New process development and process evaluation for capturing CO2 in flue gas from power plants using ionic liquid [emim][Tf2N]

Using the ionic liquid [emim][Tf_2N] as a physical solvent, it was found by Aspen Plus simulation that it was possible to attempt to capture CO_2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination, the density, isostatic heat capacity,viscosity, vapor pressure, thermal conductivity, surface tension and solubility of [emim][Tf_2N] were obtained.Based on the NRTL model, the Henry coefficient and NRTL binary interaction parameters of CO_2 dissolved in[emim][Tf_2N] were obtained by correlating [emim][Tf_2N] with the gas–liquid equilibrium data of CO_2. Firstly,the calculated relevant data is imported into Aspen Plus, and the whole process model of the ionic liquid absorption process is established. Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process. Finally, the density, constant pressure heat capacity,surface tension, thermal conductivity, and viscosity of [emim][Tf_2N] were changed to investigate the effect of ionic liquid properties on process energy consumption, solvent circulation and heat exchanger design. The results showed that based on the composition of the inlet gas stream to the absorbers, CO_2 with a capture rate of 90% and a mass purity higher than 99.5% was captured. These results indicate that the [emim][Tf_2N] could be used as a physical solvent for CO_2 capture from coal-fired units. In addition, the results will provide a theoretical basis for the design of new ionic liquids for CO_2 capture.     

Molecular dynamics simulation for the binary mixtures of high pressure carbon dioxide and ionic liquids简

Molecular dynamics simulation with an all-atom force field has been carded out on the two binary sys- tems of [bmim][PF6]-CO2 and [bmim][NO3]-CO2 to study the transport properties, volume expansion and micro- structures. It was found that addition of CO2 in the liquid phase can greatly decrease the viscosity of ionic liquids （ILs） and increase their diffusion coefficient obviously. Furthermore, the volume expansion of ionic liquids was found to increase with the increase of the mole fraction of CO2 in the liquid phase but less than 35% for the two simulated systems, which had a significant difference with CO2 expanded organic solvents. The main reason was that there were some void spaces inter and intra the molecules of ionic liquids. Finally, site to site radial distribution functions and corresponding number integrals were investigated and it was found that the change of microstructures of ILs bv addition CO2 had a great influence on the orooerties of ILs.     

Highly selective extraction of aromatics from aliphatics by using metal chloride-based ionic liquids

The separation of aromatics from aliphatics is essential for achieving maximum exploitation of oil resources in the petrochemical industry. In this study, a series of metal chloride-based ionic liquids were prepared and their performances in the separation of 1,2,3,4-tetrahydronaphthalene(tetralin)/dodecane and tetralin/decalin systems were studied. Among these ionic liquids, 1-ethyl-3-methylimidazolium tetrachloroferrate([EMIM][FeCl₄]) with the highest selectivity was used as the ext...     

Physicochemical properties of amide–AlCl_3 based ionic liquid analogues and their mixtures with copper salt

The physicochemical properties of three different amide–AlCl_3 based ionic liquid(IL) analogues and their mixtures with copper salt, such as conductivity, viscosity, density and isobutane solubility were determined over a wide range of temperatures.The effects of amide structure, amide/AlCl_3 molar ratio and CuCl modification on these physicochemical properties were investigated.Results showed that the conductivity of amide–AlCl_3 based IL analogues was much lower than that of traditional Et_3NHCl–AlCl_3 IL with same ligand/AlCl_3 molar ratio due to incomplete splitting of AlCl_3, whereas the density and viscosity of amide–AlCl_3 based IL analogues were slightly higher.The viscosity of amide–AlCl_3 based IL analogues was closely related to the amide structure,and followed the order of DMA–AlCl_3AA–AlCl_3NMA–AlCl_3 with same amide/AlCl_3 molar ratio.Meanwhile,the density of amide–AlCl_3 based IL analogues ranked in the following order: AA–AlCl_3NMA–AlCl_3DMA–AlCl_3.Increasing the amide/AlCl_3 molar ratio decreased the conductivity and density, while increased the viscosity.The solubility experiment indicated that the isobutane solubility in NMA–AlCl_3 was highest than that in two other IL analogues.Under the modification of CuCl, the conductivity, viscosity and density of these IL analogues increased, whereas the isobutane solubility decreased.These results provide the foundation for the development of a suitable IL analogue catalyst for isobutane alkylation.     

