J.T. Sipowska

Excess enthalpies for (ethane + methanol) at 298.15 and 348.15 K and 7.5 and 15 MPa, and at 323.15 K at 7.5, 10, and 15 MPa

Abstract Excess molar enthalpies HmE have been determined for (ethane + methanol) at 298.15, 323.15, and 348.15 K and at pressures of 7.5 and 15 MPa. Measurements were also made at 323.15 K at 10 MPa. (Ethane + methanol) is a type-III system (Scott and van Konynenburgs classification) which is distinguished by a discontinuous critical curve. The results reported in this paper span the critical locus so that miscible mixtures form at the highest pressure, but (liquid + liquid) or (vapor + liquid) phase separations are present at the lower pressures. The HmE results correlate well with the phase-equilibria description and are used to predict the (vapor + liquid) equilibrium curve at 7.5 MPa.

Excess enthalpies for (propane + propan-1-ol) at (298.15, 323.15, 363.15, and 368.15) K and at 5 MPa and 15 MPa

Abstract Excess molar enthalpies H m E are reported for (propane + propan-1-ol) at temperatures of (298.15, 323.15, 363.15, and 368.15) K and pressures of 5 MPa and 15 MPa. The results are explained in terms of chemical, physical, and structural effects and compared with the UNIFAC-2 prediction.

Excess enthalpies for (propane + acetonitrile) at the temperatures (298.15, 313.15, 323.15, 333.15, 338.15, and 348.15) K and at the pressures (5, 10, and 15) MPa. Determination of (liquid + liquid) equilibria from the calorimetric results

Excess molar enthalpies H E m have been determined for (propane + acetonitrile) at the temperatures (298.15, 313.15, 323.15, 333.15, 338.15, and 348.15) K and at the pressures (5, 10, and 15) MPa. The linear regions of H E m against x at 298.15 K, 313.15 K, and 323.15 K at all three pressures and at 333.15 K at 5 MPa and 10 MPa, are due to (liquid + liquid) phase separation. The T ( x ) values obtained from the discontinuity in the H E m curves were used to construct the (liquid + liquid) phase diagram.

Excess enthalpies for (propane + methanol) at the temperatures (298.15, 323.15, 348.15, and 373.15) K and pressures (5, 10, and 15) MPa, and at 363.15K and (5 and 15) MPa

Excess molar enthalpies HEm for (propane + methanol) have been determined at the temperatures (298.15, 323.15, 348.15, and 373.15) K and at the pressures (5, 10, and 15) MPa. Measurements were also made at 363.15 K and (5 and 15) MPa. (Propane + methanol) is a type-II mixture (Scott and van Konynenburgs classification) with a (liquid + liquid) phase separation at lower temperatures. The measurements reported in this paper were performed at temperatures and pressures at which both components were liquids and where phase separation does not occur.

Excess enthalpies for (ethane + butan-1-ol) at (298.15, 323.15, and 348.15) K and at (5, 10, and 15) MPa

Abstract Excess molar enthalpies H m E are reported for (ethane + ethanol) at the temperatures (298.15, 323.15, and 348.15) K and at pressures of (5, 10, and 15) MPa. According to Scott and van Konynenburgs classification, (ethane + ethanol) is a type V mixture which is distinguished by a discontinuous critical curve and a miscibility gap with upper and lower critical end points. The measurements have been made at temperatures and pressures that span the critical locus. At 10 MPa and 15 MPa, miscible mixtures are formed at all three temperatures over the entire range of composition, but (vapor + liquid) phase separation occurs at the higher temperatures at 5 MPa. The results are explained in terms of chemical, physical, and structural effects.

Excess entalpies for (butane + methanol) at the temperatures (298.15, 323.15, and 348.15) K and the pressures (5 and 15) MPa

Excess molar enthalpies H E m for (butane + methanol) have been measured at the temperatures (298.15, 323.15, and 348.15) K and at the pressures (5 and 15) MPa. (Liquid + liquid) phase separation occurs for this mixture at lower temperatures with the (liquid + liquid) and (liquid + gas) critical lines separated. Reported measurements were performed at temperatures and pressures at which the two liquid components form a homogenous liquid mixture.

Excess enthalpies for (propane + butan-1-ol) at the temperatures 298.15 K and 323.15 K and the pressures 5 MPa and 15 MPa, and at 348.15 K and 363.15 K and 5 MPa, 10 MPa, and 15 MPa

Excess molar enthalpies are reported for (propane + butan-1-ol) at the temperatures 298.15 K and 323.15 K, and the pressures 5 MPa and 15 MPa, and at 348.15 K and 363.15 K, and 5 MPa, 10 MPa, and 15 MPa. The results are explained in terms of chemical, physical, and structural effects and compared with the UNIFAC-2 prediction.

Excess enthalpies for (butane + acetonitrile) at the temperatures (298.15, 323.15, and 348.15) K and at the pressures (5, 10, and 15) MPa

Excess molar enthalpies HEm have been determined for (butane + acetonitrile) at the temperatures T = (298.15, 323.15, and 348.15) K and at the pressures p = (5, 10, and 15) MPa. The linear regions of HEm as a function of x at T = 298.15 K and 323.15 K at all three pressures are caused by (liquid + liquid) phase separation.

An apparatus for measuring the upper critical solution temperature using the effluent from a flow calorimeter: Application to mixtures of acetonitrile with cyclohexane, propane and butane☆

Abstract A thermostated sapphire capillary was inserted into the exit line of a flow calorimeter. This capillary is used to visually determine the upper critical solution temperature (UCST) for acetonitrile + cyclohexane, + propane, and + butane at several pressures. The UCST results were combined with liquid + liquid results obtained earlier from breaks in the excess molar enthalpy versus mole fraction curves to obtain the liquid + liquid phase diagrams for acetonitrile + propane, and + butane at 5 and 10 MPa.