Co-reporter:Wenfeng Li, Yingjie Li, Yong Chen, Qingnan Liu, Yingzhou Lu, Hong Meng, and Chunxi Li
Energy & Fuels September 21, 2017 Volume 31(Issue 9) pp:9035-9035
Publication Date(Web):July 18, 2017
DOI:10.1021/acs.energyfuels.7b01295
Carbon-based materials are a kind of promising sorbent for the desulfurization of fuel oils, especially for polycyclic aromatic sulfur heterocycles (PASHs), and development of new sorbents is of great significance. In this paper, six alkynyl carbon materials (ACM-1 to ACM-6) were prepared for the first time through mechanochemical reaction of calcium carbide with six full halogenated hydrocarbons, i.e., CCl4, C2Cl6, C2Cl4, C6Cl6, C6Br6, and C14H4Br10, respectively. Their carbon content and specific surface areas (SSAs) were analyzed, and their adsorption performance for thiophenic sulfurs was studied. The ACMs are mesoporous materials with relatively high SSAs and favorable adsorptive performance for PASHs with the order of DBT > BT > 3-MT. Their adsorptivity is virtually consistent with the SSA values and follows the order of ACM-6 > ACM-5 > ACM-4 > ACM-1 > ACM-3 > ACM-2. ACM-6 has the highest SSA (712 m2 g–1) and saturated adsorbance of 21.1 mg-S·g–1 for DBT in octane, as well as 6 mg-S·g–1 for real diesel. As a whole, ACM-6 represents the best ADS sorbent among all mesoporous carbon materials and may be applicable for real oils after some further modification.
Industrial & Engineering Chemistry Research May 11, 2016 Volume 55(Issue 18) pp:5257-5262
Publication Date(Web):2017-2-22
DOI:10.1021/acs.iecr.6b00484
The liquid-phase aldol condensation of acetone for the synthesis of isophorone (IP) was studied under catalysis of CaC2 powder for the first time. The reaction products were analyzed by gas chromatography, gas chromatography–mass spectrometry, and X-ray diffraction. The catalytic behavior of CaC2 was studied at varying temperature, particle size, and dosage and compared with that of Ca(OH)2 and other basic catalysts. It was found that CaC2 shows excellent catalytic performance because of its strong Lewis basicity and dehydrating ability, and CaC2 is converted to Ca(OH)2 and acetylene simultaneously by the resulting water. Higher temperature, smaller catalyst size, and higher mass ratio of CaC2 are beneficial to the IP synthesis. The overall catalytic performance of CaC2 is superior to that of all basic catalysts reported heretofore. This process combines the hydrolysis of CaC2 and the aldol condensation of acetone into a one-pot reaction, which promotes the condensation of acetone greatly along with the quantitative reclamation of acetylene. Thus, this process can be thought of as a green, cost-effective, and efficient route for the synthesis of IP and provides a valuable use of CaC2.
Industrial & Engineering Chemistry Research July 27, 2016 Volume 55(Issue 29) pp:8079-8086
Publication Date(Web):2017-2-22
DOI:10.1021/acs.iecr.6b00961
A hyper cross-linked polymer, HCPVIM, was prepared by copolymerization of vinylimidazole (VIM) and divinylbenzene (DVB), whereby three poly ionic liquids (PILs) were synthesized via quaternization of the imidazole ring by hydrochloric acid, n-butyl chloride and 1,4-bis(chloromethyl) benzene, respectively. Their composition, morphology, specific area and thermal stability were characterized, and their adsorptivity for thiophenic sulfurs was studied. The HCPVIM is a mesoporous sorbent with specific area of 675 m2 g–1, and shows much higher desulfurization ability than its monomer analogue, ethyl imidazole, being about 8.0 mg S g–1 for dibenzothiophene (DBT) at equilibrium S-concentration of 900 ppm. Its desulfurization ability follows the order of DBT > benzothiophene> thiophene, being the same order as alkyl imidazole and imidazolium based ionic liquids. Compared to HCPVIM, the PILs are also mesoporous materials but with negligible micropores, lower specific area of ∼180 m2 g–1, and lowering thermal decomposition temperature of about 150 K. The PILs show a complex adsorption behavior for different sulfur compounds. As a whole, quaternization of HCPVIM tends to decrease the desulfurization ability for all sulfur compounds except the protonated HCPVIM for thiophene, which manifests the combinative effects of the decreased porosity and specific area and the increased electrostatic interactions in the ionized sorbents.
Co-reporter:Hong Meng;Nan-Nan Ren;Wen-Yan Ma;Ying-Zhou Lu;Chang-Tao Ge
Industrial & Engineering Chemistry Research January 8, 2014 Volume 53(Issue 1) pp:355-362
Publication Date(Web):2017-2-22
DOI:10.1021/ie402599d
To develop a greener process for reclaiming phenolic compounds from low temperature coal tar, extractive performance of twelve extractants, including mono-, di-, and triethanol amines (MEA, DEA, TEA), six protonated ionic liquids (ILs) thereof with formate (FA) or acetate (Ac) anion, choline chloride, and two polyols (glycol, glycerol), were studied at varying conditions, along with the back extractability of phenols by ether. The extraction performance is MEA > DEA > TEA ≈ ILs > glycol > glycerol, while the back extraction performance of ether is just the opposite. The coexistent toluene in oil and temperature show a little influence on the extraction performance of alcoholic amines and their corresponding ILs. The extraction performance of extractants is consistent with their complexability with phenol, i.e. ethanol amines > ether > ILs > polyols, as manifested by the red shift of the UV spectrum of phenol in the above solvents. [HMEA]FA is the most promising extractant for its overall extraction performance, cheapness, and other favorable physical attributes.