N-己基-甲基吡咯烷酮溴盐与N-丁基-甲基吡咯烷酮溴盐在不同温度下的密度、电导率和粘度的实验数据(英文)

The densities, conductivities, and viscosities were measured for ternary solutions of N-hexyl, methylpyrrolidinium bromide ([PP1,6]Br)-N-butyl,methylpyrrolidinium bromide ([PP1,4]Br)-H2O and its binary subsystems [PP1,6]Br-H2O and [PP1,4]Br-H2O at (298.15, 303.15, 308.15, and 313.15) K, respectively. The results were used to test the predictability of the simple equations established for the prediction of density, conductivity, and viscosity of the mixed electrolyte solutions. The results show that the examined simple equations can offer good predictions for density, conductivity, and viscosity of the mixed ionic liquid solutions in terms of the corre-sponding properties of its binary subsystems of equal ionic strength.     

Synthesis and characterization of hybrid graphene nanocoolant for heat transfer dissipation in microchannel heat sinks

An attempt is made to examine the effect of hybrid nanocoolant in microchannel heat sink for computer cooling.Two-hybrid coolants with graphene as one of the prime components are synthesized and images of the particles are shown using scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Heat transfer properties like thermal conductivity of the hybrid fluid, specific heat, density, and viscosity are evaluated experimentally and theoretically. The heat transfer characteristics are also studied in heat sink channels of micro level in the processors of personal computers. The parameters like internal heat transfer coefficient, thermal resistances and base temperature representing the processor temperature are examined for the applied heater power of 325 W. The coolant dilution was varied in the range of 0.05 vol%, 0.075 vol% and 0.1 vol% and the base temperature is noted. The recorded lowest base temperature is 310.01 K for the concentration of 0.1 vol%graphene-iron oxide(GFO) system for 0.5 mm fin spacing for the graphene-iron oxide hybrid coolant and for graphene oxide–iron oxide(GOFO) hybrid coolant it is 311.24 K for the same operating conditions.     

Modeling of thermal conductivity and density of alumina/silica in water hybrid nanocolloid by the application of Artificial Neural Networks

In this research work, the thermal conductivity and density of alumina/silica(Al_2O_3/SiO_2) in water hybrid nanofluids at different temperatures and volume concentrations have been modeled using the artificial neural networks(ANN). The nanocolloid involved in the study was synthesized by the two-step method and characterized by XRD, TEM, SEM–EDX and zeta potential analysis. The properties of the synthesized nanofluid were measured at various volume concentrations(0.05%, 0.1% and 0.2%) and temperatures(20 to 60 °C). Established on the observational data and ANN, the optimum neural structure was suggested for predicting the thermal conductivity and density of the hybrid nanofluid as a function of temperature and solid volume concentrations. The results indicate that a neural network with 2 hidden layers and 10 neurons have the lowest error and a highest fitting coefficient o thermal conductivity, whereas in the case of density, the structure with 1 hidden layer consisting of 4 neurons proved to be the optimal structure.     

己内酰胺类离子液体的热力学性质(英文)

A series of caprolactam ionic liquids(ILs) containing incorporated halide anions were synthesized.Their physical properties,such as melting points,heats of fusion and heat capacities,were measured by differential scanning calorimeter(DSC).The results indicate that these ionic liquids exhibit proper melting points,high value of heats of fusion,and satisfying heat capacities which are suitable for thermal energy storage applications.     

Experimental investigation and development of new correlation for influences of temperature and concentration on dynamic viscosity of MWCNT-SiO2 (20-80)/20W50 hybrid nano-lubricant

In current research, MWCNT-SiO_2/oil hybrid nano-lubricant viscosity is experimentally examined. By dispersing 0.05%, 0.1%, 0.2%, 0.4%, 0.8% and 1% volume of MWCNTs and SiO_2 nanoparticle into the engine oil SAE 20W50, the temperature and solid volume fraction consequences were studied. At 40 to 100 ℃ temperature, the viscosities were assessed. The results indicated Newtonian behavior for the hybrid nano-lubricant. Moreover, solid volume fraction augmentation and temperature enhanced the viscosity enhancement of hybrid nano-lubricant. At highest solid volume fraction and temperature, nano-lubricant viscosity was 171% greater compared to pure 20W50. Existed models lack the ability to predict the hybrid nano-lubricant viscosity. Thus, a new correlation regarding solid volume fraction and temperature was suggested with R-squared of 0.9943.     

