Papers by Keyword: Ionic Liquid (IL)

Abstract: The CO₂ fixation reaction performance was carried out by using propylene oxide (PO) as reactant and medium and ionic liquid as catalyst. Through variation of reaction temperature, pressure and catalyst ratio and amount, it was found that the reaction was under kinetic control, for pressure ranging from 15 to 50 atm, rather than mass transfer control. From the kinetic data, it shows a pseudo first order kinetics with respect to PO concentration under constant CO₂ pressure. The corresponding activation energy was calculated to be 9.152 kcal/mol. The reaction kinetics was independent of catalyst ratio and amount, yet the optimal catalyst ratio of [Bmim]Br/ZnCl₂ is 2 for the fixation reaction. It is also a high conversion reaction, 96.0% (PO), with easier product separation, and as applied to industry for CO₂ reduction process, its kinetic information would be very useful for future industrial scale reactor design.

Abstract: The article has studied the effects of ionic liquids on the induction time of methane hydrate formation under different mass concentrations, temperatures and pressures. The results show: all the tested ionic liquids can postpone the induction time of hydrate forming. Among them, imimidazolium-based ones have the strongest ability; The concentrations of ionic liquids also have strong effects on the induction time, and 0.5% is optimal. In addition the inhibiting abilities of ionic liquid on the induction time change with different pressures and temperatures, but not obviously.

Abstract: This thesis is focused on the catalyst of ionic liquids. Firstly, chloroaluminate ionic liquid consisting of triethylaminia hydrochloride and anhydrous A1C1₃ was prepared, and its catalytic performance on the alkylation of benzene with 1-bromobutane was studied experimentally. The composition of the system was analyzed using gas chromatogram. The effect of such influencing factors were investigated as the constitute of ionic liquid,the dosage of catalyst, the mole ratio of benzene to 1-bromobutane, temperature,reaction time,the regeneration approach of the used ionic liquid catalyst. The results suggested that it helps to increase the conversion of propylene and the selectivity of 1-butylbenzene by increasing the mole fraction of AlCl3 in the ionic liquid, the amount of catalyst, the mole ratio of benzene to 1-butylbenzene, reaction time and by reducing reaction temperature. At optimal conditions of 66.7% of mole fraction of AlCl₃ in the ionic liquid, l0wt% of catalyst with respect to benzene, 10:1 of mole ratio of benzene to 1-bromobutane and 313 .15K, both conversion of 1-bromobutane and selectivity of butylbenzene can reach 96.6% in 20 minutes. The activity of the catalyst can be basically remained after eight times reused. For the used ionic liquid, its catalytic activity can be partially recovered via adding some extra AlCl₃ notwithstanding less satisfactory. The catalyst performance of ionic liquids on the esterification of ethanol with ethanonic acid was studied.

Abstract: Two new imidazole ionic liquid salts, 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-allyl-3-methy-imidazolium hydrogen sulfate ([EMIM]HSO₄), were synthesized with direct synthesis and two-step synthesis method, using a viscosity meter, PH meter, conductivity meter, densitometer, infrared spectrometer determined its chemical structure and properties. The results show that two ionic liquids in the range is slightly different, the trend is roughly same. As the temperature increases, the viscosity decreases, PH gradually increased, the density decreases slightly, can be regarded as constant, the conductivity gradually increased. Ionic liquids of the two IR spectra analysis show its structure and synthetic route consistent with the structure of matter.

Abstract: This paper describes the types and characteristics of ionic liquids, synthesis and application of ionic liquids in chemical and environmental applications, and naphthenic acid corrosion problems and research on ionic liquids are organically combined together, using properties, good stability and easy separating from crude oil, of ionic liquid generated by imidazole and naphthenic acid, exploring the ionic liquid deacidification process conditions and acid removal effect. The naphthenic acid and imidazole react in acetone solvent, synthesis a series of ionic liquids in different reaction ratio, reaction temperature, reaction time and stirring speed conditions,makesome physical measurements and calculation of the yield of these ionic liquids and. The results show that, in naphthenic acid and imidazole molar ratio of 1:1, reaction temperature 70°C, reaction time 7h, stirring speed 400R / min, stand half hour after reaction, the yield of naphthenic acid type ionic liquid is maximum, namely, the deacidification effect is best. At the same time measured in the ionic liquid density is 1.179g / mL, and pH is 5.8. Obtained optimum synthesis condition of naphthenic acid type ionic liquid, greatly improving the deacidification rate of high acid crude oil, more importantly, the method does not cause any pollution to the environment.

