Catalytic pyrolysis of recycled polypropylene using a regenerated FCC catalyst

Abstract

The increasing generation of plastic wastes forces us to search for final disposal technologies environmentally friendly such as pyrolysis, which becomes an interesting technique because it takes advantage of the wastes obtaining important products. In addition, catalytic pyrolysis by using commercial catalysts, e.g. such zeolites, alumina or recovered from other industrial processes, it allows decreases the activation energy and selectivity in the obtained products. In this study, we report the evaluation of the catalytic pyrolysis with a regenerated fluid catalytic cracking catalyst using thermogravimetry with polypropylene and a pyrolytic process carried out in a batch reactor with polypropylene in a 1:10 ratio (catalyst-plastic). The regeneration studies were carried using two solvents (ethanol and toluene) at different contact times, then a thermal regeneration at two heating ramps was performed and the best treatment was evaluated by scanning electron microscopy energy-dispersive X-ray spectroscopy and surface area analysis. The results showed a better action of the ethanol in the chemical treatment at 14 h of contact in the heat treatment due to longer gasification of the coke. The degradation process using recovered catalyst decreases the degradation temperature compared to the no-catalyst process. As a consequence, the yield of the liquid fraction decreases by 10% with greater orientation to aliphatic components.Graphical abstract