Mole Fraction Of Ethanol Research Articles

Laminar burning velocity of ethanol-ethyl acetate mixtures in air

Alcohols, esters, and their mixtures are ubiquitous in the process industry. However, safety data remain limited, especially for mixtures. In this work, the laminar burning velocity, Sl, of ethanol-ethyl acetate mixtures in air was investigated (at 90 °C and atmospheric pressure) through computations performed using three different detailed chemical kinetic mechanisms, and measurements obtained from pressure time histories recorded during closed vessel explosion experiments. Computations were run varying the equivalence ratio, φ, from 0.6 to 1.7, and the mole fraction of ethanol in the fuel mixture from 0 (only ethyl acetate) to 1 (only ethanol). For all systems, explosion experiments were carried out at φ = 1.1, i.e., the composition at which, according to calculations, Sl achieves its maximum value. Regardless of the kinetic mechanism, reasonable agreement is found between computed and experimental data, including experimental data retrieved from the literature for ethanol and ethyl acetate. Results show that the behavior of ethanol-ethyl acetate is bounded between the behaviors of ethanol and ethyl acetate, approaching the former/latter as the mixture is enriched in ethanol/ethyl acetate. Over the whole range of equivalence ratios explored, the values of Sl for ethanol-ethyl acetate are smaller than those obtained by averaging the corresponding values of ethanol and ethyl acetate according to their mole proportions in the fuel mixture. This is also confirmed experimentally. A simple Le Chatelier’s mixing rule-like formula is proved to predict values of Sl that closely match both computed and experimental data, suggesting that the nature of the interaction between ethanol and ethyl acetate is predominantly thermal rather than chemical.

Investigation of sustainable operation oriented- economic, process and environment based multi-criteria optimization of large scale methanol production plant

Methanol is one of the main raw materials and a building block for many essential chemicals in the industry, and it is widely produced from the synthesis gas. It is used as a fuel, solvent, inhibitor, antifreeze agent, and in producing a variety of chemicals including olefins and paraffin. The global demand for methanol is 70 million tons per year and it is estimated to grow by a factor of 6–8% per year so it is necessary to develop a methanol production process, which is economical, and environment friendly. The multi-objective optimization (MOO) approach is used to optimize the large scale Lurgi two-step methanol synthesis process using the non-dominated sorting genetic algorithm-II (NSGA-II) to find the Pareto front solutions involving the process, economic, and environmental-based objectives. Methanol production rate, total energy consumption, total annual CO2 emissions, and profit are considered as objectives. The five decision variables include syngas molar flow, reactor feed pressure, reactor 1 temperature, reactor 2 temperature, and by-product mass flow in the methanol distillation column. Two constraints are set on ethanol mole fraction in the methanol stream, and methanol mole flow in water to the treatment stream. Three optimization cases (two bi-objective and one tri-objective) are developed. In the Case 1 study, CO2 emissions decreased by 65.83%, the methanol production rate increased by 10.11%, and total energy was reduced by 57.55%. The Pareto ranking is carried out using the Preference Ranking On the Basis of Ideal-average Distance (PROBID) method and the best optimal solution is reported for all cases.

Effects of operating parameters on single-stage ultrasonic separation of ethanol from its aqueous solutions

The effects of operating parameters on separation of ethanol from its aqueous solutions using ultrasonic atomization were investigated in a single-stage process. With an experimental setup similar to those used in previous work, we measured the degree of enrichment and the combined molar collection rate of ethanol and water for a single combination of the ultrasound power and frequency at 126 combinations of bulk liquid depth, composition, and temperature; carrier-gas inlet/outlet elevation and flow rate; and collection temperature. Enrichment depends strongly on bulk liquid composition, reaching a maximum at an ethanol mole fraction below 0.1, with the maximum enrichment depending on bulk liquid depth and inlet/outlet elevation. The collection rate depends strongly on inlet/outlet elevation and bulk liquid pool depth, and for high ethanol mole fractions is nearly independent of bulk liquid composition. Enrichment and collection rate increase with increasing bulk liquid temperature and decreasing collection temperature. The fact that increasing the carrier-gas flow rate increases the collection rate and decreases enrichment is interpreted in terms of size-selective transport of drops from the ultrasonically-generated fountain where they are atomized, to the cold trap where they are collected. The results are discussed in terms of operating parameters, transport phenomena (including evaporation and gravitational settling of atomized drops), the ultrasonically-induced fountain, and previously reported drop-size distributions. The duration of the experiments, conducted in batch, was such that the results should be relevant to both batch and continuous-flow operation. The work provides guidance and critical data for process scale-up.

