The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Geert-jan Witkamp - One of the best experts on this subject based on the ideXlab platform.
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Kinetics study of a dichlorotriazine reactive dye in supercritical carbon dioxide
The Journal of Supercritical Fluids, 2004Co-Authors: M. V. Fernandez Cid, GREERT FEYE WOERLEE, M. Van Der Kraan, W. J T Veugelers, Geert-jan WitkampAbstract:The kinetics of the reaction between a dichlorotriazine reactive dye and Methanol was studied in supercritical carbon dioxide and in a solution of Pure Methanol. The experiments were carried out in a batch reactor at different temperatures between 333 and 393K and at 300bar when supercritical carbon dioxide was the solvent medium. The rate constants and the parameters of the Arrhenius equation were determined and compared. A significant influence of the supercritical carbon dioxide on the rate constants was found. The formation of methoxy-dye was faster over the whole temperature range in Pure Methanol than in supercritical carbon dioxide. But the consecutive reaction, the formation of dimethoxy-dye, was considerably faster, up to 20 times, in supercritical carbon dioxide than in Pure Methanol. Moreover, the lowest value for the activation energy, 50 ± 13kJmol−1, was found for the consecutive reaction in supercritical carbon dioxide. In this paper new kinetic data for the Methanolysis reaction of a dichlorotriazine reactive dye in supercritical carbon dioxide are shown.
I M Abdulagatov - One of the best experts on this subject based on the ideXlab platform.
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pvt measurements for Pure Methanol in the near critical and supercritical regions
Journal of Supercritical Fluids, 2007Co-Authors: A R Bazaev, I M Abdulagatov, E A Bazaev, A Abdurashidova, A E RamazanovaAbstract:Abstract PVT properties of Pure Methanol were measured in the near-critical and supercritical regions. Measurements were made with a constant-volume piezometer immersed in a precision air thermostat. The maximum uncertainty of the density measurements was estimated to be 0.15%. The uncertainties of the temperature and pressure measurements were, respectively, 15 mK and 0.05%. Measurements were performed at seven near-critical isochores between 113 and 370 kg m −3 and at pressures from 1.4 to 40 MPa. The range of temperature was 423–653 K. Using the two-phase PVT data, the values of vapor–pressure and saturated liquid and vapor density were determined by means the analytical extrapolating technique in the temperature range from 423 to 512.7 K. The measured one-phase PVT data and saturated property data ( T S , P S , ρ ′ S , ρ ″ S ) for Pure Methanol were compared with the values calculated from fundamental IUPAC and crossover equations of state and with precise experimental PVT data reported by other authors. From the saturated liquid and vapor density and vapor–pressure data in the critical region the values of the critical parameters ( T C = 512.75 ± 0.1 K, P C = 8.120 ± 0.02 MPa, and ρ C = 271.6 ± 3 kg m −3 ) were extracted. For three isochores (113.5, 252.4, and 368.2 kg m −3 ) the measurements were performed in both cooling and heating regimes to estimate the effect of thermal decomposition (chemical reaction) on the PVT properties of Methanol.
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isochoric heat capacity measurements for Pure Methanol in the near critical and supercritical regions
International Journal of Thermophysics, 2007Co-Authors: N G Polikhronidi, I M Abdulagatov, G V Stepanov, Rabiyat G BatyrovaAbstract:Isochoric heat-capacity measurements for Pure Methanol are presented as a function of temperature at fixed densities between 136 and 750 kg·m−3. The measurements cover a range of temperatures from 300 to 556 K. The coverage includes the one- and two-phase regions, the coexistence curve, the near-critical, and the supercritical regions. A high-temperature, high-pressure, adiabatic, and nearly constant-volume calorimeter was used for the measurements. Uncertainties of the heat-capacity measurements are estimated to be 2–3% depending on the experimental density and temperature. Temperatures at saturation, T S(ρ), for each measured density (isochore) were measured using a quasi-static thermogram technique. The uncertainty of the phase-transition temperature measurements is 0.02 K. The critical temperature and the critical density for Pure Methanol were extracted from the saturated data (T S,ρS) near the critical point. For one near-critical isochore (398.92 kg·m−3), the measurements were performed in both cooling and heating regimes to estimate the effect of thermal decomposition (chemical reaction) on the heat capacity and phase-transition properties of Methanol. The measured values of C V and saturated densities (T S,ρS) for Methanol were compared with values calculated from various multiparametric equations of state (EOS) (IUPAC, Bender-type, polynomial-type, and nonanalytical-type), scaling-type (crossover) EOS, and various correlations. The measured C V data have been analyzed and interpreted in terms of extended scaling equations for the selected thermodynamic paths (critical isochore and coexistence curve) to accurately calculate the values of the asymptotical critical amplitudes ( $$A_0^\pm$$ and B 0).
