Simulation of fluid catalytic cracker

Abstract

Fluid catalytic cracking unit (FCCU) performs the most vital role in modern refinery process because it is used for producing more economic refinery products. Crude oil contains hydrocarbons ranging from light gases, LPG and gasoline to residues of high boiling point range. Feed to the FCC unit is the residual product from the distillation column; fluid catalytic cracking (FCC) units convert a portion of the heavy material into lighter products, mainly gasoline, olefins, coke and LPG. Simulation of the fractional distillation was being done to find out the feed composition which is the inlet to the riser reactor. The FCC unit was later simulated to get the final yield of gasoline and other valuable product like LPG and the yield obtained by simulation is acceptable in plant scale. Later different values of flow rate, feed temperature, riser time and temperature of the reactor were varied to get the simulated data and from that graphs were plotted to study the behavior of the reactor and from there optimum conditions for the reactor is concluded. Comparison of single and dual riser is done and optimum condition. Additional unit like fractionator is used in the further simulation which hardly affects the riser reactor behavior. Also the effect of process parameters is studied in the case of dual riser reactor.as per the regenerator CFD simulation is done using ANSYS FLUENT 13.0 to show the temperature profile in the regenerator and the reaction product CO2. From the CFD analysis the catalyst bed condition and the heat supplying regenerator’s profile are described. At various concentration of oxygen enrichment temperature profile is observed and the rise of temperature is noted with high oxygen enrichment. Also rise in flow rate of air to the regenerator affect the combustion on the regenerator and hence the rise in temperature.