The discovery of new carbon materials and the reactive activation of CaC2 are challenging subjects. In this study, a series of alkynyl carbon materials (ACMs) were synthesized by the interfacial mechanochemical reaction of CaC2 with four typical polyhalogenated hydrocarbons. Their properties and structures were characterized, and their electrochemical performances were examined. The reaction was rapid and efficient arising from the intense mechanical activation of CaC2. The ACMs are micro–mesoporous materials with distinct layered structure, specific graphitization degree, and clear existence of sp-C. In addition, the ACMs exhibit high specific capacitance in the range of 57–133 F g–1 and thus can be ideal candidates for active materials used in supercapacitors. The results may imply an alternative synthesis of carbon allotropes, as well as an efficient approach for the activation of CaC2.Keywords: alkynyl carbon materials; CaC2; mechanochemistry; polyhalogenated hydrocarbons; supercapacitors;
Co-reporter:Yingjie Li, Qingnan Liu, Wenfeng Li, Yingzhou Lu, Hong Meng, Chunxi Li
Chemosphere 2017 Volume 166(Volume 166) pp:
Publication Date(Web):1 January 2017
DOI:10.1016/j.chemosphere.2016.09.135
•HCB is completely destroyed by CaC2 within 20 min via mechanochemical treatment.•CaC2 shows much higher reactivity than traditional alkaline co-milling regents.•HCB is converted to nonhazardous CaCl2 and carbon materials.•HCB is destroyed via nucleophilic substitutions of C-Cl by alkynyl in CaC2.Mechanochemical destruction (MCD) is a good alternative to traditional incineration for the destruction of persistent organic pollutants (POPs), like hexachlorobenzene (HCB), and the key is to find an efficient co-milling reagent. Toward this aim, HCB was milled with various reagents in a planetary ball mill at room temperature, and CaC2 was found to be the best one. HCB can be destroyed completely within 20 min at a mass ratio of CaC2/HCB = 0.9 and a rotation speed of 300 rpm. The ground samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results show that the destruction products are nonhazardous CaCl2 and carbon material with both crystalline and amorphous structures. On these bases, possible reaction pathways were proposed. Considering its excellent efficiency and safety, CaC2 may be the most feasible co-milling regent for MCD treatment of HCB. Further, the results are instructive for the destruction of other POPs.Download high-res image (216KB)Download full-size image
The efficient reductive decomposition of gaseous nitrous oxide (N2O) from industrial effluents is of practical importance in abating greenhouse gas emissions. In the present study, active carbon (AC) has been chosen as both a reductive agent and a catalyst support. Dozens of AC-based catalysts with different kinds and amounts of metal oxide have been prepared under various conditions and characterized. The performances of Cu-containing AC have been studied at varying gas flow rates, Cu contents, and calcination temperatures. N2O in a gas mixture (42% N2O, 58% N2) was found to be completely removed by Cu-loaded AC (9 wt% Cu, calcined at 400 °C) at 325 °C with a GHSV of 2293 h−1. This process is viable by virtue of the low cost of AC and easier manipulation and process control in comparison with alternative methods employing reductive gases such as hydrogen and ammonia.
•PEG oligomers are efficient and green extractants for dibenzothiophene.•Poly IL is used here as catalyst for extractive catalytic oxidative desulfurization.•The present process can be used successively for 6 times and regenerated easily.•The present process is viable for deep desulfurization of real diesel.An efficient and green extractive catalytic oxidative desulfurization (ECODS) process is developed for diesel by using polyethylene glycol (PEG) oligomers, H2O2 and a phosphotungstate based poly ionic liquid (HPW-PIL) as extractant, oxidant and catalyst, respectively. The PEG oligomers with repeating glycol units of 0, 4 and 8 are determined as the best extractants among acetonitrile, methanol, DMF, [BMIM]BF4, and PEG-2000 with comprehensive characteristics like non-toxicity, non-volatility, low cost, easy recycling, and good desulfurization performance. Benzothiophene (BT) and dibenzothiophene (DBT) in model oil can be removed completely within 2 h at the following conditions: PEG oligomer/oil = 0.2 (mass ratio), H2O2 usage of O/S = 20 (mole ratio), HPW-PIL catalyst/oil = 1/100 (mass ratio), at the temperature of 353 K. And the desulfurization ability of the present process can be retained as 99% even after six successive reuses without regeneration. Further, the S-content in real diesel can also be reduced from 110 to 9.3 ppm-S by the ECODS process followed by AlCl3 adsorption for the oxidized diesel. Meanwhile, the PEG extractant and the HPW-PIL catalyst can be facilely regenerated and recycled.
Co-reporter:Yong Chen, Hong-yan Song, Ying-zhou Lu, Hong Meng, Chun-xi Li, Zhi-gang Lei, and Biao-hua Chen
Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 39) pp:10394-10403
Publication Date(Web):September 6, 2016
DOI:10.1021/acs.iecr.6b02464
For the deep desulfurization of fuel oil, adsorptive desulfurization (ADS) and oxidative desulfurization (ODS) may be the most viable alternatives to the conventional HDS process. In this work, a highly cross-linked vanadate based polyionic liquid (V-PIL) was synthesized by reacting poly(vinylimidazole) (PVIM) with peroxy-vanadic acid. The as-prepared V-PIL is mesoporous with specific area of 163 m2·g–1 and good adsorptivity for the oxidized sulfur compounds. Further, it can efficiently catalyze the oxidation of dibenzothiophene and benzothiophene with cumene hydroperoxide (CHP), achieving a unified desulfurization processes of ODS and ADS. Its catalytic activity and reusability is superior to the supported vanadate catalysts, e.g. V2O5@active carbon and V2O5@zeolite. The desulfurization capacity of V-PIL is 99% in the first run under specified conditions, i.e. stirring 4 h at 323 K for 500 ppmS DBT oil, with CHP/S being 4 in mole ratio and 3 wt % V-PIL with respect to oil. And over 80% of its desulfurization capacity can be retained after five successive uses without regeneration under the above conditions. The V-PIL may represent a new type of bulk catalyst with potential application considering its rich porosity, good dispersion, accessible catalytic sites, and no soluble loss of the bonded vanadates in the recycling uses.
Co-reporter:Jing Zhang, Hui-hui Xu, Ying-zhou Lu, Hong Meng, Chun-xi Li, Biao-hua Chen, and Zhi-gang Lei
Energy & Fuels 2016 Volume 30(Issue 6) pp:5035
Publication Date(Web):May 20, 2016
DOI:10.1021/acs.energyfuels.6b00179
A hyper cross-linked ionic polymer (HCIP) PVimBCmBn was synthesized through free radical polymerization of 1-vinylimidazole (Vim) and quaternized cross-linking with 1,4-bis(chloromethyl) benzene (BCmBn). Its composition, structure, morphology, specific area, porous structure and thermal stability were characterized, and the desulfurization performance was investigated. The results show that the HCIP prepared with stoichiometric ratio of PVim and BCmBn are ultrafine powders with specific area of 99.6 m2·g–1 and average pore size of 16.1 nm, being micro/mesoporous materials. The S-removability of HCIP is superior to its precursor (ethyl imidazole) and the imidazolium-based ionic liquids (ILs), which manifests the importance of the available micropores for the accommodation of sulfur molecules with less energy barrier. The adsorption isotherms of PVimBCmBn follow the Langmuir equation with its saturated adsorbance being 7.0, 5.2, and 4.1 mgS·g–1, respectively, for dibenzothiophene, benzothiophene, and thiophene in model oil at 293 K. However, its adsorptive removal ability for DBT in diesel oil is quite low due to its limited S-selectivity with respect to the abundant confused ring aromatics wherein.
Co-reporter:Nan-nan Ren, Yin-hui Gong, Ying-zhou Lu, Hong Meng, and Chun-xi Li
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 2) pp:189-196
Publication Date(Web):January 9, 2014
DOI:10.1021/je400004j
Surface tension data were measured by the Wilhelmy plate method for the binary mixtures containing an ionic liquid of the imidazolium dialkylphosphate family and water (methanol or ethanol) at 298.15 K and atmospheric pressure. The enthalpy of vaporization Δ1gHmo and Hildebrand solubility parameter δH for the pure components are estimated from the experimental data, and a perfect correlation is found between surface tension and specific cohesive energy per unit surface area for the imidazolium dialkylphosphate series ionic liquids (ILs). The surface tension as well as the surface tension deviation against the solution composition shows a remarkable difference between the mixtures of an IL with water and with alcohols, which is interpreted qualitatively by the δH values of the corresponding pure components. Some ILs act as a surfactant in aqueous solution, but most of them more like a conventional nonelectrolyte component in the alcoholic solutions.
