Roles of ruthenium on catalytic pyrolysis of waste tire and the changes of its activity upon the rate of calcination

The catalytic pyrolysis of waste tire with Ru/SBA-1 catalysts was studied. The roles of ruthenium were elucidated since the support, a pure silica SBA-1 synthesized via silatrane route, was proven to be catalytically inactive and its structure retained after pyrolysis. Ruthenium clusters increased the yield of gaseous products, approximately 2 times as compared to thermal pyrolysis, at the expense of the liquid yield. They also decreased poly- and polar-aromatics and consequently produced lighter oil. The heating rates (1 °C/min, 5 °C/min, and 10 °C/min) during calcination were found to strongly influence the activity of the Ru/SBA-1 catalysts. The catalyst calcined with a heating rate of 5 °C/min exhibited the highest activity on poly- and polar-aromatics reduction and light oil production. The highest activity of this catalyst was attributed to its smallest mean ruthenium particle size and its highest sulfur tolerance.