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Carbonate esters and esters were commonly used as solvents, reaction carrier, and additives in organic synthesis, the pharmaceutical industry, and processing industries. Vapor–liquid equilibrium (V...

Quaternary Cu/B/Ca/Al2O3 catalyst extrudates were prepared and optimized for hydrogenation of sec-butyl acetate (SBA) to 2-butanol and ethanol. The rationally designed catalyst with a B/Cu molar ratio of 3/1 exhibited an extraordinary resistance to Cu sintering during the reaction over 1000 h, due to the enhanced interaction by B2O3 between copper species and support. The slight loss in activity after the long-term test, caused mainly by the partial transformation of surface CaO to calcium acetate, could be easily recovered by calcination and the following reduction treatments, rendering it feasible to apply the catalyst to the industrial hydrogenation of SBA.

This article proposes a novel strategy for enhancing the dispersion and stability of supported H3PW12O40 (HPW) via the charge interaction between HPW anions and amino groups originating from ethylenediamine (ED) grafted on the unsaturated metal sites of MIL-101. Due to its larger specific surface area and pore volume as well as stronger interactions between HPW and the carrier, the as-prepared catalyst exhibited a higher sec‑butyl acetate (SBAC) yield for the direct esterification of olefins than did the catalyst prepared by the encapsulation of HPW in the mesoporous cages of MIL-101. In addition, the HPW content incorporated in the as-prepared catalyst was optimized, and the results showed that among the series of catalysts, the HPW/ED-grafted MIL-101 catalyst with 40 wt% HPW had the highest activity and good stability for olefin esterification. This investigation sheds light on the conversion of 1-butene into high-value SBAC via the amine-functionalized MIL-101-supported HPW catalysts.

Liquid–liquid equilibrium (LLE) data for the ternary system sec-butyl alcohol + sec-butyl acetate + ethylene glycol were determined at 298.2, 308.2, and 318.2 K under 101.3 kPa. The extraction capa...

