Acetone System Research Articles

Gas stripping–pervaporation hybrid process for energy-saving product recovery from acetone–butanol–ethanol (ABE) fermentation broth

In this study, an integrated gas stripping–pervaporation (GS–PV) process was established to enhance the butanol concentration and to reduce the cost of the product separation processes. Batch pervaporation was integrated with in situ gas stripping system of fed-batch acetone–butanol–ethanol (ABE) fermentation. A total 706.68g/L ABE (54.2g/L of ethanol, 169.93g/L of acetone, and 482.55g/L of butanol) was collected after 11h of pervaporation separation. The recovery rates of butanol, acetone and ethanol were 98.8%, 99.5% and 82.8% (w/v), respectively. Attractively, the liquor on the permeate side of pervaporation membrane exceeded its azeotropic point which have not been achieved in previous processes basing on individual gas stripping or pervaporation. Furthermore, aiming to construct consolidate commercial guide of biobutanol producing process, GS–PV–distillation process was established and compared with traditional GS–distillation scheme. As a result, 24.83MJ/kg of butanol was consumed in the novel GS–PV–distillation process. In this scheme, the beer column was deleted from the rectifying column series. Moreover, based on the consolidate GS–PV–distillation integration process, heat recovery network was simulated and designed by Pinch Analysis, and 1.72MJ/kg of heat could be further saved after heat exchange in the distillation system. And the overall energy demand for butanol production was further decreased to 23.07MJ/kg, which was only 29.2% of the conventional distillation procedure.

ChemInform Abstract: Enantioselective, Desymmetrizing, Bromolactonization Reactions of Symmetric Olefinic Dicarboxylic Acids.

The results of studies leading to the development of enantioselective desymmetrizing, bromolactonization reactions of symmetric olefinic dicarboxylic acids, which are promoted by a C3 -symmetric trisimidazoline catalyst, are described. These processes generated carboxylic-acid-containing bromolactones in moderately high enantiomeric excesses. The results of optimization studies showed that reactions in a mixed solvent system of toluene and acetone proceeded with the highest levels of enantioselectivity. NMR studies probing the interactions between the catalyst and dicarboxylic acid substrates, as well as the effect of acetone on the stereochemistry of the process, are also described.

Characterization of polyphenol oxidase from Cape gooseberry (Physalis peruviana L.) fruit

Cape gooseberry (Physalis peruviana) is an exotic fruit highly valued, however it is a very rich source of polyphenol oxidase (PPO). In this study, Cape gooseberry PPO was isolated and biochemically characterized. The enzyme was extracted and purified using acetone and aqueous two-phase systems. The data indicated that PPO had the highest substrate affinity for chlorogenic acid, 4-methylcatechol and catechol. Chlorogenic acid was the most suitable substrate (Km=0.56±0.07mM and Vmax=53.15±2.03UPPOmL−1min−1). The optimal pH values were 5.5 for catechol and 4-methylcatechol and 5.0 for chlorogenic acid. Optimal temperatures were 40°C for catechol, 25°C for 4-methylcatechol and 20°C for chlorogenic acid. In inhibition tests, the most potent inhibitor was found to be ascorbic acid followed by l-cysteine and quercetin. This study shows possible treatments that can be implemented during the processing of Cape gooseberry fruits to prevent browning.

Synthesis of gelatin nano/submicron particles by binary nonsolvent aided coacervation (BNAC) method

A newly developed modified coacervation method is utilized to synthesize gelatin nano/submicron particles (GN/SPs) as a drug carrier. Binary nonsolvent aided coacervation (BNAC) method is a modified single step coacervation method, which has yielded approximately a threefold lower particle size and higher average yield in terms of weight percentage of around 94% in comparison to the conventional phase separation methods. In this study 0.5% (w/v) gelatin aqueous solution with a binary nonsolvent system of acetone and ethanol was used. Nanoparticle synthesis was optimized with respect to nonsolvent system type and pH. pH7 has resulted a minimum particle size of 55.67 (±43.74) nm in anhydrous medium along with a swollen particle size of 776nm (±38.57) in aqueous medium with a zeta potential of (−16.3±3.51) mV in aqueous medium. Swelling ratio of 13.95 confirms the crosslinked hydrogel nature of the particles. Furthermore, drug loading efficiency of the gelatin particles prepared at 7pH was observed with nitrofurazone as the model drug. Results of drug release study indicate the potential use of GN/SPs as drug loading matrix for wound management such as burn wound management.

