Composite zeolite beta catalysts for catalytic hydrocracking of plastic waste to liquid fuels

The conversion of model waste plastic mixture into high-value liquid product was studied in the presence of hydrogen and composites of zeolite beta catalysts. For the sake of comparison, the conversion of actual waste plastic mixture and high-density polyethylene was also carried out. The composite zeolite beta catalysts were synthesized using a range of silica-to-alumina ratios, alkali concentrations, and hydrothermal treatment times. SEM, EDX, XRD, N-2-BET, FTIR, and py-FTIR were used for the characterization of the catalysts. The catalytic experiments were conducted in a 500 ml stirred batch reactor at 20 bar initial cold H-2 pressure and the temperature of the reaction was varied between 360 and 400 degrees C. The two composite catalysts, BC27 and BC48, prepared without alkali pretreatment were found to be the most suitable catalysts. With BC27 and BC48 at 400 degrees C, 93.0 wt% conversion was obtained with actual plastic mixture and the liquid yield exceeded 68.0 wt%. Experiments with the regenerated catalysts showed their performance comparable to the fresh catalysts.