Catalytic pyrolysis of the municipal mixed plastic waste into plasto-oil using fuller's earth and commercial fluidized catalytic cracking catalysts for circular economy

Municipal mixed plastic waste (MMPWW) has become an environmental threat as well as an opportunistic source. Its pyrolysis to plasto-oil, a potential source of auto fuels, paves the circular economy for which a cost-effective catalyst is the key. The optimum temperature for the thermal pyrolysis of MMPW to maximum plasto-oil yield was found to be 550 degrees C, above which gas yield increased at the expense of plasto-oil. At this temperature, catalytic pyrolysis of MMPW was studied using fuller's earth and commercial FCC catalyst by varying their amount up to 10 wt.% of MMPW in steps of 2%. With an increase in fuller's earth and commercial FCC catalyst up to 8 wt.%, pyrolysis oil yield increased and reached 78.9 and 76.2%, respectively, compared to 53% in their absence. With further increase to 10 wt.%, the pyrolysis oil yield decreased to 76.3 and 69.2% for fuller's earth and commercial FCC catalyst, respectively, and hence the optimum amount of catalyst was found to be 8 wt.%. Both the catalysts were found to be active for the pyrolysis of MMPW and among them fuller's earth was more active owing to higher total and medium acidity and also cost-effectiveness.