• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.637-640
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• 2005

The density of polar-nonpolar liquid mixtures composed of methyl tert-butyl ether(MTBE) and 2,2,4-trimethylpentane, and methyl ethyl ketone (MEK) and 2,2,4-trimethylpentane, and the density of polar-polar liquid mixture of MTBE and MEK were measured by densitometer at 278.15 K, 288.15 K and 298.15 K, respectively. The excess molar volume of the binary systems calculated from the measured density was shown good agreement with the calculated one by the cubic Peng-Robinson- Stryjek-Vera (PRSV) equation of state together with Huron-Vidal mixing rule and it confirmed that the cubic PRSV equation of state could be used in the molar volume calculation of polar mixture.

• Fire Science and Engineering
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• v.13 no.1
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• pp.11-19
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• 1999

The flash point is generally used as a hazardous index of fire and explosion of a flammable liquid. A classification of the flash points is important for the safe handling of flammable liquids such as solvent mixtures. The flash points of pure substances and solvent mixtures can be c calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and a activity coefficient models. In this study, experimentally determined lower and upper flash points w were compared with the calculated values by using Raoult's law and van Laar equation. The flash points of pure substances were in agreement with the calculated values by vapor pressure and e explosive limits. Also, the lower flash points of M.E.K(methylethylketone)-toluene system were i in agreement with the predicted values by Raoult’s law, and the upper flash points were in a agreement with the predicted values by van Laar equation. By means of this methodology, it is possible to evaluate reliability of expermental data of the flash points of the flammable mixtures.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.70-75
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• 2008

The values of the AIT(Autoignition temperature) for fire and explosion protection are normally the lowest reported. The minimum autoignition temperature behavior(MAITB) of flammable liquid mixtures is exhibited when the AIT of mixture is below the AIT of the individual components. The MAITB is an interesting experimental features, which can be significant from the perspective of industrial safety. In this study, the AITs of m-xylene+n-butyric acid and ethylbenzene+n-butanol systems were measured using ASTM E659-78 apparatus. The AITs of m-xylene, n-butyric acid, ethylbenzene and n-butanol which constituted two binary systems were $587^{\circ}C$, $510^{\circ}C$, $475^{\circ}C$ and $340^{\circ}C$ respectively. The m-xylene+n-butyric acid system is exhibited MAITB at 0.3 mole fraction of m-xylene, and its minimum autoignition temperature was $460^{\circ}C$.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.86-91
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• 2015

The flash point is used to categorize inflammable liquids according to their relative flammability. Such a categorization is important for the safe handling, storage, and transportation of inflammable liquids. The flash point temperature of two binary liquid mixtures(n-octane+n-decane and n-octane+n-dodecane) has been measured for the entire concentration range using Seta-flash closed cup tester based on the ASTM D3278 method. The closed cup flash point temperature was estimated using the UNIFAC(Universal Functional Activity Coefficient) group contribution model. The experimentally derived flash point was also compared with the predicted flash point from the UNIFAC model. The UNIFAC model is able to estimate the flash point fairly well for n-octane+n-decane mixture and n-octane+n-dodecane mixture.

• International Journal of Safety
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• v.7 no.2
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• pp.12-16
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• 2008

Lower flash points for the binary systems, carbon tetrachloride+o-xylene and water+n-butanol were measured by Pensky-Martens closed cup tester. The Raoult's law and optimization method using van Laar equation were used to predict the lower flash points and were compared with experimental data. The calculated values based on the optimization method were found to be better than those based on the Raoult's law.

• Journal of the Korean Chemical Society
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• v.12 no.1
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• pp.26-31
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• 1968

이성분 용액에 대한 천이상태 이론의 적용 방법을 재고찰하여 이론적 보충을 하여주었으며, 이 새로운 방법에 따라서 $C_6H_{12}-CCl_4$계의 열역학적 성질들을 계산하였다. 또한 전의 방법에 따라서 계산된 $C_6H_6-C_6H_{12}$ 및 $C_6H_6-CCl_4$계의 열역학적 성질들도 재계산하였다. 이 방법에 따라서 계산된 열역학적 성질들을 측정치와 대단히 잘 맞는다.

