2-propanol System Research Articles

Understanding complexity of hydrogen-bonded liquids through Voronoi entropy

In this paper we study the short order of liquids using Voronoi entropy (SVor), computed using Voronoi Polyhedra (VP) tessellations. Voronoi tessellations partition a plane with n seeds into polyhedrons, in which each polyhedron has exactly one seed and every location within a given polyhedron is nearest to its generating seed, rather than to any other seed. The distribution of these VP is used to determine the Voronoi entropy (SVor), which shares similarities with the Shannon measure of information (H). Such studies, however, have been largely restricted to two-dimensional analysis. In this study SVor is used to quantify the orderliness of the three-dimensional structures of hydrogen-bonded systems (water, methanol, ethanol, and 1-propanol), as well as binary mixtures (methanol-ethanol, methanol-1-propanol, and ethanol-1-propanol) through molecular dynamics simulations. SVor is calculated for the VP considering all atom types and oxygen atoms to exclusively study the hydrogen bonds. The SVor for all atoms shows that the smaller molecules have a more ordered structure than the larger ones whereas the SVor calculated considering only oxygen atoms decreases as the alkyl chain length of the molecules increases indicating the smaller molecules have more ways to form hydrogen bonds than the larger ones. SVor calculated for binary mixtures for varying concentrations shows a similar trend.

Characterization of clathrate hydrates with CO2 + 1-propanol or 2-propanol: Implications for flow assurance, refrigeration, carbon capture, and skincare applications

There has been growing interest in the use of hydrate-based technology for energy and environmental applications; however, structural characterization of some hydrate phases relevant to these applications has not been dealt with sufficiently in previous studies. This paper reports crystallographic characterization of hydrates formed in [CO2 + 1-propanol (propan-1-ol) + water] and [CO2 + 2-propanol (propan-2-ol) + water] systems with powder X-ray diffraction (PXRD) and X-ray computed tomography (CT) measurements. It was revealed that structure I CO2 hydrate and a non-crystalline phase involving 1-propanol are formed in CO2 + 1-propanol system. As for CO2 + 2-propanol system, crystalline structure of the formed hydrate differs depending on thermodynamic conditions; at 3.3 MPa, 274 K and at 2.2 MPa, 263 K, sI CO2 hydrate was formed, whereas at lower pressure and temperature, i.e., 0.5 MPa and 255 K, a new tetragonal structure outside the canonical hydrates was identified. Implications of using 1-propanol as a thermodynamic inhibitor and kinetic promoter of hydrate formation are discussed, which opens some possibilities into petroleum exploration/production applications and the development of hydrate-based refrigeration systems. The structural identification of tetragonal (sII′) CO2 + 2-propanol hydrate sheds new light on developing hydrate-based CCS process and novel skin care products.

Crossed-Beam Imaging of the Reaction of OH with Propanol Isomers.

We present a crossed-beam imaging study of the reactions of OH radicals with 1- and 2-propanol at a collision energy of 8 kcal mol-1 using 157 nm probe of the radical product. Our detection is selective for the α-H and β-H abstraction in the 1-propanol case and for the α-H abstraction only in the 2-propanol case. The results show direct dynamics. A sharply peaked backscattered angular distribution is seen for the 2-propanol system and broader backward-sideways scattering for 1-propanol consistent with the different abstraction sites. The translational energy distributions peak at ∼35% of the collision energy, far from the heavy-light-heavy kinematic propensity. As this is ∼10% of the available energy, substantial vibrational excitation in the water product is inferred. The results are discussed in relation to analogous OH + butane and O(3P) + propanol reactions.

Conceptual design and process construction of [formula omitted]-propyl propionate production by reactive distillation

The purpose of this work is to perform the conceptual design and process construction of n-propyl propionate synthesis by reactive distillation. Firstly, the reaction kinetic and thermodynamic models were summarized. The isobaric vapor-liquid equilibrium data of the binary systems 1-propanol (1) + n-propyl propionate (2) and propionic acid (1) + n-propyl propionate (2) were measured. The UNIQUAC model was used to describe the thermodynamic behavior of this system. Secondly, non-reactive residue curve maps and reactive residue curve maps analyses were used for conceptual design to obtain the preliminary configuration and operating conditions of the reactive distillation column. Finally, the sensitivity analysis was used to evaluate the preliminary process configuration and identify key operational variables.

