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Article: Case Study of Barracuda, a Fluidized Bed Simulation Tool in the Petrochemical Sector. Catalytic cracking is one of the processes in oil refining; it involves breaking down heavy oils under the action of heat and catalysts to produce cracked gas, gasoline, diesel, and other products. As the core processing unit in refineries, catalytic cracking equipment is also facing an increasing number of challenges. The increasingly strict environmental regulations mainly involve higher requirements for gasoline specifications regarding olefin and sulfur content, as well as restrictions on exhaust emissions ； Changes in the proportion of demand for various products, such as the increasing proportion and volume of demand for diesel in the market, namely the so-called trend toward diesel use. All of these have a significant impact on existing catalytic cracking units and the further development of catalytic cracking. Moreover, in addition to adopting new and effective methods to reduce the sulfur content in catalytic cracking gasoline and diesel, the cost of various technologies also needs to be taken into consideration. Problems faced by catalytic cracking in our country: (1) The average capacity of each FCC unit in our country is low; (2) The energy consumption of these units is high ； (3) The development level of FCC catalysts is not high ； (4) The startup cycle of FCC units in our country is short. This is also the main gap between our country’s and foreign catalytic cracking technologies. To address the aforementioned problems at present, corresponding process flows and process equipment need to be employed. A scientific and rational process flow together with advanced technological equipment can not only enhance the value of deep processing of coal and the yield of coal-based products, but also significantly reduce the damage and impact on the surrounding ecological environment caused during coal processing. Due to its high rates of heat and mass transfer as well as fast reaction speeds, fluidization technology is widely used in the field of energy engineering, especially in processing processes such as coal chemical industry. In the early stages of research and development on fluidization technology, empirical calculations and experimental tests were the main approaches used. However, with the rapid advancement of computer technology and numerical simulation methods, people are becoming increasingly dissatisfied with empirical and experimental approaches. Instead, they attempt to start from various differential equations that describe the processes involved, in order to simulate the mechanisms and laws of heat transfer, mass transfer, and chemical reactions in real fluidization systems. Based on this, they analyze and predict the overall characteristics of such fluidization devices, providing theoretical foundations and guidance for engineering design and optimization. As a powerful tool for studying fluidized devices, numerical simulation can not only shorten the development cycle and save research costs, but also provide macroscopic and microscopic information that cannot be obtained through experiments due to limitations in experimental conditions or testing techniques. Barracuda is a well-known commercial numerical simulation software specifically designed for simulating particle-fluid flow and chemical reactions. CPFD simulates particulate multiphase flows based on the Eulerian-Lagrangian framework. Although the Eulerian–Eulerian model can simulate the inter-particle stresses near dense particle flows through the spatial gradient of the particle volume fraction, the continuity equation becomes extremely complex when the type and size distribution of particles are taken into account, as it is necessary to solve the continuity equation and momentum equations for each type and size of solid phase. The Eulerian–Lagrangian model is a cost-effective method for solving particle multiphase flows, as it takes into account a wide range of particle types, sizes, and velocities. Nevertheless, in cases with a high particle volume fraction, the collision frequency between particles is extremely high, making it impractical to use a true Lagrangian method to calculate these collisions. The CPFD technique draws on the MP-PIC (multiphase particle-in-cell) method, employing a dual treatment approach for the particle phase: particles are considered both as a continuous medium and as a discrete entity. The particle stress gradient (which is difficult to calculate for each particle in a dense particle flow) is transformed into a gradient on the fluid grid, and then interpolated onto the discrete particle mass ； The other properties of the particulate phase are calculated at the positions of the discrete particles. CPFD defines an interpolation operator that is fast to compute and can ensure global and local conservation. In this way, the CPFD method eliminates the reliance on computationally intensive implicit solutions—that are required by the particle method on the grid for stress calculation ； More importantly, the implicit coupling of the particle phase and the fluid phase enables the solution of particle-fluid systems with any particle volume fraction, from sparse to dense, providing designers with a numerically robust solution. ——Users can define the particle size distribution arbitrarily — unlimited number of particles and gaseous species — complete conservation of mass, momentum, and energy, tight coupling between fluid and particle momentum (fully implicit) — particle stress tensor ； Particle-particle collision ； Examples of particle-wall rebound applications are provided in the attachment, including FCC regeneration, wall wear, and the calculation of concentration distributions of reactants and products. 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