Solubility measurement, molecular simulations, Hansen solubility parameter and thermodynamic properties of isophthalic acid in binary solvents at 283.15–323.15 K

The solubility of isophthalic acid (IPA) in four different binary solvent systems (water + methanol, water + ethanol, water + 1-propanol, and water + isopropanol) was measured by the gravimetric method at atmospheric pressure from 283.15 K to 323.15 K. Under certain solvent compositions, the solubility of IPA increased with increasing temperature. The trend of solubility under isothermal conditions setting differs as the mole fraction of organic solvent increases. The solubility of IPA in water + methanol and water + ethanol systems increased with the mole fraction of methanol or ethanol. In the system of water + 1-propanol and water + isopropanol, as the mole fraction of organic solvent increased, the solubility of IPA increased firstly and then decreased gradually. The Hansen solubility parameters of IPA and selected solvents were analyzed, the analysis showed that the miscibility of IPA with the selected solvent was the result of many factors. Molecular electrostatic potential surface (MEPS) and Hirshfeld surface (HS) analysis were used to investigate the intermolecular interactions. The solubility data were correlated using the Apelblat equation, van't Hoff equation, λh equation, and Jouyban–Acree model. Besides, the vant Hoff equation was employed to analyze the apparent thermodynamic properties of dissolving process including the Gibbs energy, enthalpy and entropy. All positive values indicated that the dissolving process of IPA was non-spontaneous, endothermic, and entropy-driven.

Evaluation of the refractive indices of pure organic dyes using binary mixture models

The refractive index (RI) of organic dyes is highly important due to their applications in many optical and optoelectronic fields. Because the refractive indices of various organic dyes are unknown, in the present work, we have developed an easy and simple method to estimate the refractive indices of pure organic dyes using binary mixing rules. The refractive indices were measured at a temperature of 20 °C for a wavelength λ = 589.6 nm with an Abbe refractometer. The method was previously checked for two compounds with known refractive indices, Xylene and Fluorescein, both solved in ethanol. According to the acquired results, it can be stated that Arago-Biot and Gladstone-Dale mixing rules best check the RI. Afterward, this method was applied to the Phloxine B, diluted in ethanol, to determine its unknown RI. The obtained experimental refractive index data of Phloxine B + ethanol solutions at higher ethanol mole fractions were correlated satisfactorily with both models.

Structure of polyvinylpyrrolidone in water/ethanol mixture in dilute and semi-dilute regimes: Roles of solvents mixture composition and polymer concentration

This study aims to describe the structure of polyvinylpyrrolidone (PVP, Mw = 40.000 g/mol) in water/ethanol solution in dilute and semi dilute regimes at 25 °C by viscosity measurements. Intrinsic viscosity of the polymer is determined for different ethanol molar fractions, XA. The cononsolvency of PVP in water/ethanolis evident and manifested by a contraction in the 0.05–0.4ethanol molar fraction range. The overlapping concentration,CPVP∗(XA), of PVP in water/ethanol increases with increasing XA. The Flory exponent, ν(XA), and the Mark-Houwink-Sakurada(MHS) coefficients,a(XA), are deduced by plotting the double logarithm of the relative viscosity versus polymer concentration in semi-dilute regime. The Flory exponent and the MHS values are shown to be dependent on XA. The blob model theory is extended and used to study the structure of a polymer in its mixed solvents. So, the structure of PVP in water/ethanol mixture is described by determining the structural parameters: density of monomers, monomer size, correlation length and the number of monomer in each blob for the PVP concentration ranged from CPVP∗(XA) to 2CPVP∗(XA). A spectacular reduction of the correlation length is observed in the 0.1–0.3 ethanol molar fraction.

Mid-infrared light-induced photoacoustic wave in water and its application

We demonstrate photoacoustic (PA) wave generation at an air–water interface using a mid-infrared (MIR) laser pulse and observe its propagation in liquid water by shadowgraph imaging. The PA wave reaches a depth of more than 4 mm, which is over 100 times deeper than the penetration depth of MIR light in water. As one of the applications of the PA wave, we quantitatively analyze the ethanol mole fraction in a water–ethanol mixed solution. We achieve the generation of PA waves induced by a compact MIR laser system, which provides a new tool for imaging and inspecting the object in water.

