Transportation fuel from plastic wastes: production, purification and SI engine tests

Abstract Thermal pyrolysis of HDPE, LDPE, PP, PS, PET and PUR plastic wastes were performed in a batch reactor equipped with a temperature controlled reflux and the yields of pyrolysis oils and liquid fuels suitable for transportation were determined. The gasoline fractions were investigated by GC-MS and tested in a traditional spark-ignition engine without any modifications or fuel blending. Fuel consumption and exhaust gas emission (NOx, CO) were measured and compared to a commercial fuel (gasoline, RON = 95). PS generated 70.5% gasoline range hydrocarbons from the solid waste, followed by PP with 42.1%, LDPE with 40.8% and HDPE with 37.3%. Liquid product was not observed during PET pyrolysis. The engine was easily running with neat gasoline fractions obtained from HDPE, LDPE, PP and PS distillation; however, it was not able to start the engine with the neat dehydrated PUR distillate. The volumetric fuel consumption was reduced by 9.1-9.4% in case of PS compared to commercial gasoline (RON = 95) but the NOx emission was increased by 82-147%. Fuel consumption reduction was noticeable at HDPE, LDPE and PP as well. PS gasoline decreased by 91-96%, while HDPE, LDPE and PP more likely increased the CO emission of the engine compared to commercial gasoline.