*2.1. Materials and Reagents*

Purified air for DSC/TGA analysis was purchased from Qingdao Fengtai Co., Ltd. (Qingdao, China). Oxygen gas for the heating value test, with 99.99% purity, was purchased from Qingdao

Chunfeng Co., Ltd. (Qingdao, China). The upstream oily sludge that was utilized in this study was obtained from a temporary storage bin in Shengli Oil Field, Dongying, Shandong province, China, and the samples appear to be viscous and black block.