Tuning the Phytoglycogen Size and Aggregate Structure with Solvent Quality: Influence of Water-Ethanol Mixtures Revealed by X-ray and Light Scattering Techniques.

Phytoglycogen (PG) is a hyperbranched polysaccharide with promising properties for biomedical and pharmaceutical applications. Herein, we explore the size and structure of sweet corn PG nanoparticles and their aggregation in water-ethanol mixtures up to the ethanol mole fraction xEtOH = 0.364 in dilute concentrations using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS) measurements. Between 0 ≤ xEtOH ≤ 0.129, the conformation of PG contracts gradually decreasing up to ca. 80% in hydrodynamic volume, when measured shortly after ethanol addition. For equilibrated PG dispersions, SAXS suggests a lower PG volume decrease between 19 and 67% at the corresponding xEtOH range; however, the inflection point of the DLS volume contraction coincides with the onset of reduced colloidal stability observed with SAXS. Up to xEtOH = 0.201, the water-ethanol mixtures yield labile fractal and globular aggregates, as evidenced by their partial breakup under mild ultrasonic treatment, demonstrated by the decrease in their hydrodynamic size. Between 0.235 ≤ xEtOH ≤ 0.364, PG nanoparticles form larger, more cohesive globular aggregates that are less affected by ultrasonic shear forces.

Ethanol-Induced Aggregation of Nonpolar Nanoparticles in Water/Ethanol Mixed Solvents.

The dispersity of nonpolar nanoparticles (NPs) in water/ethanol mixed solvents was studied using molecular dynamics simulations. Based on the rule of "like dissolves like," nonpolar NPs should be dispersed better in a solvent with a lower polarity. As the mole fraction of ethanol in a mixed solvent (R) increases from 0% (pure water) to 100% (pure ethanol), the polarity of the mixed solvent is indicated to decrease monotonically. However, the dispersity of nonpolar NP does not increase monotonically: it first decreases after the addition of a small fraction of ethanol (R < 8.0%) and then markedly increases as R further grows. When there is a small amount of ethanol, the ethanol molecules around aggregated NPs tend to simultaneously make contact with multiple NPs, which can increase the tendency of NP aggregation. Furthermore, with a considerable ethanol ratio, the interaction of the solvent with NPs becomes notably strong, which facilitates the dissolution of NPs. Our findings may help to better understand the mechanism of dispersion of NPs in mixed solvents and may provide a useful precipitation technology for NP production.

Solubility measurement, thermodynamic modeling and solubility parameters of Clarithromycin（form ӀӀ）in aqueous ethanolic solution

ABSTRACT To develop and optimise the crystallisation process of clarithromycin, the solid–liquid equilibrium solubility and solvent effect of clarithromycin form ӀӀ in aqueous ethanol mixtures was experimentally determined at the temperature range from 273.15 K to 333.15 K under atmospheric pressure of 0.1 MPa. Experimental results confirmed that the crystal form did not change during the determination of solubility. The results indicated that the solubility of clarithromycin is dependent on the composition of the mixed solvent, and it reaches its maximum value when the mole fraction of ethanol in the mixture solvent is equal to 0.61. In addition, the solubility of clarithromycin was positively related to the temperature in the ethanol-water mixed solvent. Furthermore, solubility parameter was used to elucidate the relation between the solubility and the mixed solvent. The modified Apelblat equation, van’t Hoff equation, λh equation, CNIBS/R–K model and Jouyban–Acree model were employed to correlate the solubility data. The correlation results showed good agreement with the experimental data, the modified Apelblat equation provides the best correlation results. The NRTL equation was utilised to calculate the thermodynamic properties of the dissolution process of clarithromycin, and the dissolution process of clarithromycin was estimated to be endothermic and entropy-driven.

