Modeling and optimization of fluid catalytic cracking riser

In recent years a lot of researches and developments have been carried out to improve the conversion rate or to maximize the yield of valuable specific products in the fluid catalytic cracking unit (FCC). FCC modeling is very high complicated and complex due to many input parameters and the component of the feed which contains more than a thousand of different species. In this paper, the modeling and optimization of fluid catalytic cracking riser has been developed based on the four-lump model. The comparison of the forecast data from four-lump models and actual data shows that the four-lump model is working sufficiently. Depending on a case study, the optimization techniques were applied to modify the kinetic parameters. The final prediction result of the model which was carried out for a cracking unit with a riser of 33 meter height was found very close to the actual data from this cracking unit. Maximizing the gasoline yield depending on the riser height is the main objective of this optimization. In addition, this study concludes that most of the conversions or reactions in our case are occurring at the first 10 meters of the riser. This conclusion agreed with the most of studies that were found in the literature and industrial data. The conversion rate increases rapidly at first 10 meters, and then it slows down till reaching a stage where the conversion rate changes very slowly as the height of the riser increases.