Co-reporter:Salem A. Sakal, Ying-zhou Lu, Xiao-chuan Jiang, Chong Shen, and Chun-xi Li
Journal of Chemical & Engineering Data 2014 Volume 59(Issue 3) pp:533-539
Publication Date(Web):February 13, 2014
DOI:10.1021/je400076x
Liquid–liquid equilibria (LLE) of the following ternary systems were measured at atmospheric pressure, that is, {cyclohexane + benzene + [BMIM][FeCl4]} at T = 298.15 K and 313.15 K, {n-hexane + benzene + [BMIM][FeCl4]}, {n-heptane + toluene + [BMIM][FeCl4]} at T = 298.15 K, and {cyclohexane + benzene + [BMIM]Cl} at T = 339.15 K. The extraction performance of ionic liquid (IL) [BMIM][FeCl4] for the aromatic hydrocarbons (benzene or toluene) from their aliphatic hydrocarbons (cyclohexane, n-heptane, or n-hexane) was analyzed and compared with some imidazolium-based ILs. The results indicate that the IL [BMIM][FeCl4] shows both higher extractive selectivity and distribution factor for the systems studied herein and thus is a promising solvent for the extractive separation of aromatic and aliphatic hydrocarbons. The LLE data were well-correlated by the nonrandom two-liquid (NRTL) model of nonelectrolyte solutions with the overall average absolute relative deviation (rmsd) being about 0.0188 in terms of the mole fraction based activity.
Co-reporter:Jia-jun Gao, Hong-qiang Li, Hong-xing Zhang, Ying-zhou Lu, Hong Meng, and Chun-xi Li
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 12) pp:4682-4691
Publication Date(Web):March 5, 2012
DOI:10.1021/ie202831p
The adsorptive desulfurization ability of four inorganic Lewis acids (AlCl3, FeCl3, ZnCl2, and CuCl) for three thiophenic S-compounds, viz., 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT), from their model oils were studied here experimentally at 290 K. The results were explained in terms of the theory of hard and soft acids and bases (HSAB) reasonably. The results show that AlCl3 has excellent removal ability for 3-MT with its adsorbance being 141.4 without toluene and 123.0 mgS/g with 25 wt % toluene. It is noteworthy that 3-MT is removed solely through complexing adsorption; in contrast, BT is adsorbed, accompanied with the formation of oil soluble BT oligomers under catalysis of AlCl3 which can promote the complexation greatly. Further, the addition of benzene and toluene can accelerate the desulfurization rate of 3-MT and BT due to the concentration of aromatics on the adsorbent and the oligomerization between BT and the aromatics.
Co-reporter:Hong-Xing Zhang, Jia-Jun Gao, Hong Meng, Ying-zhou Lu, and Chun-Xi Li
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 13) pp:4868-4874
Publication Date(Web):March 8, 2012
DOI:10.1021/ie300035c
A novel integrated process is proposed for the catalytic oxidative desulfurization of fuel oil, in which the oxidant H2O2 is in situ generated by oxidizing 2-propanol with oxygen, and its feasibility is evaluated in terms of the S-conversion of 3-methylthiophene (3-MT), benzothiophene (BT), and dibenzothiophene (DBT) in octane under varying conditions. The catalysis of [π-C5H5NC16H33]3[PW4O16] is found to be much superior to H3PW12O40 and [(C4H9)4N]3[PW12O40] due to its good dispersivity in oil and adsorptivity for S-compounds. Some influencing factors for the S-conversion were studied, viz., time, temperature, various S-compounds, and the amount of 2-propanol, initiator, oxygen, and catalyst. All factors that favor the production of the 2-propanol radicals affect the desulfurization rate remarkably. Both BT and DBT can be removed efficiently at mild conditions (1.4 MPa O2, 90 °C) in 6 h with S-conversion above 96%, and the resulting sulfones can be separated via settling or filtration.
Co-reporter:Hongxing Zhang, Jiajun Gao, Hong Meng, and Chun-Xi Li
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 19) pp:6658-6665
Publication Date(Web):April 27, 2012
DOI:10.1021/ie3004545
Three Keggin-type phosphotungstates, i.e. [C5H5NH]3PW12O40, [C4H6N2H]3PW12O40·3C4H6N2 and [(C4H9)4N]3PW12O40, were synthesized and characterized by elemental analysis, X-ray diffraction, and infrared spectra, meanwhile their catalysis in an extractive catalytic oxidative desulfurization process was studied with ionic liquid (IL) as extractant and H2O2 as oxidant. The main factors affecting the desulfurization process were investigated, including temperature, hydrophobicity of IL, and variety of S-compounds, as well as the amount of catalyst, IL, and H2O2. Under the optimal conditions, the S-content of DBT oil can be decreased from 1000 to 2 ppm. A new interpretation is proposed for the current process, in which IL is assumed as a reaction phase, and the amount of the extracted S-compound and the peroxidized catalyst wherein greatly affect the desulfurization rate. Besides, the IL with the dissolved catalyst can be reused many times and regenerated easily.
Co-reporter:Hong-Xing Zhang, Hong-Liang Huang, Chun-Xi Li, Hong Meng, Ying-Zhou Lu, Chong-Li Zhong, Da-Huan Liu, and Qing-Yuan Yang
Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 38) pp:12449-12455
Publication Date(Web):September 4, 2012
DOI:10.1021/ie3020395
Four metal–organic frameworks (MOFs) are synthesized using two different metal centers and two different organic ligands, viz., Cu3[C6H3(CO2)3]2 (Cu-BTC), Cu[O2C–C6H4–CO2] (Cu-BDC), Cr(OH)[O2C–C6H4–CO2] (Cr-BDC), and Cr3F(H2O)3O[C6H3(CO2)3]2 (Cr-BTC). Their adsorption behaviors for thiophenic sulfurs in model diesel oils are systematically investigated at mild temperatures and follow the order Cu-BTC > Cr-BDC > Cr-BTC ≫ Cu-BDC. Meanwhile, the adsorption capacity of different sulfur compounds follows the order dibenzothiophene (DBT) > benzothiophene (BT) > 3-methylthiophene (3-MT). The MOFs adsorption mechanism is regarded as a combined effect of many factors involving appropriate framework structure, suitable pore size and shape, and exposed Lewis acid site matching the S-compound to be adsorbed. The difference in adsorptive activity among the organosulfurs is mainly ascribed to their π-electron number and the electron density on the S-atom. Finally, the used MOF can be easily regenerated by solvent washing and recycled at least five times.
