Cinética de producción de biodiesel en un reactor con agitación por inyección
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Date
2009
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Se evaluó la velocidad de formación de biodiesel en un reactor de transesterificación agitado mediante un circuito formado por flujos de inyección duales. Se usó una mezcla de aceites (85% soya y 15% maravilla), metanol y NaOH para estudiar la velocidad de conversión del aceite vegetal a metilésteres. Se desarrolló un reactor cilíndrico de nueve litros con fondo cónico, desde donde la descarga se conectó a dos bombas centrífugas para recircular el fluido a través de dos eyectores opuestos ubicados en la parte central de la pared del reactor. El sistema no requirió de una fuente de calentamiento debido a que el efecto de fricción al interior de las tuberías y de los eyectores generó autocalentamiento del fluido. Para evaluar el perfil de calentamiento del reactor y la cinética de formación del biodiesel, se emplearon cuatro diámetros de eyector correspondientes a números de Reynolds (Re) iniciales entre 1300 y 6470. Se detectaron diferencias claras en la cinética de transesterificación entre los diferentes régimenes de número de Reynolds correspondientes a los distintos diámetros de eyector. Los números de Reynolds mayores generaron menores tiempos de conversión y temperaturas finales más altas en el reactor. Para un 98% de conversión relativa a biodiesel, con el eyector de Re=6470 se redujo un 88% el tiempo de reacción con respecto al eyector con Re=1300 y sin necesidad de emplear una fuente externa de calentamiento.
The biodiesel formation rate was assessed in a transesterification reactor stirred with a dual jet close loop flow. A blend of 85% of soybean oil and 15% of sunflower oil, methanol and NaOH were used to study the conversion rate from vegetable oil to methyl esters. A nine liter cylindrical reactor with a conical bottom discharge connected to two centrifugal pumps for fluid recirculation through dual opposite radial ejectors located in its central part was developed for this study. The system did not require a heating supply because the frictional effect inside the recirculation hoses and nozzles produced overheating of the fluid. To assess the reactor heating profile along with the kinetics of biodiesel formation, four different diameters of ejector were tested corresponding to initial Reynolds number (Re) ranging between 1300 and 6470. Differences in transesterification kinetics among Reynolds number regimes for different ejector diameters were detected showing that a higher Re number results in lower relative conversion times along with higher final temperature in the reactor. For 98% of relative conversion to biodiesel, the ejector with Re number 6470 reduced transesterification time by 88% when compared to an ejector with a Re number 1300 and without the need to employ and external heat source.
The biodiesel formation rate was assessed in a transesterification reactor stirred with a dual jet close loop flow. A blend of 85% of soybean oil and 15% of sunflower oil, methanol and NaOH were used to study the conversion rate from vegetable oil to methyl esters. A nine liter cylindrical reactor with a conical bottom discharge connected to two centrifugal pumps for fluid recirculation through dual opposite radial ejectors located in its central part was developed for this study. The system did not require a heating supply because the frictional effect inside the recirculation hoses and nozzles produced overheating of the fluid. To assess the reactor heating profile along with the kinetics of biodiesel formation, four different diameters of ejector were tested corresponding to initial Reynolds number (Re) ranging between 1300 and 6470. Differences in transesterification kinetics among Reynolds number regimes for different ejector diameters were detected showing that a higher Re number results in lower relative conversion times along with higher final temperature in the reactor. For 98% of relative conversion to biodiesel, the ejector with Re number 6470 reduced transesterification time by 88% when compared to an ejector with a Re number 1300 and without the need to employ and external heat source.
Description
Tesis presentada para optar al título de Ingeniero Civil Agrícola
Keywords
Biodesel