE Publications. - 0265-8135 .- 1472-3417. ; 41:5, s. 813-828
-
Journal article (peer-reviewed)abstract
- Many complex networks demonstrate a phenomenon of striking degree correlations: that is, a node tends to link to other nodes with similar (or dissimilar) degrees. From the perspective of degree correlations, in this paper we attempt to characterize topological structures of urban street networks. We adopted six urban street networks (three European and three North American), and converted them into network topologies in which nodes and edges represent individual streets and street intersections, respectively, and compared the network topologies with three reference network topologies (biological, technological, and social). The urban street network topologies (with the exception of Manhattan) showed a consistent pattern that distinctly differs from the three reference networks. The topologies of urban street networks lack striking degree correlations in general. Through reshuffling the network topologies towards, for example, maximum or minimum degree correlations while retaining the initial degree distributions, we found that all the surrogate topologies of the urban street networks, as well as the reference ones, tended to deviate from small-world properties. This implies that the initial degree correlations do not have any positive or negative effect on the networks’ performance or functions.
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| 6. |
- Liu, Shaohua, et al.
(author)
-
Synthesis of chiral TiO2 nanofibre with electron transition-based optical activity
- 2012
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 3, s. 1215-
-
Journal article (peer-reviewed)abstract
- The optical chirality induced at the absorption bands due to electronic exciton coupling of the transition dipole moments between chromophores in close proximity is ubiquitous in helical organic materials. However, inorganic materials with optical activity resulting from electronic transitions have not been explored. Here we report the synthesis of chiral TiO2 fibres via transcription of the helical structure of amino acid-derived amphiphile fibres through coordination bonding interactions between the organics and the TiO2 source. Upon calcination, the as-prepared amorphous TiO2 double-helical fibres with a pitch length of ~100 nm were converted to double-helical crystalline fibres with stacks of anatase nanocrystals in an epitaxial helical relationship. Both the amorphous and anatase crystalline helical TiO2 fibres exhibited optical response to circularly polarized light at the absorption edge around ~350 nm. This was attributed to the semiconductor TiO2-based electronic transitions from the valence band to the conduction band under an asymmetric electric field.
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| 7. |
- Liu, Yuan, et al.
(author)
-
An ultralow-density porous ice with the largest internal cavity identified in the water phase diagram
- 2019
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : NATL ACAD SCIENCES. - 0027-8424 .- 1091-6490. ; 116:26, s. 12684-12691
-
Journal article (peer-reviewed)abstract
- The recent back-to-back findings of low-density porous ice XVI and XVII have rekindled the century-old field of the solid-state physics and chemistry of water. Experimentally, both ice XVI and XVII crystals can be produced by extracting guest atoms or molecules enclosed in the cavities of preformed ice clathrate hydrates. Herein, we examine more than 200 hypothetical low-density porous ices whose structures were generated according to a database of zeolite structures. Hitherto unreported porous EMT ice, named according to zeolite nomenclature, is identified to have an extremely low density of 0.5 g/cm(3) and the largest internal cavity (7.88 angstrom in average radius). The EMT ice can be viewed as dumbbell-shaped motifs in a hexagonal close-packed structure. Our first-principles computations and molecular dynamics simulations confirm that the EMT ice is stable under negative pressures and exhibits higher thermal stability than other ultralow-density ices. If all cavities are fully occupied by hydrogen molecules, the EMT ice hydrate can easily outperform the record hydrogen storage capacity of 5.3 wt % achieved with sII hydrogen hydrate. Most importantly, in the reconstructed temperature-pressure (T-P) phase diagram of water, the EMT ice is located at deeply negative pressure regions below ice XVI and at higher temperature regions next to FAU. Last, the phonon spectra of empty-sII, FAU, EMT, and other zeolite-like ice structures are computed by using the dispersion corrected vdW-DF2 functional. Compared with those of ice XI (0.93 g/cm(3)), both the bending and stretching vibrational modes of the EMT ice are blue-shifted due to their weaker hydrogen bonds.