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high temperature and high pressure experimental thermal conductivity for the Pure Methanol and binary systems Methanol n propanol Methanol n octanol and Methanol n undecanol
Fluid Phase Equilibria, 2004Co-Authors: Ya M Naziev, M M Bashirov, I M AbdulagatovAbstract:Abstract Thermal conductivity of Pure Methanol and three mixtures, Methanol + n -propanol, Methanol + n -octanol, and Methanol + n -undecanol, has been measured with a cylindrical tricalorimeter technique (λ-calorimeter). Measurements were made at nine isobars, 0.1013, 1, 5, 10, 20, 30, 40, 50, and 60 MPa. The range of temperatures was from 290 to 603 K. For each binary system, the measurements were made for three compositions: 25, 50, and 75 mass%. The total uncertainty of thermal conductivity, pressure, temperature, and concentration measurements was estimated to be less than 1.93%, 0.05%, 30 mK, and 0.001 mole fraction, respectively. The reliability and accuracy of the experimental method was confirmed with measurements on Pure Methanol for nine isobars, 0.1, 1, 5, 10, 20, 30, 40, 50, and 60 MPa, and at temperatures between 292 and 601 K. The present experimental data and the data reported by other authors for the thermal conductivity of Pure Methanol show excellent agreement within their experimental uncertainty (AAD is about 0.5–0.7%). Excess thermal conductivities were derived using measured values of thermal conductivity for the mixtures and for Pure components covering the whole range of composition. A correlation equation for excess thermal conductivity was obtained as a function of temperature, pressure, and composition by a least-squares method from the experimental data. The AAD between measured and calculated values from this correlation equation for the thermal conductivity was 1% for the mixtures.
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volumetric pvt and calorimetric cvvt measurements for Pure Methanol in the liquid phase
International Journal of Thermophysics, 2003Co-Authors: M M Aliev, Joe W Magee, I M AbdulagatovAbstract:Volumetric (PVT) and calorimetric (C V VT) properties of Pure Methanol were measured in the liquid phase with a twin-cell adiabatic calorimeter. Temperatures were measured in a range from 314 to 411 K, densities between 699.3 and 775.6 kg⋅m−3, and pressures to 20 MPa. The calorimetric cell (70 cm3 capacity) was surrounded by adiabatic thermal shielding (high vacuum). The sample pressures were measured by means of a quartz crystal transducer to within an uncertainty of about ±7 kPa. The relative uncertainty of C V was estimated to be 2%, with a coverage factor k = 2, by combining the various sources of experimental uncertainty using a root-sum-of-squares formula. The results for Pure Methanol were compared with other recent measurements performed with a second high-temperature, high-pressure adiabatic calorimeter. Deviations of less than 3% were found between the earlier C V data and the present results for Pure Methanol. The uncertainty of the density measurements was estimated to be 0.2% (k = 2). The measured densities and isochoric heat capacities were compared with values calculated with an IUPAC equation of state. Agreement of density was within 0.088% and that for isochoric heat capacity was within 0.95%. Values of vapor pressure were determined by extrapolating experimental P–T data to the saturated temperature along a fixed isochore. In the temperature range of this study, decomposition of Methanol was not observed.
A E Ramazanova - One of the best experts on this subject based on the ideXlab platform.
