Combustion Synthesis of Clay - Spinel Zinc aluminate Composite Activated by Heteroploy Acid as Catalyst for Biodiesel Production

Articles in Press

Document Type : Original Articles

Authors

Majid Paseban ¹

Hamed Nayebzadeh ²

Behgam Rahmanivahid ¹

¹ Department of Chemical Engineering, Faculty of Chemical and Material Engineering, Esfarayen University of Technology, Esfarayen, Iran

² Chemical Engineering Department, Esfarayen University of Technology

10.22067/jmme.2026.98103.1245

Abstract

In this study, a heterogeneous acidic catalyst based on ZnAl2O4 clay mineral-spinel composite was prepared. For this purpose, the solution combustion method was used and then it was modified by loading tungstophosphoric acid as the active phase by the wet-impregnation method. In order to investigate the structure and physicochemical properties of the catalyst, XRF, XRD, FTIR, FESEM and BET analyses were used. The X-ray diffraction pattern confirmed the formation of a stable spinel phase, with a crystal size reduced from about 50 nm for the clay mineral to about 40 nm for the synthesized composite. The reduction in particle size along with the type of combustion synthesis process that was accompanied by the release of a high volume of gas has caused the synthesized catalyst to have a porous configuration and a proper dispersion of the active phase with a particle size of less than 40 nm. Also, although the surface area has decreased, the average pore size has increased significantly as a key factor in utilizing the internal surfaces of the catalyst. The performance of the catalyst was evaluated in the esterification reaction of oleic acid with methanol, and a yield of 77.3% was obtained under the reaction conditions of 120℃, 1:7 molar ratio of alcohol to acid, 6% catalyst weight percentage, and 4 hours reaction time. Also, this catalyst was able to maintain its activity for four consecutive uses, indicating that it could be a suitable catalyst for industrial applications.

Keywords

Biodiesel

Esterification reaction

Heterogeneous catalyst

Clay

Zin aluminate spinel

Subjects

• Nanomaterials

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