THERMODYNAMICS OF THE EXTRACTION PROCESS OF REDISTRIBUTION OF PETROLEUM ACIDS BETWEEN AQUEOUS AND HYDROCARBON MEDIA
Rubrics: 2. CHEMICAL TECHNOLOGY
Authors:
1.
Kazan National Research Technological University (KNRTU),
2.
Kazanskiy nacional'nyy issledovatel'skiy tehnologicheskiy universitet
3.
KNITU
4.
Kazan National Research Technological University (KNRTU)
Russian Federation
Russian Federation
5.
Kazan National Research Technological University
6.
Kazan National Research Technological University
7.
Kazan National Research Technological University
Type:
Article
Pages:
from 65
to 69
Status:
In work
Language:
Russian
Keywords:
LIQUID EXTRACTION, PROTON-DONATING EXTRACTANTS, NAPHTHENIC ACIDS, THERMODYNAMIC CHARACTERISTICS, DISTRIBUTION COEFFICIENT
Abstract (English):
The study is devoted to the determination of the enthalpy ( HP), Gibbs energy ( GP) and entropy ( SP) of the distribution of naphthenic acids between aqueous solutions of isopropyl alcohol and n-decane, which can be used to justify the conditions of their extraction from oxidates of medium distillate petroleum fractions. The research was carried out on a model system consisting of naphthenic acid isolated from the diesel fraction of Baku oil and n-decane. The concentration of acids in the solution was 0.06 ÷ 0.52 mol/l. Extraction was performed with aqueous solutions of isopropyl alcohol with a water content of 15 ÷ 50% vol. at a temperature of 298-328 K. Linear approximation was performed in Excel using trend lines. A linear model with an approximation accuracy of R2 equal to 0,998 was used for the description. With an increase in the water content of isopropyl alcohol, the distribution coefficients of naphthenic acids decrease, since there is a large hydration of isopropyl alcohol molecules, which complicates the extraction process. The addition of sec-butylbenzene to n-decane also leads to the distribution coefficients of naphthenic acids decrease. This is explained by the formation of molecular complexes that impede the transition of naphthenic acid molecules into the phase of an aqueous solution of isopropyl alcohol. The naphthenic acid molecules with the isopropyl alcohol aqueous solution supramolecular structure interaction is accompanied by the release of heat, which amount increases with a decrease in the water content in isopropyl alcohol. GP has negative values up to a water content of 30% vol. The optimal water content in isopropyl alcohol is 15% vol. The process of extracting naphthenic acids from n-decane with an aqueous solution of isopropyl alcohol is thermodynamically probable up to a water content of 30% vol.
The study is devoted to the determination of the enthalpy ( HP), Gibbs energy ( GP) and entropy ( SP) of the distribution of naphthenic acids between aqueous solutions of isopropyl alcohol and n-decane, which can be used to justify the conditions of their extraction from oxidates of medium distillate petroleum fractions. The research was carried out on a model system consisting of naphthenic acid isolated from the diesel fraction of Baku oil and n-decane. The concentration of acids in the solution was 0.06 ÷ 0.52 mol/l. Extraction was performed with aqueous solutions of isopropyl alcohol with a water content of 15 ÷ 50% vol. at a temperature of 298-328 K. Linear approximation was performed in Excel using trend lines. A linear model with an approximation accuracy of R2 equal to 0,998 was used for the description. With an increase in the water content of isopropyl alcohol, the distribution coefficients of naphthenic acids decrease, since there is a large hydration of isopropyl alcohol molecules, which complicates the extraction process. The addition of sec-butylbenzene to n-decane also leads to the distribution coefficients of naphthenic acids decrease. This is explained by the formation of molecular complexes that impede the transition of naphthenic acid molecules into the phase of an aqueous solution of isopropyl alcohol. The naphthenic acid molecules with the isopropyl alcohol aqueous solution supramolecular structure interaction is accompanied by the release of heat, which amount increases with a decrease in the water content in isopropyl alcohol. GP has negative values up to a water content of 30% vol. The optimal water content in isopropyl alcohol is 15% vol. The process of extracting naphthenic acids from n-decane with an aqueous solution of isopropyl alcohol is thermodynamically probable up to a water content of 30% vol.
Keywords:
LIQUID EXTRACTION, PROTON-DONATING EXTRACTANTS, NAPHTHENIC ACIDS, THERMODYNAMIC CHARACTERISTICS, DISTRIBUTION COEFFICIENT
LIQUID EXTRACTION, PROTON-DONATING EXTRACTANTS, NAPHTHENIC ACIDS, THERMODYNAMIC CHARACTERISTICS, DISTRIBUTION COEFFICIENT
