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Concentrated solutions of a rigid ring polymer, cyclic amylose tris(n-butylcarbamate) (cATBC), have lyotropic liquid crystallinity. Phase boundary concentrations of cATBC in tetrahydrofuran (THF) a...

Two ethyl lactate (EL)-based aqueous two-phase systems (ATPSs) were studied at T = 298.15 K and atmospheric pressure. Sodium tartrate and potassium sodium tartrate organic salts have been used to f...

Ethyl lactate is an important flavor substance in baijiu, and it is also one of the common raw materials in the production of flavors and spices. In this study, we first established the ethyl lactate biosynthesis pathway in Saccharomyces cerevisiae α(L) by introducing propionyl coenzyme A transferase (Pct) and alcohol acyltransferase (AAT), and the results showed that strain α(L)-CP-Ae produced the most ethyl lactate 239.53 ± 5.45 mg/L. Subsequently, the copy number of the Pctcp gene and AeAT9 gene was increased, and the modified strain α(L)-tCP-tAe produced 346.39 ± 3.99 mg/L ethyl lactate. Finally, the porin gene (por2) and the mitochondrial pyruvate carrier gene (MPC2) were knocked to impede mitochondrial transport of pyruvate, and the final modified strain α(L)-tCP-tAeΔpor2 produced ethyl lactate 420.48 ± 6.03 mg/L.

In this work, the vapor–liquid equilibrium (VLE) data of propylene glycol methyl ether acetate + ethyl lactate and propylene glycol methyl ether + ethyl lactate was determined by a modified Rose–Wi...

Graphitic carbon nitride (g-C3N4)-supported V2O5 catalysts were prepared by the impregnation pyrolysis method, and their physicochemical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), UV–vis, TGA, N2 adsorption, and H2-TPR. These catalysts exhibit extremely high activity and selectivity in the aerobic oxidation of ethyl lactate to ethyl pyruvate. The excellent catalytic performance derives from the high surface-chemisorbed oxygen species. Low calcination temperature and interaction with g-C3N4 are conducive to increasing the surface-chemisorbed oxygen species of V2O5. The optimal catalyst 13V2O5/g-C3N4 gives 96.2% conversion of ethyl lactate with 85.6% selectivity toward ethyl pyruvate in 4 h at 130 °C and 1 atm oxygen, which is significantly superior to those of previously reported V-containing catalysts. This catalyst is also stable and reusable, and the ethyl pyruvate yield is reduced by less than 10% after four runs without any regeneration treatment.

The thrust to adopt sustainable greener technologies in chemical and pharmaceutical process industries has been growing since last two decades due to the intense usage of volatile organic solvents from synthesis to purification stages. Hence, the objective of the present study is to analyze the feasibility of replacement of the organic solvent used in the purification of an active pharmaceutical ingredient (API) in a pharmaceutical context. From this perspective, the crystallization of an API-ibuprofen using ethyl lactate as an alternate green solvent is explored for the first time in the present study. Ethyl lactate belongs to the family of lactate esters, which is 100% biodegradable in nature. The feasibility of crystallization of ibuprofen is analyzed and a methodology is developed to crystallize the same. In addition, the kinetic parameters for the unseeded batch cooling crystallization of ibuprofen grown in 50% aqueous ethyl lactate have been estimated. A model of the crystallizer is constructed based on first-principles and a nonlinear optimization based methodology is used for extracting the kinetics. The results show that ibuprofen can be crystallized from aqueous ethyl lactate and the kinetic parameters are reported for the region where the system does not pass through two phase separation.

We report a new strategy toward the development of block copolymer surfactants from chemicals of the lactic acid family. A particularly unique aspect of this work is the use of green solvents as biobased platform chemicals to generate well-defined and nanostructure-forming materials. Herein, efficient functionalization of ethyl lactate (EL) and N,N-dimethyl lactamide (DML) solvents with acrylate groups generated monomers that could be polymerized by the photoinduced copper-catalyzed living radical polymerization process to yield polymeric materials with different water solubilities. These lactic acid-derived monomers were used as a major component in well-defined diblock copolymers composed of poly(EL acrylate) and poly(DML acrylate) segments as hydrophobic and hydrophilic building blocks, respectively. The resulting amphiphilic copolymers could self-assemble in aqueous solution to form nanoparticles with different morphologies (e.g., large-compound micelles and vesicles). Subsequently, the formed amphiphilic polymers were employed as efficient stabilizers in the emulsion polymerization of methyl methacrylate and styrene, offering a facile method for the synthesis of well-defined and stable polymer latexes in the range of 100-200 nm, demonstrating the practical significance of these biobased polymers in nanomaterial synthesis.

