Table 4.

Products of pyrolysis of different tank bottom sludges

The pyrolysis conditions	The yield	Ref.
Fluidized bed and temperature range of 460–650 °C	70–84% of oil	Deng et al. (2015)
Co-pyrolysis of rice husk and petroleum sludge at 600 °C in a fixed bed reactor	While resin and asphaltene concentration decreased by 25–31% and 11–68%, respectively, saturates and aromatics in oil products increased by 15–55% and 55–86%, significantly.	Lin et al. (2018)
The interaction between accompanying the heat of reaction throughout the drying and combustion processes of oily sludge, the properties of combustion of oily sludge with fuel	Mixing biomass with oily sludge could enhance the incineration of oily sludge. At various temperatures, distinct interactions between the burning of oily sludge and biomass were found. The interaction reduced the combustion of the mixes between 280 and 390 °C, while it accelerated it between 390 and 620 °C.	Deng et al. (2016)
Using combined thermal cracking and catalytic pyrolysis to recover oil from oily sludge	The oil output improved as the temperature rose over 450 °C and peaked at 750 °C (76.84 wt%).	Jin et al. (2021)
Microwave pyrolysis oil recovery	Highest oil yield was obtained at the following optimized conditions: 450 W power using a 1:5 ratio of graphite to sludge. Oil and char were determined to have calorific values of 44,442.9 and 16,686.58 kJ/kg, respectively. Flash point, density, and kinematic viscosity of oil were determined to be 94 °C, 874.9 kg/m3, and 4.063 cSt, respectively.	Sivagami et al. (2021)