A practical countercurrent fluid catalytic cracking regenerator model for in situ operation optimization

Abstract

A practical countercurrent fluid catalytic cracking (FCC) regenerator model with improved descriptions of gas and solid flow patterns is proposed. A three-zone and two-phase gas model was utilized to describe the gas flow through the regenerator, addressing the different phase mass-transfer properties in the different zones. A new two-continuously stirredtank reactor-with-interchange model was used to describe the solid flow and to address the effect of freeboard on catalyst regeneration. Otherwise, this model also considered the usually adopted expanding section for reducing solid carryover. The model was programmed in Matlab language with coupled hydrodynamics and reaction kinetics models and tested and validated by the data from an industrial FCC regenerator operated under both partial and full CO combustion modes. After fitting a single model parameter, the interchange solid flux between the dense bed and freeboard, the model predictions were in reasonable agreement with the commercial data for both modes. Figure 12. Effects of air flow rate (a1, b1), solid inventory (a2, b2), and operating pressure (a3, b3) on carbon content in the regenerated catalysts under partial and full combustion modes.

Experimental Study and Modeling on Effects of a New Multilayer Baffle in a Turbulent Fluid Catalytic Cracking Regenerator

“…12−15 Figure 1 shows a schematic of one layer of this new baffle. 11 As seen in Figure 1a, multiple parallel flow regions are defined by several vertical partitions. In each flow region, multiple inclined vanes are mounted to the partition in parallel, as shown in Figure 1b from a section view of A−A plane in Figure 1a.…”

“…Except for the two differences, other parts of the baffled regenerator model were generally the same as our precious counter-current regenerator model. 11 Detailed information on the model setup and how the baffle's effects were incorporated into the model can be found in the long report in the Supporting Information. 4.2.…”

“…Table 1 lists the predicted effect of baffles in a FCC regenerator. Here, the base case is the incomplete regeneration mode in Zhang et al 11 In Case 1, the effect of solids backmixing suppression is shown, with the value of I BMS calculated by the fitted curve in Figure 5b. C Cr is predicted to decrease from 0.18 wt % to 0.12 wt % as a result of the reduction of solids exchange flux.…”

“…was built to measure the quantificational effects of the new baffle on bed hydrodynamics, mass transfer, and solids mixing. These data were further incorporated in a baffle-free regenerator model 11 to predict the potential effects on regeneration performance improvements.…”

Numerical Simulation of a New Porous Medium Burner with Two Sections and Double Decks

“…Porous media have many advantages such as good storage, conduction and radiation of heat, and explosion suppression, etc. These features help the porous medium to achieve super-adiabatic combustion [1,2]. Porous medium combustion technology presents a new type of combustion.…”