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| 8. |
- Lu, Yang, et al.
(author)
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Precise tuning of interlayer electronic coupling in layered conductive metal-organic frameworks
- 2022
-
In: Nature Communications. - : Nature Portfolio. - 2041-1723. ; 13:1
-
Journal article (peer-reviewed)abstract
- Layered metal-organic frameworks attract interests for optoelectronics and spintronics. Here, the authors report a strategy to tune interlayer charge transport and thermoelectric properties via side-chain induced control of the layer spacing. Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have attracted increasing interests for (opto)-electronics and spintronics. They generally consist of van der Waals stacked layers and exhibit layer-depended electronic properties. While considerable efforts have been made to regulate the charge transport within a layer, precise control of electronic coupling between layers has not yet been achieved. Herein, we report a strategy to precisely tune interlayer charge transport in 2D c-MOFs via side-chain induced control of the layer spacing. We design hexaiminotriindole ligands allowing programmed functionalization with tailored alkyl chains (HATI_CX, X = 1,3,4; X refers to the carbon numbers of the alkyl chains) for the synthesis of semiconducting Ni-3(HATI_CX)(2). The layer spacing of these MOFs can be precisely varied from 3.40 to 3.70 angstrom, leading to widened band gap, suppressed carrier mobilities, and significant improvement of the Seebeck coefficient. With this demonstration, we further achieve a record-high thermoelectric power factor of 68 +/- 3 nW m(-1) K-2 in Ni-3(HATI_C3)(2), superior to the reported holes-dominated MOFs.
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| 9. |
- Lu, Yingying, et al.
(author)
-
Telomere dysfunction promotes small vessel vasculitis via the LL37-NETs-dependent mechanism
- 2020
-
In: Annals of Translational Medicine. - : AME PUBL CO. - 2305-5839 .- 2305-5847. ; 8:6
-
Journal article (peer-reviewed)abstract
- Background: Small vessel vasculitis (SVV) is a group of systemic autoimmune diseases that are mediated by neutrophil extracellular traps (NETs) in response to cathelicidin LL37, an aging molecular marker, which could be induced by telomere dysfunction. Therefore, in this study, we evaluated the hypothesis that telomere dysfunction in neutrophils may promote SVV via an LL37-NETs-dependent mechanism. Methods: We contrasted the release of neutrophil NETs from mice with telomere dysfunction, mice with DNA damage and wide-type mice. Neutrophil telomere length, the expression of LL37, and the formation of NETs were measured in SVV patients and healthy controls (HCs). The co-expression of gamma H2AX, LL37, and NETs were detected in SVV patients to evaluate the association of the immune aging of neutrophils and pro-inflammatory conditions. LL37 inhibitor was used to verify its key role in NETs release in SVV patients and DNA damage mice. Results: We found that NETs were over-induced by telomere dysfunction and DNA damage in mice, which may be associated with a marked increase in LL37. For patients with SVV, telomeres in neutrophils were significantly shortened, which was also associated with higher levels of LL37 and NETs. Inhibition of LL37 reduced the NETs released from neutrophils. Conclusions: Taken together, the results of these studies suggest that dysfunction of telomeres may promote SVV through the mechanism of LL37-dependent NETs. Thus, targeting the LL37-NETs may be a novel therapy for SVV.
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| 10. |
- Luo, Xuhao, et al.
(author)
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Intrinsic polarization-sensitive organic photodetector with self-assembled all-polymer heterojunction
- 2022
-
In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 121:23
-
Journal article (peer-reviewed)abstract
- Intrinsic polarization-sensitive photodetectors (IPPDs) have attracted considerable attention in recent years due to their simplicity in configuration, making them ideal candidates for compact and integrated polarization-sensitive sensing and imaging systems. Photoactive films with intrinsic optical anisotropy are necessary for IPPDs. This study reports an achievement of photoactive films based on all-polymer heterojunction films with in-plane optical anisotropy using a simple bottom-up self-assembly method. Both the donor (TQ1) and acceptor (N2200) polymers have the same spatial orientation with distinct anisotropy, approaching a dichroic ratio (DR) of 8. Polarization-sensitive light absorption is due to the uniaxially oriented polymer chains, which are dominated by lamellar packing with edge-on orientation. For IPPDs based on this anisotropic all-polymer heterojunction film, a photocurrent anisotropy was found with a polarized photocurrent ratio of 2.6. The detectivity of these IPPDs was found to be 1.9 × 1011 Jones (@ ∼600 nm, 0 V bias). Our work shows that oriented polymer donor-acceptor films fabricated using bottom-up self-assembly have great potential in applications, such as polarization detection.
