Tesis doctoral de Eliana Ramirez Rangel
Hydrogenation is a major industrial chemical process. A wide variety of chemicals is obtained by catalytic hydrogenation. one typical heterogeneous catalytic hydrogenation process is the production of margarine and shortenings from vegetable oils. The hydrogenation of double bonds in fats and oils has the purpose of providing products with the desired melting profile and texture, according to their final use. the hydrogenated oil is more stable and less sensitive to oxidation. the classic process is carried out in batch reactors where the oil, hydrogen, and catalyst nickel powder are mixed intensively at temperatures between 373 k and 423 k. In this case, the compound to be hydrogenated and or the reaction products are liquid at process conditions; the reaction rate is limited by the concentration of hydrogen on the catalyst surface. The low reaction rate is caused by the low solubility of hydrogen and the high mass-transfer resistance in the liquid phase, which leads to a depletion of hydrogen at the catalyst surface. In the presence of double bonds, this lack of hydrogen also gives rise to double-bond migration and cis-trans-isomerization. despite of the fact that isomerization of cis-trans configuration increases the melting point, conflicting conclusions have resulted from studies on trans fatty acids. In several studies, these isomers formed during hydrogenation of fatty edible oils have shown to have similar effects as saturated fats increasing serum cholesterol levels in the blood, believed to be a major cause of heart desease. For this reason, apprehension and public awareness have risen regarding the potential health hazards of trans fatty acids intake in the human diet. the aim of this research is to study continuous single-phase hydrogenation of sunflower oil on supported palladium catalysts using supercritical fluids as a reaction solvent. This would be an alternative process for producing a wide variety of end product
Datos académicos de la tesis doctoral «Contribution to the study of heterogeneous catalytic reactions in scfs: hydrogenation of sunflower oil in pd catalysts at single-phase conditions«
- Título de la tesis: Contribution to the study of heterogeneous catalytic reactions in scfs: hydrogenation of sunflower oil in pd catalysts at single-phase conditions
- Autor: Eliana Ramirez Rangel
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 19/12/2005
Dirección y tribunal
- Director de la tesis
- Francisco Recasens Baxarias
- Tribunal
- Presidente del tribunal: Cocero alonso María jose
- Antonio Lopez cabanes (vocal)
- thomas Gamse (vocal)
- eduardo Garcia-verdugo cepeda (vocal)