Multi-stage heat release of multi-component fuels: Insights and implications for advanced engine operation

Multi-stage heat release (MSHR) is a unique phenomenon typically seen in lean/diluted and low- to intermediate-temperature combustion. Despite its relevance to advanced engine operation, the MSHR of multi-component fuels has barely been quantified. This study aims to characterize the MSHR of multi-component fuels in a rapid compression machine (RCM) at conditions representative of advanced combustion engines. New experimental data are first reported in the RCM at an equivalence ratio of 0.4, pressure of 60 bar and temperatures from 702 to 795 K for a research grade, multi-component gasoline surrogate, termed PACE-20. Experiments confirm the existence of MSHR for PACE-20 at all temperatures, and reveal the strong inhibiting effect of temperature on MSHR, where increasing temperature inhibits MSHR by suppressing first stage heat release and promoting second and third stage heat release. A detailed chemical kinetic model is also adopted to model the experiments, with good agreement observed. The response of MSHR characteristics to changes in different engine operating parameters (i.e., temperature, pressure, equivalence ratio and CO2 dilution level) and fuel compositions (i.e., mole fraction of n-pentane, n-heptane, isooctane, cyclopentane, 1-hexene, ethanol and aromatics in PACE-20) is further evaluated via statistical analysis coupling quasi-random sampling, extensive computer experiments and high-dimensional model representation. The change in MSHR is characterized through 8 quantities of interest (QOIs), i.e., duration and extent of each heat release stage, and their standard deviations. The analysis highlights the dependence of the QOIs on the individual parameters as well as their interplays, with temperature exhibiting the strongest impact among all parameters. Furthermore, it is demonstrated that if MSHR is to be facilitated and combustion phasing is to be extended to enable engine operation at higher compression ratios, it is recommended to operate the engine at low intake temperatures, boosted intake pressures and high CO2 dilutions (i.e., high EGR levels) with gasoline fuels containing more n-pentane and less aromatics.

Dissolution thermodynamics and preferential solvation of genistein in some (ethanol + water) mixtures at different temperatures

The solubility of genistein was measured in the binary system of ethanol and water at temperatures ranging from 288.2 to 328.2 K. The obtained data were correlated with the modified Apelblat model, Yalkowsky model, λh model, CNIBS/R-K model, Jouyban-Acree-van’t Hoff model, and modified Wilson model and their prediction accuracy was evaluated by calculating the mean relative deviation. The thermodynamic functions, Gibbs energy, enthalpy, and entropy of solution were determined using van’t Hoff equation. Moreover, the preferential solvation was analyzed by using the solubility data at 298.2 K. The solubility of genistein in the system increased with an increase in temperature and mole fraction of ethanol in the solvent mixtures. The values for solubility of genistein are ranging from 0.47 obtained in neat water at T = 288.2 K to 5.02 obtained in absolute ethanol at T = 328.2 K. The values of Δ solnG, 0 Δ solnH0 and Δ solnH0 for the dissolution of genistein in mixtures are positive, whereas the values of Δ solnH0 in neat water and absolute ethanol are negative. The thermodynamic properties of dissolution suggest that the dissolution process is non-spontaneous and endergonic. The modified Apelblat model can provide more accurate predictive solubility of genistein in the water and ethanol mixtures, whereas Yalkowsky model calculates solubility of genistein with large deviations. Genistein is preferentially solvated by water in water-rich mixtures (0 < x 2 < 0.24) but preferential solvation by ethanol in the region of 0.24 < x 2 < 1. Overall, this work could be applied for designing and optimizing the extraction, purification, and crystallization process of genistein.

3-aminoquinoline: a turn-on fluorescent probe for preferential solvation in binary solvent mixtures

3-Aminoquinoline (3AQ) has been used as a fluorescent probe for preferential solvation in hexane-ethanol solvent mixtures. Results of the present experiment have been put into context by comparison with prior observations with 5-aminoquinoline (5AQ) as the probe. 3AQ exhibits a relatively small change of dipole moment (Δμ = 2.2 D) upon photoexcitation, compared to 5AQ (Δμ = 6.1D), which might appear to be a hindrance in the way of its use as a solvation probe. Indeed, the values of parameters like spectral shifts are smaller for the present experiment with 3AQ. At the smallest concentration of alcohol used, its local mole fraction around the probe is significantly lower than in the previous experiments with 5AQ. However, these apparent disadvantages are outweighed by the significant increase in fluorescence intensity and lifetime observed with increasing concentration of ethanol in the solvent mixture, as opposed to the drastic fluorescence quenching that occurs for 5AQ. This is a marked advantage in the use of 3AQ in studies like the present one. The local mole fraction of ethanol and preferential solvation index experienced by 3AQ are in line with those reported for 5AQ. The disadvantage of the smaller magnitude of Δμ persists in the time resolved fluorescence experiments, for solvent mixtures with very low ethanol content. Negligible wavelength dependence of fluorescence transients of 3AQ is observed for x p = 0.002,. However, this effect is outweighed at higher alcohol concentrations, for which nanosecond dynamics of preferential solvation is observed.

