Reserch On Pilot Scale Test Of Catalyst Removal In FCC Slurry

FCC slurry, containing an abundance of polycyclic aromatic hydrocarbon, is an ideal feedstock for the production of needle coke, carbon fiber, plasticizer, carbon black, road asphalt and other high added-value products. However, a technical problem, arisen from the catalyst particles in the slurry, perplexes the utilization to produce succeeding products. With polyacrylamide (PAM) and ammonium sulfate selected as flocculating agent, the catalyst particle in FCC slurry can be effectively removed by aprocess of washing-demulsification-flocculating under an ultrasound wave. A series of experiments was conducted to figure out the influences of different conditions on the catalyst particle removal from the slurry having the properties of high viscosity, high ash content, high colloid and asphaltene content. Effects of mixing temperature and time as well as the molecular weight and iconicity of PAM on the catalyst particle removal were studied. In addition, effects of ultrasound irradiation power and time werealso investigated in the process. In the very process, the viscosity of FCC slurry and settling time has an influence on the removal of catalyst fines. Besides, the settling time can be markedly reduced by adding a diesel into the FCC slurry which can reduce the viscosity of FCC slurry by a very large degree.A pilot scale test with a capacity of1600t/a was carried out in Mao-ming refinery based on the preliminary laboratory work. It suggested that when FCC slurry flow rate was200kg/h with a10%water flow rate, and they were settled afterwards at105℃for24h, the catalyst content of FCC slurry was successfully lowered from3890ppm to300ppm, reaching a very high degree of removal up to95%. In the process, waste water can be repeatedly used for several times thus reducing the production cost and producing less environmental pollutions.