Thermogravimetric analysis of sludge pyrolysis oil mixed with heavy fuel oil

Pyrolysis of sewage sludge may be a viable solution to the different problems related to its management and handling. The aim of this study is to investigate the combustion characteristics of sludge pyrolysis oil (SPO), heavy fuel oil (HFO), and the blends of SPO and HFO. Different combustion characteristic parameters such as ignition temperature (Ti), burnout temperature (Te), flammability index (C), and combustion characteristics index (S) are evaluated by thermogravimetric analysis. The results show that the combustion of SPO and the blends of SPO and HFO can be divided into three stages: dewaterization, lightweight components (LWC) burning and heavyweight components (HWC) combustion. In the LWC burning stage, the fuel blends with a higher SPO content exhibits greater values for C and S due to the release and oxidation of the LWC. However, their C and S were quite similar for the HWC combustion stage. In general, adding any quantity of SPO to the SPO/HFO fuel blend enhances the combustion efficiency.