• Journal of the Korean Institute of Gas
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• v.17 no.6
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• pp.67-72
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• 2013

The flash point is the lowest temperature at which there is enough concentration of flammable vapor to form an ignitable mixture with air. The flash point is a major physical property used to analyse the fire and explosion hazards of a flammable liquid solution. The flash point data for pure components are easily available in several literature. But the flash points of the flammable binary solutions appear to be scarce in the literature. The objective of this study is to measure and estimate the flash point of acetic acid-formic acid system. Cleveland open cup tester was used to measure the flash point. The experimental data were compared with the values estimated by the Raoult's law and the optimization methods based on van Laar and Wilson equations. As a result, the estmated values by optimization methods were found to be better than those based on the Raoult's law.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.181-185
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• 2005

The flash point is one of the most important combustible properties used to determine the potential for fire and explosion hazards of industrial material. An accurate knowledge of the flash point is important in developing appropriate preventive and control measures in industrial fire protection. The flash points for the n-butanol+n-propionic acid and n-propanol+n-propionic acid systems were measured by using Tag open-cup apparatus(ASTM D 1310-86). The experimental data were compared with the values calculated by the laws of Raoult and van Laar equation. The calculated values based on the van Laar equation were found to be better than those based on the Raoult's law.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.103-108
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• 2001

Explosive limit is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limits are used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult,s law and van Laar equation(activity coefficient model) are shown to be applicable for the prediction of the explosive limits in the flammable ethylacetate-toluene system. The values calculated by the proposed equations were a good agreement with literature data within a given percent. From a given results, by the use of the proposed equations, it is possible to predict explosive limits of the other flammable mixtures. It is hoped eventually that this method will permit the estimation of the explosive Properties of flammable mixtures with improved accuracy and the broader application for other flammable stances.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.13-18
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• 2007

The multivariate statistical analysis, using the multiple linear regression(MLR), have been applied to analyze and predict the flash points of binary systems. Prediction for the flash points of flammable substances is important for the examination of the fire and explosion hazards in the chemical process design. In this paper, the flash points are predicted by MLR based on the physical properties of pure substances and the experimental flash points data. The results of regression and prediction by MLR are compared with the values calculated by Raoult's law and Van Laar equation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.88-96
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• 1983

The effect of lowering water activity of various humectants has been reported in the previous papers. In this study, that effect of humectants used in combination with each other was discussed. Additionally, the Aw measurements were also compared to the predicted values of Aw derived from the equation of Raoult's law and the linear slope method by Sloan and Labuza. Each mixed humectant was thought to be salted-out by the other, and thus Aw values were observed to be somewhat lower as the result in all model preparations. The effect of lowering water activity by NaCl was the highest, and the efficiency of reduction of Aw was decreased in the order of NaCl, sodium lactate, glycerin, propylene glycol and sorbitol when each of them was combinated with other humectants. Aw values calculated by the equation of Raoult's law were not agreed so well to the measured Aw, so it was likely not to be the useful method for predicting Aw values in mixed humectants to far as they have showed higher ability for lowering Aw in the previous papers. The equations of prediction were derived from Aw values to be measured actually in the model Kamaboko.

• Fire Science and Engineering
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• v.30 no.6
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• pp.31-36
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• 2016

The flash point is one of the most important properties for characterizing the fire and explosion hazard of liquid solutions. In this study, the flash points of two flammable binary mixtures, n-pentanol + n-propanol and n-pentanol + n-heptanol systems were measured using a Seta flash closed cup tester. The flash point was estimated using the methods based on Raoult's law and multiple regression analysis. The measured flash points were also compared with the predicted flash points. The absolute average errors (AAE) of the results calculated by Raout's law were $1.3^{\circ}C$ and $1.3^{\circ}C$ for the n-pentanol + n-propanol and n-pentanol + n-heptanol mixtures, respectively. The absolute average errors of the results calculated by multiple regression analysis were $0.4^{\circ}C$ and $0.3^{\circ}C$ for the n-pentanol + n-propanol and n-pentanol + n-heptanol mixtures, respectively. According to the AAE, the calculated values based on multiple regression analysis were better than those based on Raoult's law.

• Korean Journal of Materials Research
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• v.15 no.1
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• pp.47-53
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• 2005

The E.M.F. of the galvanic cell with fused salt was measured to determine the activities of zinc at 720-860 K over the entire composition range of liquid Zn-In and Zn-Sn alloys. The cell used was as follows: $$(-)W{\mid}Zn(pure){\mid}Zn^{2+}(KCl-LiCl){\mid}Zn(in\;Zn-In\;or\;Zn-Sn\;alloy){\mid}W(+)$$ The activities of zinc in the alloys showed positive deviation from Raoult's law over the entire composition range. The activity of cadmium and some thermodynamic functions such as Gibbs free energy, enthalpy and entropy were derived from the results by the thermodynamic relationship. The comparison of the results and the literature data was made. The liquid Zn-In and Zn-Sn alloys are found to be close tn the regular solution. The concentration fluctuations in long wavelength limit, $S_{cc}(o)$, in the liquid alloy were calculated from the experimental results.

• Clean Technology
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• v.25 no.2
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• pp.140-146
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• 2019

Flammable substances, such as organic solvents, are commonly used in laboratories and industrial processes. The flash point of flammable liquid mixtures is a very important parameter for characterizing the ignition and explosion hazards, and the flash points of mixtures of $C_2{\sim}C_3$ alcohols and 2,2,4-trimethylpentane were measured in the present study. The 2,2,4-trimethylpentane is an important component of gasoline and is frequently used in the petroleum industry as a solvent. Lower flash point data were measured for the binary systems {ethanol + 2,2,4-trimethylpentane}, {1-propanol + 2,2,4-trimethylpentane}, and {2-propanol + 2,2,4-trimethylpentane}. The flash point measurements were carried out according to the standard test method (ASTM D3278) using a Stanhope-Seta closed cup flash point tester. The measured flash points were compared with the predicted values calculated using Raoult's law and also following $G^E$ models: Wilson, Non-Random Two Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC). These models were able to predict the experimental flash points for different compositions of {$C_2{\sim}C_3$ alcohols + 2,2,4-trimethylpentane} mixtures with minimal deviations. The average absolute deviation between the predicted and measured lower flash point was less than 1.28 K. A minimum flash point behaviour was observed in all of the systems as in the many observed cases for the hydrocarbon and alcohol mixtures.

• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.352-358
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• 1971

The interaction between dimethylsulfoxide molecules and some organic molecules, i.e.nitrobenzene, m-dinitrobenzene, o-dinitrobenzene, 1,3,5-trinitrobenzene, m-xylene, mesitylene, bibenzyl, biphenyl, o-phenanthrene, naphthalene, has been studied. The organic molecules exhibit negative deviation from Raoult's law due to the formation of the charge transfer complexes with dimethylsulfoxide. The stability constants of the complexes were determined spectrophotometrically, and also some thermodynamic functions were calculated. The binding energies of the complexes appear in the range of -1 ∼ -4 kcal/mole. The stability depends on the polarity and basicity of the solvent used.

• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.39-44
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• 2016

Suitable design and operation of distillation process is very dependent on vapor-liquid equilibrium calculation. The usual calculation method is use binary interaction parameter. Flash points of n-propanol+n-butanol and 2-butanol+n-butanol were measured by Seta-flash closed cup tester. Experimental Flash points were compared with those calculated by the method based on Raoult's law and the optimization method using Wilson equation. The binary interaction parameters obtained by the optimization method are then used to calculate the bubble points of n-propanol+n-butanol and 2-butanol+n-butanol.