Co-Pyrolysis Characteristics and Kinetic Analysis of Oil Sludge with Different Additives

The addition of effective additives can effectively improve the pyrolysis performance of oil sludge (OS) and have a great potential to reduce pyrolysis costs. In the present study, co-pyrolysis performance of OS with different proportions of additives at a heating rate of 10°C/min was conducted in a thermal analyzer. Walnut shell, Fe2O3, K2CO3, PVC and the pyrolysis char produced from OS at the final pyrolysis temperature of 700°C were selected as the additives. TG results showed that the OS pyrolysis with and without additives can be divided into five reaction stages, which include volatilization of free water, the escape of light components, the cleavage of heavy components, carbon decomposition and inorganic minerals decomposition. The addition of additives decreased the maximum weight loss rate when the blending ratio was 5 wt% during OS pyrolysis. Kinetic analysis revealed that the overall activation energy of pyrolysis reaction was lower during pyrolysis of OS with the addition of walnut shells and pyrolysis char. The activation energy of three main reaction stages all decreased during co-pyrolysis of OS with K2CO3 and PVC.