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| 11. |
- Wang, Yan, et al.
(author)
-
Evaluation of precipitable water vapor from four satellite products and four reanalysis datasets against GPS measurements on the Southern Tibetan Plateau
- 2017
-
In: Journal of Climate. - 0894-8755. ; 30, s. 5699-5713
-
Journal article (peer-reviewed)abstract
- © 2017 American Meteorological Society. The southern Tibetan Plateau (STP) is the region in which water vapor passes from South Asia into the Tibetan Plateau (TP). The accuracy of precipitable water vapor (PWV) modeling for this region depends strongly on the quality of the available estimates of water vapor advection and the parameterization of land evaporation models. While climate simulation is frequently improved by assimilating relevant satellite and reanalysis products, this requires an understanding of the accuracy of these products. In this study, PWV data from MODIS infrared and near-infrared measurements, AIRS Level-2 and Level-3, MERRA, ERA-Interim, JRA-55, and NCEP final reanalysis (NCEP-Final) are evaluated against ground-based GPS measurements at nine stations over the STP, which covers the summer monsoon season from 2007 to 2013. The MODIS infrared product is shown to underestimate water vapor levels by more than 20% (1.84 mm), while the MODIS near-infrared product overestimates them by over 40% (3.52 mm). The AIRS PWV product appears to be most useful for constructing high-resolution and high-quality PWV datasets over the TP; particularly the AIRS Level-2 product has a relatively low bias (0.48 mm) and RMSE (1.83 mm) and correlates strongly with the GPS measurements (R = 0.90). The four reanalysis datasets exhibit similar performance in terms of their correlation coefficients (R = 0.87-0.90), bias (0.72-1.49 mm), and RMSE (2.19-2.35 mm). The key finding is that all the reanalyses have positive biases along the PWV seasonal cycle, which is linked to the well-known wet bias over the TP of current climate models.
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| 12. |
- Wang, Yan, et al.
(author)
-
Synergy of orographic drag parameterization and high resolution greatly reduces biases of WRF-simulated precipitation in central Himalaya
- 2020
-
In: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 54:3-4, s. 1729-40
-
Journal article (peer-reviewed)abstract
- Current climate models often have significant wet biases in the Tibetan Plateau and encounter particular difficulties in representing the climatic effect of the Central Himalaya Mountain (CHM), where the gradient of elevation is extremely steep and the terrain is complex. Yet, there were few studies dealing with the issue in the high altitudes of this region. In order to improve climate modeling in this region, a network consisting of 14 rain gauges was set up at elevations >2800 m above sea level along a CHM valley. Numerical experiments with Weather Research and Forecasting model were conducted to investigate the effects of meso- and micro-scale terrain on water vapor transport and precipitation. The control case uses a high horizontal resolution (0.03°) and a Turbulent Orographic Form Drag (TOFD) scheme to resolve the mesoscale terrain and to represent sub-grid microscale terrain effect. The effects of the horizontal resolution and the TOFD scheme were then analyzed through comparisons with sensitivity cases that either use a low horizontal resolution (0.09°) or switch off the TOFD scheme. The results show that the simulations with high horizontal resolution, even without the TOFD scheme, can not only increase the spatial consistency (correlation coefficient 0.84–0.92) between the observed and simulated precipitation, but also considerably reduce the wet bias by more than 250%. Adding the TOFD scheme further reduces the precipitation bias by 50% or so at almost all stations in the CHM. The TOFD scheme reduces precipitation intensity, especially heavy precipitation (>10 mm h−1) over high altitudes of the CHM. Both high horizontal resolution and TOFD enhance the orographic drag to slow down wind; as a result, less water vapor is transported from lowland to the high altitudes of CHM, causing more precipitation at lowland area of the CHM and less at high altitudes of CHM. Therefore, in this highly terrain-complex region, it is crucial to use a high horizontal resolution to depict mesoscale complex terrain and a TOFD scheme to parameterize the drag caused by microscale complex terrain.
