Acacia furnesiana plant as a novel green source for the synthesis of NiFe2O4 magnetic nanocatalyst and as feedstock for sustainable high quality biofuel production

Magnetic nanoparticles as heterogeneous catalysts could open up new possibilities for the development of eco-friendly biodiesel production. In the present study, the Acacia furnesiana (A. furnesiana) fruit component namely pods and seeds are successfully employed as low-cost and environmentally-safe starting materials for the syn-thesis of NiFe2O4 NPs and also as feedstock for biodiesel synthesis respectively. Interestingly, A. furnesiana seed extract is utilized for the first time as a feed stock for the biodiesel production using NiFe2O4 NPs as catalyst. Using response surface methodology and linear regression, the optimum conditions for the biodiesel production using NiFe2O4 catalyst is obtained. An excellent A. furnesiana oil methyl ester (AFOME)/biodiesel yield of 93.1% is achieved with 4.61 wt% of NiFe2O4 loading, 14:1 M ratio of methanol to oil, 53 min reaction time and at a temperature of 65 degrees C. The NiFe2O4 catalyst after transesterification reaction is recovered 100% using a per-manent magnet and can be reused up to four cycles with > 80% AFOME yield at the end of 4th cycle. The activation energy for AFOME production is found to be -44.54 kJ/mol from kinetic study and, the thermo-dynamic investigation revealed that the enthalpy and entropy of the system is -27.49 kJ/mol and -0.18 kJ mol/k, respectively.

Automated summary

Magnetic nanoparticles were used as heterogeneous catalysts for eco-friendly biodiesel production. Acacia furnesiana fruit components, pods and seeds, were successfully used as low-cost starting materials for the synthesis of NiFe2O4 nanoparticles and as feedstock for biodiesel synthesis respectively. Response surface methodology and linear regression were used to determine the optimum conditions for the biodiesel production. A high AFOME/biodiesel yield of 93.1% was achieved using NiFe2O4 catalyst, with 4.61 wt% of loading, 14:1 M ratio of methanol to oil, 53 min reaction time, and 65°C temperature. The NiFe2O4 catalyst could be recovered and reused up to four cycles with > 80% AFOME yield. The activation energy for AFOME production was -44.54 kJ/mol according to kinetic study, and the thermodynamic investigation revealed the enthalpy and entropy of the system as -27.49 kJ/mol and -0.18 kJ mol/K, respectively.