Citation suggérée :Anses. (2021). Évaluation des méthodes de mesure de neuf substances de la directive (UE) 2019/1831. (saisine 2020-SA-121). Maisons-Alfort : Anses, 269 p.; L’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (Anses) élabore et recommande plusieurs types de valeurs de référence dans l’air fondées sur des critères exclusivement sanitaires, permettant de caractériser le lien entre une exposition aérienne à une substance chimique et l’occurrence d’un effet néfaste observé. Ces valeurs élaborées par le CES « Valeurs sanitaires de référence » peuvent ensuite être utilisées par les pouvoirs publics en vue de fixer des valeurs réglementaires : • les valeurs limites d’exposition professionnelle (VLEP) ; • les valeurs guides de qualité d’air intérieur (VGAI) Le dispositif français d’établissement des VLEP comporte trois phases clairement distinctes : • une phase d’expertise scientifique indépendante confiée à l’Afsset dans le cadre du plan santé au travail 2005-2009 (PST), puis à l’Anses suite à la fusion de l’Afsset et de l’Afssa en 2010 ; • une phase d’établissement d’un projet réglementaire de valeur limite contraignante ou indicative par le ministère chargé du travail ; • une phase de concertation sociale lors de la présentation du projet réglementaire au sein du Conseil d’Orientation sur les Conditions de Travail (COCT). L’objectif de cette phase étant de discuter de l’effectivité des valeurs limites et de déterminer d’éventuels délais d’application, fonction de conditions de faisabilité technico-économique. Le contrôle technique des VLEP est encadré par les dispositions du Code du travail (articles R. 4412-27 à R. 4412-31 pour les agents chimiques dangereux et articles R. 4412-76 à R. 4412-80 pour les agents chimiques classés cancérogènes, mutagènes et toxiques pour la reproduction (CMR)). Ces dispositions sont complétées par l’arrêté du 15 décembre 2009 relatif aux contrôles techniques des valeurs limites d'exposition professionnelle sur les lieux de travail et aux conditions d'accréditation des organismes chargés des contrôles (publié au journal officiel du 17 décembre 2009). Pour faire face à l’enjeu sanitaire que représente la qualité de l’air intérieur et apporter aux pouvoirs publics des éléments utiles à la gestion de ce risque, l’Anses s’est autosaisie en 2004 afin d’élaborer des valeurs guides de qualité d’air intérieur (VGAI) en France. Les VGAI proposées par l’Anses constituent le socle initial du processus institutionnel visant à fixer des valeurs réglementaires de surveillance de la qualité de l’air intérieur. Afin d’appuyer les pouvoirs publics dans l’élaboration de valeurs opérationnelles permettant de mettre en place des actions d’amélioration de la qualité d’air intérieur, le ministère chargé de la santé sollicite usuellement le Haut conseil de la santé publique (HCSP) en vue de proposer, à partir des VGAI de l’Anses, des valeurs repères d’aide à la gestion dans l’air des espaces clos, ainsi qu’un calendrier pour leur déploiement. Le HCSP tient compte, dans ses propositions, de considérations pratiques, réglementaires, juridiques, économiques et sociologiques.Enfin, conformément à la loi du 1er août 2008 relative à la responsabilité environnementale, les VGAI réglementaires sont établies par le ministère chargé de l’écologie, inscrites dans le code de l’environnement et sont associées à des mesures de gestion. La surveillance de la qualité de l’air intérieur se met en place progressivement notamment dans les établissements accueillant des enfants. Les mesures de polluants seront en particulier mises en regard des valeurs-guides pour l’air intérieur et de valeurs déclenchant des investigations complémentaires. Les travaux d’expertise de l’Anses concernant les VGAI et les VLEP comprennent également une évaluation des méthodes de mesures disponibles pour la comparaison des niveaux d’exposition sur le lieu de travail et dans l’air intérieur avec les valeurs recommandées par l’Anses et les directives européennes.

Citation suggérée : Anses. (2021). Evaluation des méthodes de mesure de neuf substances de la directive (UE)2019/1831. (saisine 2020-SA-121). Maisons-Alfort : Anses, 269 p.; Des objectifs européens de protection des travailleurs vis à vis des risques liés à des expositions à des agents chimiques sont fixés via des directives européennes notamment sous la forme de VLEP.Dans la mesure où pour l’établissement de VLEP européennes, la Commission européennes’appuie sur des recommandations émises par des comités d’experts scientifiques européens (le SCOEL ou le RAC), une réévaluation des effets sanitaires des substances concernées n’est pas effectuée par l’Anses lorsque des directives européennes fixant des VLEP sont publiées.Par contre, étant donné qu’aucune évaluation approfondie des méthodes de mesure disponibles au regard des VLEP européennes n’est réalisée par ces comités européens, l’Anses est saisie pour réaliser ces évaluations afin que le ministère français chargé du travail puisse disposer de l’ensemble des éléments nécessaires pour fixer la nature contraignante ou indicative de la valeur limite dans le droit national.La directive (UE) 2019/1831 de la Commission du 24 octobre 2019 établit une cinquième liste de valeurs limites indicatives d’exposition professionnelle pour 10 agents chimiques en application de la directive 98/24/CE du Conseil et modifiant la directive 2000/39/CE de la Commission.

Isobaric vapor–liquid equilibrium (VLE) data at 101.3 kPa for three binary systems, which are 1,2-dichloroethane + sec-butyl acetate, 1,2-dichloroethane + n-propyl acetate, and 1,2-dichloroethane + tert-butyl acetate, were reported in this work. The thermodynamic consistency of all experimental data was performed with the Herington and Van Ness tests, and the regression of the VLE data for the nonrandom two-liquid, universal quasi-chemical, and Wilson activity coefficient models gave binary interaction parameters that can be used in process simulation. Both the 1,2-dichloroethane + sec-butyl acetate and 1,2-dichloroethane + n-propyl acetate binary systems exhibit positive deviations from ideality, while the 1,2-dichloroethane + tert-butyl acetate binary system exhibits a negative deviation from ideality.