The design and development of zeolitic transition metal oxides for selective oxidation are interesting due to the combination of the redox properties and microporosities. Redox-active zeolitic transition metal oxides based on e-Keggin iron molybdates were synthesized. O2 can be activated by the materials via an electron-transfer-based process, and the materials can be oxidized even at room temperature. The materials are oxidized and reduced reversibly while the crystal structures are maintained. V is uniformly incorporated in the materials without changing the basic structures, and the redox properties of the materials are tuned by V. The materials are used as robust catalysts for ethyl lactate oxidation to form ethyl pyruvate using O2 as an oxidant.

Two commercial scale ethyl lactate (L1E) production processes are studied in the work. The L1E processes can be divided into the reaction part and the separation section. For the reaction part, instead of the three-column design presented by Miller et al.,(1) the proposed configuration only contains two reactive distillation (RD) columns, where the L1E product is taken from the first RD column as a sidedraw. This novel improvement can reduce 22.26% of energy consumption in the reaction part. Additionally, disparate separation approaches such as extractive distillation (ED) and the pervaporation (PV) are then implemented to deal with the ethanol/water azeotrope. Economics for alternative configurations are analyzed to find the most competitive and cost-effective process. As a result, the RD with PV design can save at least 31.46% of total annual cost compared to the RD with ED configuration.

The conversion of methyl and ethyl lactate to their corresponding alkyl 2-(propionyloxy)propanoate esters was achieved by Pd catalyzed hydroesterificative coupling with carbon monoxide (CO) and ethylene (C2H4) at moderate temperatures and CO/C2H4 pressures. A screening of reaction conditions showed that the reaction could be carried out at low loadings of catalyst, which was generated in situ from inexpensive and commercially available reagents. High conversions and product yields were obtained in a variety of solvents and even under neat conditions. Product analysis identified transesterification to be the primary competing reaction, which could be mitigated by changing solvents, as well as minimizing the amount of excess acid present in solution. Pyrolysis of methyl and ethyl 2-(propionyloxy)propanoate transformed these esters into their respective acrylates suitable for subsequent polymerization, along with propionic acid as a valuable coproduct.

Cu(0) wire-catalyzed single electron transfer–living radical polymerization (SET-LRP) of (−)-menthyl acrylate, a biobased hydrophobic monomer, was investigated at 25 °C in ethanol, isopropanol, ethyl lactate, 2,2,2-trifluoroethanol (TFE), and 2,2,3,3-tetrafluoropropanol (TFP). All solvents are known to promote, in the presence of N ligands, the mechanistically required self-regulated disproportionation of Cu(I)Br into Cu(0) and Cu(II)Br2. Both fluorinated alcohols brought out their characteristics of universal SET-LRP solvents and showed the proper polarity balance to mediate an efficient polymerization of this bulky and hydrophobic monomer. Together with the secondary alkyl halide initiator, methyl 2-bromopropionate (MBP), and the tris(2-dimethylaminoethyl)amine (Me6-TREN) ligand, TFE and TPF mediated an efficient SET-LRP of MnA at room temperature that proceeds through a self-generated biphasic system. The results presented here demonstrate that Cu(0) wire-catalyzed SET-LRP can be used to target polyMnA...

Highly efficient oxidation of ethyl lactate (ELA) to ethyl pyruvate (EP) was realized over TS-1 in the presence of aqueous H2O2 (30 wt %) at low temperature without other solvent. A 100% ELA conversion and 97.8% EP yield were obtained at 50 °C after 9 h. The conversion rate of ELA is sensitive to the reaction temperature. High reaction temperature (70 °C) leads to an increase in conversion rate of ELA but causes the fast hydrolysis and decarboxylation of EP to form byproducts of acetic acid and CO2. On the basis of the characterization (pyridine-FTIR and UV–vis) and reaction results, active species of Ti(OOH) were proven. In addition, a nonradical mechanism for conversion of ELA to EP for this catalytic system was proposed. By kinetic analysis, the formation of Ti(OOH) is confirmed as the rate-determining step. The apparent activation energy (103.4 kJ mol–1) was also obtained. Furthermore, TS-1 was highly stable for the oxidation of ethyl lactate. There were almost no change in ELA conversion and EP yield...

Novel experimental data of density for mixtures containing CO2 + ethanol, CO2 + ethyl lactate, CO2 + glycerol + ethanol, and CO2 + glycerol + ethyl lactate at low/moderate temperatures (308 and 323 K), pressures between 5 and 30 MPa, and high amounts of the organic solvent (molar fraction x = 0.5–0.9) are presented. The chosen organic solvents (ethanol, ethyl lactate, and glycerol) are green and applicable in food industry and present different polarizabilities. The density of CO2 + ethanol increased with the increment in the molar fraction of CO2, and the opposite was observed for the mixtures of CO2 + ethyl lactate. By adding a small amount of glycerol to the mixture of CO2 + ethanol and CO2 + ethyl lactate, it was possible to increase the density even a little further. The experimental data of density were well-correlated using the Peng–Robinson equation of state (PR-EOS) combined with Peneloux volume translation.

