Optimization conversion of beef tallow blend with waste used vegetable oil for fatty acid ethyl ester (FAEE) synthesis in the presence of bio-base derived from Theobroma cacao pod husks

The purpose of this study is to derive CaO-base catalysts from Theobroma cacao pod husks, apply them to synthesize fatty acid ethyl ester: FAEE using the blend of beef tallow-waste in the presence of ethanol. Process optimization of the production step (transesterification reaction) was carried out using a hybrid design so as determine optimum FAEE yield. Furthermore, the efficiencies of the catalyst were tested via the refining and reusability test.The produced catalysts (burnt, submerged and calcined) were analysed and characterized using Scanning Electron Microscopy (SEM), X-ray diffraction analysis (XRD), Fourier transforms infrared spectroscopy (FTIR), BET adsorption analysis, and Hammett indicator. The oil blends were carried out in the ratio of 5:95 (BTO5), 10:90 (BTO10),15:85 (BTO15), 20:80 (BTO20), 95:5 (BTO95), respectively, to produce low viscous oil to enhanced biodiesel production (FAEE). The productions of FAEEs were carried out by transterification in a single three-batch-necked reactor due to low acid value. Optimum biodiesels yield were determine using statistical analysis, while catalysts strength were tested by recycling, refining and reusability test. Results: revealed the oil blends ratio of BTO60: WUO40 was sufficient to produced low viscous oil. Catalysts characterization revealed that the three catalysts produced high CaO-base of 68.20, 81.46, and 87.65 (wt.%). Based on process optimization and validation, the statistical model predicted a FAEE1 yield of 93.4998 (%wt.), FAEE2 yield of 95.2411 (%wt.), and FAEE3 yield of 99.8081 (%wt.) at the following variables conditions: reaction time of 78.58 min, catalyst amount of 3.37 (wt.%), reaction temperature of 79.23 °C, and EtOH/OMR of 1:6.66 (vol/vol), respectively. These values were validated in triplicate and an average optimum values of FAEEs obtained were: 92.8100 (%wt.) for FAEE1, 93.0200 (%wt.) for FAEE2, and 99.6400 (%wt.) for FAEE3, respectively. The qualities of the FAEEs are within the standard specification and the produced catalysts can serve as feedstocks for industrial applications.