Enthalpy of combustion and enthalpy of vaporization of 2-ethyl-2-methoxypropane and thermodynamics of its gas-phase synthesis from (methanol + a 2-methylbutene)

Rozhnov, A. M.; Сафронов, В.В.; Verevkin, Sergey P.; Sharonov, K. G.; Alenin, V. I.

doi:10.1016/s0021-9614(05)80199-5

Cited by 19 publications

(11 citation statements)

References 8 publications

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“…Rozhnov et al measured the energy of combustion and hence the standard enthalpy of formation of tert -amyl methyl ether during a study of the thermodynamics of the gas-phase synthesis reaction of this important gasoline oxygen additive. Because the unresolved problems with the earlier sample noted above pointed to difficulty in obtaining a pure sample and the measurements of Rozhnov et al were not based on CO 2 analyses, a repeat of the measurement of the energy of combustion was thought necessary. The energy of combustion obtained by Rozhnov et al, Δ c / M = −(39 273 ± 14) J·g -1 , compares with the value of Δ c / M = −(39 337.5 ± 1.2) J·g -1 obtained here (Table ).…”

Section: Discussionmentioning

confidence: 99%

“…Evans and Edlung 105 report an enthalpy of vaporization at 298.15 K of 33.3 kJ·mol -1 . Rozhnov et al list four different values for the enthalpy of vaporization of methyl tert -amyl ether at 298.15 K: 35.8 kJ·mol -1 from unpublished calorimetric measurements, 34.8 kJ·mol -1 derived from the vapor-pressure results of Cervenkova and Boublik, an evaluated value of (34.8 ± 1.5) kJ·mol -1 derived from group additivity, and an “assessed” value of (35.3 ± 1.5) kJ·mol -1 . Values of H m (C 6 H 14 O, 298.15 K) = (34.42 ± 0.12) kJ·mol -1 and (C 6 H 14 O, 298.15 K) = (34.64 ± 0.12) kJ·mol -1 are obtained in this research for the enthalpies of vaporization of tert -amyl methyl ether to the real and ideal gases, respectively, at 298.15 K.…”

Section: Discussionmentioning

confidence: 99%

“…r H°m ) -(27( 1) kJ‚mol -1 for reaction 13, and a standard enthalpy of formation for tert-amyl methyl ether of ∆ f H°m(C 6 H 14 O(l)) ) -(335 ( 1) kJ‚mol -1 , all in excellent agreement with the results obtained in this research. Using the Rozhnov et al96 enthalpy of formation ∆ f H°m(C 6 H 14 O(l)) ) -(341.79 ( 0.79) kJ‚mol -1 gives values for reactions 12 and 13 which are approximately 7 kJ‚mol -1 more negative, outside the boundaries set by the equilibria studies.…”

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confidence: 98%

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Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Methyl Benzoate, Ethyl Benzoate, (R)-(+)-Limonene, tert-Amyl Methyl Ether, trans-Crotonaldehyde, and Diethylene Glycol

Steele¹,

Chirico²,

Cowell³

et al. 2002

J. Chem. Eng. Data

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Ideal-gas enthalpies of formation of methyl benzoate, ethyl benzoate, (R)-(+)-limonene, tert-amyl methyl ether, trans-crotonaldehyde, and diethylene glycol are reported. The standard energy of combustion and hence standard enthalpy of formation of each compound in the liquid phase has been measured using an oxygen rotating-bomb calorimeter without rotation. Vapor pressures were measured to a pressure limit of 270 kPa or the lower decomposition point for each of the six compounds using a twin ebulliometric apparatus. Liquid-phase densities along the saturation line were measured for each compound over a range of temperature (ambient to a maximum of 548 K). A differential scanning calorimeter was used to measure two-phase (liquid + vapor) heat capacities for each compound in the temperature region ambient to the critical temperature or lower decomposition point. For methyl benzoate and tert-amyl methyl ether, critical temperatures and critical densities were determined from the DSC results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for each of the remaining compounds. The results of the measurements were combined to derive a series of thermophysical properties including critical temperature, critical density, critical pressure, acentric factor, enthalpies of vaporization (restricted to within ±50 K of the temperature region of the experimentally determined vapor pressures), and heat capacities along the saturation line. Wagner-type vapor-pressure equations were derived for each compound. All measured and derived values were compared with those obtained in a search of the literature. Recommended critical parameters are listed for each of the compounds studied. Group-additivity parameters, useful in the application of the Benson gas-phase group-contribution correlations, were derived.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 98%

