Catalytic Conversion of Waste Plastics/Petroleum Resid Mixtures into Transportation Fuels

Catalytic conversion of waste plastics (low-density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS)) and petroleum resid mixtures into transportation fuels was studied. The fractions obtained were hexane-soluble materials; toluene-soluble, hexane-insoluble material; toluene-insoluble material (THF); THF-soluble; and THF-insoluble material or insoluble organic matter (IOM). The LDPE and HDPE/resid yielded a conversion of ∼ 90% while PS was almost completely converted followed by PP. LDPE gave the highest yields of gases. Gas analysis from different binary systems showed that the main gases produced were hydrogen, methane, ethane, ethylene, propane, propylene, butane and butene. The reaction systems that contained LDPE and HDPE had less recovery of material boiling at < 550°C than systems containing PS or PP. The coprocessing of plastics with resid showed a significant improvement in the conversion rates indicating that the reaction chemistry of resid and plastics were very compatible.