Ethyl lactate, which is an expected renewable solvent, was tested as an entrainer candidate for the separation of the binary methanol + dimethyl carbonate (DMC) azeotropic system by extractive distillation. Isobaric vapor–liquid equilibria (VLE) for two binary constituent systems, that is, methanol + DMC and DMC + ethyl lactate of the methanol + DMC + ethyl lactate ternary system, were determined by an ebulliometric method at pressures of (40.00 to 101.3) kPa. The experimental VLE data were fitted by the nonrandom two-liquid (NRTL) model. Predictions of the binary systems were also performed by the NIST-modified universal functional activity coefficient (UNIFAC) group contribution model. The separation effects of ethyl lactate were examined by two methods: residue curve map and relative volality α12 using the binary NRTL parameters. Both sets of calculated results indicated that ethyl lactate can be used as entrainer. Compared to other entrainers reported in the previous works, ethyl lactate would be a mo...

A highly efficient, eco-friendly protocol has been developed for synthesis of spirooxindole-pyran derivatives via one-pot, three-component reaction of isatins, malononitrile, and enolizable C–H activated compounds (2-hydroxynaphthalene-1,4-dione, 4-hydroxycoumarine and dimedone) under visible-light irradiation in water-ethyl lactate at room temperature. The reported approach shows significant advantages such as a high yield, mild and clean reaction conditions, the application of clean visible light as a source of energy, the absence of catalyst, the use of ethyl lactate/water as an environmentally friendly solvent, a one-pot multicomponent reaction at room temperature, no chromatographic separation, and applicability for large-scale synthesis.

The synthesis of polyfunctionalized aminothioalkenes has been realized via the direct C-H sulfenylation of enaminones and analogous enamines. These cross-coupling reactions have been achieved by simple KIO3 catalysis under aerobic conditions without employing any transition metal catalyst or additional oxidant. The employment of bio-based green solvent ethyl lactate as the reaction medium constitutes another sustainable feature of the present work.

Esterification of lactic acid and ethanol is typically a reversible reaction. The yield of ethyl lactate is low due to the limitation of chemical equilibrium. In this study, pervaporation composite membranes (glutaral crosslinked chitosan (GCCS)/carbomer (CP)/polyacrylonitrile (PAN), glutaral crosslinked gelatin (GCGE)/PAN, and glutaral crosslinked hyaluronic acid (GCHA)/hydrolysis modification (HM)-PAN) inspired by the bioadhesion phenomena were fabricated and used for the synthesis of ethyl lactate, which could promote the reaction by removing the water perferentially. The influence of dehydration rate on chemical equilibrium shift in different operating conditions was investigated. Pervaporation-assisted esterification results suggested that the yield of ethyl lactate was determined by the match between reaction rate and dehydration rate. The process is controlled by the reaction rate initially and the dehydration rate as time goes by. The incorporation of the pervaporation process could break the limi...

Lewis acid Snβ-type zeolites with varying amounts of Bronsted acid Al in the framework were synthesized using a simple two-step procedure comprising partial dealumination of β zeolite under action of acid, followed by grafting with SnCl4·5H2O in dry isopropanol. Characterization of the thus-prepared Al-containing Snβ (Sn/pDeAlβ) zeolites with ICP, (pyridine probed) FTIR, and 27Al MAS NMR demonstrates the presence of Bronsted acid framework AlIII. Tetrahedral Lewis acidic SnIV is present, as ascertained by a combination of techniques such as EPMA, 119Sn Moβbauer, XPS, (pyridine probed) FTIR, and UV–vis. A closed SnIV configuration was implied by comparing of 119Sn solid-state MAS NMR and deuterated acetonitrile probed FTIR spectra with literature. The catalytic activity of the Al-containing Snβ was tested for the conversion of 1,3-dihydroxyacetone (DHA) into ethyl lactate (ELA), proceeding via pyruvic aldehyde (PAL). Despite the difference in synthesis between the classic hydrothermal Snβ reference and Sn/...

2-Hydroxypropionic acid, commonly known as lactic acid (LA), is a valuable chemical widely used for the manufacture of green solvents such as ethyl lactate and biodegradable polymers such as poly(lactic acid) (PLA). LA is manufactured by fermentation molasses and whey. Isolation of LA from aqueous broths by conventional methods is energy intensive. Reactive extraction through membranes using specific reagents could prove to be a cost-effective alternative for LA recovery. This study focuses on reactive separation of LA using a novel indigenously developed hydrophobic H-beta zeolite/polyvinylidene fluoride (PVDF) mixed matrix membrane. Experiments were conducted using a stirred cell assembly consisting of two bell shaped glass pipe reducers containing aqueous LA separated by the membrane from an organic solution of tri-n-octylamine (TOA) carrier in alcoholic medium. Effects of experimental parameters such as the concentration of TOA in organic phase and zeolite loading on the rate of acid extraction were e...

