Experimental investigation on petroleum sludge valorization into fuel via pyrolysis process

Abstract

Oil sludge (OS) has been of key concern due to its continuing effect on the environment degradation. The huge quantities thrown yearly of this waste contain a high proportion of hydrocarbons which are valuable for recovery. This study focused on the oil sludge conversion into a fuel for a diesel engine by thermal/catalytic pyrolysis process. The experiments were conducted at atmospheric pressure in a batch reactor operated without and with two catalyst types: TiO2 (3 and 5 wt%) and Al2O3(3 and 5 wt%). Overall all test conditions followed in the OS pyrolysis, a considerable liquid fraction is recovered (around 70%), as compared to the gaseous fraction (around 25%) and the solid residue (around 5%). The characterization of the pyrolytic oil samples, containing approximately 11.70% of oxygen, showed also that the use of 5% of Al2O3 catalyst in the OS cracking provide the best fuel quality with a minimum viscosity value (3.5 mm2/s), a maximum heating value (45.72 MJ/kg) with a hydrocarbon compounds in the range (C7–C32) which are detailed by GC–MS analysis. The others properties (density, flash point, pour point and cloud point) are found to be close to those of diesel fuel. Also, the catalysts effect is studied on the others pyrolysis products. The obtained results allow to predict the good usability as a diesel like fuel. Further tests to control engine performance and pollutant emissions could be done Graphic Abstract