Using 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate as an Entrainer for the Extractive Distillation of Ethanol + Water Mixtures
Isobaric vapor−liquid equilibria (VLE) for the ethanol + water + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. The ethanol + water binary system was also obtained. Furthermore, data were simulated with the Mock’s electrolyte nonrandom two-liquid (NRTL) model, using the solvent−solvent interaction parameters obtained from VLE data of the ethanol + water system and taking the solvent−ionic liquid (IL) interaction parameters for the other binary systems from previous works. The agreement between experimental and calculated data is very good, showing the predictive capacity of the model. The addition of [emim][triflate] produces the disappearance of …
Isobaric Vapor−Liquid and Liquid−Liquid Equilibria for Chloroform + Methanol + 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate at 100 kPa
Isobaric vapor−liquid equilibria for the binary system chloroform + methanol as well as the vapor−liquid equilibria for the chloroform + methanol + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. The ternary ionic liquid (IL) system presents an immiscibility zone at high chloroform composition, which increases with the temperature. Liquid−liquid equilibria for this system have also been determined. The measured ternary vapor−liquid equilibrium data were correlated using the Mock’s electrolyte nonrandom two-liquid (NRTL) model which reproduces reasonably well the experimental values and predicts the total disappearance of the azeotrope when the mole…
Volumetric and Acoustic Properties of Aqueous Solutions of Trifluoromethanesulfonate-Based Ionic Liquids at Several Temperatures
In this work, densities and sound velocities of three ionic liquids, 3-butyl-1-ethylimidazolium trifluoromethanesulfonate, 3-butyl-1-methylimidazolium trifluoromethanesulfonate, and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, and their binary mixtures with water have been obtained at p = (101 ± 2) kPa and T = (278.15 to 338.15) K, covering the whole range of concentration. The isentropic compressibility and molar isentropic compression of pure components and mixtures have been calculated using the Newton–Laplace equation. Moreover, the excess molar volume and excess molar isentropic compression of mixtures have been then determined, and they have been fitted to temperature and …
Vapor–liquid equilibrium of binary mixtures of trichloroethylene with 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol at 100 kPa
Abstract Isobaric vapor–liquid equilibria (VLE) have been obtained for the systems trichloroethylene+1-pentanol, trichloroethylene+2-methyl-1-butanol and trichloroethylene+3-methyl-1-butanol at 100 kPa using a dynamic still. The experimental error in temperature is ±0.1 K, in pressure ±0.1 kPa, and in the liquid and vapor mole fraction ±0.001. The three systems satisfy the point-to-point thermodynamic consistency test. All the systems show positive deviations from ideality. The data have been correlated with the Margules, van Laar, Wilson, NRTL and UNIQUAC equations.
Can Macroscopic Parameters, Such as Conversion and Selectivity, Distinguish between Different Cracking Mechanisms on Acid Catalysts?
n-heptane cracking has been carried out for very short time periods on an established reaction mechanism which includes the following group of stream reactions on different zeolites: Initiation reactions (protolytic cracking), charge isomerization, chain isomerization, hydride transfer, β-scission–alkylation, desorption–adsorption, and hydrogen transfer–cyclization. It has been observed that a given experimental distribution of products can be explained by more than just one reaction scheme. This does not allow one to clearly distinguish the fraction of reactant which disappears via monomolecular initiation reactions with respect to bimolecular hydride transfer reactions.
Low temperature conversion of levulinic acid into γ-valerolactone using Zn to generate hydrogen from water and nickel catalysts supported on sepiolite
1 scheme, 2 tables, 7 figures.-- Supplementary material available.
Isobaric vapor-liquid equilibrium of binary mixtures of 1-propanol + chlorobenzene and 2-propanol + chlorobenzene
Abstract Isobaric vapor-liquid equilibria were obtained for the system 1-propanol + chlorobenzene at 20 and 100 kPa and for the system 2-propanol + chlorobenzene at 100 kPa using a dynamic still. The experimental error in temperature was ±0.1 K, in pressure ±0.01 kPa and ±0.1 kPa for the experiments carried out at 20 and 100 kPa, respectively, and in the liquid and vapor mole fraction 0.001. The two systems satisfy the point-to-point thermodynamic consistency test. Both systems show a positive deviation from ideality. The data were well correlated with the Margules, Van Laar, Wilson, NRTL and UNIQUAC equations.