The Journal of Chemical Thermodynamics 2012 Volume 53() pp:167-175
Publication Date(Web):October 2012
DOI:10.1016/j.jct.2012.05.001
Vapour pressures were measured using a quasi-static ebulliometer for the pseudo-binary mixtures of (water + ethanol), (water + methanol), and (methanol + ethanol) containing an alkanolammonium-based ionic liquid (IL), namely, mono-ethanolammonium formate ([HMEA][HCOO]) and di-ethanolammonium formate ([HDEA][HCOO]), respectively, with fixed IL mass fraction of 0.30 and over the temperature ranges of (292.12 to 371.13) K. The vapour pressures of the IL-containing ternary systems were favourably correlated using the NRTL model with an overall average absolute relative deviation (AARD) of 0.0082. Further, the salt effects of [HMEA][HCOO] and [HDEA][HCOO] on isobaric vapour liquid equilibria (VLE) of azeotrope and close boiling mixture, especially for the mixtures of (water + ethanol) and (methanol + ethanol), were investigated and compared with other ILs in terms of the x′–y phase diagrams predicted with the binary NRTL parameters. It is demonstrated that the relative volatilities of ethanol to water and ethanol to methanol are enhanced, and [HMEA][HCOO] might be used as a promising entrainer for the efficient separation of ethanol aqueous solution by special rectification.Highlights► Vapour pressures for six ternary systems containing an IL were measured. ► Components studied were water, ethanol, methanol, and alkanolammonium formates. ► The isobaric VLE were predicted using the fitted binary NRTL parameters. ► The ILs studied can generate a promising salt effect on VLE of azeotrope. ► [HMEA][HCOO] might be used as a potential entrainer in extractive distillation.
Co-reporter:Yin-hui Gong, Chong Shen, Ying-zhou Lu, Hong Meng, and Chun-xi Li
Journal of Chemical & Engineering Data 2012 Volume 57(Issue 1) pp:33-39
Publication Date(Web):October 27, 2011
DOI:10.1021/je200600p
The experimental data of viscosity and density for six binary mixtures of water (methanol or ethanol) with an ionic liquid, 1-butyl-3-methylimidazolium dimethylphosphate ([BMIM][DMP]) or 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]), were measured in the temperature range of (293.15 to 333.15) K at atmospheric pressure using a viscometer and densimeter. The solution behavior of the mixtures is discussed in terms of the variation of the excess viscosity and excess volume with temperatures and compositions. It is found that both excess volume and viscosity of the mixtures studied show a negative deviation from the ideal solution behavior, and the viscosity of the mixtures decreases drastically with the increase of temperatures and mole fractions of solvents. The excess volume of the binary mixtures is quite low, in the range of (1.0 to 1.9) cm3·mol–1; moreover, it shows a monotonic decrease with increasing temperature for the aqueous solution of ILs and a reverse trend for the IL solutions of methanol or ethanol at any concentrations.
Co-reporter:Salem A. Sakal, Chong Shen, Chun-xi Li
The Journal of Chemical Thermodynamics 2012 Volume 49() pp:81-86
Publication Date(Web):June 2012
DOI:10.1016/j.jct.2012.01.010
(Liquid + liquid) equilibrium data of the following ternary and quaternary systems at different temperatures and mass fractions of ionic liquids (ILs) were measured at atmospheric pressure, i.e., {cyclohexane + benzene + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])} at 298.2 K, {cyclohexane + benzene + 1-methylimidazolium tetrafluoroborate ([MIM][BF4])} at 338.2 K, {cyclohexane + benzene + [MIM][BF4] + [MMIM][DMP]} at (298.2 and 313.2) K, and {cyclohexane + benzene + 1-methylimidazolium perchlorate [MIM][ClO4] + [MMIM][DMP]} at 298.2 K. The results indicate that both selectivity and distribution factor of the IL mixture for benzene are lower than that of pure IL [MMIM][DMP] at a specified condition, and decrease with the increase of the mass fraction of [MIM][BF4] or [MIM][ClO4] in its mixture of [MMIM][DMP] and the mole fraction of benzene. The extremely high selectivity of [MIM][BF4] and [MIM][ClO4] for aromatic compounds as predicted by the COSMOS-RS model is not justified by the present experimental results, and on the contrary, they show a relatively lower selectivity and extraction capacity for benzene than [MMIM][DMP].Highlights► (Liquid + liquid) equilibrium for two quaternary and two ternary systems were measured. ► The components include cyclohexane, benzene, [MIM][BF4], [MIM][ClO4] and [MMIM][DMP]. ► The (liquid + liquid) equilibrium data can be well correlated by the NRTL model. ► Separation of benzene and cyclohexane by pure ILs and their mixtures were discussed.
Co-reporter:Ru-Hao He, Bing-Wen Long, Ying-Zhou Lu, Hong Meng, and Chun-Xi Li
Journal of Chemical & Engineering Data 2012 Volume 57(Issue 11) pp:2936-2941
Publication Date(Web):October 23, 2012
DOI:10.1021/je3003783
To study the possibility of using ionic liquids (ILs) as a novel solvent for the absorption of hydrogen chloride (HCl) from the industrial tail gases, the solubility of HCl gas in three ILs has been measured at four temperatures, (298.15, 323.15, 348.15, and 363.15) K, in the pressure range of (0 to 100) kPa. The ILs used are 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), 1-hexyl-3-methylimidazolium chloride ([Hmim]Cl), and 1-octyl-3-methylimidazolium chloride ([Omim]Cl). The results indicate that these ILs show high solubility for HCl gas, and the solubility decreases with the increasing length of the alkyl substitutes of the ILs, following the order [Bmim]Cl > [Hmim]Cl > [Omim]Cl. The solubility of HCl in [Bmim]Cl at 298.15 K is about 0.68 mole fraction at ca. 100 kPa partial pressure of HCl, which is much higher than that of 36.5 % HCl aqueous solution. The solubility of different ILs is discussed in detail, and the experimental data (P–T–x) are correlated successfully by an empirical relation.
Catalytic hydrodesulfurization (HDS) of dibenzothiophene (DBT) was carried out in a temperature range of 320–400 °C using in situ generated hydrogen via steam reforming of ethanol and the effect of some organic additives was studied for the first time. Four kinds of alumina-based catalysts, i.e. Co–Mo/Al2O3, Ni–Mo/Al2O3 and their corresponding Pd promoted catalysts Pd–Co–Mo/Al2O3 and Pd–Ni–Mo/Al2O3, prepared through incipient impregnation method, were used for the desulfurization process. Catalytic activity was investigated in a batch autoclave reactor in the complete absence of external hydrogen gas. Experiments showed that organic additives like diethylene glycol (DEG), phenol, naphthalene, anthracene, o-xylene, tetralin, decalin and pyridine can affect the HDS activity of the catalysts in different ways, and only naphthalene is inhibitive for the catalytic activity towards HDS. The results showed that Ni-based catalysts are more active than Co-based ones while Pd shows a high promotion effect. DBT conversion of up to 97% was achieved with Pd–Ni–Mo/Al2O3 catalyst at 380 °C temperature and 13 h reaction time. Catalyst systems followed the HDS activity order of: Pd–Ni–Mo/Al2O3 > Ni–Mo/Al2O3 > Pd–Co–Mo/Al2O3 > Co–Mo/Al2O3 at all conditions. Qualitative analysis of the products stream was carried out using GC–MS technique. The present HDS process using in situ generated hydrogen might be applied as an alternative approach for the catalytic HDS of DBT on industrial level due to its cost effectiveness, mild operating conditions and high activity of the catalysts.