Weak hydrogen bonding interaction S–H···O[dbnd]C studied by FT-IR spectroscopy and DFT calculations

Interactions between the thiolate group of tri-tert-butoxysilanethiol (TBST) and carbonyl group of acetone are described. With the use of FT-IR spectroscopy the formation of weak hydrogen bond has been detected in the TBST – acetone system. The interaction results in the change of the frequency of donor S–H stretching vibration (υS–H). To confirm the interpretation of spectral results hydrogen bonded system has been studied with the use of DFT calculations. General energies of solutions components, stabilization energies of hydrogen bonds in solution, geometrical parameters of TBST and acetone, energies of molecular orbitals HOMO and LUMO of donor and acceptor molecules engaged in the formation of hydrogen bonds have been analyzed.

Measurement and correlation of ternary solid–liquid equilibrium of 2-methyl-1,4-naphthoquinone + phthalic anhydride + acetone system

The solid–liquid equilibrium or the ternary system of 2-methyl-1,4-naphthoquinone + phthalic anhydride + acetone were determined at three temperatures of (283.15, 293.15 and 303.15) K, respectively. Three isothermal phase diagrams of the system were constructed on the basis of the measured solubility. Two pure solid phases were formed at (283.15, 293.15 and 303.15) K, including pure PA and pure 2-MNQ, which were confirmed and determined by the method of Schreine makers' wet residue. The densities of equilibrium liquid phase were determined experimentally at the corresponding temperatures versus mass fraction of component. The phase diagram at 283.15 K is similar to those at (293.15 and 303.15) K and the crystalline fields of 2-MNQ and PA decrease with an increase in temperature. The ternary diagram can provide the fundamental basis for separation of 2-MNQ and PA.

Effect of VLE uncertainties on the design of separation sequences by distillation – Study of the benzene–chloroform–acetone system

It is widely recognized by experts that the computer-based design of chemical processes depends strongly on the correlated thermodynamic and transport properties, and that the effect of the property uncertainties should be accounted for in the design. The most significant source of property uncertainties on process design comes from the correlations of mixture phase equilibrium. Many approaches to uncertainty analysis have been proposed, but uncertainty analysis is not a routine element of today's industrial practice, mainly because education and awareness are lacking, and the proposed methods are difficult to apply.In order to help rectify the situation, the author developed an intuitive and easy-to-apply phase-equilibrium (specifically, activity coefficient) perturbation method based upon treating the mixture, for the purpose of uncertainty perturbation, as a set of pseudobinaries described by the Margules equation. The approach was applied to two case studies – (1) a propylene-propane superfractionator for which small changes in correlated relative volatilities have a large effect on the design of the distillation column; and (2) a dehexanizer column that separates a mixture containing many close-boiling components – and demonstrated that the proposed methodology provides quantitative insight into the effect of property uncertainties, and helps to estimate the safety factors that should be imposed upon the design.In this paper the Margules perturbation method is applied to the “textbook” separation of an acetone–chloroform–benzene ternary mixture; this case study was proposed in 1996 by Westerberg and Wahnshafft, and was previously studied by Parodi and Campanella. The approach of Parodi and Campanella used different levels of data fitting to identify uncertainties, while the present methodology is to obtain the best fit of the data, and then apply uncertainties based upon estimated combined model uncertainties, which includes experimental uncertainties and any model inadequacies. The purpose of this paper is to further study whether the Margules approach to mixture uncertainty offers insight, and is a useful technique to perform uncertainty analysis.

