Effect on naphtha yield, overall conversion and coke yield through different operating variables in FCC unit using Aspen-Hysys simulator

Abstract

Fluid Catalytic Cracking Unit is the pump house of any refinery. Distillation is the initial step in the processing of crude oil and the residue which is coming out from the distillation column enters as the feed in the FCC unit. Gasoline is the main product of the FCC unit and it also produces byproduct which is more olefinic and hence more valuable. Simulation of the fractional distillation has been done to find out the feed composition which is the feed to the riser reactor. The unit was further simulated under the desired specifications to get the naphtha yield and compared with the plant data. Different graphs were plotted by varying feed temperature, flow rate, catalyst to oil ratio and were successfully compared with the modeled data. Further simulation was done with two regenerators and production of SOx was studied. The simulation result concludes that the SOx emission is lesser in case of one regenerator. Two sets of catalyst were chosen and the final yields were compared. Based on the plant requirement different types of catalyst are used. Finally the effect of riser height was studied in one riser and dual riser by keeping the operating parameters to be same and concluded with the fact that naphtha yield increases in case of dual riser.