Vapor pressure data were measured for nine binary systems containing water, ethanol, or methanol with one of three protonic ionic liquids (PILs), viz. mono-, di- and tri-ethanolammonium tetrafluoroborate ([HMEA][BF4], [HDEA][BF4], and [HTEA][BF4]), at varying temperatures and PIL-contents using a quasi-static ebulliometer. The vapor pressure data were correlated by NRTL model with an overall average absolute relative deviation (AARD) of 0.0175. It is showed that the effect of PILs on the vapor pressure lowering of solvents follows the order of [HMEA][BF4] > [HDEA][BF4] > [HTEA][BF4], and the vapor pressure lowering degree follows the order of water > methanol > ethanol. Besides, the activity coefficients of solvent for binary system {solvent + PIL} at fixed PIL mole fraction of 0.10 were calculated using the regressed NRTL parameters. The results indicate that three PILs can give rise to a negative deviation from the Raoult's law for water and methanol and a positive deviation for ethanol to a varying degree, leading to the variation of relative volatility of a solvent.Research highlights► Vapor pressure data for nine binary systems {solvent + ionic liquid} were measured. ► Water, ethanol, methanol, and ethanolammonium-based tetrafluoroborate were studied. ► The vapor pressure data can be well correlated by NRTL model. ► The activity coefficients of solvents were calculated by NRTL model. ► The vapor pressure lowering degree follows the order of water > methanol > ethanol.
Co-reporter:Chong Shen, Xue-mei Li, Ying-zhou Lu, Chun-xi Li
The Journal of Chemical Thermodynamics 2011 Volume 43(Issue 11) pp:1748-1753
Publication Date(Web):November 2011
DOI:10.1016/j.jct.2011.06.002
Measurements of vapour pressure data were conducted using a quasi-static ebulliometer for systems containing water, methanol, ethanol, and a mixture of {water + ethanol} in the presence of an ionic liquid (IL), namely, 1-methylimidazolium chloride ([MIm]Cl), wherein the IL-content ranged from w2 = (0.10 to 0.50). The vapour pressure data of IL-containing binary systems were correlated by the NRTL model with an overall average absolute relative deviation (AARD) of 0.0103, and the resulting binary parameters were used to predict the vapour pressures of a ternary system {water + ethanol + [MIm]Cl} with an AARD less than 0.0077. Further, the isobaric vapour liquid equilibria (VLE) for the ternary system {water + ethanol + IL} with IL-content of w3 = (0.10, 0.30, and 0.50) for [MIm]Cl and x3 = 0.15 for [MIm]Cl, [C4MIm]Cl, and [C6MIm]Cl were predicted at 101.3 kPa, respectively. It is indicated that [MIm]Cl presents the strongest ability to enhance the relative volatility of ethanol to water in the mixture of {water + ethanol} than that of [C4MIm]Cl and [C6MIm]Cl, which is consistent with the cationic sizes and hence the ionic hydration ability. Therefore, distillation separation of the azeotrope of {water + ethanol} can be sufficiently facilitated by the addition of [MIm]Cl at a specified content.Highlights► Vapour pressure data for three binary systems and a ternary system were measured. ► Water, ethanol, methanol, and 1-methylimidazolium chloride were studied. ► The vapour pressure data can be well correlated by the NRTL model. ► The isobaric (vapour + liquid) equilibria were predicted by the NRTL model. ► The salt effect of ILs on the VLE of {water + ethanol} mixture was investigated.
Co-reporter:Chong Shen, Ying-zhou Lu, Xue-mei Li, and Chun-xi Li
Journal of Chemical & Engineering Data 2011 Volume 56(Issue 5) pp:1933-1940
Publication Date(Web):February 24, 2011
DOI:10.1021/je100948e
Vapor pressure data were measured for binary and ternary systems containing water, methanol, ethanol, and a halogen-free ionic liquid (IL) triethylmethylammonium dimethylphosphate ([N1222][DMP]) with IL content ranging from mass fractions of (0.1 to 0.5) at varying temperatures, using a quasi-static ebulliometer. The vapor pressure data of IL-containing binary systems were well-correlated by the nonrandom two-liquid (NRTL) equation with an overall average absolute relative deviation (AARD) of 0.0088, and the resulting binary parameters were used to predict the vapor pressure of three ternary systems with an overall AARD less than 0.0169. Further, the isobaric vapor−liquid equilibrium (VLE) data for ternary systems {water + ethanol + [N1222][DMP]} and {methanol + ethanol + [N1222][DMP]} with IL mass fractions of 0.1, 0.3, and 0.5 at 101.3 kPa were predicted, respectively. It is demonstrated that the relative volatilities of ethanol to water and ethanol to methanol are enhanced. Therefore, a separation of the azeotrope of {water + ethanol} mixture can be sufficiently facilitated by the addition of [N1222][DMP] at a specified content.
Co-reporter:Chong Shen, Xiao-yan Ma, Ying-zhou Lu, Chun-xi Li
The Journal of Chemical Thermodynamics 2011 Volume 43(Issue 3) pp:452-457
Publication Date(Web):March 2011
DOI:10.1016/j.jct.2010.10.019
Vapour pressures were measured using a quasi-static ebulliometer for the binary mixture of (water + ethanol) containing one of three protonic ionic liquids (PIL), namely, mono-, di- or tri-ethanolammonium tetrafluoroborate, over the temperature range of (318.24 to 356.58) K at fixed PIL content of 0.30 in mass fraction. The vapour pressure data of the PIL-containing ternary systems were correlated using the NRTL equation with an overall root mean square deviation (RMSD) of 0.0092. The regressed NRTL parameters were used to predict the isobaric vapour liquid equilibria (VLE) for ternary systems (water + ethanol + PIL) at varying mass fraction of PIL and atmospheric pressure (101.3 kPa). It is shown that the effect of PILs on the VLE of the (water + ethanol) mixture follows the order: [HTEA][BF4] > [HDEA][BF4] > [HMEA][BF4]. In addition, the relative volatilities of ethanol to water for pseudo-binary systems (water + ethanol + PIL) were calculated. The results indicate that the PILs studied can enhance the relative volatility of ethanol to water and even break the azeotropic behaviour of ethanol aqueous solution when PIL content is increased to a specified content.
