Conversion of spent carbon to working carbon using spent FCC catalyst-derived zeolite X

The spent fluidized catalytical cracking catalyst from refinery is used as a raw material for the synthesis of zeolite X by hydrothermal method. The converted zeolite X is characterized by powder X-ray diffraction, BET surface area, infrared spectroscopy and inductive coupled plasma spectroscopy analysis confirming good match to the zeolite made from conventionally used raw materials. The converted zeolite X is further used as a heterogeneous catalyst in synthesis of five-membered cyclic carbonate. The path chosen for the preparation of styrene carbonate is ecofriendly, which not only utilizes the carbon dioxide (CO₂) but also replaces the toxic chemical like phosgene. The influence of various parameters like varying amounts of catalyst and temperature was investigated carefully to get optimized conditions for desired product. Product was analyzed by gas chromatography. The recyclability of catalyst was tested and could be used successfully for three cycles without any significant loss in activity. Graphical abstract:

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