Catalytic pyrolysis of spent bleaching clay for its regeneration and simultaneously producing aromatic hydrocarbons

This study was focused on the value-increment of spent bleaching clay (SBC) to produce aromatic hydrocarbons and regenerated bleaching clay (RBC) via ex-situ catalytic pyrolysis with HZSM-5. The catalytic pyrolysis experiments were conducted to clarify the regulatory functions of pyrolytic temperature and SBC-to-HZSM-5 ratio (S/H) on the product distribution and aromatics generation. The adsorbed oil in SBC could be decomposed almost completely at 450 °C. The optimum aromatics yield of 3.49 wt% was achieved at catalytic temperature of 600 °C and S/H of 15. The solid product obtained under this condition underwent calcination at 500 °C and acid treatment successively to prepare RBC. The treatment did not affect the montmorillonite structure of clay. The RBC possessed good porous structures with newly generated micropores . The specific surface area and pore volume of RBC reached 163.32 m 2 /g and 0.29 cm 3 /g, higher than those of 146.17 m 2 /g and 0.25 cm 3 /g of fresh activated bleaching clay (ABC), indicating the better adsorption performance of RBC.