Guishe biochar as heterogeneous catalyst for biodiesel production: synthesis and transesterification modeling

• Published in: Reaction kinetics, mechanisms and catalysis mechanisms and catalysis, 2022-10, Vol.135 (5), p.2643-2661
• Main Authors: González García, Ana Paloma, Figueroa Díaz, Andrea Belén, Carlos Hernández, Salvador, Padmadas, Padmasree K., Díaz Jiménez, Lourdes
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Physical Chemistry
• ISSN: 1878-5190; 1878-5204
• DOI: 10.1007/s11144-022-02264-0

Biochar from guishe was synthesized by pyrolysis at 800 °C and evaluated as a heterogeneous catalyst in a transesterification reaction. Batch experiments were performed, and a mathematical model to explain the kinetic behavior was also validated. The obtained results show that guishe contains 32% ash due to inorganic substances such as calcium (28%); besides, the raw material reaches the thermal steady state around 800 °C, which is selected as pyrolysis temperature. The biochar yield was 48%, and calcium compounds [Ca(OH) 2 , CaO, and CaCO 3 ] were detected; the specific surface area of the biochar was 10.7 m 2  g −1 . On the other side, the biodiesel production yield was 98%; the Eley–Rideal mechanisms explain better the experimental conversion of soybean oil; this implies the adsorption of methanol on the surface of the guishe biochar is the limiting step of the reaction; finally, the transformation of triglycerides to biodiesel as well as the glycerol production and alcohol consumption is correctly predicted by the model.