We previously identified and characterized 1 novel deep-sea microbial esterase PHE21 and used PHE21 as a green biocatalyst to generate chiral ethyl (S)-3-hydroxybutyrate, 1 key chiral chemical, with high enantiomeric excess and yield through kinetic resolution. Herein, we further explored the potential of esterase PHE21 in the enantioselective preparation of secondary butanol, which was hard to be resolved by lipases/esterases. Despite the fact that chiral secondary butanols and their ester derivatives were hard to prepare, esterase PHE21 was used as a green biocatalyst in the generation of (S)-sec-butyl acetate through hydrolytic reactions and the enantiomeric excess, and the conversion of (S)-sec-butyl acetate reached 98% and 52%, respectively, after process optimization. Esterase PHE21 was also used to generate (R)-sec-butyl acetate through asymmetric transesterification reactions, and the enantiomeric excess and conversion of (R)-sec-butyl acetate reached 64% and 43%, respectively, after process optimization. Deep-sea microbial esterase PHE21 was characterized to be a useful biocatalyst in the kinetic resolution of secondary butanol and other valuable chiral secondary alcohols.

Data for two systems of isobaric vapor–liquid equilibrium (VLE), n-heptane + sec-butyl acetate (SBAC) and methylcyclohexane + SBAC, were determined under atmosphere with an Ellis vapor–liquid equilibrium still. The Herington method and Wisniak test were employed to determine the thermodynamic consistency of the two systems. The experimental results of n-heptane + SBAC and methylcyclohexane + SBAC were correlated by three activity coefficient models, which are the nonrandom two-liquid, universal quasichemical, and Wilson, and the correlation results fit well with experimental data. The binary interaction parameters of these models were obtained, and the results showed that these models can give good predictions. The VLE data provide theoretical basis and data support for the further study on separation of n-heptane + SBAC and methylcyclohexane + SBAC.

The vapor–liquid equilibrium (VLE) data of the ethanol + sec-butyl acetate, 1-propanol + sec-butyl acetate, and 2-propanol + sec-butyl acetate mixtures were determined at 101.3 kPa. The first principle quantum chemistry calculation method, which focuses on the hydrogen bond and interaction energies, is used to give insight into interactions at the molecular level. The experimental VLE data passed the thermodynamic consistency test. The data were regressed using Wilson, nonrandom two liquids, and universal quasi-chemical equations. The 1-propanol + sec-butyl acetate mixture forms a minimum temperature azeotropic mixture. The azeotropic temperature is 370.01 K, and the composition of 1-propanol is 89.2 mol % when calculated with the Wilson model.

Two supported ionic liquids using molecular sieve SBA-15 as supporter were prepared and employed as efficient catalysts for the synthesis of 2-butanol (SBOH) via the transesterification of sec-butyl acetate and methanol (MeOH). [SBA-15-Ps-im]HSO4 performed better in the catalytic activity and was chosen for further studying the influence of experimental conditions. The effects of various parameters, such as the catalyst dosage, initial reactant molar ratio, and reaction time on the reaction were investigated systematically. The maximum conversion of sec-butyl acetate (89.2%) was obtained under the optimum reaction conditions. In addition, the catalyst of supported ionic liquids can be easily separated by simple filtration, and the reusability test indicates that the catalyst has outstanding utility for repeated use. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.