Exploring the solvent effect on risperidone (form I) crystal morphology: A combination of molecular dynamics simulation and experimental study

The solvent effect significantly influences the morphology of a substance crystallized from the solution. It is crucial to select appropriate solvent systems to produce active pharmaceutical ingredients (API) with ideal crystal habits. In this work, the effect of different solvent systems on the crystal morphology of risperidone (form I) was investigated by combining molecular dynamics (MD) simulation with experimental studies. The crystals of risperidone (form I) were obtained from solvents via a method of slow-cooling crystallization. The modified attachment energy (MAE) model was used to predict the crystal habits of risperidone (form I) in six pure solvent systems (methanol, ethanol, 1-propanol, 2-propanol, ethyl acetate and acetone) and three binary solvent systems (ethanol + water, 2-propanol + water and acetone + water). It turns out that the MAE model has good applicability in predicting the crystal habits of risperidone (form I) in the solvents. In addition, the structure of the dominant crystal faces was analyzed to explain the solvent effect on the crystal morphology. It is found that the vast u-shape structures on the (11–1) and (011) faces can prevent the adsorption of the solute molecules, resulting in the large morphological importance of these two crystal faces. Besides, the analysis of the radial distribution function (RDF) and mean square displacement (MSD) were conducted to help understand the interactions between solvents and crystal faces. The results show that the interactions between crystal faces and solvents are composed of three types of forces, and the rapid diffusion of the solvent molecules on the (11–1) and (011) face can lead to strong interactions.

P-x,y Equilibrium Data of the Binary Systems of 2-Propanol, 1-Butanol and 2-Butanol with Carbon Dioxide at 313.15 K and 333.15 K

The ability to predict the behaviour of high-pressure mixtures of carbon dioxide and alcohol is important for industrial purposes. The equilibrium composition of three binary carbon dioxide-alcohol systems was measured at temperatures of 313.15 K and 333.15 K and at pressures of up to 100 bar for carbon dioxide-2-propanol, up to 160 bar for carbon dioxide-1-butanol and up to 150 bar for carbon dioxide-2-butanol. Different equilibrium compositions of carbon dioxide in alcohols were observed despite their similar molecular weight (M2-propanol = 60.100 g mol-1, M1-butanol = 74.121 g mol-1 and M2-butanol = 74.122 g mol-1) and place in the functional hydroxyl group (first or second carbon molecule). It is assumed that the differences in the phase equilibria are due to different vapor pressures, polarities and solute-solute interactions.

Sequential and concerted C-C and C-O bond dissociation in the Coulomb explosion of 2-propanol.

We study the competing mechanisms involved in the Coulomb explosion of 2-propanol CH3 2CHOH2+ dication, formed by an ultrafast extreme ultraviolet pulse. Over 20 product channels are identified and characterized using 3D coincidence imaging of the ionic fragments. The momentum correlations in the three-body fragmentation channels provide evidence for a dominant sequential mechanism, starting with the cleavage of a C-C bond, ejecting CH3 + and CH3CHOH+ cations, followed by a secondary fragmentation of the hydroxyethyl cation that can be delayed for up to a microsecond after ionization. The C-O bond dissociation channels are less frequent, involving proton transfer and double proton transfer, forming H2O+ and H3O+ products, respectively, and exhibiting mixed sequential and concerted character. These results can be explained by the high potential barrier for the C-O bond dissociation seen in our ab initio quantum chemical calculations. We also observe coincident COH+ + C2Hn + ions, suggesting exotic structural rearrangements, starting from the Frank-Condon geometry of the neutral 2-propanol system. Remarkably, the relative yield of the H3 + product is suppressed compared with methanol and alkene dications. Ab initio potentials and ground state molecular dynamics simulations show that a rapid and direct C-C bond cleavage dominates the Coulomb explosion process, leaving no time for H2 roaming, which is a necessary precursor to the H3 + formation.

Numerical Study of the Micro-Jet Formation in Double Flow Focusing Nozzle Geometry Using Different Water-Alcohol Solutions

The purpose of this work is to determine, based on the computational model, whether a mixture of a binary liquid is capable of producing longer, thinner and faster gas-focused micro-jets, compared to the mono-constituent liquids of its components. Mixtures of water with two different alcohols, water + ethanol and water + 2-propanol, are considered. The numerical study of pre-mixed liquids is performed in the double flow focusing nozzle geometry used in sample delivery in serial femtosecond crystallography experiments. The study reveals that an optimal mixture for maximizing the jet length exists both in a water + ethanol and in a water + 2-propanol system. Additionally, the use of 2-propanol instead of ethanol results in a 34% jet length increase, while the jet diameters and velocities are similar for both mixtures. Pure ethanol and pure 2-propanol are the optimum liquids to achieve the smallest diameter and the fastest jets. However, the overall aim is to find a mixture with the longest, the smallest and the fastest jet. Based on our simulations, it appears that water + 2-propanol mixture might be slightly better than water + ethanol. This study reveals the dominant effect of liquid viscosity on the jet breakup process in a flow focusing nozzles operated under atmospheric conditions.

