Energy consumption Pattern as affected by machine operating parameters in mechanically expressing oil from Pentaclethra macrophylla: Modeling and optimization

Abstract

this study investigated the influence of operating speed, applied pressure and feed rate on the Specific Mechanical Energy Consumption (SMEC) of an expeller while extracting oil from Pentaclethra macrophylla kernels. Independent variables included speed (15, 30, 45, 60 and 75 rpm) which was varied using pulley arrangement, pressure (5, 10, 15, 20 and 25 MPa) which was varied through adjustment the worm-shaft distance of the expeller, and feed rate (100, 200, 300, 400 and 500 g/min) while the dependent variable was SMEC. All parameters and levels were chosen based on preliminary investigations and literature reports for similar oil crop. Response surface methodology was used for analysis, modeling and optimization. The predicted and experimental values were compared in validating the model. The SMEC was minimized and independent variables were set at ranges of levels used for experimentation in order to optimize the process. Optimum SMEC of 0.053 kW h/kg was obtained at 45rpm, 8 MPa applied pressure and 327 g/min feed rate with a desirability of 0.99. The quadratic model predicting the SMEC showed that speed and pressure had significant influence on SMEC and also showed an excellent agreement between the variable due to low standard error and deviations between calculated and predicted values. • Pentaclethra macrophylla is an underutilized oil seed with potentials for dietary improvement ailments. This study investigated the influence of operating parameters on Specific Mechanical Energy Consumption (SMEC) of an expeller used for expressing oil from the kernels. • Independent variables (operating speed, applied pressure and feed rate) were carefully selected based on preliminary investigations and literature review. Response surface methodology was used for analysis, modeling and optimization. Predicted and experimental values were compared to validate the model. • Optimum SMEC of 0.053 kW h/kg was obtained at 45rpm, 8 MPa applied pressure and 327 g/min feed rate with a desirability of 0.99. The quadratic model predicting the SMEC showed that speed and pressure had significant influence on SMEC and also showed an excellent agreement between the variable. • Speed and pressure applied had significant influence on the energy consumption. The expeller is cost-effective in operation and poses no environmental threat; simple to operate and the obtained oil is environmentally benign. • The data reported will aid quality assurance and can serve as benchmark for scale-up and/or comparing different manufacturing operations and determining the cost of utilizing processing equipment.