Study of pore-scale coke combustion in porous media using lattice Boltzmann method

Lattice Boltzmann Simulation of Multicomponent Porous Media Flows With Chemical Reaction

“…Second, separate LB equations with reactive source terms are developed to account for homogeneous reactions between multiple solutes, like A + B → C. Third, for heterogeneous reaction at the solid-fluid interface, additional source terms and the bounce-back scheme are built to realize the conjugate heat transfer and species conservation conditions, without iterative calculations. In addition, different from our recent LB models [37][38][39][40], the present one offers a capacity to achieve these advances simultaneously.…”

“…More details about the derivation can be found in our recent work [39]. It should be noted that that for compressible fluids with fixed ρ l ρ 0 , the terms F r2 and z t (ρc p ) in F T2 are reduced to zero.…”

“…On the other hand, coke combustion is described using Eqs 8-10 and implemented using the bounce-back scheme in Eqs 44,45. The conversion between physical and lattice units is based on dimensionless parameters in Eq. 11 and the characteristic parameters are selected as L 0.5r x , U α l /L, ρ ch ρ l,0 , and T ch 3,000 K [39]. In the subsequent simulations, the required parameters are set as A 9.717 × 10 6 m/s, E 131.09 kJ/mol, hr 388.5 kJ/mol, ρ s c p,s /ρ l c p,l 368, and α s /α g 0.119, respectively.…”

“…In the subsequent simulations, the required parameters are set as A 9.717 × 10 6 m/s, E 131.09 kJ/mol, hr 388.5 kJ/mol, ρ s c p,s /ρ l c p,l 368, and α s /α g 0.119, respectively. The Reynolds, Prandtl, and Peclet numbers are fixed as Re 1.4, Pr 0.7, and Pe 1.5, the driving force is F * Our recent work has investigated the general coke combustion dynamics and evaluated the key influencing conditions, with the fluid viscosity being assumed to be a constant [39]. In practical applications, however, fluid viscosity varies with heat and mass transfer.…”

“…For example, changes in fluid density or viscosity with temperature are usually not accounted for, models for multicomponent reactions (like A + B → C) are underdeveloped, and iterative boundary schemes for conjugate heat transfer are complex and time-consuming. We have developed a series of LB models to overcome these shortcomings separately [37][38][39][40]. Nevertheless, a uniform LB model is still needed.…”