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| 13. |
- Xie, Yujiao, et al.
(author)
-
Energy consumption analysis for CO2 separation using imidazolium-based ionic liquids
- 2014
-
In: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 136, s. 325-335
-
Journal article (peer-reviewed)abstract
- CO2 solubility in ionic liquids has been measured extensively in order to develop ionic liquid-based technology for CO2 separation. However, the energy consumption analysis has not been investigated well for such technology. In order to carry out the energy consumption analysis for CO2 separation using ionic liquids based on available experimental data, in this work, the experimental data of the CO2 solubility in imidazolium-based ionic liquids at pressures below 10 MPa was surveyed and evaluated by a semi-empirical thermodynamic model firstly. Based on the reliable experimental solubility data, the enthalpy of CO2 absorption was further calculated by the thermodynamic model. The results show that the CO2 absorption enthalpy in the studied ionic liquids is dominated by the enthalpy of CO2 dissolution and the contribution of excess enthalpy increases with increasing CO2 solubility in ionic liquids. The magnitude of the CO2 absorption enthalpy decreases with increasing chain length in cation and strongly depends on the anion of ionic liquids. Furthermore, the energy consumption for a CO2 separation process by pressure swing and/or temperature swing was investigated. For the pressure swing process, the Henry’s constant of CO2 in ionic liquids is an important factor for energy consumption analysis; If CO2 is absorbed at 298 K and 1 MPa and ionic liquid is regenerated by decreasing the pressure to 0.1 MPa at the same temperature, among the studied ionic liquids, [emim][EtSO4] is the solvent with the lowest energy consumption of 9.840 kJ/mol CO2. For the temperature swing process, the heat capacity of ionic liquids plays a more important role; If CO2 is absorbed at 298 K and desorbed at 323 K and 0.1 MPa, [emim][PF6] is the solvent with the lowest energy demand of 888.9 kJ/mol CO2. If the solvent is regenerated by releasing pressure and increasing temperature, both the Henry’s constant of CO2 in ionic liquids and the heat capacity of ionic liquids are important for analyzing the energy consumption; If CO2 is absorbed at 298 K and 1 MPa and ionic liquid is regenerated at 323 K and 0.1 MPa, [bmim][Tf2N] is the solvent with the lowest energy consumption of 57.71 kJ/mol CO2.
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| 14. |
- Zhang, Yingying, et al.
(author)
-
Application of choline-based deep eutectic solvents in CO2 capture and separation
- 2014
-
In: Huagong Xuebao/Journal of Chemical Industry and Engineering. - 0438-1157. ; 65:5, s. 1721-1728
-
Journal article (peer-reviewed)abstract
- Choline-based deep eutectic solvents (DESs) are a new class of ionic liquids. With similar properties to ionic liquids, choline-based DESs have the advantages of easy synthesis, low price, low toxicity and biodegradability. In this work, the properties of choline-based DESs related to CO2 capture and separation were investigated, such as gas solubility, CO2 absorption-desorption, density, thermal stability, viscosity and surface tension. The influence of the structure of choline-based DESs on their properties were analyzed. The comparison of choline-based DESs with traditional ionic liquid showed that choline-based DESs could be used as absorbents for CO2 capture and separation due to high CO2 solubility and low viscosity. However, more research needs to be done before commercial application, for example, CO2 selectivity compared to other components in gas mixtures, surface tension as well as thermal-stability.
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| 15. |
- Zhang, Yingying, et al.
