Synthesis of Pure and High Surface Area Sodalite Catalyst from Waste Industrial Brine and Coal Fly Ash for Conversion of Waste Cooking Oil (WCO) to Biodiesel

Recently, the devastating environmental threat of coal usage in power generation and high biodiesel production costs had led to worldwide energy discourse. The cost of producing and thus economical and environmentally sustainable use of biodiesel could be reduced by non-waste derived heterogeneous catalysts prepared from waste products. In this preliminary study, coal fly ash and industrial waste brine of South African origin were valorized for the synthesis of waste-derived solid hydroxy sodalite (HSOD) catalyst. Catalysts derived from non-waste are not sustainable economically and environmentally. However, the method of hydrothermal synthesis was used to synthesize the catalysts used in a batch reactor to produce biodiesel. The catalyst's physicochemical characteristics were studied using X-ray diffraction, Scanning electron microscopy and Fourier transform infrared. The catalyst's textural property was acquired at 77K through nitrogen physiosorption using Brunauer-Emmett-Teller (BET) technique. The catalyst was subjected to performance evaluation to produce biodiesel from waste cooking oil under the following reaction conditions: 15:1 methanol-to-waste cooking oil ratio, 3 wt percent of catalysts, 300-500 r.p.m. agitation speed, 8 h reaction time and 60 degrees C temperature. The biodiesel yield for the waste catalyst and the non-waste catalyst was 89.4 and 85.0 percent respectively, with a peak conversion of 97.0 percent of the waste cooking oil. BET analytical results indicate that the surface area of waste derived and non-waste derived catalysts was respectively 33.05 m(2)g(-1) and 0.1645 m(2)g(-1).