Utilization of milli-scale coiled flow inverter in combination with phase separator for continuous flow liquid–liquid extraction processes

Process-design intensification situated under the umbrella of Novel Process Windows heads for process integration and here most development is needed for flow separators. The vision is to achieve multi-step synthesis in flow on pilot scale. This calls for scale-up of separation units. This study is rare and thus conducted here. The coiled flow inverter (CFI) was considered as the right tool to work at higher flow rates. A milli-scale CFI with tube internal diameter of 3.2mm and tube length of 210cm was used where partitioning takes place in slug flow. Phase separation was achieved with PTFE membrane flow separator or slit shaped flow separator composed of glass and Teflon rectangular capillaries. The microextraction unit was tested for model systems of toluene–water–acetone and n-butyl acetate–water–acetone. High extraction efficiency close to thermodynamic equilibrium was achieved for both systems. The CFI setup was also compared with straight tube and CFI showed about 20% higher extraction performance with the increase in flow rate. In straight tube, parallel flow developed at higher flow rates whereas the CFI kept operating in the slug flow regime. Membrane separator could be used up to 20ml/min, however pure organic phase was attained throughout. With slit shaped separator, for the butyl acetate–water–acetone system, 20% breakthrough occurred at a flow rate of 32ml/min. For the model system of toluene–water–acetone flow rate up to 120ml/min (7.2l/h) was achieved at same breakthrough level indicating the influence of interfacial tension on the operating window of separator. It is important to point out that slug flow regime that is limited to microfluidic systems was maintained even at such pilot scale (58m3/y).

OPTIMIZATION OF PRODUCTION OF 5-HYDROXYMETHYLFURFURAL FROM GLUCOSE IN A WATER: ACETONE BIPHASIC SYSTEM

5-Hydroxymethylfurfural (HMF) is considered to be an important building block for biorefineries and has a high potential for the production of chemicals and fuels. Production of HMF from glucose was studied using phosphoric acid as catalyst, in a water:acetone system with volume ratio of 1:2 and NaCl. An experimental design was applied to examine the influence of temperature, time and concentration of catalyst on the HMF yield. HMF yields of more than 50 % were obtained when using 200 oC, 8.4 min and 0.8% of catalyst. The temperature is the main factor influencing the HMF yield.

Simplified Conceptual Design Methodology for Double-Feed Extractive Distillation Processes

Shortcut methods have an important role in the conceptual design of distillation processes because they rapidly provide constraints for important design parameters such as minimum reflux ratio, number of stages, process feasibility, possible splits, and, specifically for extractive distillation, minimum solvent feed ratio and maximum reflux ratio. In this work, a simplified method using reversible distillation models has been applied to the conceptual design of double feed extractive distillation columns. This work uses continuation methods for calculating the curves that determine the feasibility region and all of the resulting design parameters. Combining continuation methods with the column equations yields a simple method for calculating the pinch curves that border the feasibility region. As previously found by other authors, we observed that these extractive distillation pinch curves, in addition to determining the feasibility region, are also useful for calculating an approximate minimum entrainer feed ratio independent of other parameters, as well as accurately pinpointing the minimum and maximum reflux ratios. Applications to example extractive distillation systems allow us to conclude that the method is reliable, fast, and much easier to implement than other methods presented previously in the literature. The systems acetone–methanol–water and ethanol–water–ethylene glycol were employed as case studies, allowing a graphical assessment of the method; however, it can be used in the analysis of systems with more than three components.

Synthesis of push-pull chromophores including an N-[4-(4-methoxyphenoxy)butyl]carbazole fragment

Organic substances with nonlinear optical properties of the second order are the promising materials for molecular electronics and photonics, that is, finally, for telecommunication and electro optical devices [1–6]. These materials possess some advantages if compared with their inorganic analogs: they have high values of nonresonance susceptibility, high nonlinear optic response, high transmissibility, low dielectric permittivity, besides they are sufficiently easy to process and economic [1, 7]. However certain drawbacks in their practical application also exist, e.g., the strong intermolecular electrostatic interaction, poor solubility in common organic solvents, thermal and photochemical instability. By altering the chemical structure of material, namely, by selecting the optimum electron-donor and electron-acceptor substituents it is possible to obtain the maximum nonlinearity on the molecular level and also affect the chemical, photochemical, and thermal stability. The introduction of electron-donor orthoor para-alkoxyphenyl groups into the monomers is known to change the optical properties of chromophores. It results in increasing of the electro optic coefficient value (r33) and molecular hyperpolarizability β [8–10]. When such a group is situated in the peripheral part of a long aliphatic chain and is incorporated into the chromophore structure both intermolecular and intramolecular interaction may occur between the donor and acceptor parts of the chromophore. Besides, the introduction of long-chain substituents in the structure of compounds affects the character of their packing in the solid state and their thermal stability [11]. In this work we continued to study carbazolecontaining compounds including in their structure ω(4-methoxyphenyl)alkyl substituents at the nitrogen atom of this heterocycle [12, 13] and have synthesized two new chromophores 8 and 9 including N-[4-(4methoxyphenoxy)butyl]carbazole moiety as a donor fragment. The optical and electrochemical properties of all prepared during thes work compounds were examined. First from the corresponding α,ωdibromoalkane and p-methoxyphenol 1 in acetone the starting bromides 2 and 3 were prepared [12]. The subsequent alkylation of carbazole with the synthesized bromides under the conditions of the phasetransfer catalysis in the system acetone–16 M water solution of NaОН–benzyltriethylammonium chloride led to the formation of the corresponding N-substituted carbazoles 4 and 5 [13]. The acetylation of the latter at room temperature in dichloroethane in the presence of SnCl4 afforded 3-acetylcarbazoles 6 and 7.