(author)
-
Carbon Dioxide Capture
- 2019
-
In: Deep Eutectic Solvents. - : John Wiley & Sons. - 9783527345182 - 9783527818488 ; , s. 297-319
-
Book chapter (other academic/artistic)abstract
- Carbon capture and storage (CCS) is proposed as an effective way to reduce anthropogenic carbon dioxide (CO2) from the combustion of fossil fuels, in which CO2 capture or separation is an important step. Meanwhile, CO2 separation is also needed in biofuel production, for example, biogas upgrading to obtain biomethane or biosyngas purification to get syngas for producing biofuels. Many technologies have been developed for CO2 capture, while there still remains a need to develop new technologies. Ionic liquids (ILs) have been considered as “green” solvents and developed as liquid absorbents for CO2 capture; and deep eutectic solvents (DESs) as a new class of ILs or IL analogues show advantages on cost, environmental impact, and synthesis. In this chapter, the properties of DESs related to CO2 capture, such as gas solubility, viscosity, molar heat capacity, and gas absorption/desorption rate, are summarized and discussed. On the basis of the properties of DESs, the screening and evaluation of DESs for CO2 separation as well as the contribution of DESs to CO2 conversion are further discussed. In summary, the research work is still limited and more research needs to be carried out.
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| 16. |
- Zhang, Yingying, et al.
(author)
-
Choline-based deep eutectic solvents for CO2 separation : Review and thermodynamic analysis
- 2018
-
In: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 97, s. 436-455
-
Journal article (peer-reviewed)abstract
- CO2 separation plays an important role in energy saving and CO2 emission reduction, both of which are necessary to address the issue of global warming. Ionic liquids (ILs) have been proposed to be “green” solvents for CO2 separation. Unfortunately, the high cost, toxicity, and poor biodegradability of these compounds limit their large-scale application. Deep eutectic solvents (DESs) were recently considered a new type of IL with additional advantages in terms of cost, environmental impact, and synthesis. DESs based on choline salts (i.e., choline-based DESs) are promising candidates for CO2 separation. In this work, the microstructures, physicochemical properties, and water effect of choline-based DESs are surveyed and compared with those of conventional ILs. The properties of choline-based DESs are similar to those of conventional ILs, but research on the latter remains limited. Further study on the microstructures, properties, and separation performance of choline-based DESs considering dynamic factors must be carried out through experimental measurements and model development. Thermodynamic analysis based on Gibbs free energy change is conducted to investigate the performances of choline-based-DESs during CO2 separation from biogas. Choline-based-DESs are screened on the basis of energy use and amount of absorbent needed. The performances of the screened choline-based-DESs are further compared with those of conventional ILs screened in our previous work, as well as commercial CO2 absorbents. Comparisons indicate that the screened DES-based absorbents show great application potential due to their nonvolatility, low energy use, or low amount required. The performances of physical choline-based-DES and 30 wt% MEA for CO2 separation from other gas streams (e.g., flue gas, lime kiln gas, and bio-syngas) are discussed. Considering the high amounts of physical absorbents required to enable separation, further study with techno-economic analysis needs to be carried out.
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| 17. |
- Zhang, Yingying, et al.
(author)
-
Choline-Based Deep Eutectic Solvents for Mitigating Carbon Dioxide Emissions
- 2015
-
In: Novel Materials for Carbon Dioxide Mitigation Technology. - : Elsevier. - 9780444632593 ; , s. 87-116
-
Book chapter (peer-reviewed)abstract
- Global warming is a critical issue facing human beings due to greenhouse gas emissions, especially CO2 emissions. Mitigating CO2 emissions by Carbon capture and storage (CCS) has become a hot topic today. CO2 separation is a crucial step in CCS and is an energy-intensive process. Ionic liquids (ILs) as green solvents have gained tremendous attention for use as liquid absorbents for CO2 separation. However, the high price, toxicity, and poor biodegradability limit the application of ILs. Recently, deep eutectic solvents (DESs) based on choline chloride (ChCl) (i.e., choline-based DESs) were proposed as a new type of ILs but with additional advantages in cost, environmental impact, and synthesis. To promote the application of choline-based DESs in CO2 separation, the research work on the microstructure and physicochemical properties of choline-based DESs as well as the water effect were surveyed and compared with traditional ILs. The potential applications of choline-based DESs in CO2 separation and the challenges were further analyzed. It is shown that choline-based DESs are promising for use as liquid absorbents for CO2 separation, and the performance of ChCl/urea (1:2) is better than that for other choline-based DESs. However, uncertainties and bottlenecks still exist, and further study on the microstructure and properties needs to be carried out from experimental measurements to model developments
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| 18. |
- Zhang, Yingying, et al.