Co-reporter:Junfeng Wang, Zhibao Li, Chunxi Li and Zihao Wang
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 9) pp:4420-4425
Publication Date(Web):March 26, 2010
DOI:10.1021/ie901590h
Based on the electrolyte perturbation theory, a group contribution equation of state that embodies hard-sphere repulsion, dispersive attraction, and ionic electrostatic interaction energy was established to calculate the density of ionic liquids (ILs). According to this method, each ionic liquid is divided into several groups representing cation, anion, and alkyl substituents. The performance of the model was examined by describing the densities of a large number of imidazolium-based ILs over a wide range of temperatures (293.15−414.15 K) and pressures (0.1−70.43 MPa). A total number of 202 data points of density for 12 ILs and 2 molecular liquids (i.e., 1-methylimidazole and 1-ethylimidazole) were used to fit the group parameters, namely, the soft-core diameter σ and the dispersive energy ε. The resulting group parameters were used to predict 961 data points of density for 29 ILs at varying temperatures and pressures. The model was found to estimate well the densities of ionic liquids with an overall average relative deviation (ARD) of 0.41% for correlation and an ARD of 0.63% for prediction, which demonstrates the applicability of the model and the rationality of the soft-core diameter and dispersive energy parameters.
Co-reporter:Kuilong Tan, Chunxi Li, Hong Meng, Zihao Wang
Polymer Testing 2009 Volume 28(Issue 1) pp:2-7
Publication Date(Web):February 2009
DOI:10.1016/j.polymertesting.2008.08.003
In order to develop applications for the abundant waste rubber powder, chlorinated waste rubber (Cl-WR) was prepared by a water based chlorination method using chlorine as chlorinating agent. In this paper, Cl-WR was used as an elastic filler and blended with poly(vinyl chloride) (PVC) matrix to develop a new thermoplastic elastomer PVC/Cl-WR. The mechanical properties, hydrophilicity, swelling resistance, morphology and thermal properties of PVC/Cl-WR were characterized and compared with those of PVC/waste rubber powder (PVC/WR) blends. The results indicated that the mechanical properties, hydrophilicity, swelling resistance and thermal properties of the PVC/Cl-WR blends showed noticeable improvements over PVC/WR blends due to the improved polarity of Cl-WR. Also, the excellent miscibility and compatibility of Cl-WR with PVC was demonstrated by scanning electron microscope (SEM) images of the resulting blends.
Co-reporter:Yingzhou LU;Yong QUE;Chunxi LI;Hong MENG ;Zihao WANG
Chinese Journal of Chemistry 2009 Volume 27( Issue 4) pp:768-772
Publication Date(Web):
DOI:10.1002/cjoc.200990127
Abstract
In order to choose a suitable adsorbent for the removal of chloroform from its hydrochloric acid solution, the adsorptive ability of some polymer adsorbents was investigated in terms of their adsorption curves in water and 20% hydrochloric acid solutions at 298.15 K, and compared with that of active carbon (AC) and solid paraffin (SP). The adsorbents studied include the fine powders of chlorinated rubber (CR), polypropylene (PP), chlorinated polypropylene (CPP) and polyvinylchloride (PVC). The results showed that the adsorption behavior followed the Langmuir equation and the adsorption ability of these adsorbents followed the order AC>PVC>CR>PP>CPP>SP. This order is basically in line with the decrease of chloro-content of the adsorbents from PVC to SP. The adsorptivity of PVC and CR was nearly equivalent to that of AC with their saturated adsorption being about 1.4 g-CHCl3 (g-absorbent)−1. For all adsorbents studied, the adsorption capacity always decreases with the increase of hydrochloric acid concentration. It is showed that the commercial polymer powder of PVC or CR can be used as an efficient absorbent for the removal of chloroform from its aqueous solution for its low cost, good adsorption ability and ease of thermal desorption for recycling.
Co-reporter:Kuilong TAN;Chunxi LI;Hong MENG;Zihao WANG
Chinese Journal of Chemistry 2009 Volume 27( Issue 1) pp:174-178
Publication Date(Web):
DOI:10.1002/cjoc.200990013
Abstract
Two novel hydrophobic ionic liquids (IL) with partial substitution of chlorine and fluorine in the 1-butyl-3-methylimidazolium cation (noted as [BMIM] or [C8H15N2] hereafter), viz. [C8H12.28Cl0.96F1.76N2]Cl and [C8H12.75Cl1.58F0.67N2][PF6], were reported, which were prepared from the precursors [BMIM]Cl and [BMIM][PF6], respectively through chlorination with chlorine gas and fluorination with potassium fluoride. The position of the chlorine substitution in the resulting IL was identified using proton nuclear magnetic resonance (1H NMR). The results showed that chlorination mainly took place in the imidazolium ring and partly in the methyl of butyl group. Moreover, the physico-chemical properties of the resulting IL were measured experimentally including thermal stability, viscosity, and mutual solubility with water. It is showed that the hydrophobic property and viscosity of the IL [C8H12.28Cl0.96F1.76N2]Cl and [C8H12.75Cl1.58F0.67N2][PF6] increased greatly while the decomposition temperature decreased to some extent compared to their corresponding non-modified IL [C8H15N2]Cl and [C8H15N2][PF6]. This study proposed an alternative and cost-effective approach for tuning the hydrophobic property of IL.
Chinese Journal of Chemistry 2009 Volume 27( Issue 9) pp:1741-1748
Publication Date(Web):
DOI:10.1002/cjoc.200990293
Abstract
An efficient way of converting carbon tetrachloride (CTC) to alkyl chlorides is reported, which uses the catalysts of ionic liquids supported on granular active carbon. The catalytic performance was evaluated in a temperature range of 120–200°C and atmospheric pressure for different ionic liquids, namely 1-butyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, hydrochloric salts of N-methylimidazole (MIm), pyridine and triethylamine, as well as bisulfate and dihydric phosphate of N-methylimidazole. On this basis, the reaction mechanism was proposed, and the influences of the reaction temperature and the attributes of ionic liquids were discussed. The overall reaction was assumed to be comprised of two steps, the hydrolysis of CTC and reaction of HCl with alcohols under acidic catalyst. The results indicate that the conversion of CTC increased monotonically with temperature and even approached 100% at 200°C, while the maximum selectivity to alkyl chlorides was obtained around 160°C. This reaction might be potentially applicable to the resource utilization of superfluous byproduct of CTC in the chloromethane industry.
Co-reporter:Jun-feng Wang, Xue-mei Li, Hong Meng, Chun-xi Li, Zi-hao Wang
The Journal of Chemical Thermodynamics 2009 Volume 41(Issue 2) pp:167-170
Publication Date(Web):February 2009
DOI:10.1016/j.jct.2008.10.001
The boiling temperature at atmospheric pressure were measured for 12 binary systems within the range T = (316 to 379) K and 7 ternary systems using a dual circulation. The systems studied contained water, methanol or ethanol with the following ionic liquids (ILs): monoethanolammonium acetate ([HEMA][Ac]), diethanolammonium acetate ([HDEA][Ac]), triethanolammonium acetate ([HTEA][Ac]) and diethanolammonium chloride ([HDEA]Cl). The experimental VLE results of the IL-containing binary systems were correlated by NRTL equation, and the binary NRTL parameters were used for the prediction of VLE of ternary systems with average absolute deviation of 0.73 K in boiling temperature. The results indicate that [HDEA]Cl can be used as an efficient solvent for the extractive distillation of (ethanol + water) mixture due to its notable salting-out effect, which lower the vapour pressure of water, increase the volatility of ethanol and eliminate the azeotropic phenomenon of the (water + ethanol) mixture at definite IL concentration.
