<p>Severe fixed Coke in the industrial resid fluid catalytic cracking (RFCC) riser reactor often results in the reduction of product yield and unplanned unit shutdown. It is difficult to investigate fixed coking formation near wall especially in the feed injection zone of riser due to no model to depict the processes of physical and chemical. In this paper, the complex gas-solid-liquid three phase flow, mixing and cracking reaction are 3D simulated with energy-minimization multi-scale (EMMS) drag and mass transfer models in agreement with the industrial data. A new coking correlation model is developed to predict the possibility of fixed coke formation based on the 3D accurate simulation. The effects of different diameter of feed oil droplet on the vaporizing process and reaction yield are discussed by simulation. The results indicate that the fixed coke formation can be well depicted by the coking index. The predicted of fixed coke in the feedstock injection zone are same with the actual positions in industrial unit, which mainly located near the walls of the 0.5~3.0m height above the feed nozzles and the circumferential between adjacent nozzles. A suitable oil droplet diameter can improve the mixing of catalyst and oil and the yield of target products, such as gasoline and LPG.</p>

Reactive CFD Simulation of Fixed Coke Formation in an Industrial RFCC Riser Reactor

Paper Proceedings: https://asmedigitalcollection.asme.org/PVP/PVP2021/volume/85314

ASME 2021 Pressure Vessels & Piping Conference (PVP2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.