Characteristics Study on the Co-Fluidized Thermal Conversion of Vacuum Residue and Rice Husk Pyrolysis Oil

Co-cracking of refining residue and bio-oil derived from biomass pyrolysis can improve the refining residue cracking performance and strengthen the efficient utilization of bio-oil. In the present study, Kazakhstan vacuum residue (KVR) and rice husk pyrolysis oil (RPO) are selected as the experimental materials to perform the fluidized thermal conversion process using FCC catalyst. The comparison between the experimental and calculated values of TG data revealed that adding RPO had a synergistic effect on the thermal weight loss of KVR. Fluidized thermal conversion experiments demonstrated that at 480 degrees C the addition of RPO increased the proportion of dry gas because the deoxygenation of RPO during cracking released more CO and CO2. Simultaneously, the deoxygenation would produce more H2O, resulting in a decrease in oil yield from 69.3% (10%-RPO mixed oil) to 62.8% (50%-RPO mixed oil). However, the yield of light oil (gasoline, light diesel, and heavy diesel) increased with increasing RPO addition because the active components in RPO were prone to polymerization. The reaction temperature intensified the cracking and condensation of the oil mixture, decreasing the oil yield from 70.8% to 59.3% in the temperature range of 440-540 degrees C while increasing the coke yield from 16.4% to 24.7%. When the FCC catalyst was continuously used twice, the cracking product distributions changed slightly, indicating that the activity of FCC catalyst remained stable.