ABSTRACT
This study focused on developing a new cocktail extraction agent (CEA) composed of solvent and a new surfactant material (SM) for enhancing the efficiency of fuel recovery from real waste oil sludge (WSO). The effects of different solvents (e.g. methyl ethyl ketone (MEK), naphtha, petrol and kerosene), SMs (Dowfax and sodium thiosulfate), extraction time (10-20 min), extraction temperatures (20-60 °C) and CEA/sludge ratios (1-4) on the extraction performance were investigated. SMs and DBBE design enhanced the extraction efficiency by increasing the dispersion of solvent in WSO and enhancing the mixing and mass transfer rates. Results proved that Dowfax was the best SM for oil recovery under various conditions. The best CEA (e.g. MEK and Dowfax) provides the maximum fuel recovery rate of 97% at a period of 20 min, temperature of 60 °C and 4:1 CEA/sludge ratio. The produced fuel was analysed and fed to the distillation process to produce diesel oil. The characteristics of diesel oil were measured, and findings showed that it needs treatment processes prior its use as a finished fuel.
ABSTRACT
The oxidative desulfurization (ODS) of dibenzothiophene in diesel fuel cut using a homogeneous liquid catalytic system in a novel reactor is presented. Hydrogen peroxide was the oxidizing agent and acetic acid was the liquid catalyst. The oxidation process was conducted in a meso-oscillatory baffled reactor ("mesoOBR") under mild operating conditions: atmospheric pressure, and 60 to 80 °C. The reactor was operated over a range of residence times (1-3 min), and frequencies and amplitudes of oscillation, leading to oscillatory Reynolds numbers in the range 64-383, and net flow Reynolds numbers in the range 5 to 16. The results showed that dibenzothiophene (DBT) removal in the OBR was significantly higher than in conventional processes under the same conditions (pressure of 1 atm and temperature near room temperature). The maximum DBT conversion was 94%, which was achieved in 3 min at 4 Hz and 6 mm amplitude. A significant improvement in the removal efficiency of DBT was achieved in OBR within only 3 minutes compared to previous studies, which required at least a half-hour reaction time to achieve the same or less removal efficiency. A reaction kinetic model was developed using the optimum experimental results achieved in the OBR. The apparent reaction order was 1, with significantly low apparent activation energies (24.7-29.0 kJ mol-1).
