Research On Liquid-solid Separating Technique Of Fluid Catalytic Cracking Slurry

FCC slurry oil, rich in polycyclic aromatic hydrocarbons, can be used to produce high value-added products such as needle coke, activated carbon fiber, road asphalt and plasticizer. However, catalyst powders in the slurry restrict its development of high value-added products seriously.The influences of flocculanting agent dosage, filtering aid, mixing time, settling time,dosage of filtering aid and the pressure of filtration on removing solid from catalytic cracking slurry was studied, using FCC slurry as the material, alkylphenol-formaldehyde resin as the flocculant, kieselguhr as the filtering aid, and the flocculanting agent- filtering aid filtration process was adopted. The optimized process conditions was obtained: adding100 ppm alkylphenol-formaldehyde resin alkosylate as settling auxiliaries, dosage of flocculanting agent 3g/100 g material, mixing 15 mins and settling for 12 hours at 90?,pressure drop of filtration 0.15MPa(G). Powders can be removed to under 100 ppm in FCC slurry, and the rate of removal can reach a very high degree of 98%.FCC clear slurry was extracted with furfuraldehyde, the aromatic hydrocarbons content was separated from FCC clear slurry and the saturates was decreased. The influences of different solvent-oil ratioes and temperatures to selectivity and yield was studied. The result shows that optimum extraction condition was at 50? and with the solvent-oil ratio of 2:1. The aromatic hydrocarbon content were raised to 90.5%. The saturates and gum asphaltic content were decreased significantly. The raw material can be used to produce the high-grade needle coke through carbonization reaction. The saturates content of raffinate oil can up to 70%, and it can be used as catalytic cracking raw material.At last, a pilot scale test have been designed based on the laboratory research to provide design ideas for industrialization..