Research · Clean energy

Pyrolysis of refinery oily sludge

Oily sludge from petroleum refineries is hazardous, wet and hard to dispose of. We use fluidized and fixed bed pyrolysis, with and without catalysts, to turn it into oil, fuel gas and char. See also gasification of high-ash coal and biomass.

Background: pyrolysis oil recovered at 400 °C and 500 °C

Pyrolysis oil samples in flasks and vials of different colours and API gravity
Pyrolysis oil recovered at 400 °C and 500 °C, and samples graded by API gravity

With GAIL, we built a lab-scale fluidized bed pyrolyser that runs in fixed and fluidized bed modes. It separates oil and water from the sludge and yields combustible gas and char, recovering about 250 ml of oil per kg of sludge.

Adding a catalyst shifts the products: more liquid oil and less char, with a gas richer in hydrogen at the right catalyst loading. GAIL has expressed interest in a pilot plant.

Pawar & De, Energy (2026, accepted) · GAIL project, 2022 – 2025

Stacked bars of gas, char and liquid oil yield at temperatures from 400 to 600 degrees
Product yield vs temperature (fluidized bed)
Gas composition and heating value against temperature without catalyst
Gas composition and LHV vs temperature, no catalyst
Stacked bars of product yield against catalyst ratio
Product yield vs catalyst ratio
Gas composition and heating value against catalyst percentage
Gas composition and LHV vs catalyst loading

Publications

  • 2026A. Pawar, S. De. Catalytic valorization of petroleum-derived high-moisture oily sludge using a fixed bed pyrolyzer. Energy (accepted).Find paper ↗
  • 2021M. Moiz, S. Gupta, S. De. Investigation of co-pyrolysis characteristics of high-ash Indian coal and rice husk. IOP Conf. Ser.: Materials Science and Engineering 1146(1), 012014.Publisher ↗

All publications →

Student theses

  • R. R. Pandey (M.Tech, 2024)Pyrolysis in a fixed bed reactor and upgrading of pyro-oil using catalysts
  • S. Satnami (M.Tech, 2022)Experimental investigation of rice husk pyrolysis in a fixed bed reactor

Funding

  • GAILValorisation of oil sludge by bubbling fluidized bed pyrolysis, 2022 – 2025

People

  • Ajay PawarCatalytic pyrolysis of oily sludge
  • Dr. Bhoopendra PandeyOily sludge pyrolysis (postdoc, GAIL project)