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pvt measurements for Pure Methanol in the near critical and supercritical regions
Journal of Supercritical Fluids, 2007Co-Authors: A R Bazaev, I M Abdulagatov, E A Bazaev, A Abdurashidova, A E RamazanovaAbstract:Abstract PVT properties of Pure Methanol were measured in the near-critical and supercritical regions. Measurements were made with a constant-volume piezometer immersed in a precision air thermostat. The maximum uncertainty of the density measurements was estimated to be 0.15%. The uncertainties of the temperature and pressure measurements were, respectively, 15 mK and 0.05%. Measurements were performed at seven near-critical isochores between 113 and 370 kg m −3 and at pressures from 1.4 to 40 MPa. The range of temperature was 423–653 K. Using the two-phase PVT data, the values of vapor–pressure and saturated liquid and vapor density were determined by means the analytical extrapolating technique in the temperature range from 423 to 512.7 K. The measured one-phase PVT data and saturated property data ( T S , P S , ρ ′ S , ρ ″ S ) for Pure Methanol were compared with the values calculated from fundamental IUPAC and crossover equations of state and with precise experimental PVT data reported by other authors. From the saturated liquid and vapor density and vapor–pressure data in the critical region the values of the critical parameters ( T C = 512.75 ± 0.1 K, P C = 8.120 ± 0.02 MPa, and ρ C = 271.6 ± 3 kg m −3 ) were extracted. For three isochores (113.5, 252.4, and 368.2 kg m −3 ) the measurements were performed in both cooling and heating regimes to estimate the effect of thermal decomposition (chemical reaction) on the PVT properties of Methanol.
M. V. Fernandez Cid - One of the best experts on this subject based on the ideXlab platform.
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Kinetics study of a dichlorotriazine reactive dye in supercritical carbon dioxide
The Journal of Supercritical Fluids, 2004Co-Authors: M. V. Fernandez Cid, GREERT FEYE WOERLEE, M. Van Der Kraan, W. J T Veugelers, Geert-jan WitkampAbstract:The kinetics of the reaction between a dichlorotriazine reactive dye and Methanol was studied in supercritical carbon dioxide and in a solution of Pure Methanol. The experiments were carried out in a batch reactor at different temperatures between 333 and 393K and at 300bar when supercritical carbon dioxide was the solvent medium. The rate constants and the parameters of the Arrhenius equation were determined and compared. A significant influence of the supercritical carbon dioxide on the rate constants was found. The formation of methoxy-dye was faster over the whole temperature range in Pure Methanol than in supercritical carbon dioxide. But the consecutive reaction, the formation of dimethoxy-dye, was considerably faster, up to 20 times, in supercritical carbon dioxide than in Pure Methanol. Moreover, the lowest value for the activation energy, 50 ± 13kJmol−1, was found for the consecutive reaction in supercritical carbon dioxide. In this paper new kinetic data for the Methanolysis reaction of a dichlorotriazine reactive dye in supercritical carbon dioxide are shown.
D L Gurina - One of the best experts on this subject based on the ideXlab platform.
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solvation of salicylic acid in Pure Methanol modified and water modified supercritical carbon dioxide molecular dynamics simulation
Journal of Supercritical Fluids, 2015Co-Authors: V E Petrenko, M L Antipova, D L GurinaAbstract:Abstract In the present work, solvation of the salicylic acid in Pure, Methanol-modified and water-modified (by adding 0.035 Methanol or 0.0079 water mole fraction) supercritical carbon dioxide (sc-CO 2 ) at 318 K and 0.7 g/cm 3 has been studied by computer simulation techniques. It was shown that solvation of salicylic acid in Pure sc-CO 2 is governed by electron donor–acceptor interactions and proceeds more slowly than in modified sc-CO 2 , where salicylic acid forms solvate complex with co-solvent by means of hydrogen bonding through carboxyl group. Salicylic acid hydroxyl group participates only in intramolecular hydrogen bond and does not interact with solvent molecules. The salicylic acid–co-solvent complexes are stable: the duration of their existence is much higher than lifetime of other hydrogen bonds in the fluid. The behavior of two co-solvents is different: Methanol exists in the form of monomers and hydrogen-bonded dimers in the supercritical fluid, the water molecules tend to form microclusters with spatially-branched structure.
