Title: Waste to energy: effect of reaction parameters on the transesterification of animal fat oil to biodiesel over a solid hydroxy sodalite catalyst

Authors: Chabisha P. Makgaba; Thomas C. Aniokete; Michael O. Daramola

Addresses: Faculty of Engineering and the Built Environment, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa ' Faculty of Engineering and the Built Environment, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa ' Faculty of Engineering and the Built Environment, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa

Abstract: In this study, SOD crystals, synthesised via a hydrothermal synthesis method, were used as solid catalyst to convert beef tallow oil (BTO) into biodiesel. Transesterification reaction was conducted at methanol-to-oil ratio of 7.5 : 1 using 3 wt. % SOD catalyst. Reaction conditions were varied as: mixing intensity (700-1250 rpm); catalyst particle size (200-300 Å); reaction time (6-24 h); and reaction temperature (40-60°C). The physicochemical characterisation of the SOD catalyst was conducted using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), N₂ physisorption at 77 K (for textural property) and thermogravimetric analysis (for thermal stability). The FFA content of the BTO was 4.53%. Physicochemical characterisation shows that SOD crystals were synthesised. The reaction products analysed with a pre-calibrated gas chromatography-mass spectrometer (GC-MS) confirmed the influence of reaction process parameters on the yield of biodiesel leading to a highest FAME (fatty acid methyl ester) yield of 78.3% at agitation speed of 1000 rpm and catalyst particle size of 200 Å. The reaction temperature and reaction time at this condition were 60°C and 24 h, respectively.

Keywords: biodiesel; animal fat; hydroxy sodalite; waste beneficiation; solid catalyst.

DOI: 10.1504/PIE.2018.097144

Progress in Industrial Ecology, An International Journal, 2018 Vol.12 No.4, pp.331 - 344

Received: 31 Aug 2017
Accepted: 27 Apr 2018
Published online: 02 Jan 2019 *

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