Response surface optimization of biodiesel synthesis over a novel biochar-based heterogeneous catalyst from cultivated (Musa sapientum) banana peels

• Published in: Biomass conversion and biorefinery 2021-12, Vol.11 (6), p.2795-2811
• Main Authors: Jitjamnong, Jakkrapong, Thunyaratchatanon, Chachchaya, Luengnaruemitchai, Apanee, Kongrit, Napaphat, Kasetsomboon, Naparat, Sopajarn, Arrisa, Chuaykarn, Narinphop, Khantikulanon, Nonlapan
• Format: Article
• Language: English
• Subjects: Biodiesel fuels; Biotechnology; Catalysts; Catalytic activity; Chemical synthesis; Design factors; Design of experiments; Energy; Independent variables; Methanol; Optimization; Original Article; Palm oil; Potassium; Potassium carbonate; Potassium hydroxides; Pyrolysis; Reaction time; Renewable and Green Energy; Response surface methodology; Transesterification
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-020-00655-8

In this work, response surface methodology (RSM) was utilized to optimize the biodiesel yield of the transesterification reaction. A novel solid carbon-supported potassium hydroxide catalyst derived from the pyrolysis of cultivated banana ( Musa sapientum ) peels and potassium carbonate (K 2 CO 3 ) was used as the catalyst for biodiesel production. A five-level (− 2, − 1, 0, + 1, and + 2) RSM with a four-factor central composite design of independent variable factors (methanol to palm oil molar ratio (6:1–18:1), catalyst loading (3–7 wt.%), reaction time (30–150 min), and reaction temperature (50–70 °C)) were randomly setup using the Design of Experiment program. The 30 wt.% K 2 CO 3 catalyst calcined at 600 °C under atmosphere pressure exhibited the highest catalytic activity, since the pyrolysis ash was rich in K that formed a basic heterogeneous catalyst. Within the range of selected operating conditions, the optimized methanol:oil molar ratio, catalyst loading, reaction time, and reaction temperature were found to be 15:1, 4 wt.%, 120 min, and 65 °C, respectively, to give a biodiesel yield of 99.16%. The actual biodiesel yield of 98.91% was obtained under the predicted optimal conditions. The high R 2 (96.76%) and R 2 adj (92.97%) values indicated that the fitted model showed a good agreement with the predicted and actual biodiesel yield.