The focus of this work is on the growth mechanism of ethyl lactate-based plasma polymer film (ELPPF) that could be used as barrier coatings. In such an application, the ester density of the plasma polymer has to be controlled to tune the degradation rate of the material. Our strategy consists of correlating the plasma chemistry evaluated by RGA mass spectrometry and understanding, via DFT calculations, the chemistry of the synthesized thin films. The theoretical calculations helped us to understand the plasma chemistry in plasma ON and OFF conditions. From these data it is unambiguously shown that the signal m/z 75 can directly be correlated with the precursor density in the plasma phase. The combination of XPS and chemical derivatization experiments reveal that the ester content in the ELPFF can be tailored from 2 to 18 at. % by decreasing the RF power, which is perfectly correlated with the evolution of the plasma chemistry. Our results also highlight that the ELPPF chemistry, especially the ester content, is affected by the plasma mode of operation (continuous or pulsed discharge, at similar injected mean power) for similar ester content in the plasma. This could be related to different energy conditions at the interface of the growing films that could affect the sticking coefficient of the ester-bearing fragments.

In this work, we have investigated the behavior of 4-aminophthalimide (4-AP) in solvent mixtures of ethyl lactate (EL)− water and EL−n-heptane and in reversed micelles (RMs) media made of EL−water/sodium 1,4-bis(2-ethylhexyl)- sulfosuccinate (AOT)/n-heptane. We have used dynamics light scattering (DLS) and absorption, steady-state and time-resolved emission (TRES) techniques. 4-AP is a very interesting and unique molecule used to study preferential solvation in water mixtures since its emission profile changes dramatically when its sphere shell is solvated by water molecules. Thus, in homogeneous media 4-AP is strongly solvated by water in the EL−water mixture and by EL in the EL−n-heptane mixture, results that show the importance of the hydrogen bonding in the 4-AP solvation. We were motivated by this feature of 4-AP and have used it to monitor properties in AOT RMs. Thus, we use 4-AP spectroscopic behavior in conjunction with DLS technique to reveal the location of each polar solvent of the mixture encapsulated within the RMs media. We found that in the EL−water/ AOT/n-heptane RMs the results strongly depend on the amount of water dissolved. Below W0 = [water]/[AOT] = 5, there are no reversed micelles and EL, water, AOT and n-heptane forms a nonstructured mixture. For W0 values between 5 and 10, the droplet sizes are independent of the EL content because of its strong intermolecular interactions forms an EL polar core and only water is found at the interface. For W0 values higher than 10, the droplets size increase with the EL content and EL molecules are detected at the AOT RMs interface. We inferred that the RMs sizes will change only if the polar solvent encapsulated interacts with the interface changing the surfactant packing parameter. Then, we can assume that it is possible to create RMs with solvents that do not interact with the interface but can be encapsulated in the polar core. These results, give evidence that expand the knowledge about which are the factors that determine when RMs droplet sizes changes with the polar solvent content, giving insights that will help to control the sizes of the AOT RMs. This will open diverse avenues since RMs are interesting nanoreactors for heterogeneous chemistry, templates for nanoparticles and models for electron transfer reaction that happens in membranes. Fil: Durantini, Andres Matías. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Erbium(III) chloride in ethyl lactate is used as an environmentally very friendly system for the reaction of furfural and amines to yield diastereoselectively differently N,N-substituted trans-4,5-diaminocyclopent-2-enones as versatile synthetic intermediates to the formation of densely functionalized derivatives.

The aroma chemical composition of three sets of Spanish red wines belonging to three different price categories was studied by using an array of gas chromatographic methods. Significant differences were found in the levels of 72 aroma compounds. Expensive wines are richest in wood-related compounds, ethyl phenols, cysteinil-derived mercaptans, volatile sulfur compounds, ethyl esters of branched acids, methional, and phenylacetaldehyde and are poorest in linear and branched fatty acids, fusel alcohols, terpenols, norisoprenoids, fusel alcohol acetates, and ethyl esters of the linear fatty acids; inexpensive wines show exactly the opposite profile, being richest in E-2-nonenal, E-2-hexenal, Z-3-hexenol, acetoin, and ethyl lactate. Satisfactory models relating quality to odorant composition could be built exclusively for expensive and medium-price wines but not for the lower-price sample set in which in-mouth attributes had to be included. The models for quality reveal a common structure, but they are characteristic of a given sample set.

