Slurry-phase desulphurization of tyre derived oil using unsupported and supported alkaline earth metal oxides

• Tyre derived oils contain various sulphur containing species • Alkaline earth oxides can function as effective adsorbents for sulphur • Dispersed alkaline earth oxides have higher sulphur removal capacity The aim of this study was to synthesize, characterize and test supported alkaline earth metal oxides for desulphurization of tyre-derived oils. The primary benefit of employing a metal oxide dispersed on a high surface area support is the potential for high sulphur removal capacity due to smaller crystallites and a larger number of active sites for reactive adsorption. The silica-supported alkaline earth metal oxides were synthesized using the wet impregnation technique. The alkaline earth metal oxides of calcium, magnesium, and barium were chosen to desulphurize tyre derived oil. The untreated and treated tyre derived oil was analysed using a GC-PFDP to determine the performance of the alkaline earth metal oxides in terms of the total sulphur adsorbed. The desulphurization results, using supported alkaline earth metal oxides, suggested that pore diameter and mesh particle size do not significantly impact desulphurization for the operating conditions studied. Combining the supported alkaline earth metal oxides did not improve the desulphurization of the tyre derived oil. A 56.76 wt.% desulphurization was optimally achieved at a temperature of 240°C for 30 min with a 0.0375 g/ml sorbent-to-oil ratio, using supported calcium oxide. Supported alkaline metal oxides were found to offer satisfactory desulphurization performance, and even higher sulphur removal capacity at some combinations of reaction conditions, demonstrating that they can be used in an effective, low cost system for desulphurization of TDO.