Isobaric vapor–liquid equilibrium (VLE) for the binary system N , N -dimethyl formamide (DMF) + N , N -dimethyl acetamide (DMAC) and the quaternary system sec -butyl alcohol (SBA) + sec -butyl acetate (SBAC) + DMF + DMAC were determined at 101.3 kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the experimental data was checked by Van Ness point test. The binary VLE data were correlated with the NRTL, UNIQUAC and Wilson activity coefficient models respectively. And the VLE data of the quaternary system predicted by the correlated binary interaction parameters agree well with the experimental data. And the mixture of DMF (3) and DMAC (4) can eliminate the pseudo-azeotrope of sec -butyl alcohol (1) + sec -butyl acetate (2). Thus, the mixture of DMF and DMAC is appropriate for separation of the pseudo-azotrope of SBA and SBAC by extractive distillation.

Sec-butyl alcohol (SBA), an important chemical intermediate, is widely used in the synthesis of methyl ethyl ketone, herbicides and other products. However, there are some problems, such as high energy consumption and high equipment investment, in the traditional method of SBA production. With the mature application of the synthesis method of sec-butyl acetate (SBAC) in industry, the excess capacity of SBAC gradually appears. The synthesis of SBA from SBAC has become a research hotspot. SBA synthesized via the hydrolysis of SBAC has the advantages of fewer byproducts and wide sources of raw materials, but it has the limitation of a low degree of hydrolysis. In this study, based on Douglas’s economic optimization model, taking the total annual cost (TAC) as the objective function, the influencing factors and suitable operating conditions of the SBAC hydrolysis reactive extractive distillation process were explored, and TAC was obtained under the optimal operating conditions. The environmental performance of the process was studied according to life cycle analysis. The exergy efficiency was obtained based on thermodynamic analysis. The process was analyzed from the aspects of exergy, environment and economy, which provided theoretical guidance for the industrial design of the new SBA process.

Isobaric vapour - liquid equilibrium (VLE) data for the binary systems of sec-butyl acetate (SBAC) + acetamide and sec-butyl alcohol (SBA) + acetamide and the ternary system of SBAC + SBA + acetamide were measured at 101.3 kPa using a modified Othmer still. The thermodynamic consistency tests for the experimental data were checked by Van Ness point test and Wisniak’s L-W method. The experimental VLE data of the binary systems were correlated with NRTL, Wilson and UNIQUAC activity coefficient models. The results indicate that the binary and ternary VLE data predicted by the three models agree well with the experimental data. And the ‘pseudo-azeotropic’ phenomenon of sec-butyl acetate + sec-butyl alcohol mixture can be eliminated by acetamide.

Isobaric vapor–liquid equilibrium (VLE) data for the quaternary system sec-butyl alcohol + sec-butyl acetate + N, N-dimethyl formamide (DMF) + dimethyl sulfoxide (DMSO) and the constituent binary system DMF + DMSO were determined at 101.3 kPa with a modified Othmer still. The measured experimental data of binary and quaternary systems were certified to be thermodynamically consistent according to the Van Ness method. And the experimental binary data were correlated by Wilson, NRTL and UNIQUAC activity coefficient models. The rest of binary interaction parameters have been obtained in our previous work. Then, the binary and quaternary vapor–liquid equilibrium were predicted by the models with the correlated parameters. The results show that the three models yield a good prediction for the binary and quaternary systems. But NRTL model performed better than the other two models in predicting VLE of the quaternary system.

The isobaric vapor–liquid equilibrium (VLE) data of methyl ethyl ketone (MEK) + sec-butyl acetate (SBAC), 2-methoxyethanol + SBAC, and 1, 2-dimethoxyethane (DME) + SBAC were determined at 101.3 kPa by using an Ellis vapor–liquid equilibrium still. The experimental data passed the thermodynamic consistency test by Herington method and Wisniak test. The VLE values were correlated by the nonrandom two-liquid (NRTL), universal quasichemical activity coefficience (UNIQUAC), and Wilson activity-coefficient models. The results indicated that the three models had good agreement with the experimental data. The 2-methoxyethanol + SBAC system forms a minimum temperature binary azeotrope at 101.3 kPa. The azeotropic temperature is 383.86 K, and the composition of SBAC is 85.1 mol %.