Vapor–liquid equilibrium of binary mixtures of chlorobenzene with 3-methyl-1-butanol, 3-methyl-2-butanol and 2-methyl-2-butanol, at 100 kPa
Abstract Isobaric vapor–liquid equilibria have been obtained for the systems 3-methyl-1-butanol+chlorobenzene, 3-methyl-2-butanol+chlorobenzene and 2-methyl-2-butanol+chlorobenzene at 100 kPa, using a dynamic still. The experimental error in temperature is ±0.1 K, in pressure ±0.1 kPa, and in the liquid and vapor mole fraction ±0.001. The three systems satisfy the point-to-point thermodynamic consistency test. All the systems show positive deviations from ideality. The data have been correlated with the Margules, Van Laar, Wilson, NRTL and UNIQUAC equations.
Steam catalytic cracking of naphtha over ZSM-5 zeolite for production of propene and ethene: Micro and macroscopic implications of the presence of steam
One option to produce more ethene and propene can be to crack naphtha type fractions in dedicated smaller FCC units. We present here the results obtained for high temperature steam catalytic cracking (SCC) of a representative naphtha product (n-heptane) with ZSM-5. It has been found that under those conditions the presence of steam produces an irreversible dealumination of the zeolite as well as a reversible deactivation due to the interaction of water with active sites with a negative effect on protolytic cracking. A kinetic decay model that takes into account the two phenomena has been developed. The apparent activation energy is lower in the presence of steam. It appears that whilst the …
Influence of Some Ionic Liquids Containing the Trifluoromethanesulfonate Anion on the Vapor–Liquid Equilibria of the Acetone + Methanol System
Isobaric vapor–liquid equilibria (VLE) for the binary systems acetone + 1-butyl-3-ethylimidazolium trifluoromethanesulfonate ([beim][triflate]), methanol + [beim][triflate], acetone + 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][triflate]), and methanol + [bmpyr][triflate] as well as the VLE for the acetone + methanol + [beim][triflate] and acetone + methanol + [bmpyr][triflate] ternary systems have been obtained at 100 kPa using a recirculating still. The addition of both ionic liquids to the solvent mixtures produced an important salting-out effect, and the azeotrope tended to disappear for small amounts of ionic liquid. The experimental binary data sets were independe…
Isobaric Vapor–Liquid Equilibria for the Extractive Distillation of Ethanol + Water Mixtures Using 1-Ethyl-3-methylimidazolium Dicyanamide
Isobaric vapor–liquid equilibria (VLE) for the binary systems ethanol + 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]) and water + [emim][DCA] as well as the VLE for the ternary system ethanol + water + [emim][DCA] have been obtained at 100 kPa using a recirculating still. The effect of [emim][DCA] on the ethanol + water system has been compared with that produced by another ionic liquid reported in the literature on the basis of the variation of solvent activity coefficients in ionic liquid (IL) + molecular solvent binary systems. From the results, [emim][DCA] appears as one of the best entrainers for the extractive distillation of the ethanol + water mixtures, causing the azeotrope…
Gamma-valerolactone from levulinic acid and its esters: Substrate and reaction media determine the optimal catalyst
13 figures, 7 tables.-- © 2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0
Isobaric Vapor−Liquid Equilibria for 1-Propanol + Water + 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate at 100 kPa
Isobaric vapor−liquid equilibria for the binary systems 1-propanol + water, 1-propanol + 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][triflate]), and water + [emim][triflate] as well as the vapor−liquid equilibria for the 1-propanol + water + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. Electrolyte NRTL fitting parameters for the 1-propanol + water and water + [emim][triflate] systems were calculated. The measured ternary data were correlated using Mock’s electrolyte NRTL model which reproduces reasonably well the experimental values. The results show that the addition of [emim][triflate] to 1-propanol + water produced an import…
Volumetric properties, viscosities and refractive indices of binary liquid mixtures of tetrafluoroborate-based ionic liquids with methanol at several temperatures
