Heavy oil catalytic upgrading under methane environment: A small pilot plant evaluation

The effects of variable factors such as temperature, pressure, weight hourly space velocity (WHSV), catalyst regeneration and reaction time on catalytic upgrading of heavy oil under methane environment over Ag-Ga/HZSM-5 catalyst are evaluated by small pilot plant tests. The viscosity, TAN and average molecular weight of the heavy oil samples are notably reduced accompanied with a low olefin content after the catalytic upgrading. Methane incorporation to product molecules results in increased liquid product yield. The simulated distillation and compositional analysis results illustrate the conversion of resin and asphaltene components to small molecules. After the upgrading at 430 °C and 5 MPa, the percentage of gasoline content is increased to 17% from 3% in the feedstock, and the percentage of diesel fraction is increased to 27% from 21%. The percentage of light end volatiles is increased from 4.4% to 22.2%. During the catalytic upgrading, a higher temperature and pressure benefits the oil quality improvement and methane participation while maintaining the high liquid yield and low coke generating rate. Outstanding stability of the product oil samples is witnessed by comparing the products obtained at variable reaction time. A higher WHSV results in slightly compromised performance of the catalytic upgrading of heavy oil under methane. A positive effect of catalyst regeneration is witnessed. Stable oil quality from the upgrading process is observed when catalysts have been regenerated twice or more. The knowledge obtained in this study would benefit the potential industrial application of this innovative technology at larger scales and guide the further reaction condition optimization.