Comparative study of catalytic performance and degradation kinetics of biodiesels produced using heterogeneous catalysts from kaolinite

• Main Authors: Abnisa, Faisal, Sanni, Samuel Eshorame, Alaba, Peter Adeniyi
• Format: Article
• Published: Elsevier Science Ltd 2021
• Subjects: TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.um.edu.my/27017/

This study comparatively investigates the catalytic activities and degradation kinetics of the produced biodiesels using kaolinite-based heterogeneous catalysts to examine the stability. The performance of the catalysts was tested under the same operating parameter (methanol/oil ratio, 5:1, at 200 degrees C for 6 h). The obtained biodiesel was analyzed using TGA equipment to obtain the yield, as well as the degradation kinetic parameters. It was observed that the solid superacid SHY zeolite gave the highest biodiesel yield (90.76%) because of higher acid strength. The catalysts performance is in the order of HY<ALK<HLK<NaLK<SHY zeolite. The lower performance of HY (72.42% yield) is attributed to the presence of high basic sites, being that shea butter has high FFA. The degradation kinetics of each biodiesel sample was performed using the TGA data to examine the thermal and oxidative stability. The frequency factor (A), activation energy, and reaction order were determined by employing the Coats-Redfern model. It was observed that first-order reaction mechanism can satisfactorily describe all the biodiesel kinetics. Further, the biodiesel from SHY zeolite gives the highest EA (98.65 kJ/mol). This result indicates that SHY zeolite is the best catalyst in terms of biodiesel yield and stability.