The role of the symmetry and the flexibility of the anion on the characteristics of the nanostructures and the viscosities of ionic liquids☆

The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion.     

Efficient SO2 removal using aqueous ionic liquid at low partial pressure

The development of novel absorbents is essential for SO₂ removal. In this study, a novel ionic liquid(IL,[BHEP][HSO₄]) was prepared, and water was selected as the co-solvent. The density and viscosity of aqueous [BHEP][HSO₄] were measured and the SO₂ absorption performance was systematically investigated.Furthermore, the thermodynamic properties of SO₂ in aqueous [BHEP][HSO₄] were calculated.Additionally, the mechanism of SO_2...     

离子液体；石油沥青质的新型溶剂

The dissolution of petroleum asphaltenes with ionic liquids is studied for the first time. The results show that the ionic liquids could be used as novel solvents for asphaltenes. The important parameters governing the ability of ionic liquids for dissolution of asphaltenes are discussed. It is found that, the ionic liquids based on the cations containing a conjugated aromatic core or the anions which are strong hydrogen bond acceptors are most effective, whereas the ionic liquids containing ＇non coordinating＇ anions such as [BF4]^- and [PF6]^- are nonsolvents for asphaltenes. Increase in the effective anion charge density enhances the ability of ionic liquids to break the extensive asphaltene associations and thus enhances the solubility of asphaltenes in the ionic liquid. The dissolution ability of ionic liquid decreases apparently with increasing the substituted alkyl chain length of its cationic head ring. Temperature is found to play an important role on dissolution of asphaltenes, and the dissolution can be significantly imoroved bv microwave heatinz.     

Modified graphite filled natural rubber composites with good thermal conductivity

The rubber composites with good thermal conductivity contribute to heat dissipation of tires. Graphite filled natural rubber composites were developed in this study to provide good thermal conductivity. Graphite was coated with polyacrylate polymerized by monomers including methyl methacrylate, n-butyl acrylate and acrylic acid. The ratios between a filler and acrylate polymerization emulsion and those between monomers were varied. Eight types of surface modification formulas were experimentally investigated. Modification formula can affect coating results and composite properties greatly. The best coating type was achieved by a ratio of 1:1 between methyl methacrylate and n-butyl acrylate. The coating of graphite was thermal y stable in a running tire. Filled with modified graphite, the tire thermal conductivity reached up to 0.517–0.569 W·m-1·K-1. In addition, the mechanical performance was improved with increased crosslink density, extended scorch time and short vulcanization time.     

由各向同性双势能测定含有CO2的稀二元混合物的传输性质简

The present work is concerned with extracting information about intermolecular potential energies of binary mixtures of CO2 with C2H6, C3H8, n-C4Hlo and iso-C4Hlo, by the usage of the inversion method, and then predicting the dilute gas transport properties of the mixtures. Using the inverted pair potential energies, the Chap- man-Enskog version of the kinetic theory was applied to calculate transport properties, except thermal conductivity of mixtures. The calculation of thermal conductivity through the methods of Schreiber et al. and Uribe et al. was discussed. Calculations were performed over a wide temperature range and equimolar composition. Rather accurate correlations for the viscosity coefficients of the mixtures in the temperature range were reproduced from the pre- sent unlike intermolecular potential energies. Our estimated accuracies for the viscosity are within ±2%. Acceptable agreement between the predicted values of the viscosity and thermal conductivity with the literature values demon- strates the predictive power of the inversion scheme. In the case of thermal conductivity our results are in favor of the preference of Uribe et al.＇s method over Schreiber et al.＇s scheme.     

Effects of imidazolium-based ionic liquids on the isobaric vapor–liquid equilibria of methanol + dimethyl carbonate azeotropic systems

The separation of methanol(MeOH) and dimethyl carbonate(DMC) is important but difficult due to the formation of an azeotropic mixture. In this work, isobaric vapor–liquid equilibrium(VLE) data for the ternary systems containing different imidazolium–based ionic liquids(ILs), i.e. MeOH + DMC + 1-butyl-3-methy-limidazolium bis[(trifluoromethyl)sulfonyl]imide([Bmim][Tf_2N]), MeOH + DMC + 1-ethyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide([Emim][Tf_2N]), and MeOH + DMC + 1-ethyl-3-methylimidazolium hexafluorophosphate([Emim][PF6])) were measured at 101.3 kPa. The mole fraction of IL was varied from0.05 to 0.20. The experimental data were correlated with the NRTL and Wilson equations, respectively. The results show that imidazolium-based ILs were beneficial to improve the relative volatility of MeOH to DMC,and [Bmim][Tf_2 N] showed a much more excellent performance on the activity coefficient of MeOH. The interaction energies of system components were calculated using Gaussian program, and the effects of cation and anion on the separation coefficient of the azeotropic system were discussed.     

