Calcium oxide on coal fly ash cancrinite-type zeolite as a catalyst for biodiesel production

Abstract

This paper discloses the synthesis of new supported catalyst in which the main components of the catalyst, catalyst support and active component, derived from waste material, and its catalytic properties tested in the reaction of the production of biodiesel. Cancrinite-type zeolite catalyst support was synthesized from coal fly ash using hydrothermal technique with NaOH as the activation reagent in a rotating PTFE autoclave reactor. The active component, CaO, was derived from waste chicken eggshells by calcination at 900 °C. Supported catalytic material was synthesized by impregnation. The content of CaO in the prepared catalysts was varied from 5 to 20 wt%. The catalysts were characterized using XRD, FT-IR, SEM, N2-physisorption, and Hg-porosimetry. The methanolysis of sunflower oil was carried out in a batch reactor at 60 °C, with methanol to oil molar ratio of 12:1, and catalyst concentration of 4 wt.%. The fatty acid methyl ester content (% FAME) was analyzed using HPLC method. Structural information related to phase identification and vibration of chemical bonds in molecular units indicates that a multiphase zeolitic structure was obtained. The structure of cancrinite-type zeolite was found to be dominantly present. It was found that the catalyst impregnated with 20% of CaO gave the highest FAME percentage of 96.46 for the reaction time of 2 h.