Isobaric vapor–liquid equilibrium (VLE) of sec-butyl acetate + para-xylene binary system and methyl acetate + para-xylene + sec-butyl acetate + acetic acid quaternary system were determined at 101.3 kPa in a modified Rose still, so as to provide a basis for the design and simulation of the separation process of acetic acid dehydration system. In the present study, the L–W integral test was used to check the thermodynamic consistency of binary VLE data. The results indicated that the thermodynamic consistency of binary VLE data measured in this paper was satisfactory. Furthermore, binary experimental data were correlated well by three models, which are the NRTL, Wilson and UNIQUAC models, respectively. Subsequently, the corresponding binary interaction parameters of each model were obtained. In addition, the NRTL activity coefficient model in combination with Marek–Standart chemical theory was used to predict the quaternary system VLE data for the association of acetic acid.

Isobaric vapor–liquid equilibrium (VLE) data were measured for the binary systems sec-butyl alcohol + N,N-dimethyl acetamide (DMAC), sec-butyl acetate + DMAC and the ternary system sec-butyl alcohol + sec-butyl acetate + DMAC at 101.3 kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the binary experimental data was made by Herington method and McDermott–Ellis method. And the thermodynamic consistency test for the ternary experimental data was made by McDermott–Ellis method. The binary VLE data were correlated with the NRTL, Wilson and UNIQUAC activity coefficient models. The obtained binary interaction parameters were used to predict the binary and ternary VLE data. The results indicate that the calculated values of vapor phase mole fraction and boiling temperature by the NRTL, Wilson and UNIQUAC models agree well with the experimental data. And the binary pseudo-azeotrope of sec-butyl alcohol and sec-butyl acetate was eliminated when the mass ratio of DMAC to the pseudo-azeotrope mixture is 6:5. Thus, DMAC is an appropriate solvent for separation of the mixture of sec-butyl alcohol and sec-butyl acetate in extractive distillation.

Cu/ZrO2 catalysts with or without boron modification were prepared, characterized, and evaluated in the hydrogenation of sec-butyl acetate (SBA) to 2-butanol. Cu/ZrO2 catalysts were active for the hydrogenation of SBA but suffered serious deactivation due to the leaching of Cu. Introduction of boron onto Cu/ZrO2 catalysts improved the dispersion of Cu species, the surface Cu+/Cu0 ratios, and the catalyst stability owing to the enhanced interaction between Cu species and support. However, it decreased the intrinsic activity of Cu towards the hydrogenation of SBA and complicated the reaction network by accelerating acid-catalyzed isomerization and transesterification processes as a result of the strengthened acidity by boron. A further kinetic analysis unravelled that the reaction orders for SBA and H2 are 0.58 and 0.83, respectively, and the apparent activation energy is 47 kJ/mol. Such understanding of the structural evolution of CuB/ZrO2 catalysts and the consequent catalytic performances with the B contents may provide insights useful for the design of Cu catalysts with desirable stability for hydrogenation of SBA and other esters.

Isobaric vapor–liquid equilibrium (VLE) data were measured for the binary systems sec-butyl alcohol + dimethyl sulfoxide (DMSO), sec-butyl acetate + DMSO and the ternary system sec-butyl alcohol + sec-butyl acetate + DMSO at 101.3 kPa using a vapor–liquid equilibrium still. The thermodynamic consistency test for the binary experimental data was made by Herington method, Wisniak's L–W method and a point to point method of Van Ness test described by Fredenslund et al. And the thermodynamic consistency of the ternary system was checked by Van Ness test. The VLE data for the binary systems were correlated with the NRTL, Wilson and UNIQUAC activity coefficient models. And the binary and ternary VLE data predicted by the obtained binary interaction parameters agree well with the experimental data. The experimental results show that the relative volatility between sec-butyl alcohol and sec-butyl acetate is changed obviously when the mass ratio of DMSO to the pseudo-azeotrope mixture is 6:5. And DMSO is a promising extractive agent for the separation of the mixture of sec-butyl alcohol and sec-butyl acetate in extractive distillation.

