Study of the fast pyrolysis of oilfield sludge with solid heat carrier in a rotary kiln for pyrolytic oil production

• A flash pyrolysis of oilfield sludge was carried out in a rotary kiln reactor.
• The maximum oil yield was achieved at temperature of 550 °C and MR of 1:2.
• Functional group of pyrolytic oils are similar as extraction oils.
• The pyrolytic oils are the major linear chain hydrocarbons in the range C13–C25.

In this work, an experimental study of flash pyrolysis of oilfield sludge in different operation conditions was carried out under inert condition in a rotary kiln reactor. The effects of pyrolysis temperature, mixture ratio (MR) of sludge and solid heat carrier on the characteristics of product distribution were investigated. The composition of oils obtained from extraction and pyrolysis process were analyzed by Fourier transform infrared spectroscopy (FT-IR) and gas chromatography–mass spectrometry (GC–MS), respectively. The results indicated that, the maximum oil yield was achieved at temperature of 550 °C and MR of 1:2, which was 28.98% (wt% of sludge oil) and oil recovery rate was 87.9% basing on the oil content in the sludge. High fraction of saturates (72.5%) was obtained at 550 °C. The increasing temperature and solid heat carrier favor of pyrolysis gases increase. FT-IR analysis of pyrolytic oils shows that the oils have similar IR features as extraction oils. The pyrolytic oil was also found to contain the major linear chain hydrocarbons in the range of C13–C25.