Ion-Specific and Solvent Effects on PDADMA–PSS Complexation and Multilayer Formation

Among various parameters that influence the formation of polyelectrolyte complexes and multilayers, special emphasis should be placed on ion-specific and solvent effects. In our study, we systematically examined the above-mentioned effects on poly(diallyldimethylammonium chloride) (PDADMACl)-sodium poly(4-styrenesulfonate) (NaPSS) complexation in solution and at the surface by means of dynamic light scattering, ellipsometry and atomic force microscopy measurements. As solvents, we used water and water/ethanol mixture. The obtained results confirm the importance of ion-specific and solvent effects on complexes prepared in solution, as well as on multilayers built up on a silica surface. The experiments in mixed solvent solution showed that at a higher ethanol mole fraction, the decrease in monomer titrant to titrand ratio, at which the increase in the size of complexes is observed, takes place. The difference between chloride and bromide ions was more pronounced at a higher mole fraction of ethanol and in the case of positive complex formation, suggesting that the larger amount of bromide ions could be condensed to the polycation chain. These findings are in accordance with the results we obtained for polyelectrolyte multilayers and could be helpful for designing polyelectrolyte multilayers with tuned properties needed for various applications, primarily in the field of biomedicine.

Optimization of Cold Flow Properties of Biodiesel by Addition of Cold Flow Improver

Despite the renewable and sustainable characteristics, biodiesel is poor in cold flow property (CFP) which causes a significant drawback that have limited its application. Thickening or crystallization of biodiesel in low temperature can readily result in the clogging of fuel pipes and fuel filters. The purpose of this study is to determine the optimum properties of blended biodiesel that gives the most accurate simulation results of blended biodiesel’s CFP. TmoleX18 and COSMOthermX were used to identify the viscosities and densities of pure palm oil biodiesel and pure ethanol under different temperatures. The densities, viscosities and pour points of ethanol blended biodiesel was then calculated by using Grunberg-Nissan and, Riazi and Daubert equations. The simulation results were obtained under different compositions of ethanol added from 0 to 0.2 mole fraction at temperature range of 30 °C to -5 °C. The optimum combination of viscosities and densities of blended biodiesel for the blended cold flow properties was at 10 °C and 30 °C respectively. The simulation error at 0.1 mole fraction of ethanol was 0.92 %.

Unraveling the octane response of gasoline/ethanol blends: Paving the way to formulating gasoline surrogates

Ethanol is widely used as a gasoline octane booster, and yet, its blending response is not fully understood. Blending ethanol with gasoline most often leads to a synergistic effect (higher than expected relative to linear blending), but can also lead to a linear or antagonistic blending (lower than expected relative to linear blending). To address the knowledges gap in ethanol blending, this study provides new research octane number (RON) and motor octane number (MON) measurements of ethanol blended with various gasoline surrogates. The first set of blends are ternary mixtures, designed to study the interactions between primary reference fuels (PRFs) and certain gasoline components when blended with ethanol. These gasoline components are 1-hexene, 1,2,4-trimethylbenzene and cyclopentane, which, represents the olefin, aromatic and naphthenes classes in commercial gasoline fuels, respectively. The second set represents multicomponent surrogates for Fuels for Advanced Combustion Engines (FACE) gasolines, developed in our previous work (Badra et al., Applied Energy 2017 p. 778-793). This study developes an octane blending model of ethanol/gasoline surrogates that utilize the new measurements along with datasets available in literature. The model consists of the conventional linear by ethanol molar fraction correlation, with the addition of non-linearity terms that depend on base fuel properties, namely, the octane sensitivity and the mole fraction of gasoline components. The model can predict the octane numbers (RON and MON) of blends containing gasoline surrogates composed of n-heptane, n-pentane, iso-octane, iso-pentane, toluene, 124-trimethylbenzene, cyclopentane, cyclohexane (for RON only) and 1-hexene. To ensure the generality of the developed model and avoid over-fitting, the model is trained using 85% of the available dataset while the remaining measurements have been used to test the model. The proposed model outperforms many ethanol blending models available in literature with 87% of the RON and 83% of the MON measurements being within the reproducibility limits. This model can be integrated to the process of designing gasoline surrogates that contain ethanol.