Statistical mechanics and artificial intelligence to model the thermodynamic properties of pure and mixture of ionic liquids

In this paper, the volumetric properties of pure and mixture of ionic liquids are predicted using the developed statistical mechanical equation of state in different temperatures, pressures and mole fractions. The temperature dependent parameters of the equation of state have been calculated using corresponding state correlation based on only the density at 298.15 K as scaling constants. The obtained mean of deviations of modified equation of state for density of al pure ionic liquids for 1662 data points was 0.25%. In addition, the performance of the arti-ficial neural network (ANN) with principle component analysis (PCA) based on back propagation training with 28 neurons in hidden layer for predicting of behavior of binary mixtures of ionic liquids was investigated. The AADs of a col ection of 568 data points for al binary systems using the EOS and the ANN at various temperatures and mole fractions are 1.03%and 0.68%, respectively. Moreover, the excess molar volume of all binary mixtures is predicted using obtained densities of EOS and ANN, and the results show that these properties have good agree-ment with literature.     

四氟硼酸盐类离子液体对典型柴油的萃取脱硫研究

The extractive removal of sulfur compounds （S-compounds） from Dongying and Liaohe diesel fuels with [BF4]^--based ionic liquids were systematically investigated. The results show that the absorption capacity of an ionic liquid for the S-compounds in diesel fuels relies on its structure and its size. In the case of the two examined diesel fuels, both elongating the cation tail length and increasing the mass ratio of ionic liquid/diesel fuel promote the desulfurization ability of the examined ionic liquids. The results also show that imidazolium-based ionic liquids display higher extraction efficiencies than pyridinium-based ionic liquids, presumably owing to the fact that the rings of the S-compounds are similar to the imidazolium head ring. With the 1 ： 1 mass ratio of ionic liquid/diesel fuel, the rates of the first desulfurization of Dongying and Liaohe diesel fuels using [C8mim][BF4] amount to 29.96% and 39.76%, suggesting that [C8mim][BF4] is a promising extractant for desulfurization of these diesel fuels.     

Optimization of Compressed Ceramics Fiber Insulating Layers

Compressed thin layers of ceramic fiber insulation are used as high temperature insulating layers as well as mechanical support for catalyst coated ceramic monoliths in automotive emission control devices.Minimization of energy losses,choice of material and thickness of compressed insulating layer are based on knowledge of their thermal physical properties.Currently,consistent measurements of materials in a compressed state, as they would be in emission control applications,are absent due to the absence of suitable methods for such tests.A test method was developed for measurement of the thermal conductivity of compressed thin fiber layers.This paper summarizes the results of thermal conductivity and diffusivity measurements of 27 compressed fiber alumina- silica- vermiculite materials in the range of 200- 950 ℃.Thermal physical properties as a function of temperature,density / mechanical pressure,thickness and composition of insulating layers are presented.The whole set of experimental data is generalized on 3D surface plots and described by polynomial functions.The possible heat transfer mechanisms governing apparent thermal conductivity of pressed insulation layers are discussed.     

Physical Properties in Drying of Food Products with Combined Sublimation and Evaporation

Drying is an important unit operation in processing of biological resources. The drying process may influence the product properties and quality, which may shrink, break or undergo rheological, physical and biochemical changes. The important parameters responsible for such changes are drying conditions, type of drying technology and residence drying time. Thermal conductivity, thermal-mass diffusivity, enthalpy, porosity and density are the main material property and heat-mass transfer parameters, which are essential for understanding the changes in product quality and for designing and dimensioning the drying processes. In this paper physical properties of food products undergoing a combined sublimation and evaporation were studied. Pieces of vegetables and potatoes were dried in a heat pump fluidized bed dryer at combined modes with temperatures below the freezing point in the beginning and a final drying step at temperatures above the freezing point. Samples of products were tested at different moistu     

CO2/N2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures

The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.