The Effects of Vaporisation Models on the FCC Riser Reactor

Abstract

This work presents a steady-state one-dimensional model of the FCC riser considering the vaporisation of the gas oil feed and subsequent cracking reactions. The evaporation of droplets is studied using three models: the classical homogeneous model and the heterogeneous vaporisation models from the literature. Droplets are modelled using the Lagrangian framework model for particles moving through a fluid. This was coupled with the gas–solid flow field describing the catalyst particulate transport in the riser. Cracking reaction kinetics are modelled using a four-lumped model. The model was then validated against published plant data. The model performed well in terms of gas oil conversion, gasoline yield, pressure drop, and phase temperature profiles. Therefore, it is suitable for use in the design and optimisation of new and existing FCC unit risers, particularly in cost–benefit analysis considering the current push away from petroleum energy sources. It was found that vaporisation models are largely insignificant in terms of gas oil conversion profiles and gasoline yield for usual operation conditions of FCC risers, which is a finding that had yet to be proven in the literature. Vaporisation models are shown to only affect conversion and yield when the initial droplet exceeds 2000 μm.

Generalized Net Model of Heavy Oil Products’ Manufacturing in Petroleum Refinery

“…It is treated in the petroleum refinery to extract additional amounts of light oil products and produce heavy oil products like fuel oil, marine fuels, and road pavement bitumen [7][8][9][10][11]. All processes involved in the technological chain of heavy oil treatment have been the subject of modeling and simulation with the aim to better understand the behavior of the heavy oil plants and determine the values of the operation variables providing the optimum performance from economical, energy saving, and environmental points of view [12][13][14][15][16][17][18][19][20]. Gaikwad et al [12] have simulated the operation of atmospheric residue vacuum distillation using Chemcad 5.1 software, with the aim to reduce the energy consumption.…”

“…Ye et al [14] have employed a molecular-level reaction kinetic model of delayed coking of vacuum residue based on the structure-oriented lumping method to predict the product yield and group composition in the actual delayed coking process. Selalame et al [15][16][17] have reviewed traditional modeling methodologies used in modeling and simulation of the fluid catalytic cracking (FCC) unit that converts vacuum gas oils and atmospheric residues into high-value light oil products. Wang et al [18] have modeled and simulated a real-life industrial residue hydrotreating process based on Aspen HYSYS/Refining process simulation software.…”

“…Piskunov et al [20] have reviewed the main principles of modeling the dependencies of bitumen properties on their chemical composition, dispersed structure, and other quality parameters. All heavy oil models discussed in references [12][13][14][15][16][17][18][19][20] are partial models of diverse heavy oil treatment processes taking place in the petroleum refining. Their output is typically fed into linear programming refinery models to evaluate the most economically valuable scenario to follow during the oil-refining process [21,22].…”