Molecular dynamics simulation on spreading of mixture nanodroplets on a smooth and homogeneous surface

The dynamic wetting of mixture droplets on the solid surface is important for various industrial technologies and applications, such as evaporation, microfluidics, surface self-cleaning, and power cycling. Due to the influence of different components, the dynamic wetting process of mixture droplets is quite different from that of pure fluids. Currently, the understanding of the spreading mechanism of mixture droplets is lacking. In this paper, molecular dynamics simulation is used to study the dynamic spreading process of ethanol/water and difluoromethane (R32)/2,3,3,3-tetrafluoroprop-1-ene (R1234yf) mixture droplets on a smooth and homogeneous surface. The droplets have different component mole fractions and various diameters of 9.4–12.8 nm. The influences of the component mole fraction on the spreading radius and dynamic contact angle are analyzed and compared with molecular kinetic theory. It is found that for the R32/R1234yf mixture droplets, the component mole fractions in the bulk and at the interface of the droplet are close and the dynamic spreading process is similar to that of pure fluids. However, for the ethanol/water mixture droplets, the mole fraction of ethanol is higher at the vapor–liquid and solid–liquid interfaces than in the bulk, and the spreading is faster than that of pure fluids. The mole fraction and the physical properties in the triple contact region are analyzed, and an improved prediction is proposed for the moving velocity of the triple contact line and the spreading process of the mixture droplet.

Effect of CaCl2 and ZnCl2 salts on isobaric vapor-liquid equilibrium in separation of the azeotropic mixture of ethanol + water

Present work analyzes potential of calcium chloride (CaCl2) and zinc chloride (ZaCl2) salts as entrainer for breaking the minimum boiling azeotrope of ethanol and water. Isobaric vapor-liquid equilibrium (VLE) data for the binary systems of water + ethanol and ternary system of water + ethanol + calcium chloride, and water + ethanol + zinc chloride were measured at a constant pressure of 94.5 kPa. The effect of salts on the relative volatility of ethanol to water as well as on the vapor phase mole fractions of ethanol were also studied experimentally. From the experimental results, it is observed that with addition of salts, the azeotropic point of the ethanol and water system can be eliminated. Salting out effects in case of calcium chloride was more than that zinc chloride salt. The results obtained in this work showed that calcium chloride could be a better choice for separation of the water + ethanol azeotrope. Electrolyte nonrandom two-liquid (eNRTL) model was used to correlate the experimental VLE data. The model prediction with the regressed parameters was found in well agreement with the experimental data. The experimental data obtained in this work was found thermodynamically consistent using van Ness test.

Reaction Condition Effects on the Photocatalytic Production of H2 from Ethanol in the Gas Phase over Pt/TiO2

AbstractThe effects of reaction parameters on H production from ethanol photocatalysis in the gas phase have been investigated. The photocatalytic activity evolves from an early mass‐transfer limited regime to an independent one at later irradiation times, which is interpreted in terms of a photocatalytic site activity distribution. Ethanol molar fraction exhibits two different domains, with H production increasing up to a molar fraction of 0.12, beyond which it plateaus. H :AcH ratios are very sensitive to reaction conditions, reaching 1.8 at low reactant flows. UV light is converted to H with an efficiency of nearly 3 %.

Separation and Semi-Empiric Modeling of Ethanol-Water Solutions by Pervaporation Using PDMS Membrane.

High energy demand, competitive fuel prices and the need for environmentally friendly processes have led to the constant development of the alcohol industry. Pervaporation is seen as a separation process, with low energy consumption, which has a high potential for application in the fermentation and dehydration of ethanol. This work presents the experimental ethanol recovery by pervaporation and the semi-empirical model of partial fluxes. Total permeate fluxes between 15.6–68.6 mol m h (289–1565 g m h), separation factor between 3.4–6.4 and ethanol molar fraction between 16–171 mM (4–35 wt%) were obtained using ethanol feed concentrations between 4–37 mM (1–9 wt%), temperature between 34–50 C and commercial polydimethylsiloxane (PDMS) membrane. From the experimental data a semi-empirical model describing the behavior of partial-permeate fluxes was developed considering the effect of both the temperature and the composition of the feed, and the behavior of the apparent activation energy. Therefore, the model obtained shows a modified Arrhenius-type behavior that calculates with high precision the partial-permeate fluxes. Furthermore, the versatility of the model was demonstrated in process such as ethanol recovery and both ethanol and butanol dehydration.