An improved gravimetric method applied to co-processing of polyethylene terephtalate and petroleum blend using HY zeolite as a catalyst.

The co-processing of petroleum and polyethylene terephthalate (PET) was carried out in the presence and absence of a catalyst in an open vessel batch reactor at temperatures of 200, 300, 400, and 500 °C, which corresponds to temperatures of distillation and cracking. The catalyst used was the acidic HY zeolite, which is widely used in petroleum refining. The catalytic co-processing was carried out with the PET–oil charge, at a mass ratio of 1:1, containing 10% of HY zeolite. The conversion degree was measured by knowing the initial sample mass and amount of degraded material for each temperature and reaction time, using an improved gravimetric method consisting of a precision balance and an oven with a heating rate controller. The conversion values obtained were compared for petroleum and PET samples with and without the zeolite catalyst. At temperatures of 200 and 300 °C, the PET showed low conversions, about 5–10%. However, for the catalytic co-processing of PET–oil/HY at these same temperatures, an increase in conversion to about 25–30% was observed. At temperatures of 400 and 500 °C, conversions above 90% were obtained for the two samples, with a subsequent reduction in the activation energy, from 76 kJ mol−1(PET) to 56 kJ mol−1(PET–oil/HY). The decrease in the activation energy proved the efficiency of the HY zeolite and the synergistic effect when PET was blended to the oil for the catalytic co-processing, proving to be a viable alternative for the chemical recycling of PET in the petroleum industry. [ABSTRACT FROM AUTHOR]