• Fire Science and Engineering
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• v.29 no.5
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• pp.1-6
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• 2015

Flash point is one of the most important variables used to characterize fire and explosion hazard of liquids. The lower flash point data were measured for the binary systems {methanol + 1-butanol}, {ethanol + 1-butanol} and {2-propanol + 1-butanol} at 101.3 kPa. Experiments were performed according to the standard test method (ASTM D 3278) using a SETA closed cup flash point tester. The measured flash points were compared with the predicted values calculated using the following activity coefficient models: Wilson, Non-Random Two Liquid (NRTL), and UNIversal QUAsiChemical (UNIQUAC). The measured FP data agreed well with the predicted values of Raoult's law, Wilson, NRTL and UNIQUAC models. The average absolute deviation between the predicted and measured lower FP was less than 1.14 K.

• Fire Science and Engineering
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• v.29 no.6
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• pp.45-50
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• 2015

The flash point is one of the most important properties for characterizing the fire and explosion hazard of liquid solutions. In this study, a Tag open-cup apparatus was used to measure the flash points of two flammable binary mixtures, n-decane + n-octanol and acetic acid + n-butanol. The flash point temperature was estimated using the UNIFAC (Universal Functional Activity Coefficient) group contribution model and optimization method. The experimentally derived flash point was also compared with the predicted flash point. The two methods can estimate the flash point fairly well for the n-decane + n-octanol and acetic acid + n-butanol systems.

• Korean Chemical Engineering Research
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• v.62 no.2
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• pp.173-180
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• 2024

Under ordinary atmospheric circumstances, the gravimetric technique was used to measure the solubility of L-cysteine (L-Cys) and L-alanine (L-Ala) in various solvents, including methyl alcohol, ethyl acetate, and mixtures of the two, in the range o 283.15 K to 323.15 K. Both individual solvents and their combinations showed a rise in the solubility of L-Cys and L-Ala with increasing temperature, according to the analyzed data but when analyzed at a constant temperature in the selected mixed solvents, the solubility declined with decreasing of initial mole fractions of methyl alcohol. To further assess, the relative utility of the four solubility models, we fitted the solubility data using the Jouyban-Acree (J-A), van't Hoff-Jouyban-Acree (V-J-A), Apelblat-Jouyban-Acree (A-J-A), and Ma models followed by evaluation of the values of the RAD information criteria and the RMSD were. The dissolution was also found to be an entropy-driven spontaneous mixing process in the solvents since the thermodynamic parameters of the solvents were determined using the van't Hoff model. In order to support the industrial crystallization of L-cysteine and L-alanine and contribute to future theoretical research, we have determined the experimental solubility, correlation equations, and thermodynamic parameters of the selected amino acids during the dissolution process.

• Analytical Science and Technology
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• v.24 no.6
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• pp.467-476
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• 2011

Solubility data of carbon dioxide ($CO_2$) in the imidazolium-based ionic liquids with methylsulfate anion are presented at pressures up to about 45 MPa and at temperatures between 303.15 K and 343.15 K. The ionic liquids studied in this work were 1-ethyl-3-methylimidazolium methylsulfate ([emim][$mSO_4$]), 1-butyl-3-methylimidazolium methylsulfate ([bmim][$mSO_4$]). The solubilities of $CO_2$ were determined by measuring the bubble point or cloud point pressures of the binary mixtures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The equilibrium pressure increased very steeply at high $CO_2$ compositions. The $CO_2$ solubility in ionic liquids increased with increase of the total length of alkyl chains attached to the imidazolium cation of the ionic liquids. The phase equilibrium data for the $CO_2$ + ionic liquid systems have been correlated using the Peng-Robinson equation of state.