Dimensionless evaluation and kinetics of rapid and ultradeep desulfurization of diesel fuel in an oscillatory baffled reactor.

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).

Nanoparticle catalyzed hydrodesulfurization of diesel fuel in a trickle bed reactor: experimental and optimization study.

This work focuses on the preparation, simulation, and optimization of the hydrodesulfurization (HDS) of dibenzothiophene (DBT) using a nanocatalyst. A homemade nanocatalyst (3 percent Co, 10 percent Mo/γ-Al2O3 nanoparticles) was used in a trickle bed reactor (TBR). The HDS kinetic model was estimated based on experimental observations over ranges of operating conditions to evaluate kinetic parameters of the HDS process and apply the key parameters. Based on these parameters, the performance of the TBR catalyzed by the nanocatalyst was evaluated and scaled up to a commercial scale. Also, the selectivity of HDS reactions was also modeled to achieve the highest yield of the desired hydrogenation product based on the desirable route of HDS. A comprehensive modeling and simulation of the HDS process in a TBR was developed and the output results were compared with experimental results. The comparison showed that the simulated and experimental data of the HDS process match well with a standard error of up to 5%. The best reaction kinetic variables obtained from the HDS pilot-plant (specific reaction rate expression, rate law, and selectivity) TBR have been utilized to develop an industrial scale HDS of DBT. The hydrodynamic key factors (effect of radial and axial dispersion) were employed to obtain the ratio of the optimal working reactor residence time to reactor diameter.