Poly(lactic acid) is a biodegradable polymer that has enormous potential for use as a replacement for some petroleum-based materials. However, the properties of this polymer depend strongly on the quality of the lactide monomer from which it is often synthesized. In this work, lactide was synthesized from alkyl lactate via a prepolymer route, and the reaction kinetics was compared with lactide synthesis from lactic acid. A number of different parameters were investigated in order to obtain the highest possible yield of lactide, as well as to achieve l-isomer selectivity. Among the various acid catalysts tested, Sn(Oct)2 was found to be the most effective for L-lactide selectivity as well as for producing a high oligomer yield from the alkyl lactate. The effect of the alkyl group length of the starting materials was investigated with the highest lactide yield being obtained from ethyl lactate, over methyl and butyl lactate. The deoligomerization reaction was also studied in detail. It was found that an oli...

Catalytic conversions involving water as a reactant, product, or solvent are of high importance in biomass conversion into fuels and chemicals. In this context, water-tolerant solid acids are highly valued. Polymer-oxide hybrid materials based on nonporous silica-supported sulfonic acid-containing polymer brush materials are proposed here as a new class of potentially water-tolerant solid acid catalyst. Atom transfer radical polymerization (ATRP), using both (i) an established and (ii) a new ATRP initiator that is designed to improve the hydrolytic stability of the catalyst, leads to creation of poly(styrene) brushes on the surface of fumed silica. These brushes are sulfonated to produce an acid catalyst akin to an acidic Merrifield resin, but with enhanced accessibility of the active sites. The catalysts are evaluated in the hydrolysis of ethyl lactate, with the polymer brush materials having the same activity as a homogeneous catalyst, p-toluenesulfonic acid, and being substantially more active than an ...

Isobaric vapor−liquid equilibrium (VLE) data were determined for the binary systems 3-methylbutan-1-ol (3-methyl-1-butanol) + ethyl (2S)-2-hydroxypropanoate (ethyl lactate) and pentan-1-ol (1-pentanol) + ethyl lactate at two pressures (13.0 and 101.3 kPa). The data were obtained using a vapor recirculating-type equilibrium device. Calculations of the nonideality of the vapor phase were made with the second virial coefficients evaluated from the Hayden−O’Connell method. VLE experimental data were tested by Herrington and a modified DECHEMA test, which proved their thermodynamic consistency. The activity coefficients and boiling points of the solutions were well correlated with the mole fraction using Wilson, NRTL, and UNIQUAC equations. The mixtures do not present azeotropes.

As a reversible reaction, the hydrolysis conversion of ethyl lactate is controlled by thermodynamic equilibrium. In order to improve the yield and conversion rate of hydrolysis of ethyl lactate, et...

Density, refractive index and speed of sound at 298.15 K, together with isobaric vapor−liquid equilibria data (VLE) at 101.3 kPa are reported for two binary mixtures, methanol + ethyl lactate and 1-propanol + ethyl lactate. Excess molar volumes on mixing were determined from the experimental data and consequently fitted with Redlich−Kister polynomials. VLE experimental data were tested by Dechema test, which proved their thermodynamic consistency. The activity coefficients were correlated with the Margules, van Laar, UNIQUAC, NRTL, and Wilson equations. The Analytical Solutions of Groups and Universal quasichemical Functional group Activity Coefficients models were also used for the prediction. Investigated binary systems did not show any azeotrope.

The mixed green solvent ethyl lactate + water is studied from macro- and microscopic viewpoints using a wide collection of experimental and computational tools. High-pressure thermophysical data, density, and dynamic viscosity provide valuable information on the macroscopic behavior of the mixed fluid, which is of remarkable importance for industrial purposes, and through the analysis of the derived excess and mixing properties lead to relationships with molecular level properties. Large deviations from ideality are obtained, which are related to the development of strong intermolecular hydrogen bonding between both molecules upon mixing. Computational studies, using the density functional theory, both in gas phase and water solution, allow to characterize, from energetic and structural viewpoints, the different ethyl lactate/water association complexes. The use of atoms in a molecule and natural bond orbital methods sheds light into the properties of ethyl lactate/water hydrogen bonding. Classical molecular dynamics simulations are carried out for the whole composition range, and as a function of pressure and temperature. Force field validation is done by comparison of predicted thermophysical properties with measured ones. Structural features are inferred from the analysis of radial distribution functions and their evolution with composition, pressure, and temperature, and dynamic aspects are inferred from the calculated self-diffusion constants and mean square displacements. The whole study points to a highly structured fluid, in which hydrogen bonding is developed both for water-rich and ethyl-lactate-rich solvents, showing a remarkable effect in the fluid structure upon the addition of the second component for both pure compounds, even more important for the effect of ethyl lactate on water hydrogen bonding network.

Room-temperature ionic liquids have been identified as nonvolatile, nonflammable compounds with a wide range of applications. However, numerous thermal studies have identified volatile decomposition products and a source for fuel, raising questions regarding the fire hazard of ionic liquids. To address these questions, the flammability properties of imidazolium-based ionic liquids have been measured using cone calorimetry and microscale combustion calorimetry. The combustion data are compared to flashpoints estimated from thermal gravimetric analysis data. The resulting flammability properties of ionic liquids are comparable to aliphatic hydrocarbon plastics (polyethylene and polyamide) and lower than high boiling organic solvents (ethyl lactate and dimethyl sulfoxide). Several structure−property relationships are observed, including alkyl chain length and anion type.