Isobaric vapor–liquid equilibrium (VLE) data for the sec-butyl acetate + acetic acid binary system, as well as the sec-butyl acetate + acetic acid + water ternary system, were measured at 101.33 kPa using a modified Rose still. The second virial coefficients and apparent fugacity coefficients were calculated to analyze the nonideal behavior in vapor phase caused by the association of acetic acid, which were corrected by the chemical theory and Hayden–O’Connell method. The binary experimental data were tested for thermodynamic consistency by the Herington method and the point-to-point test and correlated by the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) models using the nonlinear least-squares method. The model parameters of the binary system were used to correlate the ternary VLE data. The ternary correlated values obtained in this way agreed well with the experimental values.

以经氧化钙和氧化硼改性的氧化铝为载体，采用浸渍法制备了负载型CuO/Al 2 O 3 催化剂，采用XRD、BET、TPR和NH 3 -TPD技术对催化剂CuO/Al 2 O 3 进行了表征. 结果表明，氧化硼既可以作为结构性助剂提高铜在催化剂表面的分散度，又可以作为电子性助剂有利于催化剂表面氧化铜物种的稳定；氧化钙的引入降低了催化剂表面酸性，有利于催化剂的选择性提高. 采用氧化硼和氧化钙改性的Cu10B20Ca30为催化剂，醋酸仲丁酯转化率可达99.5%，生成仲丁醇和乙醇的选择性分别达98.9%和97.8%.

Isobaric vapor-liquid equilibrium(VLE) data for acetic acid + sec -butyl acetate and water + acetic acid + sec -butyl acetate systems were determined at 101.3 kPa using a modified Rose type. The nonideality of the vapor phase caused by the association of the acetic acid was corrected by the chemical theory and Hayden-O'Connell method. Thermodynamic consistency was tested for the binary VLE data. The experimental data were correlated successfully with the Non-Random Two Liquids (NRTL) model. The Root Mean Square Deviation (RMSD) of the ternary system was 0.0038. The saturation vapor pressure of sec -butyl acetate at 329 to 385 K was measured by means of two connected equilibrium cells. The vapor pressures of water and sec -butyl acetate were correlated with the Antoine equation. The binary interaction parameters and the ternary VLE data were obtained from this work.

A material-conserving analytical solubility measurement technique, with in-line reversed HPLC separation protocol, was employed to measure the mole fraction solubility of lovastatin in methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, tert-butyl acetate, acetone, and 2-butanone between (285 and 313) K. We examine three methods for the estimation of the ideal solubility of lovastatin by using different approximations for the difference between the heat capacity of the solid and the liquid at the melting point ΔCP = CPL − CPS. The solubility data were combined with calculated ideal solubility data to determine the activity coefficients of lovastatin which are then fitted to a van’t Hoff form equation to obtain estimated values of the partial molar enthalpy of mixing, ΔmixH∞, and partial molar entropy of mixing, ΔmixS∞, respectively. Thermodynamic consistency was confirmed when ΔCP = CPL − CPS was used in the ideal solubility calculation.

A simple and efficient method based on the technique of packed column switching-back flushing was established for the analysis of the ester compounds (including ethyl acetate, sec-butyl acetate, dimethyl carbonate) in gasoline. With the use of a non-polar pre-column, we successfully separated the components in gasoline by back flushing out components heavier than n-octane, while the lighter components and the ester compounds were flushed into a polar analytical column. In this method, external standard method was applied for quantification. As a result, good linear relationships existed among the three ester compounds in the range of 50 mg/L to 50 000 mg/L. The linear correlation coefficients (r2) for ethyl acetate, sec-butyl acetate and dimethyl carbonate were 0.999 99, 1.000 00 and 0.999 95, respectively. The relative standard deviations (RSDs) of standard samples in six continuous tests were within 1.0%. The recoveries were between 98.7% and 107.9%. The detection limit of the method (S/N = 3) was 5 mg/L. No pretreatment was needed. This method is simple, accurate, quick as well as efficient, and can be used as an ideal method for the analysis of the ester compounds in gasoline.

