A study of petrol and diesel fuel blends with special reference to their thermodynamic propeties and phase equilibria
- Authors: Hayward, Caroline
- Date: 1986
- Subjects: Gasoline , Diesel fuels , Thermodynamics , Liquid-liquid equilibrium , Alcohol as fuel
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4065 , http://hdl.handle.net/10962/d1004902 , Gasoline , Diesel fuels , Thermodynamics , Liquid-liquid equilibrium , Alcohol as fuel
- Description: The ternary phase behaviour of the n-heptane-l-propanol-water system was studied and compared with the theoretical prediction based on the UNIQUAC model for non-electrolyte solutions. The results showed that this model adequately approximated experimental studies. The excess enthalpies and excess volumes for several binary mixtures were determined. The excess enthalpies were measured using a LKB flow microcalorimeter and the excess -volumes determined using a PAAR densitometer. The study showed that no significant enthalpy or volume changes occurred when petrol/n-heptane were mixed with alcohols . Ternary phase diagrams, including tie lines have been determined for a number of petrol-alcohol-water systems (including the Sasol blend of alcohols). The tie line results show that the concentration of water in the water-rich layer is strongly dependent on the type of alcohol used. The Sasol alcohol blended with petrol resulted in a high water concentration in the water-rich layer which forms on phase separation. This is believed to contribute significantly to the corrosion problems experienced by motorists using the Sasol blended fuel on the Witwatersrand. The effect of temperature on several of these blends was included in the study. Diesel-alcohol blends and the co-solvent properties of ethyl acetate investigated. Ethyl acetate ensures miscibility at low concentrations for diesel-ethanol blends. Octyl nitrate and two cetane improvers from AECI were assessed in terms of their ability to restore cetane rating of blended diesel fuel to that of pure diesel fuel. The results indicated that all three samples were successful in this application. , KMBT_363
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- Date Issued: 1986
The thermodynamics of binary liquid mixtures
- Authors: Scoones, Brett Warren Hamilton
- Date: 1983 , 2013-03-15
- Subjects: Thermodynamics , Thermodynamics -- Tables , Solution (Chemistry) , Liquids
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4392 , http://hdl.handle.net/10962/d1005893 , Thermodynamics , Thermodynamics -- Tables , Solution (Chemistry) , Liquids
- Description: A systematic study of the excess thermodynamic properties of two-ring compounds and n-alkanes was conducted. The excess enthalpies were determined at 288,15 K and 298,15 K by using a flow microcalorimetric technique. The excess volumes of tetralin and cycloalkanes, and tetralin and --alkans at 288,15 K and 298,15 K were determined by using a vibrating tube densitometer. The results showed trends relating to the size and shape of the n-alkane and cycloalkan molecules. The theory developed by Flory was applied to the decalin + cycloalkane and + n-alkane systems and this gave qualitative predictions of the excess enthalpies from the excess volumes and vice versa. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
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- Date Issued: 1983