An analytical procedure for the separation and quantification of ethyl acetate, ethyl butyrate, ethyl hexanoate, ethyl lactate, ethyl octanoate, ethyl nonanoate, ethyl decanoate, isoamyl octanoate, and ethyl laurate in cachaca, rum, and whisky by direct injection gas chromatography-mass spectrometry was developed. The analytical method is simple, selective, and appropriated for the determination of esters in distilled spirits. The limit of detection ranged from 29 (ethyl hexanoate) to 530 (ethyl acetate) microg L(-1), whereas the standard deviation for repeatability was between 0.774% (ethyl hexanoate) and 5.05% (isoamyl octanoate). Relative standard deviation values for accuracy vary from 90.3 to 98.5% for ethyl butyrate and ethyl acetate, respectively. Ethyl acetate was shown to be the major ester in cachaca (median content of 22.6 mg 100 mL(-1) anhydrous alcohol), followed by ethyl lactate (median content of 8.32 mg 100 mL(-1) anhydrous alcohol). Cachaca produced in copper and hybrid alembic present a higher content of ethyl acetate and ethyl lactate than those produced in a stainless-steel column, whereas cachaca produced by distillation in a stainless-steel column present a higher content of ethyl octanoate, ethyl decanoate, and ethyl laurate. As expected, ethyl acetate is the major ester in whiskey and rum, followed by ethyl lactate for samples of rum. Nevertheless, whiskey samples exhibit ethyl lactate at contents lower or at the same order of magnitude of the fatty esters.

The catalytic conversion of esters and carboxylic acids into synthesis gas or chemicals could permit optimal utilization of organic intermediates such as pyrolysis bio-oils. To examine the ester moiety, two esters, ethyl lactate and ethyl propionate, and two acids, lactic acid and propionic acid, were reformed by catalytic partial oxidation. Autothermal reforming was examined over platinum and rhodium based catalysts supported on alumina foam monoliths at a contact time on the order of 10 ms. Conversions >98% were observed for all four fuels. The addition of cerium or lanthanum was found to increase the selectivity to synthesis gas. At higher fuel to oxygen ratios, nonequilibrium species such as ethylene and acetaldehyde were observed. Ethyl propionate produced twice as much ethylene as ethyl lactate but very little acetaldehyde. The additional hydroxyl group in ethyl lactate produced acetaldehyde such that the ratio of ethylene to acetaldehyde was ∼1:1. The results provide evidence that the homogeneous d...

Simultaneous decontamination of organic compounds and copper ions in the wastewater discharged from semiconductor manufacturing facilities by a UV/TiO2 photocatalytic degradation was investigated in this study. Two organic compounds of ethyl lactate and phenol and copper ions were studied due to their common applications in various wafer fabrication processes and higher toxicities. The optimal TiO2 dosage and initial pH for the photocatalytic oxidation of ethyl lactate and phenol were 0.1 g/L and 3.0−4.0. Photocatalytic degradation under these optimal conditions was able to simultaneously mineralize those solvents and remove copper(II) in the synthetic wastewater. Under anoxic condition, oxygen inhibited copper reduction and copper(II) ions were removed through precipitation. Under anaerobic conditions, the removal rate of copper(II) ions and the rate of reduction of the organic solvents content were lower than that in the aerobic condition.

The hydroformylation of vinyl acetate to form 2-acetoxypropanal (an important intermediate in the synthesis of the environmentally friendly solvent ethyl lactate) catalyzed by Rh(CO)2(acac) using p...

Densities and viscosities at (298.15, 308.15, and 318.15) K are presented as a function of mixture composition for the binary mixtures of ethyl lactate with methacrylic acid, benzyl methacrylate, and 2-hydroxyethyl methacrylate. From the experimental data, the excess molar volumes V E and viscosity deviations δη have been calculated. These results have been correlated with the Redlich−Kister type polynomial to derive the coefficients and standard deviation σ. McAllister's three-body and four-body interaction models were also used to correlate the kinematic viscosities. These model's parameters were treated to be temperature dependent.

A simple vapor−liquid equilibrium (VLE) apparatus has been constructed to successfully measure the VLE of binary ethyl lactate systems that have relatively high differences in volatility (P2sat/P1sat ∼ 7.0). Degassing is done in situ, reducing the experimental time considerably. Isothermal VLE of the ethyl lactate + ethanol system was measured at (40.0, 60.1, and 80.2) °C, and the isothermal VLE of the ethyl lactate + water system was measured at (40.0 and 60.0) °C. The ethyl lactate + ethanol system is slightly nonideal, and the ethyl lactate + water system forms a minimum boiling azeotrope. Isothermal data for ethanol + water were measured at 40.0 °C to demonstrate reliability of the apparatus.