A kinetic isotope effect of ca. 2 was obtained for the pyrolysis of either 1,1,1-trideuterio-2-butyl acetate or erythro-2-butyl-3-d 1 acetate over glass beads. Under the same reaction conditions, except for the use of a high surface area silica rather than glass beads, the isotope effect was lower. With the high area silica, 2-butanol dehydration produced no isotope effect, and, in contrast to acetate pyrolysis, the silica catalyzed H-D exchange during the formation of the butene products. Butene and D 2 O did not undergo exchange under the alcohol dehydration conditions. It is concluded that surface catalysis during acetate pyrolysis over low surface area glass beads does not make an important contribution but may with high surface area silica

Measurements of the rates of disappearance of n -propyl and sec-butyl acetates and of tetrahydrofuran, relative to that of isobutene, in irradiated NO x -hydrocarbon mixtures in air at 1 atmosphere total pressure in two environmental chambers (each of ≈6000-l volume) have been used to derive relative rate constants for the reaction of the hydroxyl radical with these organics. Using a literature rate constant for the reaction of OH radicals with isobutene of 3.05 × 10 10 l mole −1 s −1 the following absolute rate constants at 305 ± 2 K are obtained: ( k × 10 −9 l mole −1 s −1 ) n -propyl acetate, 2.6 ± 0.5; sec-butyl acetate, 3.4 ± 0.7; tetrahydrofuran, 8.8 ± 1.8. In addition, a flash photolysis-resonance fluorescence technique has been used to obtain an upper limit of k ⩽ 1 × 10 8 l mole −1 s −1 at 299 ± 1 K for the reaction of OH radicals with peroxyacetyl nitrate (PAN) which is structurally related to the acetates by the replacement of an alkyl group by an NO 3 group. The reactions of OH radicals with the ethers and acetates are fast and are discussed in terms of the effects of structure on reactivity, as well as their implications to assessments of hydrocarbon reactivity.

The decomposition of sec-butyl acetate on de-ashed 20-to 30-mesh coconut-shell charcoal (1500 m2/g) was studied in a fixed bed reactor in the temperature range 300–375°C, and at partial pressures of 1 atm. and 0.29 atm. The ester decomposed principally to n-butene and acetic acid, and only small amounts of other products were found. The ratio of 1-butene to 2-butene was about 1:1, very close to that observed for thermal decomposition of the ester but far removed from the equilibrium butene ratio. The butene selectivity was independent of conversion. The rate of reaction followed the rate equation r = kA PE/1 + APE This expression corresponds to surface reaction on one site being rate controlling. The activation energy of rate constant k was 32.7 kcal/mole, compared to 46.6 kcal/mole for the gas-phase reaction. The temperature dependence of adsorption constant A showed a heat adsorption of 12 kcal/mole. Gas chromatographic measurements confirmed this value and also showed that ester is the principal adsor-bate on the charcoal.

Vapor-liquid equilibrium data of hexamethyl disiloxane + sec-butyl acetate system at 101.3 kPa was measured by using double circulating vapor-liquid equilibrium still. The thermodynamic consistency of the VLE data was examined by Herrington method. Experimental data was correlated by NRTL and UNIQUAC parameter models. Both of the models satisfactorily correlated with the VLE data. The result showed that the UNIQUAC model was the most suitable one to represent experimental data satisfactorily. The UNIQUAC standard deviation in temperature and in vapor phase composition were 0.3338, and 0.0114, respectively.