Browsing by Author "Hachemane, Khadidja"
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- Evaluation and kinetic study of alkaline ionic liquid for biodiesel production through transesterification of sunflower oilPublication . Lima, Ana Carolina Coelho; Hachemane, Khadidja; Ribeiro, António E.; Queiroz, Ana; Gomes, Maria Carolina Sérgi; Brito, PauloBiodiesel production is performed in the industry by alkaline transesterification of oils with a low amount of free fatty acids. In order to reduce the disposal of conventional catalysts used industrially, ionic liquids (ILs) have been studied to be applied as catalysts in transesterification since they can be recovered and reused in subsequent reaction cycles. In this work, the ionic liquid choline hydroxide (ChOH) was successfully applied as a catalyst for the transesterification reaction of triacylglycerols present in sunflower oil with methanol. A kinetic modeling study under the specific conditions of 2 wt% catalyst dosage, 1:10 oil/methanol molar ratio, for 0–120 min at 35–65 ℃ was conducted, and liquid–liquid extraction with water/butanol was evaluated as a process to recover the IL. A 95.0% ester yield content was achieved in this work for a short reaction time (30 min). Furthermore, the results of the kinetic study demonstrated that a first-order model was the best fit for the reaction with a rate constant (k) estimated as 0.1182 min 1 and activation energy (Ea) of 13.64 kJ/mol. For the tested conditions, the complete recovery of the IL using liquid–liquid extraction did not occur since it is noted the presence of ChOH in both phases.
- Kinetic study of biodiesel production using choline hydroxide as catalystPublication . Hachemane, Khadidja; Adjdir, Mehdi; Queiroz, Ana; Ribeiro, António E.; Brito, PauloDue to the finite stock of fossil fuels and its negative impact on the environment, many countries across the world are now learning toward renewable sources energies like solar energy, wind energy, biofuel, hydropower, geothermal and ocean energy to ensure energy for the society development security.
- Kinetic study of biodiesel production using choline hydroxide as catalystPublication . Hachemane, Khadidja; Adjdir, Mehdi; Queiroz, Ana; Ribeiro, António E.; Brito, PauloThe present work aims to study the use of choline hydroxide (ChOH) ionic liquid (IL) as a potentially reusable catalyst for the production of biodiesel. A kinetic study was carried out for the transesterification of a previously characterized vegetable oil sample with methanol, under the following fraction conditions: 2 wt.% catalyst dosage, 1:10 oil/methanol molar ratio, reaction time of 10, 20, 30, 45, 60 and 120 minutes, and reaction temperature values of 35 45 55 and 65ºC. The transesterification reaction with ChOH provided a 95.7% conversion value, expressed in FAME content, using a time reaction of 30 min and a temperature reaction of 65ºC. The experimental kinetic study results demonstrated that a first order model represents for all the studied temperatures, the model that best fits the experimental results. The reaction rate constant was estimated as 0.1182 min-1 for 65ºC and an activation energy of 13.64 kJ/mol
- Study of the application of choline hydroxide as a catalyst in biodiesel productionPublication . Hachemane, Khadidja; Queiroz, Ana; Ribeiro, António E.; Brito, Paulo; Adjdir, AdjdirDue to the finite stock of fossil fuels and its negative impact on the environment, many countries across the world are now leaning toward renewable energy sources like solar energy, wind energy, biofuel, hydropower, geothermal and ocean energy to ensure energy for the society development security. Biodiesel is one type of biofuel that is renewable, biodegradable and has similar properties of fossil diesel fuels. Biodiesel is a mixture of fatty acids methyl esters (FAMEs) and can be produced through esterification of fatty acid mixtures or transesterification of vegetable oils and animal fats, using homogeneous and heterogeneous catalysts. Ionic liquid (IL) based catalysts are more and more used since they can be recovered and reused and can have the ability to catalyze both esterification and transesterification reactions. Thus, these types of catalysts, represent clear environmental and safety advantages in relation to classical catalysts. The present work aims to study the use of choline hydroxide (ChOH) IL as a potentially reusable catalyst for the production of biodiesel. A kinetic study was carried out for the transesterification of a previously characterized vegetable oil sample, with methanol, under the specific conditions: 2 wt.% catalyst dosage, 1:10 oil/methanol molar ratio, for the reaction times of 10, 20, 30, 45, 60 and 120 minutes at 65, 55, 45, and 35 ℃. Transesterification with ChOH provided a 95.7% conversion in FAME content for 30 min of reaction at 65 ℃. The results of the kinetic study demonstrated that the first-order model was generally the best fit for the reaction kinetics considering all the temperatures, with a rate constant (k) estimated as 0.1182 min-1 for 65 ℃, and an estimated activation energy of 13.64 kJ/mol. An activation of LDHs by intercalation was made with 0 (blank test), 1, 2, 4 and 5 wt% of IL (BMIM HSO4). The activation of LDH by intercalation with BMIM HSO4 was not successful, because the conversion values are very low.