High purity FAU-type zeolite catalysts from shale rock for biodiesel production

- FAU-type zeolite prepared from hydrothermal treatment of shale rock.
- Preparation conditions varied systematically to give high purity zeolite.
- Activity of FAU-type zeolite comparable with commercial zeolite Y in oleic acid esterification.

FAU-type zeolite was prepared using Irish shale rock and tested as a catalyst in the liquid-phase esterification of oleic acid (a model test reaction for biodiesel production). A systematic study was conducted (over the stated preparation ranges) by varying the water:shale ratio (4:1-15:1 by mass), and mixing (1-24 h), aging (6-48 h) and hydrothermal treatment times (6-72 h) to determine the optimal parameters. XRD confirmed that the product purity was highly dependent on the experimental conditions used. The BET surface area of the calcined FAU-type zeolite was 571 m2 g−1 and its crystal purity was comparable to that of a commercial zeolite Y. The prepared zeolite was catalytically active in the esterification of oleic acid with ethanol reaching a maximum of 78% conversion after 90 mins, which is practically identical to that recorded for commercial zeolite Y.