Experimental study on catalytic pyrolysis of oil sludge under mild temperature

The pyrolysis performance of oil sludge (OS) was studied using a thermal gravimetric analysis apparatus and a tube furnace reactor. The oil recovery rate of OS pyrolysis showed a rapid growth trend at 450 °C. Moreover, the co-pyrolysis experiments of the OS and catalysts, including walnut shells, Fe₂O₃, K₂CO₃, polyvinyl chloride (PVC), and OS pyrolysis char with addition ratios of 5, 7, and 9 wt%, respectively, were conducted in a tube furnace reactor at 450 °C. The experiments demonstrated that all catalysts increased the oil recovery rate, but the optimal addition ratios differed. The pyrolysis chars produced above 450 °C had a well-developed pore structure, and the catalytic pyrolysis of OS at 450 °C could increase the yield of pyrolysis oil and reduce the potential ecological risk of heavy metals in the pyrolysis char. Therefore, catalytic pyrolysis is an inexpensive and highly efficient approach for treating solid waste.