Porous carbon nanospheres in situ doped KxFeyOz as novel magnetic nanocatalyst for biodiesel production

Thayee Al-Janabi, Omer Yasin, Ali, Baidaa M., Abdulkareem, Hiba A., Hussein, Arab H., Al-Tikrity, Emaad T.B. and Foot, Peter J.S. (2025) Porous carbon nanospheres in situ doped KxFeyOz as novel magnetic nanocatalyst for biodiesel production. Fuel, 398, p. 135456. ISSN (print) 0016-2361

Abstract

Waste frying oils (WFO) are cheap and can be used as feedstocks for biodiesel production. Researchers are striving to develop a cost-effective and green heterogeneous catalyst for the transesterification of WFO to produce biodiesel. In this work, a new magnetic carbon nanospheres catalyst doped with KxFeyOz (K30PMCNS700) was synthesized via template-free hydrothermal carbonization (HTC) of glucose followed by in situ functionalization with Fe3O4 NPs, potassium activation, and calcination. The operating conditions for the transesterification process were optimized by response surface methodology RSM-CCD. It was found that the prepared K30PMCNS700 was thermally stable, possessed a specific surface area of 95.8 m2 g−1, was superparamagnetic with a saturation magnetization of 26.2 emu g−1, and featured a total basicity of 3584 µmol g−1. The new nanocatalyst was used to catalyse the transesterification reaction of WFO to produce biodiesel fuel. The results indicated that K30PMCNS700 converted 98.3 % of WFO into biodiesel in 80 min at 60 °C with a 9:1 MeOH:WFO ratio. The catalyst durability tests confirmed excellent reusability under optimum conditions, achieving 93.4 % WFO conversion and negligible rates of potassium leaching into the biodiesel (i.e. 3.5 µg L-1) at the 5th cycle. The biodiesel production reaction followed pseudo-first order kinetics (k = 0.1044 min−1), with an activation energy and Gibbs free energy of 70.46 and 255.14 kJ mol−1, respectively. A diesel engine running on BD25 blend (25 % biodiesel and 75 % petroleum diesel) consumed less fuel, generated more brake thermal energy, and produced lower gas emissions.

Actions (Repository Editors)

Item Control Page Item Control Page