Removal Of Solid Particles From FCC Slurry By Washing

Slurry is a by-product produced by catalytic cracking process.It contains a large amount of heavy aromatic hydrocarbons,which is valuable for chemical raw materials.However,the catalyst solid particles contained in slurry seriously affected the quality of deep processed products.Therefore,it is of great significance to study the removal of solid particles from FCC slurry.The washing process was used to removal of solid particles from FCC slurry.On the basis of selecting many kinds of demulsifier,it is found that demulsifier SPJ-PR-2011 has good demulsification effect on oil slurry.The dehydration efficiency reached more than 90%and ash content of slurry was reduced from 0.26%to 0.022%and the Al+Si content in slurry was decreased from 1013.7 mg/kg to 85.8mg/kg under the optimized demulsification,which conditions is 130℃,16%washing water,50μg/g SPJ-PR-2011 and voltage 1800 V.With the dosage of demulsifier increasing,the dehydration efficiency was increased.When the dosage of demulsifier reaching the critical micelle concentration,and then the dosage of demulsifier was increased,the dehydration efficiency was basically unchanged.With the temperature and the amount of washing water increasing,the dehydration efficiency increased.The molecular structure of demulsifier SPJ-PR-2011 was analyzed by infrared spectrum,nuclear magnetic resonance spectrum,elemental analysis and gel chromatography.It was showed that SPJ-PR-2011 was a poly ether with molecular weight of 2688,which contained EO and PO chain and chain ratio of 3:2.The effect of solid particles and demulsifier SPJ-PR-2011 on model oil emulsion stability was investigated by using Zeta potential,surface tension,fully functional stability analysis and micro particle size analysis method.The results showed that the solid particles increased the Zeta potential,which increased the stability.While SPJ-PR-2011 reduced interfacial tension and lead to the demulsification.Three stage washing process was used to remove solid in slurry.After washing,the ash content and Al+Si content were reduced to 0.018%and 70.2 mg/kg and removal efficiency reached 93%respectively under the condition of demulsifier SPJ-PR-2011 70μg/g,washing water 7%,130℃ and voltage 1800 V.