Co-reporter:Hong Meng, Shuang Zhang, Chunxi Li, Liangshi Li
Journal of Membrane Science 2008 Volume 322(Issue 2) pp:436-440
Publication Date(Web):15 September 2008
DOI:10.1016/j.memsci.2008.05.072
The heat stable salts (HSS) generated from the gas desulfurization using N-methyldiethanolamine (MDEA) solvents caused many problems such as solution froth, corrosion and fouling of the equipment. In this paper, a specially designed electrodialysis (ED) was employed to remove the heat stable salts from industrial aqueous MDEA solutions. The heat stable salts were successfully removed by adjusting the arrangement of cation- and anion-exchange membranes. To ensure a stable and durative desalination process, appropriate operation parameters such as applied potential and the flow rate were selected as voltage; 9 V and flow rate; 40 L/h. The experimental results show that about 90% of HSS were removed from aqueous solutions of MDEA solvents while the loss ratio is less than 9% under the appropriate conditions.
Co-reporter:Hong Meng, Hui Li, Chunxi Li, Liangshi Li
Journal of Membrane Science 2008 Volume 318(1–2) pp:1-4
Publication Date(Web):20 June 2008
DOI:10.1016/j.memsci.2008.02.020
In this paper, a novel method was proposed to synthesize ionic liquids by using a specially designed four-compartment configuration electrodialyzer. 1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4), used as a model ionic liquid, was successfully synthesized and concentrated. The products of [BMIM]BF4 could be easily obtained by using the permselectivity of ion-exchange membranes and the migration of ions under dc electric field. The structure of the products was identified with Fourier transform spectra (FTIR) and 1H NMR. It was noted that 92% yield ratio could be achieved while the purity was over 95% after operating 1 h under the voltage of 10 V.
Infinite dilution activity coefficient is an important thermodynamic property, which is widely used in evaluating the intermolecular interaction and screening potential solvents for the separation of a fluid mixture by extraction, distillation or selective absorption. In this paper, UNIFAC model and a new group segmentation method are used to correlate infinite dilution activity coefficients based on the experimental data. Among the groups considered in this work, 1,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([MMIM][BTI]) and 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]) are treated as the main groups. A number of infinite dilution activity coefficients of some molecular solutes are well correlated based on the method proposed, which include alkanes, alkenes, aromatics, alcohols, ketones and water in six ionic liquids (ILs), viz. 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides with alkyl being methyl, ethyl, butyl, hexyl, octyl ([MMIM][BTI], [EMIM][BTI], [BMIM][BTI], [HMIM][BTI], [OMIM][BTI]), and [MMIM][DMP] in the temperature range of 303.15–373.15 K. It is found that the overall accuracy is within 9% in terms of root-mean-square deviation (RMSD); and the overall RMSD is less than 4.2% when the resulting parameters from obtained UNIFAC model are used to predict the vapor pressure of binary mixtures containing IL at varying composition and temperature. The results manifest the applicability of the UNIFAC model and the rationality of the group interaction parameters.
Co-reporter:Xiaochuan Jiang, Yi Nie, Chunxi Li, Zihao Wang
Fuel 2008 Volume 87(Issue 1) pp:79-84
Publication Date(Web):January 2008
DOI:10.1016/j.fuel.2007.03.045
N-ethyl-imidazolium-based alkylphosphate ionic liquid (IL), viz. N-ethyl-N-methyl-imidazolium dimethylphosphate ([EMIM][DMP]), N-ethyl-N-ethyl-imidazolium diethylphosphate ([EEIM][DEP]) and N-butyl-N-ethyl-imidazolium dibutylphosphate ([BEIM][DBP]) were demonstrated to be effective for the removal of aromatic sulfur compounds (S-compound) 3-methylthiophene (3-MT), benzothiophene (BT) and dibenzothiophene (DBT) from fuel oils in terms of sulfur partition coefficients (KN) at 298.15 K. It was shown that the extractive ability of the alkylphosphate ILs was dominated by the structure of the cation and followed the order [BEIM][DBP] > [EEIM][DEP] > [EMIM][DMP] for each S-compound studied with their KN-value being 1.72, 1.61 and 1.17, respectively for DBT. For a specified IL the sulfur selectivity followed the order DBT > BT > 3-MT with their KN-value being 1.61, 1.39 and 0.78, respectively for [EEIM][DEP]. The alkylphosphate ILs are insoluble in fuel while the fuel solubility in ILs varies from 20.6 mg(fuel)/g(IL) for [EMIM][DMP] to 266.9 mg(fuel)/g(IL) for [BEIM][DBP]. The results suggest that [EEIM][DEP] might be used as a promising solvent for the extractive desulfurization of fuel, considering its higher sulfur extractive ability, lower solubility for fuel and thus negligible influence on the constituent of fuel, and the ease of regeneration for the spent IL via water dilution process.
Co-reporter:Ruijie Wang, Chunxi Li, Hong Meng, Junfeng Wang and Zihao Wang
Journal of Chemical & Engineering Data 2008 Volume 53(Issue 9) pp:2170-2174
Publication Date(Web):July 31, 2008
DOI:10.1021/je800376f
Liquid−liquid equilibrium (LLE) data for ternary systems of (benzene + cyclohexane + N-methylimidazole (MIM), or N-ethylimidazole (EIM), or N-methylimidazolium dibutylphosphate [HMIM][DBP]) were measured at 298.2 K and atmospheric pressure, and the experimental data were correlated using the nonelectrolyte NRTL equation. It was found that the selectivity of MIM, EIM, and [HMIM][DBP] for benzene is in the range of (413.6 to 10.7), (5.4 to 1.5), and (2.3 to 1.3), respectively. The variation of extractive performance of these solvents for the benzene component from its cyclohexane mixture is interpreted in terms of the molecular structure and corresponding variation of intermolecular interaction involved, e.g., polar-induced polar interaction, π−π complexation, and dispersive interaction among different components.
