The polyolefin to lighter molecules reaction reduces the waste-plastic residues to produce fuels and valuable chemicals. Commercial MgO light and CaO were used as catalysts for the direct polyethylene and polypropylene liquefaction in N2 or CO2 atmospheres. The products were analyzed (ATR-FTIR, GC-FID/TCD, GC-FID, density, refractive index). The use of MgO light and CaO improved the conversion of propylene and ethylene to liquid products. In addition, low gaseous and solid products yields were obtained. A good production of organic liquids in the gasoline, diesel and kerosene boiling range was obtained. The use of CO2, in some cases, led to a higher conversion into liquids compared with the reactions performed in the N2 atmosphere. In addition, the use of the CO2 atmosphere led to a higher content of products with a boiling range in the diesel and kerosene ranges.
Keywords: CaO; MgO; direct liquefaction; plastic; polyethylene; polypropylene; waste.