Optimization of the novel hydrodynamic cavitation based waste cooking oil biodiesel production process parameters using integrated L9 Taguchi and RSM approach

Abstract

The present work investigated the optimization of the production method of biodiesel from waste cooking oil (WCO) using hydrodynamic cavitation process. To achieve the maximum WCO biodiesel yield with a minimum number of experimental trials, one of the most popular optimization technique L9 Taguchi has been used for the validation of hydrodynamic cavitation (HC) process. In this HC experimental process, 260 mL of methanol were mixed with 0.5% of wt. KOH into a 500 mL conical flask. The mixture was later added to 1000 mL of warmed WCO, preheated to 35 °C in a storage tank of 30 L capacity. The HC reactor then ran for 30 min. The products were allowed to settle for 30 min and then the final sample of biodiesel were collected. The same process was repeated for all nine readings. The controllable features that were selected for the investigation, were the catalyst concentration (5 ≤ B ≤ 20 g), reaction temperature (35 ≤ C ≤ 55 °C), reaction time (30 ≤ D ≤ 50 min) and molar ratio (1:6 ≤ A ≤ 1:12). After the optimized setting, it was observed that at the molar ratio of 12:1, and other parameters such as catalyst concentration (5 g), reaction temperature (55 °C), and reaction time (40 min), 97% WCO biodiesel yield was observed. During the investigation, it was found that the reaction temperature has significant contribution on the WCO biodiesel yield. The value of coefficient of determination was found to be unity which shows the efficacy of the present investigation. The investigation has provided low cost feedstock for the WCO biodiesel production with maximum yield.