Abstract Densities, speeds of sound, viscosities and refractive indices of two binary systems 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] + methanol and 1-ethyl-3-methylimidazolium tetrafluoroborate [emim][BF4] + methanol, as well as of all pure components, have been measured covering the whole range of compositions at T = (278.15 to 318.15) K and p = 101 kPa. From this data, excess molar volumes, excess isentropic compressibilities, viscosity deviations and refractive index deviations were calculated and fitted to extended versions of the Redlich–Kister equation. Estimated coefficients of these equations taking into account the dependence on composition and temperature simult…
Isobaric vapor-liquid equilibria for the 1-propanol + water + 1-ethyl-3-methylimidazolium dicyanamide system at 100 kPa
Abstract Isobaric vapor–liquid equilibria for the 1-propanol + 1-ethyl-3-methylimidazolium dicyanamide ([emim [DCA] binary system and for the 1-propanol + water + [emim] [DCA] ternary system have been obtained at 100 kPa using a recirculating still. The electrolyte nonrandom two-liquid (e-NRTL) model was used for fitting successfully the experimental data. The effect of [emim][DCA] on the 1-propanol + water system has been compared with that produced by other ionic liquids reported in the literature. From the results, [emim][DCA] appears as a potential entrainer for the extractive distillation of this solvent mixture, causing the azeotrope to disappear at 100 kPa when the ionic liquid mole …
Isobaric vapor–liquid equilibria for acetone + methanol + lithium nitrate at 100 kPa
Abstract Isobaric vapor–liquid equilibria for the ternary system acetone + methanol + lithium nitrate have been measured at 100 kPa using a recirculating still. The addition of lithium nitrate to the solvent mixture produced an important salting-out effect and the azeotrope tended to disappear for small contents of salt. The experimental data sets were fitted with the electrolyte NRTL model and the parameters of the Mock's model were estimated. These parameters were used to predict the ternary vapor–liquid equilibrium which agreed well with the experimental one.
Isobaric vapor-liquid equilibria for the extractive distillation of 2-propanol + water mixtures using 1-ethyl-3-methylimidazolium dicyanamide ionic liquid
Abstract Isobaric vapor–liquid equilibria for the binary systems 2-propanol + water, 2-propanol + 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]), and water + [emim][DCA] as well as the vapor–liquid equilibria for the 2-propanol + water + [emim][DCA] ternary system have been obtained at 100 kPa using a recirculating still. The electrolyte nonrandom two-liquid (e-NRTL) model was used for fitting successfully the experimental data. The effect of [emim][DCA] on the 2-propanol + water system has been compared with that produced by other ionic liquids reported in the literature. From the results, [emim][DCA] appears as a good entrainer for the extractive distillation of this solvent mixtur…
Isobaric Vapor−Liquid Equilibria for Ethyl Acetate + Ethanol + 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate at 100 kPa
Isobaric vapor−liquid equilibria for the binary systems ethyl acetate + ethanol, ethyl acetate + 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][triflate]), and ethanol + [emim][triflate] as well as the vapor−liquid equilibria for the ethyl acetate + ethanol + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. NRTL fitting parameters for the ethyl acetate + ethanol and ethanol + [emim][triflate] systems were calculated. The measured ternary data were correlated using the Mock electrolyte NRTL model, which reproduces reasonably well the experimental values. The results suggest that the addition of [emim][triflate] to the ethyl acetate + e…
1-Ethyl-3-methylimidazolium Dicyanamide as a Very Efficient Entrainer for the Extractive Distillation of the Acetone + Methanol System
Isobaric vapor–liquid equilibria (VLE) for the ternary system acetone + methanol +1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]) as well as the two solvent + IL binary systems have been obtained at 100 kPa using a recirculating still. The addition of [emim][DCA] to the solvent mixture produced a salting-out effect greater than that produced by other ionic liquids, showing that this ionic liquid is, until now, the best IL tested as an entrainer for the extractive distillation of the acetone + methanol mixtures, causing the azeotrope to disappear for an ionic liquid mole fraction as low as 0.031, at 100 kPa. This behavior can be explained on the basis of the influence of the IL concent…
Product selectivity effects during cracking of alkanes at very short and longer times on stream