Isobaric Vapor–Liquid Equilibrium for Acetone + Methanol + Phosphate Ionic Liquids

Isobaric vapor–liquid equilibrium (VLE) at atmospheric pressure (101.3 kPa) for the binary systems of acetone + methanol, acetone + phosphate ionic liquids (ILs), and methanol + phosphate ILs, and for the ternary system of acetone + methanol + phosphate ILs are measured using a circulation VLE still. The phosphate ILs include 1,3-dimethylimidazolium 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP]), 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]), and 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP]). The addition of these phosphate ILs to the azeotropic acetone + methanol system results in a salting-out effect on acetone and makes the azeotropic point disappear. The relative volatility α12 of acetone over methanol increases with increasing molar fraction of ILs. The equilibrium data were well fitted by the electrolyte nonrandom two-liquid model (e-NRTL). Compared with some reported ILs previously such as pyridinium hexafluorophosphate, imidazolium trifluoromethane sulfonate and ...

Mass transfer performance in an asymmetric rotating disc contactor

The volumetric overall mass transfer coefficients have been measured in a pilot scale asymmetric rotating disc contactor of 113mm diameter for the toluene–water–acetone system. The experiments are carried out for both mass transfer directions. The effects of operational variables such as rotor speed and continuous and dispersed phase velocities on mass transfer performance are investigated. The results show that the column performance is strongly dependent on agitation speed but only slightly dependent on phase velocities. An empirical equation for prediction of overall continuous phase Sherwood number is proposed based on Reynolds number and dispersed phase holdup for each mass transfer direction. Good agreement between prediction and experiments is found for all operating conditions.

Phase Equilibrium Study of Binary and Ternary Mixtures of Ionic Liquids + Acetone + Methanol

The vapor–liquid equilibrium (VLE) data for binary systems of acetone + 1-ethyl-3-methylimidazolebromine ([EMIM][Br]), methanol + 1-ethyl-3-methylimidazolebromine ([EMIM][Br]), acetone + 1-butyl-3-methylimidazolebromine ([BMIM][Br]), methanol + 1-butyl-3-methylimidazolebromine ([BMIM][Br]), and ternary VLE data for systems of acetone + methanol + 1-ethyl-3-methylimidazolebromine ([EMIM][Br]), acetone + methanol + 1-ethyl-3-butylimidazolebromine ([BMIM][Br]) were detected at 101.3 kPa in an all-glass dynamic recirculating still. With the addition of bromine–based ionic liquids, the relative volatility of acetone to methanol was enhanced and the azeotropy was eventually eliminated. As for the separating effect, [EMIM][Br] is better than [BMIM][Br]. The measured binary and ternary VLE data were correlated with the nonrandom two-liquid activity coefficient model, and the results demonstrated that the experimental data and the correlated data were in good agreement.

Extraction and Determination of Copper(II) in Seafood Using an Acetone-(NH4)2SO4 Aqueous Two-Phase System

An aqueous two-phase system of acetone and (NH4)2SO4 mixture has been developed for the extractive separation of copper (Cu). The complex formed by Cu(II) and Nuclear Fast Red was found to be extracted into the acetone-rich upper phase, and the absorbance of the complex was determined at 465 nm. Beer’s law was obeyed over the concentration range of ~0.6–3.2 mg/l for Cu(II) with a good linearity. The proposed method has been applied to the separation and determination of Cu(II) in seafood samples with a coefficient of variation less than 2.8%. The recovery obtained was ~96.3–101.7%.