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Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Methyl Benzoate, Ethyl Benzoate, (R)-(+)-Limonene, tert-Amyl Methyl Ether, trans-Crotonaldehyde, and Diethylene Glycol

Steele¹,

Chirico²,

Cowell³

et al. 2002

J. Chem. Eng. Data

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“…The few papers to have been published so far report experimental data. Equilibrium constants of the gas phase synthesis of TAME from methanol and methylbutene were determined by Rozhnov et al [4] at three temperatures. Safronov [5] examined the thermodynamics of the liquid-phase synthesis in the temperature range from 343 to 423 K; however, the authors combined the two reactive isoamylenes to a pseudo-component in their calculations, so that separate equilibrium constants of the two etherification reactions were not given.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of tertiary amyl methyl ether (TAME): Equilibrium of the multiple reactions

1995

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The octane enhancer tertiary amyl methyl ether (TAME) is produced by liquid phase synthesis from methanol and a mixture of isoamylenes, namely 2-methyl-1 -butene and 2-methyl-2-butene, using a sulfonic acid ion exchange resin as catalyst. Three reactions take place simultaneously in TAME synthesis: etherification of the two methylbutenes and their isomerisation. In order to study the equilibrium of the multiple reactions in TAME synthesis, the thermodynamic properties of the compounds in the liquid phase and equilibrium constants were calculated using a modified UNIFAC method to describe the nonideality of the system. Four parameters influencing the equilibrium conversion were derived and discussed in detail. Supplemental experiments were performed at three temperatures in the range from 303 to 343 K and at different initial molar ratios of educts. Equilibrium conversions of methanol were determined from these experiments and compared with calculated values. At 298 K the predicted activity based equilibrium constant was 22.9 for TAME synthesis from 2-methyl-1-butene and 1.6 for TAME synthesis from 2-methyl-2-butene; for isomerisation of 2-methyl-I-butene to 2-methyl-2-butene a value of 14.3 was obtained.

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“…(20) where R 2 is a correlation coefficient. Replacing the calculated ∆ vap H m 0 (298.15) value of MTAE by the appropriate calorimetric one 37 (Table 17) decreases the R 2 coefficient down to 0.9903 which proves a poor quality of the calorimetric data in ref 37.…”

Section: Table 12 Comparison Between Experimental and Calculated Entmentioning

confidence: 99%

Phase Equilibria and Thermodynamic Properties of Some Branched Alkyl Ethers

et al. 2009

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The low-temperature heat capacity and thermodynamic properties of the solid-to-solid transition and fusion of di-isobutyl ether (DIBE) were determined by adiabatic calorimetry in the temperature range from (8 to 373) K. The saturation vapor pressure of DIBE was determined by a comparative ebulliometry over the moderate pressure range from (10.8 to 99.6) kPa. A density of liquid DIBE was measured in the temperature interval from (298 to 313) K using a quartz pycnometer. The normal boiling temperature, T n.b. , the enthalpy of vaporization at T ) 298.15 K and T n.b. , and the ideal gas thermodynamic functions (changes of the entropy, enthalpy, and Gibbs energy) at T ) 298.15 K were derived. Appropriate thermodynamic functions over a wide temperature range from (150 to 1000) K and the standard enthalpy of formation at T ) 298.15 K were computed by the methods of statistical thermodynamics (ST) and the density functional theory (DFT) on the level B3LYP/6-31G(d,p). The experimental data on the vapor pressure of DIBE were extended to the entire range of liquid phase from the triple to the critical temperatures by the corresponding states law and combined treatment of the pT-parameters and the low-temperature differences between the heat capacities of the ideal gas and liquid. The data on thermodynamic properties of some branched ethers, C 5 to C 9 , studied earlier and in this work were critically analyzed for verification of their reliability and mutual consistency.

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Enthalpy of combustion and enthalpy of vaporization of 2-ethyl-2-methoxypropane and thermodynamics of its gas-phase synthesis from (methanol + a 2-methylbutene)

Cited by 19 publications

References 8 publications

Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Methyl Benzoate, Ethyl Benzoate, (R)-(+)-Limonene, tert-Amyl Methyl Ether, trans-Crotonaldehyde, and Diethylene Glycol

Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Methyl Benzoate, Ethyl Benzoate, (R)-(+)-Limonene, tert-Amyl Methyl Ether, trans-Crotonaldehyde, and Diethylene Glycol

Synthesis of tertiary amyl methyl ether (TAME): Equilibrium of the multiple reactions

Phase Equilibria and Thermodynamic Properties of Some Branched Alkyl Ethers

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