Abstract Cracking of C 7 , C 10 , C 12 and C 14 n-alkanes, over USY, Beta and ZSM-5 zeolites was carried out in a reaction system which allows to obtain instantaneous conversions at very short times on stream. With this system the influence of operation variables, chain length of the paraffin fed, and catalyst structure on product selectivity was established. Positive and negative effects of catalyst decay on product selectivity were obtained, and this behaviour could be simulated by using a deactivation model in which the rate of deactivation depends on the product concentration. It was observed that olefin/paraffin, branched/normal paraffin, branched/normal olefin ratios and aromatic sele…
IM-5 zeolite for steam catalytic cracking of naphtha to produce propene and ethene. An alternative to ZSM-5 zeolite
Steam catalytic cracking of naphtha in smaller FCC units can be considered an option to produce more ethene and propene. These units will operate at high reaction temperatures and in the presence of steam. The profitability of these units could be improved with the use of new catalysts with higher activity and hydrothermal stability, without compromising the selectivity to light olefins. We have explored the possibilities of IM-5 zeolite for high temperature steam catalytic cracking (SCC) of a naphtha, as an alternative to commonly used ZSM-5 zeolite. So, we compare the catalytic activity, the effect of operating variables of the process and the yields of interest products between the two z…
Catalytic cracking of n-alkane naphtha: The impact of olefin addition and active sites differentiation
An extended dual kinetic model allows to fit the n-heptane cracking results working in a wide range of reaction conditions. The duality of the model is provided by the contribution of monomolecular and bimolecular cracking mechanisms. It takes into account the role played by the olefins formed on the global cracking or added within the feed. Furthermore by means of this model and the kinetic parameters obtained when cracking n-heptane on ZSM-5, it has been observed that, while some characterization techniques show a homogeneous zeolite surface from the point of view of the active sites, rigorous kinetic experiments point to the possibility that the reactant sees a heterogeneous surface with…
Volumetric properties of binary mixtures of ionic liquid 1-butyl-3-methylimidazolium octylsulfate with water or propanol in the temperature range of 278.15 K to 328.15 K
Abstract Densities of 1-butyl-3-methylimidazolium octylsulfate ([bmim][OcOSO3]) solutions in water and 1-propanol have been measured with an oscillating-tube densimeter at temperatures from 278.15 K to 328.15 K. From these densities, apparent molar volumes Vϕ of [bmim][OcOSO3] in both solvents have been calculated, and its dependence on the molality has been treated with the Redlich and Meyer equation. Debye–Huckel limiting slopes for 1-propanol at working temperatures have been calculated, and apparent molar volumes of [bmim][OcOSO3] at infinite dilution V ϕ ∘ in both solvents have been evaluated. The partial molar volume at infinite dilution of [bmim][OcOSO3] in water is higher than in 1-…
Theta-1 zeolite catalyst for increasing the yield of propene when cracking olefins and its potential integration with an olefin metathesis unit
[EN] There is a need for on-purpose propene production technologies beyond energy-intensive steam cracking. Hexene is a compound with limited value that can be found in several streams in the refinery and can readily crack on zeolites at lower temperatures and shorter contact times than those used for cracking alkanes. Cracking over ZSM-5 zeolite yields high selectivity to light olefins. These results are improved by Theta-1 zeolite, which can yield a remarkable propene molar selectivity of 180% (90 wt%) at 90% conversion, close to the maximum thermodynamic yield. Moreover, crystal engineering allowed its TOF to increase by more than 50%. Based on these results we also identified some prosp…
Stabilization of ZSM-5 zeolite catalysts for steam catalytic cracking of naphtha for production of propene and ethene
In order to increase ethene and propene, naphtha steam catalytic cracking has been considered. The cracking of C 5-C 12 n-alkanes with ZSM-5 has been studied in absence and in presence of steam and the influence of the operation variables was studied. Irreversible catalyst deactivation by dealumination also occurs in the reactor when the cracking is carried out in the presence of steam. To diminish steam deactivation, the influence of zeolite Si/Al framework and a postsynthesis treatment by phosphorous have been studied and optimized. Much more stable catalyst can be achieved that result in an increase in activity without penalty for production of ethene and propene.