Separation of acetone and methanol azeotropic system using ionic liquid as entrainer

In this work, three ionic liquids (ILs), namely monoethanolamine chloride ([HMEA][Cl]), monoethanolamine acetate ([HMEA][OAC]) and 1-ethyl-3-methylimidazole acetate ([EMIM][OAC]), were studied as entrainers to separate acetone+methanol azeotropic mixture by extractive distillation. Isobaric vapor liquid equilibrium of ternary systems containing ILs was investigated to examine the effect between the structure of ionic liquids and separation performance on acetone+methanol. The measurements were carried out at 101.3kPa and the headspace chromatograph was employed to analyze the VLE data. From the experimental results, it is found that the addition of ILs can remarkably increase the separation factor (relative volatility) of acetone to methanol. The azeotropic point is pulled up and the azeotropy is even eliminated eventually. Comparison of the separation effect of ILs is that [EMIM][OAC] outperforms [HMEA][Cl] and [HMEA][OAC]. The experimental VLE data are well correlated using nonrandom two-liquid model (NRTL).

Modeling of liquid–liquid equilibrium in the quinary system of water, acetone, n-butanol, ethanol, and ionic liquid

Acetone–butanol–ethanol (A–B–E) fermentation is the most common way to produce biobutanol. This valuable product may be removed from the fermentation broth by extraction using a convenient hydrophobic solvent such as ionic liquid, which is suggested in this study. A proper design of the extraction unit requires an experimentally validated model of thermodynamic liquid–liquid equilibrium in the two-phase mixture containing all components of the aqueous fermentation broth and extracting solvent. Here, for modeling of LLE, the NRTL model was employed. The equation parameters were determined from data measured for three hydrophobic ionic liquids: 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [Bmim][Tf2N], 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF6], and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide [Bmp][Tf2N].

Enantioselective, Desymmetrizing, Bromolactonization Reactions of Symmetric Olefinic Dicarboxylic Acids

The results of studies leading to the development of enantioselective desymmetrizing, bromolactonization reactions of symmetric olefinic dicarboxylic acids, which are promoted by a C3 -symmetric trisimidazoline catalyst, are described. These processes generated carboxylic-acid-containing bromolactones in moderately high enantiomeric excesses. The results of optimization studies showed that reactions in a mixed solvent system of toluene and acetone proceeded with the highest levels of enantioselectivity. NMR studies probing the interactions between the catalyst and dicarboxylic acid substrates, as well as the effect of acetone on the stereochemistry of the process, are also described.

A Raman spectroscopic method for the determination of high pressure vapour liquid equilibria

A straight forward and non-invasive strategy to quantify vapour–liquid equilibria (VLE) of the ternary system acetone, water and carbon dioxide (CO2) is reported. The strategy is based on extracting the composition of a ternary mixture from its Raman spectrum. An isolated Raman signal of acetone, which is not interfered with Raman signals of water or CO2, is used as a reference signal. The capability of the strategy introduced is demonstrated by the agreement with VLE data obtained by the other authors that used conventional methods at elevated pressures up to 10MPa and temperatures up to 353K. The advantages of the introduced method are its non-invasive sampling method, its insensitivity to misalignment or distortions of the excitation and signal paths as well as power fluctuations of the excitation beam, its fast accessibility to the mixture composition and the general transferability to all systems whose Raman spectrum shows a spectrally isolated strong Raman signal which can be assigned to one specific compound.

Vapour–liquid equilibria in the polymer + solvent system containing lower concentrations of solute at normal or reduced pressures

Vapour–liquid equilibria have been determined in the polymer+solvent systems, namely the poly(acrylic acid)+water, and poly(methyl methacrylate)+acetone system. Each system has been measured at three isothermal conditions. An all-glass microebulliometer with circulation of the liquid phase was used for dynamic measurements of total pressure over liquid mixtures. The determined data were correlated with the UNIQUAC equation.