(author)
-
Energy consumption analysis for CO2 separation from gas mixtures
- 2014
-
In: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 130:S1, s. 237-243
-
Journal article (peer-reviewed)abstract
- CO2 separation is an energy intensive process, which plays an important role in both energy saving and CO2 capture and storage (CCS) implementation to deal with global warming. To quantitatively investigate the energy consumption of CO2 separation from different CO2 streams and analyze the effect of temperature, pressure and composition on energy consumption, in this work, the theoretical energy consumption of CO2 separation from flue gas, lime kiln gas, biogas and bio-syngas was calculated. The results show that the energy consumption of CO2 separation from flue gas is the highest and that from biogas is the lowest, and the concentration of CO2 is the most important factor affecting the energy consumption when the CO2 concentration is lower than 0.15 in mole fraction. Furthermore, if the CO2 captured from flue gases in CCS was replaced with that from biogases, i.e. bio-CO2, the energy saving would be equivalent to 7.31 million ton standard coal for China and 28.13 million ton standard coal globally, which corresponds to 0.30 billion US$ that can be saved for China and 1.36 billion US$ saved globally. This observation reveals the importance of trading fossil fuel-based CO2 with bio-CO2.
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| 19. |
- Zhang, Yingying, et al.
(author)
-
Energy Consumption Analysis for CO2 Separation from Gas Mixtures with Liquid Absorbents
- 2014
-
In: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 61, s. 2695-2698
-
Journal article (peer-reviewed)abstract
- CO2 separation is an energy intensive process, and it plays an important role in both energy saving and CO2 capture and storage (CCS) to deal with global-warming. CO2 can be from different sources in a wide temperature, pressure and concentrations range. Meanwhile, new liquid absorbents are under-development to cost-effectively separate CO2 from gas mixtures. All this makes it crucial to analyze the energy consumption for CO2 separation from different streams and with different absorbents. In this work, the theoretical energy consumption of CO2 separation from flue gas (CO2/N2), lime kiln gas (CO2/N2), biogas (CO2/CH4) and bio-syngas (CO2/H2/CO) was calculated. The results show that the energy consumption of CO2 separation from flue gas is the highest and that from biogas is the lowest. If the CO2 captured from flue gases was substituted by that from biogases, the energy saving would be equivalent to 28.13 million ton standard coal globally. The energy consumption of CO2 separation from biogas using traditional absorbent of 30%MEA and new developed ionic liquids (ILs) was further studied, in which 1-ethyl-3-methy- limidazolium bis[(trifluoromethyl)sulfonyl]imide ([Emim][NTf2]), 1-butyl-3-methylimida- zolium tetrafluoroborate ([Bmim][BF4]), 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide ([Hmim][Tf2N]) and 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide ([Bmpy][Tf2N]) were screened from 75 ILs. The energy consumptions of CO2 separation using ILs are lower than those of 30%MEA and that of [Bmim][BF4] is the lowest in the four screened ILs. With a very low vapor pressure and high CO2 solubility, it's promising to use ILs as absorbents for CO2 separation.
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| 20. |
- Zhang, Yingying, et al.