Refractive Indices and Deviations in Refractive Indices of Trifluoromethanesulfonate-Based Ionic Liquids in Water
Refractive indices were determined for four different ionic liquid + water binary systems, from (288.15 to 338.15) K, and covering the entire composition range. The four ionic liquids used were 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 3-butyl-1-ethylimidazolium trifluoromethanesulfonate, 3-butyl-1-methylimidazolium trifluoromethanesulfonate, and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, all of them being completely miscible in water. From the experimental data, deviations in refractive indices, defined on a volume fraction basis, have been calculated and fitted to an extended version of the Redlich–Kister equation. The behavior of the deviations in refractive in…
Isobaric Vapor–Liquid Equilibria of 1-Propanol + Water + Trifluoromethanesulfonate-Based Ionic Liquid Ternary Systems at 100 kPa
Isobaric vapor–liquid equilibria (VLE) for the 1-propanol + 1-butyl-3-ethylimidazolium trifluoromethanesulfonate ([beim][triflate]), water + [beim][triflate], 1-propanol + 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][triflate]), and water + [bmpyr][triflate] binary systems, as well as the VLE for the 1-propanol + water + [beim][triflate] and 1-propanol + water + [bmpyr][triflate] ternary systems have been obtained at 100 kPa using a recirculating still. The salting-out effect on the 1-propanol produced by the [bmpyr][triflate] was stronger than that produced by the [beim][triflate], although for the IL concentrations used in this study the effect was not enough to break …
Selective Introduction of Acid Sites in Different Confined Positions in ZSM-5 and Its Catalytic Implications
Controlling the location of acid sites in zeolites can have a great effect on catalysis. In this work we face the objective of directing the location of Al into the 10R channels of ZSM-5 by taking advantage of the structural preference of B to occupy certain positions at the channel intersections, as suggested by theoretical calculations. The synthesis of B-Al-ZSM-5 zeolites with variable Si/Al and Si/B ratios, followed by B removal in a postsynthesis treatment, produces ZSM-5 samples enriched in Al occupying positions at 10R channels. The location of the acid sites is determined on the basis of the product distribution of 1-hexene cracking as a test reaction. The higher selectivity to prop…
Thermophysical properties of binary mixtures of 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ionic liquid with alcohols at several temperatures
Abstract Densities, speeds of sound, and refractive indices for the binary systems made up by 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate and methanol, ethanol, 1-propanol, or 2-propanol, as well as for the pure components, have been measured covering the whole range of compositions at atmospheric pressure and T = (278.15–338.15) K. From densities and speeds of sound, isentropic compressibilities were calculated using the Newton-Laplace equation. Liquid ideal-mixture properties have been defined and calculated, and they have been used to determine excess molar volumes, excess isentropic compressibilities, and deviations in refractive indices. Excess and deviations in properties …
Ionic Liquids as Entrainers in Extractive Distillation: Isobaric Vapor−Liquid Equilibria for Acetone + Methanol + 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate
Isobaric vapor−liquid equilibria for the binary systems acetone + methanol, acetone + 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][triflate]), and methanol + [emim][triflate] as well as the vapor−liquid equilibrium for the acetone + methanol + [emim][triflate] ternary system have been obtained at 100 kPa using a recirculating still. The addition of the ionic liquid to the solvent mixture produced an important salting-out effect, and the azeotrope tended to disappear for small contents of ionic liquid. The experimental binary data sets were independently fitted with the electrolyte NRTL model, and the parameters of Mock's model were estimated for each binary system. These pa…