Study of the thermal decomposition of petrochemical sludge in a pilot plant reactor

• Pyrolysis of oil refinery sludge has been studied in a pilot plant reactor.
• Temperatures in the range 350–530 °C were used in a nitrogen atmosphere.
• Gas, liquid and char fractions were characterized.
• An increase of liquid fraction is observed when increasing the temperature.
• Light hydrocarbon yields increase with temperature.

The pyrolysis of a sludge produced in the wastewater treatment plant of an oil refinery was studied in a pilot plant reactor provided with a system for condensation of semivolatile matter. The study comprises experiments at 350, 400, 470 and 530 °C in nitrogen atmosphere. Analysis of all the products obtained (gases, liquids and chars) is presented, with a thermogravimetric study of the char produced and analysis of main components of the liquid. In the temperature range studied, the composition of the gas fraction does not appreciably vary. In the liquids, the light hydrocarbon yield increases with increasing temperature, whereas the aromatic compounds diminish. The decomposition of the solid fraction has been analyzed, finding a material that reacts rapidly with oxygen regardless of the conditions it is formed.