Biodiesel production by esterification of oleic acid over zeolite Y prepared from kaolin

• Published in: Renewable energy 2016-11, Vol.97, p.19-23
• Main Authors: Doyle, Aidan M., Albayati, Talib M., Abbas, Ammar S., Alismaeel, Ziad T.
• Format: Article
• Language: English
• Subjects: Aluminum; Biodiesel; Catalysts; Esterification; Kaolin; Oleic acid; Si/Al ratio; Silicon; Y zeolite; Zeolites
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2016.05.067

Zeolite Y, with a Si/Al ratio 3.1, was prepared using Iraqi kaolin and tested as a catalyst in the liquid-phase esterification of oleic acid (a simulated free fatty acid frequently used as a model reaction for biodiesel production). XRD confirmed the presence of the characteristic faujasite structure of zeolite Y, and further analysis was conducted using BET adsorption, FTIR spectroscopy, XRF, DLS particle size and SEM. A range of experimental conditions were employed to study the reaction; alcohol/oleic acid molar ratio, temperature, and catalyst mass loading. The optimum conditions for the reaction were observed at 70 °C, 5 wt% catalyst loading and 6:1 ethanol to oleic acid molar ratio. The oleic acid conversion using the zeolite prepared from kaolin was 85% after 60 min, while the corresponding value for a commercial sample of HY zeolite was 76%. Our findings show that low Si/Al ratio zeolite Y is a suitable catalyst for esterification, which is in contrast to the widespread view of the unsuitability of zeolites, in general, for such applications. [Display omitted] •Zeolite Y, Si/Al ratio 3.1, prepared from hydrothermal treatment of kaolin.•Prepared zeolite Y catalysed esterification of oleic acid and ethanol.•Finding challenges consensus view that zeolites unsuitable to biodiesel catalysis.