Carbon-templated meso-design of nanostructured CeAPSO-34 for biodiesel production from free fatty acid and waste oil

The SAPO-34 zeotype with suitable physicochemical properties, was used to produce biodiesel as a clean fuel. The micropore nature of this catalyst limits the reaction because elainic acid molecules are too large to penetrate and access the internal pores of zeotype. The physicochemical properties of the synthesized catalysts were evaluated and compared using BET, XRD, TPD, EDX, FESEM, and HRTEM analyses. The simultaneous use of a carbon template and a heteroatom for doping in the synthesis of the catalyst (MCeAPSO-34) has a synergistic effect on increasing the pore diameter up to 4.1 nm. As expected, the MCeAPSO-34 zeotype gained 17, 12, and 27% more conversion rates than the CeAPSO-34 (doping effect), MSAPO-34 (carbon-template effect), and conventional SAPO-34 zeotypes in the production of biodiesel from elainic acid, respectively. Accommodation of CeO2 on the nanostructured MCeAPSO-34 zeotype by the solvothermal method increased the zeotype acidic sites from 73% to 89%. The use of ultrasound energy for distribution of the active phase increased the catalyst acidity and the conversion of 95% was obtained for the Ce/MCeAPSO-34 (U) catalyst. This catalyst has also converted 93% of the synthetic waste oil into biodiesel as a clean fuel.