Densities, refractive indices, speeds of sound, and isentropic compressibility at 298.15 K and isobaric vapor−liquid equilibria data at 101.3 kPa were reported for the binary mixtures ethyl acetate + ethyl lactate and methyl acetate + ethyl lactate. Excess molar volumes, refractive index deviations, changes of speed of sound, and changes of isentropic compressibility on mixing were calculated from the measurement results that were fitted with Redlich−Kister polynomials. VLE experimental data were tested for thermodynamic consistency by means of Dechema test and were demonstrated to be consistent. The activity coefficients were correlated with the Margules, van Laar, UNIQUAC, NRTL, and Wilson equations. The ASOG model also was used for prediction.

A large collection (n = 95) of Mexican Agave spirits with protected appellations of origin (Tequila, Mezcal, Sotol, and Bacanora) was analyzed using ion and gas chromatography. Because of their production from oxalate-containing plant material, all Agave spirits contained significant concentrations of oxalate (0.1-9.7 mg/L). The two Tequila categories ("100% Agave" and "mixed") showed differences in the methanol, 2-/3-methyl-1-butanol, and 2-phenylethanol concentrations with lower concentrations in the mixed category. Mezcal showed no significant differences in any of the evaluated parameters that would allow a classification. Sotol showed higher nitrate concentrations and lower 2-/3-methyl-1-butanol concentrations. Bacanora was characterized by exceptionally high acetaldehyde concentrations and a relatively low ethyl lactate content. The methanol content was the most problematic compound regarding the Mexican standards: two Tequilas (4%), five Sotols (31%), and six Bacanoras (46%) had levels above the maximum methanol content of 300 g/hL of alcohol. In conclusion, the composition of Mexican Agave spirits was found to vary over a relatively large range.

The continuous formation of ethyl lactate (L1E) from aqueous lactic acid solution and ethanol is carried out in a reactive separation column. Nearly complete conversion of lactic acid can be achieved with L1E yield exceeding 85%; byproduct lactate oligomer esters and acids formed can be further converted to additional L1E. Concentrated (88 wt % in water) lactic acid feedstock gives the best results, with as little as 40% excess ethanol required to achieve >95% conversion of lactic acid. Similar conversion can be obtained using 50 wt % lactic acid feed solution, but with much higher ethanol feed rates. Optimal column operation in both cases is observed with no reflux, so that operation is as a reactive stripping column. Limiting the quantity of ethanol added or vaporizing feed ethanol makes it possible to eliminate ethanol and water from the bottom stream of the column, thus simplifying recovery and purification of L1E product and facilitating the recycle of byproduct oligomers. Reaction of oligomeric bypr...

Reactors coupled with membrane separation, such as pervaporation, can help enhance the conversion of reactants for thermodynamically or kinetically limited reactions via selective removal of one or more product species from the reaction mixture. An example of these reactions is esterification of carboxylic acids and alcohols. Esterification of lactic acid (C3H6O3) and ethanol (C2H5OH) is studied in well-mixed reactors with/without a solid catalyst (Amberlyst XN-1010) in this paper. Rate expressions for homogeneous and heterogeneous esterification are obtained from the experimental data using differential and integral methods. Experiments with a closed-loop system of a “batch” catalytic reactor and a pervaporation unit reveal that fractional conversions of the two reactants and yield of ethyl lactate exceeding the corresponding maximum values in a reaction-only operation are obtained by stripping of the byproduct (water). The efficacy of pervaporation-aided esterification is illustrated by the substantial ...

Purified lactic acid is used for production of biodegradable polymer. Esterification with ethanol and subsequent hydrolysis in distillation columns to produce purified lactic acid without catalyst has obvious advantages. In this paper, we present a pilot-plant study of ethyl lactate hydrolysis to produce 3.86 kg/h lactic acid (99.85% purity) using three distillation columns. Simulation of distillation columns at steady state has been carried out, and the results obtained tally with the experimental results of the pilot plant.

Nine Saccharomyces cerevisiae and four Saccharomyces bayanus strains used in the production of Trebbiano wine were examined. The aim of this study is to evaluate the different abilities of various yeast strains in wine-making. The possibility of yeast discrimination on the basis of their volatile production is another possibility. Wine chemical analyses showed statistically significant differences depending on the yeast strain used. Some compounds such as 2-phenylethanol, 2-phenethyl acetate, ethyl lactate, 3-ethoxypropanol, and, to a lesser extent, diethyl succinate and propionic acid characterized examined Saccharomyces bayanus yeasts. Moreover, these strains did not produce any undesirable compounds, such as acetic acid and sulfur anhydride. For these reasons and because they synthesized malic acid, they could be more suitable for white wine production. The other yeasts showed great differences, which are difficult to correlate with the strain. However, some strains had peculiar characteristics, such as an uncommonly high concentration of n-propanol and 3-ethoxypropanol.