Abstract: This paper uses a metal hung weight loss method, acidic ionic liquid desulfurizer as the media, by adding different inhibitor (Polyethylene Glycol, SDBS, Functional ionic liquids), contrast to carbon steel corrosion in the absence of inhibitor, understanding of their respective inhibition effect. In the experiment, the carbon steel material, different kinds and concentrations of the inhibitor in the medium, the corrosion rate measured by weight loss method. Contrast to the blank experiment the inhibition rate can be calculated. The experiment proved that the inhibition effect of several inhibitor at room temperature, and calculate their respective optimal concentration. The experiment also investigated the compound of several corrosion inhibition synergies, confirm the good corrosion inhibiting effect of polyethylene Glycol and SDBS complex, the inhibition rate reached 69.2%.Excellent inhibition effect of the ionic liquid corrosion inhibitor and the inhibition rate reached 88.3%, showing a clear advantage.

Abstract: An tungstate ionic liquid (IL) 2-(1-propyl-3-methyl-imidazolium) ([C₃mim]₂[WO₄]), was prepared. The density and surface tension of the IL were determined in the temperature range of (293.15 to 343.15) K. Using Kabo’s method and Rebelo’s method, the molar enthalpy of vaporization of the IL, Δ_l^gH_m⁰ (298 K), at 298 K and, Δ_l^gH_m⁰ (T_b), at hypothetical normal boiling point was estimated, respectively.

Abstract: 3-O-caffeoyl-quinide, a dehydration compound of 3-O-caffeoylquinic acid, was obtained using p-toluenesulfonic acid as a catalyst via esterification in traditional organic solvent and transesterification in ionic liquid, respectively. The quinide, identified by ¹H-NMR spectrum, was prepared as an intermediate product for the synthesis of 3-O-caffeoyl-quinide, and the products was identified by LC-MS. Results indicated that the developed purification method of quinide was much simple than before with a higher yield, and [Bmim][Tf₂N] was selected as the suitable reaction medium.

Abstract: The chiral monomer,N-acryloyl-L alanine, was synthesized by condensation reaction between acryloyl chloride and L-alanine using ethyl acetate and water as two-phase solvents, tetrabutyl ammonium bromide as phase transfer catalyst and ethyl acetate as the extraction solvent.And then, poly (N-acryloyl-L-alanine) was successfully prepared by free radical polymerization of above synthesized monomer using 2,2'-Azobis (2-methylpropionitrile) AIBN as initiator in ionic liquids. Their structures were characterized by ¹HNMR and IR. Optically activities were tested with Rotary Spectrometer. Melting point and glass transition temperature were tested with DSC. The molecular weight of the polymer was characterized with GPC.

Abstract: The paper is closely related to the challenge of the most important greenhouse gas - carbon dioxide. Both, the effective capture and secure storage of CO₂, is an urgent environmental problem. Approximately ¾ of all anthropogenic emissions of CO₂ are related to the use of fossil fuels. Great attention is given to the absorption processes for the capture of the gas. Carbon Capture and Storage (CCS) is a promising solution for achieving a significant reduction in CO₂- emissions. Capture of combustion gases using standard volatile organic solvents are the source of numerous problems like environmental pollution, instability and corrosivity of such solvents. An effective solution seems to be the use of ionic liquids. Ionic liquids are a relatively new class of compounds, which are chemically and thermally stable and are able to dissolve a wide range of substances. The negligible volatility of ionic liquids is their most important property. Research and development of the CO₂- capture technology has not yet reached the stage of commercial exploitation under economically acceptable conditions. The aim of this article is to show the possibilities of use of ionic liquids in the absorption separation processes for CO₂ -capture.