(author)
-
Properties and applications of choline-based deep eutectic solvents
- 2013
-
In: Huaxue jinzhan. - 1005-281X. ; 25:6, s. 881-892
-
Journal article (peer-reviewed)abstract
- Choline-based deep eutectic solvents (DESs) are considered as a new class of ionic liquids. Comparing to traditional ionic liquids, choline-based DESs are low-toxic, biodegradable, and the price is generally low, which make them more and more attractive in green chemistry and industrial chemistry. In the current work, the properties of choline-based DESs, such as freezing point, melting point, solubility, viscosity, surface tension and conductivity, were collected and summarized. The dependences of these properties with different factors, such as temperature, mole ratios and water content, and the models which can be used to predict the properties were studied and discussed. The applications of choline-based DESs in the area of lubrication, functional material preparation, electrochemistry, organic synthesis and catalytic conversion of biomass were introduced. Finally, the problems and difficulties in research and applications were illustrated and then prospective was provided.
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| 21. |
- Zhang, Yingying, et al.
(author)
-
Screening of conventional ionic liquids for carbon dioxide capture and separation
- 2016
-
In: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 162, s. 1160-1170
-
Journal article (peer-reviewed)abstract
- CO2 capture and storage could efficiently mitigate CO2 emissions, wherein CO2 capture is a crucial energy-intensive process. Ionic liquids (ILs) have been proposed as potential liquid absorbents for CO2 separation. The CO2 absorption capacity and selectivity of ILs have also been investigated extensively. Although ILs have been screened for CO2 separation, only specific ILs have been examined in terms of energy consumption. In this study, 76 conventional ILs were collected and screened in terms of energy consumption to establish potential ILs for CO2 separation. Seventeen ILs were screened according to the CO2 dissolution enthalpy and CO2 working capacity criteria obtained from the Henry’s law constant in the preliminary screening. Seven ILs were then screened from the 17 ILs according to the CO2 working capacity from the measured CO2 solubility in the final screening. The energy consumptions of the seven screened ILs (i.e., [Emim][NTf2], [Bmim][BF4], [Bmim][PF6], [Bmim][NTf2], [Hmim][NTf2], [Bmpy][NTf2], and [Hmpy][NTf2]) were calculated, and the corresponding gas solubility selectivities were discussed. The energy consumptions and properties of the seven screened ILs were compared with those of the commercial CO2 absorbents of 30 wt% MEA, 30 wt% MDEA, and dimethyl ethers of polyethylene glycol (Selexol™ or Coastal AGR®). The results showed that the energy consumptions of the seven screened ILs were lower than those of the commercial CO2 absorbents. [Hmpy][NTf2] showed the lowest energy consumption among the seven screened ILs under the operating conditions set in this study.
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| 22. |
- Zhang, Yingying, et al.
(author)
-
Thermodynamic analysis of CO2 separation from biogas with conventional ionic liquids
- 2018
-
In: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 217, s. 75-87
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Journal article (peer-reviewed)abstract
- CO2 separation plays an important role in energy saving and CO2 emission reduction to address global warming. Ionic liquids (ILs) have been proposed as potential absorbents for CO2 separation, and a large amount of ILs have been synthesized to achieve this purpose. To screen ILs for CO2 separation, CO2 absorption capacity/selectivity and energy use have been considered, whereas the required amount of IL has been seldom involved. In this work, CO2 separation from biogas with 30 conventional ILs was analyzed theoretically on the basis of the Gibbs free energy change combining the amount of IL needed and the energy use. The desorption temperature was estimated from the absorption pressure, and then the amount of IL needed and the energy use were calculated. Thermodynamic analysis shows that the absorption pressure and the desorption temperature need to be changed to achieve optimal separation. Several ILs were screened with certain criteria, namely, the amount of IL needed and energy use. The performance of the screened ILs was compared with that of commercial CO2 absorbents (30 wt% MEA, 30 wt% MDEA, DEPG, and water). The comparison with DEPG and water shows that the screened physical ILs are promising for IL-based technologies because of their advantages of negligible vaporization enthalpy, low amount of absorbent needed, or low energy use. A comparison with 30 wt% MEA and 30 wt% MDEA indicates that chemical IL has negligible vaporization enthalpy and low energy use. These findings show that the screened ILs are promising for CO2 separation from biogas.
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