Co-reporter:Ruijie Wang, Junfeng Wang, Hong Meng, Chunxi Li and Zihao Wang
Journal of Chemical & Engineering Data 2008 Volume 53(Issue 5) pp:1159-1162
Publication Date(Web):April 16, 2008
DOI:10.1021/je700759h
To screen suitable ionic liquids (ILs) for the extraction separation of benzene and cyclohexane, a close-boiling mixture, measurement of the corresponding liquid−liquid equilibria (LLE) data is necessary. Toward this aim, LLE data for ternary systems of ILs + benzene + cyclohexane were measured at atmospheric pressure and (298.2 and 313.2) K, and the experimental data were correlated using the nonelectrolyte NRTL equation. The ILs used in this work are 1-methyl-3-methylimidazolium dimethylphosphate ([C1mim][DMP]) and 1-ethyl-3-methylimidazolium diethylphosphate ([C2mim][DEP]). It was found that the selectivity of [C1mim][DMP] and [C2mim][DEP] for benzene is in the range of (4.4 to 2.9) and (4.3 to 2.5), respectively, and the selectivity is virtually independent of temperature in the temperature and concentration range studied. Considering the high extraction capacity and selectivity for benzene as well negligible solubility in benzene + cyclohexane mixtures, [C2mim][DEP] may be used as a potential extracting solvent for the separation of benzene and cyclohexane.
Vapor pressure data were measured for water, methanol and ethanol as well as their binary mixtures with an ionic liquid (IL) 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]) at varying temperature and IL-content ranging from mass fraction of 0.10–0.70 by a quasi-static method. The vapor pressure data for the IL-containing binary systems were correlated using NRTL equation with average absolute relative deviation (ARD) within 0.0076, and the binary NRTL parameters was used for predicting the vapor pressure of the IL-containing ternary systems with reasonable accuracy. In addition, the infinite activity coefficients of solvents in [EMIM][DMP] and isobaric vapor–liquid equilibrium for IL-containing ternary systems at 101.325 kPa and mass fraction of IL being 0.5 were predicted with the regressed NRTL parameters. The results indicate that ionic liquid [EMIM][DMP] can depress the volatility of the solvents of water, methanol and ethanol but to a varying degree, leading to the variation of relative volatility of a solvent and even removal of azeotrope for water–ethanol mixture.
Materials Science and Engineering: B 2005 Volume 116(Issue 1) pp:47-53
Publication Date(Web):15 January 2005
DOI:10.1016/j.mseb.2004.09.010
Potassium dihydrogen phosphate (KDP) crystal was grown from solutions in the presence of doping ethylenediamine tetra acetic acid (EDTA) in the concentration range of 0–100 ppm. Its Raman spectra were measured at room temperature with different geometrical configurations. On the basis of the group theory and lattice dynamics theory, all the Raman peaks were assigned, and a correlation between thermal conductivity and the Raman scattering strength was presented. The calculated thermal conductivity enhancements agree well with experimental enhancement of laser damage threshold, which indicates that the laser damage is a result of local thermal damage of KDP crystals.
Chemical Physics Letters 2003 Volume 368(3–4) pp:269-275
Publication Date(Web):17 January 2003
DOI:10.1016/S0009-2614(02)01855-9
Abstract
Er3+- and Yb3+-doped yttrium calcium oxoborate Er:Yb:YCa4O(BO3)3 (Er:Yb:YCOB) crystallizes with a fluorapatite-type structure in the monoclinic system. Its lattice vibrational modes were calculated by using space group theory, and Raman spectra were measured at room temperature with different scattering geometry projects. The experiments show that the characteristic lattice vibrational modes of Er:Yb:YCOB crystal arise mainly from the internal vibrations of the , and YO6 groups. The three-dimensional network structure of Er:Yb:YCOB crystal is identified, and its excellent nonlinear optical (NLO) properties are mainly attributed to the BO3 clusters that connects all the distorted YO6 and CaO6 octahedral clusters together. The combination of the strong absorption at 976 nm and the strong emission at 1537 nm makes this material very promising for use in an infrared laser system.
Two-body integral with hard sphere reference fluid is of significance in thermodynamic modelling with perturbation theory. In this paper, the two-body integral is recalculated by using Tang–Lu radial distribution function (RDF) expression, which is superior to P–Y RDF in representing the structure of hard sphere fluid in whole density region and especially in contact-distance region. It is found that the two-body integral values calculated with Tang–Lu RDF are between those of Larsen et al.’s and Henderson et al.’s, and their difference is negligible. In order to investigate the accuracy of two-body integrals, properties of Lennard–Jones fluid are calculated with B–H perturbation theory under local-compressible approximation and compared with computer simulation results. It is shown that the accuracy of internal energy and compressibility calculated with two-body integrals of this paper and with Larsen et al.’s are 6.78, 8.60, 6.85 and 9.08%, respectively for 170 computer simulation data. As a whole, the accuracy of the present two-body integral with Tang–Lu RDF is a little superior to that of Larsen et al.’s.
Co-reporter:Hongyan SONG, Jiajun GAO, Xingyu CHEN, Jing HE, Chunxi LI
Chinese Journal of Chemical Engineering (June 2014) Volume 22(Issue 6) pp:713-720
Publication Date(Web):1 June 2014
DOI:10.1016/S1004-9541(14)60093-8
For efficient removal of thiophenic sulfur (S-) compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization (OADS), in which oil insoluble chlorinated polymer such as polyvinyl chloride (PVC) is used as the alkylating regent with Lewis acid as catalyst. The aromatic S-compounds are grafted to the polymer through Friedel-Crafts reaction and removed facilely along with the polymer. The OADS mechanism is identified by scanning electron microscope and analyzer with surface area and pore size of the polymer. The influence of some factors on the OADS is studied, e.g. the type and amount of chlorinated polymers and Lewis acids. It is proved that thiophene and benzothiophene can be removed efficiently from oil by PVC+AlCl3 mixture even in the presence of 25% (by mass) of benzene due to the synergetic effects of the adsorptive desulfurization of AlCl3 and the alkylation desulfurization of PVC.
Co-reporter:Chong Shen, Chun-xi Li, Xue-mei Li, Ying-zhou Lu, Yaseen Muhammad
Chemical Engineering Science (15 June 2011) Volume 66(Issue 12) pp:2690-2698
Publication Date(Web):15 June 2011
DOI:10.1016/j.ces.2011.03.027
In this paper, the Valderrama and Robles group contribution model for the critical properties is extended to the prediction of densities of ionic liquids (ILs) at varying temperatures and pressures, where the critical properties of ILs are represented by the modified Lydersen–Joback–Reid group contribution method, and the density is predicted by virtue of the Patel–Teja (PT) equation of state (EOS). The group increments for totally 47 groups with respect to the extended Group Contribution Patel–Teja (GC–PT) model were determined on the basis of experimental density data for 747 pure ILs at atmospheric pressure and ambient temperature. The group increments are suitable for both the GC–PT model and the original Valderrama and Robles model for the density prediction of ILs. The correlation accuracy in terms of overall average absolute relative deviation (AARD) is 4.4% for 918 data points of density at ambient temperature and atmospheric pressure. The applicability of the GC–PT model is justified by predicting the densities of imidazolium-, pyridinium-, and phosphonium-based ILs containing various anions over a wide range of temperatures and pressures and the vapor pressures of five alkylimidazolium-based ILs at varying temperatures, which implied the rationality of the group increments and the critical properties of ILs, as well as the potential uses of the GC–PT model for the thermodynamic modeling of IL-containing systems.
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