Liquid–liquid equilibrium data of ethyl lactate and poly(lactic acid) binary mixtures were measured at 0.1 MPa nominal pressure in the temperature range from (260 to 265) K. Cloud-point temperatures were measured using a dynamic method with visual detection of phase transitions (naked-eye determination of turbidity). This system exhibits an upper critical solution temperature (UCST) at Tc = 265.1 K and wPLA,c = 0.03776. The experimental data were modeled with the PC-SAFT equation of state, and new parameters for both compounds within the PC-SAFT frame are provided. The model correlates well with the observed experimental data.

A dynamic headspace analysis was performed on the volatile components of E802 Mazoferm steepwater, a condensed fermented corn extractive, that is highly attractive in laboratory and field tests to adult Mexican fruit flies, Anastrepha ludens (Loew). Chemical characterization was accomplished by capillary GC and GC/MS methods. A total of 19 compounds were identified, and these were comprised of 6 alcohols, 5 esters, 3 aldehydes, 2 lactones, an alkyl furan, an acid, and a trisulfide. When E802 Mazoferm steepwater was analyzed at pH 3.9, the five most abundant compounds in the volatiles (in descending order) were 3-methyl-1-butanol (43.9%), ethyl lactate (23.7%), ethanol (15.4%), 2-methyl-1-propanol (12.8%), and ethyl acetate (0.71%). At pH 8.0, the same five compounds were again the most abundant. Except for a reversal in order for the first two compounds, the order was the same: ethyl lactate (37.3%), 3-methyl-1-butanol (32.5%), ethanol (14.2%), 2-methyl-1-propanol (10.4%), and ethyl acetate (3.09%). Keyw...

2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DMHF) in absolute alcohol containing chlorophyll was exposed to light while being bubbled with oxygen. The photooxidation products, including ethyl pyruvate, ethyl lactate, acetic acid, ethyl 2-acetoxypropionate, acetoxyacetone, 1,2-ethanediol, acetoxy-2,3-butanedione, 2-oxopropyl 2-acetoxypropionate, lactic acid, and 2-acetoxypropionic acid were identified using gas chromatography (GC) and gas chromatography−mass spectrometry (GC-MS). Possible formation mechanisms for these products are postulated. The antiphotooxidative effect of capsanthin and lutein on DMHF in absolute alcohol containing chlorophyll was studied under light exposure while bubbling with oxygen. Both capsanthin and lutein showed the antiphotooxidative effect on DMHF, and their antiphotooxidative activity increased with increasing concentration. The activity of capsanthin, which contains 11 conjugated double bonds, a conjugated keto group, and one cyclopentane ring, was higher than that of lutein, wh...

Binary oxide, TeO 2 -MoO 3 , converted ethyl lactate selectively to pyruvate in a vapor-phase fixed-bed flow system. A synergy in activity was observed for TeO 2 -MoO 3 calcined at 500°C, showing a sharp maximum at a composition of MoO 2 -2TeO 3 , and it is concluded with evidence from powder XRD, IR, DTA-TGA, and SEM/PMA that α-Te 2 MoO 7 is the active species for the present system. TeO 2 -MoO 3 calcined at 400°C was a mixture of the component oxides and crystallized at 450°C to give α-Te 2 MoO 7 . Phase transition of the α-form to less active amorphous β-Te 2 -MoO 7 was observed by calcination at 600°C. An optimized catalyst with a composition of MoO 3 .2TeO 2 calcined at 500°C in air revealed a high conversion of lactate over 99% with 93% selectivity to pyruvate at 300°C

INDUSTRIAL CLEANING JOBS SUCH AS degreasing metal, stripping paint, and removing graffiti make heavy demands on a solvent: It should be effective, easy to remove, and cheap, but not harm the environment. Such a solvent does not exist, but the makers of ethyl lactate believe it comes pretty close. Halogenated hydrocarbons such as methylene chloride and other solvents based on petroleum are unquestionably effective, and their volatility makes them easy to remove. In addition, they are not expensive—30 to 35 cents per lb. But their problems on the environmental front are well documented. Ethyl lactate, though not as well known, offers an alternative to these traditional solvents since it has a high solubility for many materials and is environmentally benign. However, it is currently restricted to applications that are able to tolerate higher cost— $1.50 to $2.00 per lb, says Larry Cunningham, senior vice president for corporate affairs at Archer Daniels Midland (ADM). The current ...

Using pyridinium chlorochromate, ethyl lactate can be oxidized to ethyl pyruvate in a convenient time by carrying out the reaction in refluxing acetone.