Thermal Coefficients of the Water–Aliphatic Alcohol Binary System

The results of thermal coefficients calculations (к T , α, β) of water–aliphatic alcohol (methanol, ethanol, 1-propanol) systems of different compositions (x=0.2, 0.5, 0.8 mole fractions of alcohol) in liquid and vapor phases, as well as at critical and supercritical regions of state parameters have been presented. The dependence of values of thermal coefficients from density temperature and composition at different states is shown. The calculations are based on the polynomial equation of state, represented by expansion of the compressibility factor into a power series of reduced density (ω=ρ/ρcr) and reduced temperature . The mean percentage errors of the calculated pressure values relative to the experimental values depending on system and number of carbon atom is varied 0.6-3.3%.

Investigations on the Thermophysical Properties of the Binary Mixtures of Ethyl Laurate with Four n-Alkanols

The density, viscosity and excess properties of biodiesel–alcohol fuel blends are investigated for research into the blending of fuels. Four n-alkanols (1-propanol, 1-butanol, 1-pentanol and 1-hexanol) as additives were mixed with ethyl laurate to form binary systems for density and viscosity measurement. Excess molar volumes and viscosity deviations of the four binary systems (1-propanol + ethyl laurate), (1-butanol + ethyl laurate), (1-pentanol + ethyl laurate), and (1-hexanol + ethyl laurate) were calculated from the experimental density and viscosity data and fitted with the Redlich–Kister equation. Grunberg–Nissan and McAllister equations were used to correlate viscosities and the correlated values from McAllister equation are in good agreement with the experimental data. The results may be useful for the research and development of biodiesel–alcohol fuel blends.

Alcohol-based aqueous biphasic system applied to partition four different natural bioactive compounds from Garcinia indica Choisy

ABSTRACT An attempt was made to simultaneously partitioning Anthocyanins (ACN), Hydroxycitric acid (HCA), Garcinol (GL), and Isogarcinol (IGL) from fruit rinds of Garcinia indica using the 1-propanol and magnesium sulfate system. The influences of 1-propanol and magnesium sulfate concentration and Tie line Length (TLL) were investigated to obtain the optimal partitioning and recovery of GL and IGL into the top-phase and ACN and HCA to the bottom phase. The 25% w/w 1-propanol and 12% w/w magnesium sulfate system showed the maximum extraction efficiency for all the compounds. The purity and recovery were further improved by employing the second stage ATPS.

Tannin-derived bimetallic CuCo/C catalysts for an efficient in-situ hydrogenation of lauric acid in methanol-water media

Integration of aqueous-phase reforming of methanol (APRM) into the production of value-added fatty alcohols via hydrogenation of fatty acids is an attractive and efficient process in biomass conversion. Herein, we present tannin-derived carbon-supported monometallic Cu/C, Co/C and bimetallic Cu-Co/C catalysts with different Cu/Co ratios for in situ hydrogenation of lauric acid in a methanol-water hydrothermal system. The catalysts were made by a simple mixture of tannin and the metal salts, followed by pyrolysis in an H2 atmosphere. Through synergism induced by Cu-Co interactions, the bimetallic Cu-Co/C catalyst with Cu/Co ratio of 1:4 (CuCo4/C) exhibits higher catalytic activity than monometallic Cu/C catalyst towards lauric acid conversion, as well as higher selectivity to lauryl alcohol than monometallic Co/C catalyst. The CuCo4/C catalyst is composed of metallic Cu, metallic Co, and amorphous carbon, characterized by high surface area (194.5 m2/g) and hierarchical structure. The obtained lauryl alcohol yield in the methanol-water hydrothermal system is significantly higher than other alcohol-water systems, namely ethanol, 1-propanol, and isopropanol hydrothermal systems, highlighting its higher generation rate of hydrogen. Also, the effects of process parameters including the quantity of methanol, catalyst loading and reaction time on the conversion of lauric acid were systematically studied and optimized.

Polycarbonate Microchip Containing CuBTC-Monopol Monolith for Solid-Phase Extraction of Dyes.

