| At present, the needs of light fuel oil have been growing rapidly in China, meanwhile the heavy crude qualitative and catalyst cracking bring coking, fouling and other adverse effects to FCC, so that the devices could not be function properly, and this seriously affected the quality of products and product distribution. What's more, the irrational use of FCC slurry caused a great of waste. Therefore, the research of effective removal of catalyst particles technology and rational use of FCC slurry had important significance.This paper choose Shenghua and Lanzhou FCC slurry as the research objects, using the chemical additives to reduce the content of catalyst particles in the slurry oil, and study the removal process, then discuss the removal mechanism. It is proposed that using the furfural as the solvent in FCC slurry oil system could product the environmental-friendly rubber filling oil and FCC feedstock. One-stage extraction, multi-stage cross-flow extraction and multi-stage countercurrent extraction experiments were designed to study the effects of extraction temperature, the ratio of solvent to oil and the series of extraction.If polyacrylamide solution were used to remove the solid catalysts from FCC slurry, the best reaction conditions were that: the addition of polyacrylamide was 250μg/g, stirring at 80℃for 30 minutes, the removal ratio of catalyst particles could reach 87.5%; If 50% volume fraction of glycerol solution were used to remove the solid catalysts from FCC slurry, the best reaction conditions were that: the addition of glycerol solution was 60wt% of the slurry, stirring at 80℃for 30 minutes, The glycerol solution was washed, filtered and concentrated to achieve recycling, then the third removal ratio of catalyst particles could still reach more than 80%; If LAL-2 were used as chemical additives to reduce the content of catalyst particles, the best reaction conditions were that: the addition of LAL-2 was 200μg/g, stirring at 80℃for 30 minutes and resting for 24h, the removal ratio of catalyst particles could reach 95.2%. It could be obtained that the main effect of the catalyst particle removal was related to the viscosity and molecular structure of settlement agents.The FCC slurry was separated further into saturation fractions and aromatic fraction by using furfural extraction. Cross current extraction and counter-current extraction were studied in this dissertation. The best extraction conditions in primary cross current solvent extraction were that: reaction temperature was 50℃, and the ratio of solvent/oil was 2.5:1. In the extraction process series, the optimal series was twice. In the solvent stripping process level 3 was the optimal series. Then in simulation experiments on three counter-current extraction, when the reaction temperature was 50℃, the ratio of solvent/oil was 2.5:1, and the extraction series was three, the product conforms to the Europe standard requirements, and the yield could reach 30%.The saturation fractions could be the raw materials of FCC unit. The aromatic fraction could be used as the rubber oil because of its poor property of cracking. Thus, the FCC slurry was first extracted into easy cracking fractions and difficult cracking fractions instead of recycling straight into FCC. The easy cracking fractions were recycled into FCC and the difficult cracking fractions are used as rubber oils. This method may lower the coke quantity of FCC and improve e the production of liquid products.
|
PDF Full Text Request