LIQUID LIQUID EQUILIBRIA OF WATER PLUS ACETIC-ACID PLUS PHTHALIC ESTERS (DIMETHYL PHTHALATE AND DIETHYL PHTHALATE) TERNARIES

Experimental liquid-liquid equilibria of water + acetic acid + dimethyl phthalate and water + acetic acid + diethyl phthalate systems were investigated at 293.16 +/- 0.20 K. The reliability of experimental tie-line data was ascertained through an Othmer-Tobias plot. Distribution coefficients and separation factors were evaluated over the immiscibility region. It is concluded that the high-boiling solvents dimethyl phthalate and diethyl phthalate are suitable separating agents for dilute aqueous acetic acid solutions

Catalytic esterification of methyl alcohol with acetic acid

Esterification of methyl alcohol with acetic acid catalysed by Amberlyst-15 (cation-exchange resin) was carried out in a batch reactor in the temperature ranging between 318-338 K, at atmospheric pressure. The reaction rate increased with increase in catalyst concentration and reaction temperature, but decreased with an increase in water concentration. Stirrer speed had virtually no effect on the rate under the experimental conditions. The rate data were correlated with a second-order kinetic model based on homogeneous reaction. The apparent activation energy was found to be 22.9 kJ.mol(-1) for the formation of methyl acetate. The methyl acetate production was carried out as batch and continuous in a packed bed reactive distillation column with high purity methyl acetate produced

Predicting liquid-liquid equilibria of amine extraction of carboxylic acid through solvation energy relation

Long-chain, aliphatic tertiary amines (e.g., Alamine 336 or 308) dissolved in suitable organic solvents are known to be effective extractants for carboxylic acids. A log-basis approach SERAS (solvation energy relation for amine systems) has been proposed to estimate the properties and liquid-liquid equilibria (LLE) of amine/diluent/organic acid associated systems containing protic and nonprotic components. The model combines the solvatochromic parameters of solvation energy of solution with the thermodynamic factors derived from a group-contribution method, i.e., UNIFAC-Dortmund activity-coefficient model. The reliability of the model has been analyzed against the LLE data for distribution of pyruvic (2-oxopropanoic) acid between water and Alamine 308 (triisooctylamine) dissolved in C-6-ring-included diluents of proton-donating and -accepting (cyclohexanone, methylcyclohexanol), polar (1,2-dichlorobenzene), and inert (toluene) types. The proposed solvatochromic approach SERAS is expected to be an improvement in data fit clarifying the simultaneous impact of hydrogen bonding, solubility, and thermodynamic factors of components on LLE. The model matches the experimental data, yielding a mean relative error of +/- 13.9%. The results were also correlated using a version of the mass-action law, i.e., a chemodel approach comprising the formation of one or two acid-amine complexes

Volatile constituents of Turkish bergamot oil

The analysis of bergamot (Citrus bergamia Risso et Poiteau) oil of Turkish origin was carried out by capillary GC and GC/MS. Forty-nine compounds, constituting 99.4% of the oil, were identified. The composition of the Turkish bergamot oil was compared with the Italian bergamot oil. They could be differentiated from their sesquiterpenes, carbonyl compounds, hydrocarbons and monoterpenes. The main components of the Turkish bergamot oil were linalyl acetate (38.7%), limonene (23.7%), linalool (14.7%), gamma-terpinene (4.7%), beta-pinene (3.0%) and myrcene (2.0%). The bergamot oil yield was about 1.2% for fresh bergamot rinds

(Liquid plus liquid) equilibria of (water plus 1-propanol plus solvent) at T=298.2 K

(Liquid + liquid) equilibrium (LLE) data for (water-1-propanol-solvent) were measured at T = 298.2 K and atmospheric pressure. Thesolvents were methyl acetate, ethyl acetate and n-propyl acetate. The UNIQUAC and UNIFAC models were used to correlate the experimental data. A comparison of the extracting capabilities of the solvents was made with respect to distribution coefficients, separation factors. (c) 2005 Elsevier B.V. All rights reserved

Liquid-liquid equilibria of propionic acid - water - solvent (n-hexane, cyclohexane, cyclohexanol and cyclohexyl acetate) ternaries at 298.15 K

The experimental liquid-liquid equilibrium data on propionic acid-water-solvent ternary mixtures at a temperature of 298.15 K are presented. The solvents are n-hexane, cyclohexane, cyclohexanol and cyclohexyl acetate. The distribution coefficients and separation factors are reported. The tie line data are correlated using the methods of Othmer-Tobias and Hand. The experimental results are compared with the values predicted by the UNIFAC group-contribution method

(Liquid plus liquid) equilibria of (water plus propionic acid plus dimethyl phthalate) at several temperatures

(Liquid + liquid) equilibrium (LLE) data for (water + propionic acid + dimethyl phthalate) were measured under atmospheric pressure and at T = (298.2, 303.2, 308.2 and 313.2) K. Phase diagrams were obtained by determining solubility and tie-line data. The LLE data of the ternary systems were predicted by UNIFAC method. Distribution coefficients and separation factors were evaluated over the immiscibility regions. (c) 2004 Elsevier Ltd. All rights reserved

(Liquid plus liquid) equilibria of (water plus butyric acid plus isoamyl alcohol) ternary system

(Liquid + liquid) equilibrium (LLE) data for the ternary system (water + butyric acid + isoamyl alcohol) have been determined experimentally at T = (298.15, 308.15 and 318.15) K. Complete phase diagrams were obtained by determining solubility and the tie-line data. Tie-line compositions were correlated by Othmer-Tobias method. The UNIFAC method was used to predict the phase equilibrium in the system using the interaction parameters determined from experimental data between groups CH3, CH2, CH, COOH, OH and H2O. It is found that UNIFAC group interaction parameters used for LLE could not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region. (c) 2004 Elsevier Ltd. All rights reserved

The compositions of Turkish bergamot oils produced by cold-pressing and steam distillation

Bergamot oil was obtained from Turkish bergamot fruit (Citus bergamia Risso et Poit.) peels by cold pressing and steam distillation. The analysis of bergamot oil was carried out by capillary CC and GC/MS. In total, 47 components were fully characterized and grouped in six component classes (monoterpenes hydrocarbons, oxygenated compounds, sesquiterpenes, carbonyl compounds, alcohols, and esters) for an easier comparison of all oils. Variations during the fruit development of the percentage of the six classes were also described. The composition varied during the season; since the reported values referred to oil obtained from ripe fruits. The main components of the cold pressed Turkish bergamot oil coming from ripe fruits were limonene (37.2%), linalyl acetate (36.3%), linalool (7.9%), gamma-terpinene (5.9%), beta-pinene (3.9%) and myrcene (1.3%). The concentation of linalyl acetate was maximum level when the bergamot fruits reached full maturity characterized by a yellow coloration