Abstract:
Cheap alumino-silicate materials such as clay materials and Y zeolite were selected for the catalytic pyrolysis of waste
engine oil in a fxed bed reactor. A cheaper route of Y zeolite synthesis involving hydrothermal activation of the raw clay
and hydrothermal synthesis was employed. X-ray difraction technique, scanning electron microscopy, Fourier transform
infra-red, and nitrogen desorption method were used to characterize the intermediate phases formed during the hydrothermal
treatment of the clay and the synthesized Y zeolite during the hydrothermal processes. The chemical compositions of the
liquid phase of catalytic pyrolysis were characterized by gas chromatography coupled with mass spectroscopy (GC–MS).
The results revealed that the alkaline concentration strongly infuenced the activation of the raw clay to obtain a useful phase
for the subsequent synthesis of the Y zeolite. The synthesis improved the surface area from 29 m2
/g for the clay to 745 m2
/g
for the zeolite. The catalytic pyrolysis resulted in diesel fractions of 64.8 and 54.7%, respectively for the Y zeolite and the
clay. It was observed that the gasoline fractions increased to 20.5 and 19.1%, respectively for the zeolite and the clay. In the
diesel fraction, the zeolite selectively improved the yield of the cyclo-alkanes which are key constituents in terms of the
quality of diesel. Y zeolite was successfully derived from a natural clay and tested in the pyrolysis of waste engine oil. The
synthesis route provides the opportunity to improve the catalytic property of the natural clay.
