Thermodynamic excess property measurements for acetonitrile-benzene-n-heptane system at 45.deg.

1972 ◽  
Vol 17 (1) ◽  
pp. 71-76 ◽  
Author(s):  
David A. Palmer ◽  
Buford D. Smith
Keyword(s):  
Excess Property ◽  
Thermodynamic Excess

Vapour-Liquid Equilibria and Excess Thermodynamic Properties in Binary Systems of Cyclopentanone + Chloroalkanes in View of the Disquac and Unifac Group Contribution Models Extention

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Alexandru Birhala ◽  
Dana Dragoescu ◽  
Mariana Teodorescu
Keyword(s):  
Binary Systems ◽  
Excess Enthalpy ◽  
Group Contribution ◽  
Excess Properties ◽  
Structural Effects ◽  
Liquid Equilibrium ◽  
Excess Thermodynamic Properties ◽  
Different Types ◽  
Thermodynamic Excess Properties ◽  
Thermodynamic Excess

The data available in the literature and our recent data on vapour�liquid equilibrium (VLE), excess Gibbs energy, GE, and excess enthalpy, HE, for the homologous series of cyclopentanone + chloroalkane mixtures are examined in terms of the predictive group contribution models DISQUAC and UNIFAC. In our treatment, we present also how the structural effects and different types of molecular interactions are reflected by the thermodynamic excess properties of the mentioned series mixtures.

Thermodynamische Interpretation der Schmelzdiagramme binärer Systeme aus Methylchlorsilanen und Pyridazin bzw. Pyrazin

1987 ◽  
Vol 42 (4) ◽  
pp. 341-351
Author(s):  
Karl Hensen ◽  
Jens Gaede
Keyword(s):  
Melting Point ◽  
Thermodynamic Functions ◽  
Liquidus Curve ◽  
Optical Measurements ◽  
Miscibility Gap ◽  
Excess Functions ◽  
Cooling Curves ◽  
Acid Base ◽  
Thermodynamic Excess Functions ◽  
Thermodynamic Excess

By analyzing the cooling curves and the resulting melting point diagrams of the chloromethylsilane- pyridazine and pyrazine systems the existence of the incongruently melting addition compounds CH3SiCl3 • Pyridazine, (CH3)2SiCl2 • (Pyridazine)2, (CH3)3SiCl • (Pyridazine)2, CH3SiCl3 • (Pyrazine)2, (CH3)2SiCl2 • (Pyrazine)2 , (CH3)3SiCl • (Pyrazine)2 was proved. By electro-optical measurements of the turbidity point it was proved that the system (CH3)3SiCl- Pyridazine exhibits a miscibility gap which intersects the liquidus curve of the amine. Based on certain approximations it was possible to fit thermodynamic functions to the experimental results to obtain the excess data of mixing of the corresponding systems. These data allow for a more profound understanding of the Lewis-acid base behaviour of the silanes and amines.Chloromethylsilanes, Pyridazine, Pyrazine, Phase Diagrams, Addition Compounds, Thermodynamic Excess Functions

scholarly journals USING EXERGY LOSS PROFILES AND ENTHALPY-TEMPERATURE PROFILES FOR THE EVALUATION OF THERMODYNAMIC EFFICIENCY IN DISTILLATION COLUMNS

2005 ◽  
Vol 4 (1) ◽  
pp. 76 ◽  
Author(s):  
S. H. B. Faria ◽  
R. J. Zemp
Keyword(s):  
Energy Balance ◽  
Distillation Column ◽  
Enthalpy Of Solution ◽  
Exergy Loss ◽  
Thermodynamic Efficiency ◽  
Consistency Test ◽  
Distillation Columns ◽  
Water Distillation ◽  
Ideal Solutions ◽  
Thermodynamic Excess

In this work the temperature-enthalpy profile and the exergy loss profile are used together to improve thermodynamic efficiency of distillation columns, by identifying possible benefits of using side exchangers. The method proposed is to compute the exergy loss profile and to analyse the distribution of the losses across the column stages. The present work aims at applying the stage-by-stage exergy analysis to the distillation of non-ideal mixtures, e.g. methanol/water. For these systems the use of thermodynamic excess properties is required: Gibbs free energy for phase equilibrium and enthalpy of solution for energy balance. Initial studies showed that the enthalpy of solution has a small effect on the overall energy balance of the distillation column, but a significant impact on the exergy loss profiles. Some profiles even showed a violation of the second law of thermodynamics, with entropy being destroyed on some stages, clearly indicating that a wrong approach to exergy calculation was being used.A model for exergy calculations of non-ideal solutions is presented. The exergy values so computed are then checked by a consistency test, using the reversible column profile. Finally, the exergy procedures are used to study a typical methanol/water distillation columns, where the exergy profiles are used to identify scope for intermediate heat exchange.

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