The molar heat capacities
of the pure samples of acetone and methanol, and the azeotropic mixture composed
of acetone and methanol were measured with an adiabatic calorimeter in the
temperature range 78–320 K. The solid–solid and solid–liquid
phase transitions of the pure samples and the mixture were determined based
on the curve of the heat capacity with respect to temperature. The phase transitions
took place at 126.160.68 and 178.961.47 K for the sample of
acetone, 157.790.95 and 175.930.95 K for methanol, which were
corresponding to the solid–solid and the solid–liquid phase transitions
of the acetone and the methanol, respectively. And the phase transitions occurred
at 126.580.24, 157.160.42, 175.500.46 and 179.740.89
K corresponding to the solid–solid and the solid–liquid phase
transitions of the acetone and the methanol in the mixture, respectively.
The thermodynamic functions and the excess thermodynamic functions of the
mixture relative to standard temperature 298.15 K were derived based on the
relationships of the thermodynamic functions and the function of the measured
heat capacity with respect to temperature.
Authors:H.-L. Liu, S.-J. Liu, Z.-L. Xiao, Q.-Y. Chen, and D.-W. Yang
Excess molar enthalpies of binary mixtures for tributyl
phosphate (TBP)+methanol/ethanol were measured with a TAM air Isothermal calorimeter
at 298.15 K and ambient. The results for xTBP+(1–x)CH3OH
are negative in the whole range of composition, while the values for xTBP+(1–x)C2H5OH
change from positive values at low x to
small negative values at high x. The experimental
results have been correlated with the Redlich–Kister polynomial. IR
spectra of the mixtures were measured to investigate the effect of hydrogen
bonding in the mixture.
The influence of microporous carbon oxidation on thermodynamic properties of methanol and ethanol adsorbed at 308, 328, and
348 K was investigated. Adsorption mechanisms are suggested and the obtained results are compared with the presented previously
for adsorption of methane and carbon tetrachloride on nonoxidised and oxidised microporous carbons.
Authors:G. Péter, D. Dlauchy, E. Szűcs, and J. Tornai-Lehoczki
In this study a simple and effective method was developed for the isolation of Saccharomyces strains from grapes. Aseptically collected grape samples were processed by enrichment in a nutritive basal medium supplemented with 10% (v/v) methanol followed by isolation of yeast strains. Sixteen of the 18 grape samples yielded Saccharomyces strain(s). More than 70% of the isolates belonged to the genus Saccharomyces. Based on phenotype and electrophoretic karyotyping, all strains of Saccharomyces were identified as S. cerevisiae. For several grape samples, varying physiological characters, the number of spores per asci, and the observed chromosome length polymorphisms provided evidence for diversity of S. cerevisiae strains obtained by this enrichment in methanol-containing broth. Results indicated that enrichment in methanol-containing broth is an effective alternative method to facilitate isolation of Saccharomyces strains from grapes. The enrichment method described in this work provides a simple and effective tool for isolation of Saccharomyces strains from grapes. The method may be applied in studying wine fermentation ecology, as well as for the isolation of potential starter strains from grapes.
Authors:B. Hunger, S. Matysik, M. Heuchel, and W.-D. Einicke
Using temperature-programmed desorption (TPD), we have investigated the desorption behavior after subsequent co-adsorption
of methanol and water and after adsorption of their mixtures on a NaZSM-5 zeolite. The course of desorption indicates that
a strong mutual displacement of both components occurs. However, on the strongest adsorption sites methanol is preferentially
adsorbed, and already the addition of small amounts of methanol leads to a displacement of water. Our results support the
idea of a subdivision of the pore space for adsorption of water/methanol mixtures. Above all, the experiments show that in
the part of the pore space where both components are adsorbed, different sites are of importance which vary significantly
in their interaction strength.
Authors:L. G. Gordeeva, A. A. Khassin, G. K. Chermashentseva, and T. A. Krieger
Methanol synthesis from carbon monoxide and hydrogen is one of the most important processes in chemical industry. The conversion of the reactants in a conventional tubular fixed-bed reactor is limited by the
Authors:T. Kimura, T. Matsushita, K. Ueda, K. Tamura, and S. Takagi
Excess enthalpies of six binary mixtures of CH3 OD+CH3 OH, CH3 OD+CD3 OD, CD3 OD+CH3 OH, C2 D5 OD+C2 H5 OH, C2 D5 OD+C2 H5 OD, C2 H5 OD+C2 H5 OH have been determined over the whole range of mole fractions at 298.15 K in order to know the isotopic effect on hydrogen-bonding
accurately, although there are many reports on the differences in the strength of hydrogen-bonding between OH and OD.
All excess enthalpies measured are very small and endothermic. The mixtures of CH3 OD+ CH3 OH, and C2 D5 OD+C2 H5 OH showed the largest excess enthalpies among each methanol and ethanol mixtures. The difference of intermolecular interaction
between OH and OD in methanol and ethanol was almost same value of (1.820.04) J mol-1
Excess enthalpies of 1,4-dimethylbenzene+1,3-dimethylbenzene and 1,4-dimethylbenzene+1,2-methylbenzene were measured by three
different principle calorimeters at 298.15 K in order to know the precision of calorimetry for a small enthalpy change.
Authors:B. Kupcsulik, B. Sevella, A. Ballagi, and J. Kozma
, H. & Delgado, J. M. (1997): Different methanol feeding strategies to recombinant Pichia pastoris cultures producing high level of dextranase. Biotech. Tech. , 11 , 461-466.
Different methanol feeding strategies to
Catalytic generation of hydrogen by the steam reforming of methanol is an attractive option for use in the decentralized production of clean electrical energy from fuel cells [ 1 ].
The main reactions that