This paper presents an analysis of the effect of two synthetic antioxidants on the vaporization processes of coconut and linseed oils for fuel use. Several studies agree on the effectiveness of synthetic or natural an...This paper presents an analysis of the effect of two synthetic antioxidants on the vaporization processes of coconut and linseed oils for fuel use. Several studies agree on the effectiveness of synthetic or natural antioxidants against the polymerization of vegetable oils. The principle of action of the latter is to increase the rate of vaporization, to the detriment of polymer formation. The droplet suspension technique where a fiber is used to hold a stationary droplet has been used. The vaporization was conducted within a closed chamber under ambient pressure conditions in an inert and oxidizing environment at temperatures of 703 K. The method involves monitoring the projected surface area of vegetable oil droplet blended with antioxidants. The projected area (mm2) of the droplet during the vaporization process as a function of time (s) has been used to determine the vaporization coefficient, or the residue formation rate. The main findings are that the two antioxidants used at 200 ppm and 500 ppm have no influence on the vaporization of saturated oils like coconut, while on unsaturated oils like linseed the two antioxidants appear to reduce slightly the deposition of residues which are identified as polymers and increase slightly vaporization rate. In practice, antioxidants could be used as additives in vegetable oils to facilitate their combustion in diesel engines, representing a potential solution for improving combustion efficiency. To enhance the reliability of the findings, it would be advisable to increase the number of antioxidants and extend the study to encompass a wider range of vegetable oils.展开更多
This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Kno...This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.展开更多
文摘This paper presents an analysis of the effect of two synthetic antioxidants on the vaporization processes of coconut and linseed oils for fuel use. Several studies agree on the effectiveness of synthetic or natural antioxidants against the polymerization of vegetable oils. The principle of action of the latter is to increase the rate of vaporization, to the detriment of polymer formation. The droplet suspension technique where a fiber is used to hold a stationary droplet has been used. The vaporization was conducted within a closed chamber under ambient pressure conditions in an inert and oxidizing environment at temperatures of 703 K. The method involves monitoring the projected surface area of vegetable oil droplet blended with antioxidants. The projected area (mm2) of the droplet during the vaporization process as a function of time (s) has been used to determine the vaporization coefficient, or the residue formation rate. The main findings are that the two antioxidants used at 200 ppm and 500 ppm have no influence on the vaporization of saturated oils like coconut, while on unsaturated oils like linseed the two antioxidants appear to reduce slightly the deposition of residues which are identified as polymers and increase slightly vaporization rate. In practice, antioxidants could be used as additives in vegetable oils to facilitate their combustion in diesel engines, representing a potential solution for improving combustion efficiency. To enhance the reliability of the findings, it would be advisable to increase the number of antioxidants and extend the study to encompass a wider range of vegetable oils.
基金A.S.Zongo expresses his gratitude to French Cooperation in Burkina Faso who,through the Service for Cooperation and Cultural Action(SCAC),financed this study by awarding an internship fellowship in 2017 at CIRAD Montpellier.
文摘This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.
