Fuel Range Properties of Oil and Wax Obtained from Catalytic Pyrolysis of Linear Low-Density Polyethylene in a Fluidized Bed Reactor (FBR)

Abstract

Virgin linear low-density polyethylene was subjected to pyrolysis in a fluidized bed reactor pilot plant segmented into three heating zones with both sand and Magnofil BT 80 catalyst as bed materials. The pyrolysis oil and wax products were extracted at an average bed temperature of 600 and 700 °C. The oil yield decreased between 600 (8.7 wt %) and 700 °C (8.1 wt %) in an inverse relationship with the reaction time (358 and 384 min, respectively). This was attributed to an increase in the vibration of the polyolefin polymer matrix as a result of the absorbed thermal energy with an increase in temperature. The experiments performed at 700 °C showed no wax formation but high yields of gaseous products and oils, which are more lucrative in managing accumulated plastic waste, of which polyethylene constitutes large proportions, via thermochemical conversion technologies. The estimated calorific value at 600 °C was 45.5 MJ kg-1, which is in the acceptable range for both diesel and gasoline fuel market specifications. The sulfur content in the pyrolysis oil was estimated to be 0.013% and was not affected by changes in the temperature of the fluidized reactor. However, desulfurization will be required in the future to obtain oil within acceptable ranges of clean fuels. In addition, to support this work's results in obtaining fuels from such feedstock materials, the fuel range hydrocarbons were also analyzed. The diesel fuel hydrocarbon range (C10-C19) was between 37 and 60% in the pyrolysis oils examined. The results determined experimentally from the pilot-plant work herein are quite promising for sustainable fuel integration plans in the near future with existing petroleum refining complexes.