In the present study, preparation of CuBTC-monopol monoliths for use within the microchip solid phase extraction was undertaken through a 20-min UV lamp-assisted polymerization for 2,2-dimethoxy-2-phenyl acetophenone (DMPA), butyl methacrylate (BMA), and ethylene dimethacrylate (EDMA) alongside inclusion of the porogenic solvent system (1-propanol and methanol (1 : 1)). The resultant coating underwent coating using CuBTC nanocrystals in ethanolic solution of ethanolic solution of 1,3,5-benzenetricarboxylic acid (H3BTC, 10 mM) and 10 mM copper(II) acetate Cu(CH3COO)2. This paper reports enhanced extraction, characterization, and synthesis studies for porous CuBTC metal organic frameworks that are marked by different methods including SEM/EDAX analysis, atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FT-IR). The evaluation of the microchip's performance was undertaken as sorbent through retrieval of six toxic dyes (anionic and cationic dyes). Various parameters (desorption and extraction step flow rates, volume of desorption solvent, volume of sample, and type of desorption solvent) were examined to optimize dye extraction using fabricated microchips. The result indicated that CuBTC-monopol monoliths were permeable with the ability of removing impurities and attained high toxic dye extraction recovery (83.4–99.9%). The assessment of reproducibility for chip-to-chip was undertaken by computing the relative standard deviations (RSDs) of the six dyes in extraction. The interbatch and intrabatch RSDs ranged between 3.8 and 6.9% and 2.3 and 4.8%. Such features showed that fabricated CuBTC-monopol monolithic disk polycarbonate microchips have the potential of extracting toxic dyes that could be utilized for treating wastewater.

Effect of temperature on the phase-separation ability of KCl in aqueous two-phase systems composed of propanols: Determination of the critical temperature and extension of the results to other salts

The phase-forming ability of KCl in propanols has been investigated, aiming to assess its utility in aqueous two-phase extraction. Equilibrium data of the different equilibrium regions (SLLV, SLV, LLV, and LV) of aqueous two-phase systems (ATPSs) of water + KCl + 1-propanol and water + KCl + 2-propanol have been determined at the boiling temperatures of the mixtures and 101.3 kPa. In addition, the lowest critical solution temperature (LCST) for the water + KCl + 1-propanol system was measured to be 271.2 K, and the equilibrium behavior of the system in the vicinity of the LCST (at 268.1 and 273.1 K) was also determined. Finally, using various methods such as the effective excluded volume (EEV) theory, Setchenov-type equations, and the plait point of the liquid-liquid region, different salt and alcohol systems have been studied and classified according to their ability to produce ATPSs.

Salts Effect on Isobaric Vapor–Liquid Equilibrium for the Azeotropic Mixture 2-Propanol + Water

Vapor–liquid equilibrium (VLE) data for the systems 2-propanol + water + calcium chloride, 2-propanol + water + magnesium chloride, 2-propanol + water + calcium nitrate, and 2-propanol + water + magnesium nitrate were measured at the pressure of 101.3 kPa. Experimental data of all ternary systems passed the thermodynamic consistency test by modified McDermott–Ellis method. Then, the effects of salts on the vapor phase mole fraction of 2-propanol and the relative volatility of 2-propanol to water were analyzed. Results show that the azeotropic point of the system 2-propanol and water can be removed with addition of the salts, and the salting-out effects follow the order calcium nitrate > calcium chloride > magnesium nitrate > magnesium chloride. Furthermore, the LIQUAC model was adopted to correlate the VLE experimental data of the systems. The comparative results of the average relative deviation (Δz̅) and the corresponding standard deviations (σ) between the experimental and calculated values indicate that LIQUAC model is suitable for the VLE calculation for the systems of 2-propanol + water + salts.

Consistency of experimental data in SLLV equilibrium of ternary systems with electrolyte. Application to the water + NaCl + 2-propanol system at 101.3 kPa

The authors wish to thank the DGICYT of Spain for the financial support of project CTQ2014-59496.

