Upgrading vacuum distillation residue of oil refinery using microwave irradiation

Vacuum distillation residue upgrading of Tehran oil refinery, Iran, using microwave was performed, and the effects of different parameters on temperature, viscosity, API(1) gravity, and asphaltene were evaluated. The various catalysts effects (iron, nickel, copper, MoS2, Fe2O3), microwave power level at three levels (50, 70, 100%), activated carbon at four levels (5, 10, 15, 20 wt%), iron catalyst at four levels (0, 10, 15, 20 wt%), NaBH4 as hydrogen source at four levels (0, 3, 6, 10 wt%), desulphurization agent at four levels (0, 2, 5, 10 wt%) and process time at four levels (15, 30, 45, 60 min) were investigated. The vacuum residue specifications include API gravity: 8.79, viscosity (60 degrees C): 16391 cSt, and asphaltene: 13.3 wt%. The results showed that Fe was the best catalyst. Power level, activated carbon, Fe catalyst, and process time presented very positive effects on the process. 3 wt% NaBH4 was the optimum amount, but desulphurization agent had no positive impact on upgrading. At the best conditions (power level: 100%, Fe catalyst: 20 wt%, activated carbon: 20 wt%, NaBH4: 3 wt %, 1 h process time) asphaltene decreased by 94.22%, viscosity reduced by 99.53% and API gravity increased by 88.56%.