Hydrocracking of heavy crude/residues with waste plastic

Abstract

Residue hydroprocessing requires a large quantity of hydrogen. The utilization of the low-cost hydrogen donor for the hydroprocessing reaction can helps to reduce the high cost of hydrogen. Generally, hydroaromatic compounds such as tetralin, decalin, naphthalene, and anthracene are considered solvents that are efficient for donating hydrogen. The present study investigates the use of waste plastic as a hydrogen-donor to improve the yield and quality of distillates in the hydroprocessing of heavy crude/residue. For this study, the thermal cracking of heavy crude and vacuum residues was performed with waste plastic at a 420 °C reaction temperature and 6 MPa hydrogen pressure. The results indicate that at 420 °C, the yield of the middle distillate fraction is maximized due to the minimization of retrogressive polymerization reactions occurring during the process. Adding waste plastic to vacuum residue feeds helps to reduce the coke formation and increase metal and asphaltene removal activities. This work presents waste plastic as very cheap material to serve as a hydrogen-donating hydrocarbon for upgrading heavy oil/residue feeds to produce transportation fuels.