Phase equilibria of clathrate hydrates in CO2/CH4 + (1-propanol/2-propanol) + water systems: Experimental measurements and thermodynamic modeling

Hydrate equilibrium/dissociation conditions of methane/carbon dioxide in the presence of aqueous solutions of 1-propanol/2-propanol have been studied in this communication. The hydrate dissociation conditions of water + CO2 and water + CO2 + 2-propanol systems have been measured in concentration range of 0, 0.02, 0.05, 0.10, 0.15 and 0.25 mass fractions in 274.5–283.1 K and 1.93–4.54 MPa, temperature and pressure ranges using an isochoric pressure-search method. A thermodynamic model has been developed to estimate the hydrate dissociation conditions for the systems of water + CH4/CO2 + 1-propanol/2-propanol based on combinations of van der Waals and Platteeuw model, Peng-Robinson equation of state (PR EOS), and NRTL and Wilson activity coefficient models. The parameters of Langmuir constants have been obtained by fitting experimental data while structural, and interaction parameters of activity coefficient models have been taken from literature. Based on our experimental data, 2-propanol likely acts as thermodynamic inhibitor for CO2 hydrate. The results of the model are in satisfactory agreement with the experimental data.

Experimental studies and thermodynamic analysis of isobaric vapor-liquid-liquid equilibria of 2-propanol + water system using n-propyl acetate and isopropyl acetate as entrainers

Heterogeneous azeotropic distillation is a widely used technique in chemical industries for the purification of alcohols from their aqueous mixtures. This study aims at exploring the possibility of using n-propyl acetate and isopropyl acetate as entrainers for heterogeneous azeotropic distillation to effect the separation of 2-propanol + water azeotropic mixture. A novel yet simple still was constructed to measure the vapor-liquid equilibrium (VLE) and vapor-liquid-liquid equilibrium (VLLE) data for the binary and ternary systems. The isobaric VLE data for the binary systems 2-propanol + water, 2-propanol + n-propyl acetate and 2-propanol + isopropyl acetate and isobaric VLLE data for the ternary systems 2-propanol + water + n-propyl acetate and 2-propanol + water + isopropyl acetate were measured at atmospheric pressure. Subsequently, the experimental data was compared with predictions by thermodynamic models such as UNIFAC, UNIQUAC and NRTL. The feasibility of the entrainers n-propyl acetate and isopropyl acetate in separating the azeotropic mixture 2-propanol + water was studied using the Residue Curve Map (RCM). The experimental data showed the existence of a ternary homogeneous azeotrope in the 2-propanol + water + n-propyl acetate system and a heterogeneous ternary azeotrope in the 2-propanol + water + isopropyl acetate system. Since the heterogeneous azeotropic distillation process depends on the presence of ternary heterogeneous azeotrope, n-propyl acetate is not considered a suitable entrainer for the separation of 2-propanol + water mixture. Finally, a separation sequence for the heterogeneous azeotropic distillation of 2-propanol + water system using isopropyl acetate as entrainer has been proposed.

Isobaric vapor-liquid equilibria for extractive distillation of 1-propanol + water mixture using thiocyanate-based ionic liquids

This paper presents vapor-liquid equilibrium (VLE) data at 101.3kPa for the ternary systems 1-propanol+water+1-ethyl-3-methylimidazolium thiocyanate [emim][SCN] and 1-propanol+water+1-butyl-3-methylimidazolium thiocyanate [bmim][SCN] and their constituents binary systems. The experimental data obtained were correlated using the NRTL, eNRTL and UNIQUAC models. It was found that the addition of these ionic liquids enhance the relative volatility of 1-propanol to water, and the separation ability follows the order of [emim][SCN]>[bmim][SCN]. The results obtained were compared with the VLE data of the system containing this azeotropic mixtures with different imidazolium-based ionic liquids reported in the literature.

Isobaric Vapor–Liquid–Liquid Phase Equilibria Measurements of Three Ternary Water + 2-Butanone + Aliphatic Alcohol (Ethanol, 1-Propanol, 2-Propanol) Systems at 101.3 kPa

Vapor–liquid–liquid equilibrium (VLLE) data were measured for the ternary systems water + 2-butanone + alcohol at 101.3 kPa by means of a Gillespie type still equipped with an ultrasonic homogenizer. VLLE were observed in the temperature ranges of 346.65–346.79 K, 346.74–352.70 K, and 346.52–346.75 K for the water + 2-butanone + ethanol, water + 2-butanone + 1-propanol, and water + 2-butanone + 2-propanol systems, respectively. For all three systems, a region of liquid–liquid immiscibility was observed, and the vapor phase compositions were outside the liquid–liquid phase envelope. The absence of ternary heterogeneous azeotropes was thus established. The nonrandom two-liquid (NRTL), universal quasichemical (UNIQUAC), and universal functional (UNIFAC) activity coefficient models were used for comparison with experimental results. The parameters were fitted to the binary subsystems vapor–liquid and liquid–liquid equilibrium experimental data. While correct estimations of experimental vapor phase trends were...