Synthesis, evaluation, and optimal stability of a biowaste-based catalytic oxidative desulfurization of model fuel in a trickle bed reactor

Abstract

Oxidative Desulfurization (ODS) is one of the promising alternative processes. However, the lifetime of the ODS catalysts is an issue that restricted the use of the process. In this work, Activated Carbon (AC) prepared from biowaste (apricot stones (AS)) was impregnated with Mn and coated with aluminum oxide to prolong the lifetime of the ODS process. To evaluate the performance of the prepared catalysts for a continuous three-phase ODS process, a trickle bed reactor (TBR) was used to conduct the ODS process at mild oxidation temperatures. The ODS evaluation study was conducted under different temperatures (60 and 70 °C), LHSVs (1, 1.35, 2, and 4 h-1), pressures (6 and 800 kPa), and initial sulfur concentrations (100 and 300 ppm). Both coated and uncoated catalysts showed high removal efficiency of the n-butyl mercaptan in the TBR. The maximum conversions obtained were 97.29 % and 95.19 % for the coated and uncoated Mn/AC catalysts at T = 70 °C, P = 800 kPa, LHSV= 1 hr-1, and initial sulfur concentration= 300 ppm. Besides the high performance, the coated Mn/AC showed outstanding stability during the continuous oxidation process.A kinetic model was formulated for the ODS process for the estimation of kinetic parameters of the high stability process.gPROMS has been used for modeling, simulation, and parameter estimation via optimization. The simulation results showed good consistency with the experimental data of all lumps with an absolute average error of up to 5 % and the optimization resulted in the optimal kinetics parameters of the high stability ODS process