Engineering Solutions for CO2 Conversion - Группа авторов

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oxy‐fuel combustion of solid particulate fuels such as the work presented by Wu et al. [49], where the Eulerian approach discussed earlier was implemented in order to track the movement of the solid phase, and the work of Bhuiyan and Naser [50], who applied the Eulerian–Lagrangian method. Table 2.3 summarizes some recent CFD studies in oxy‐fuel technologies. Also, a look at the literature shows that some reported studies on oxy‐fuel CFD simulations have been combined with process simulations in co‐simulation strategies. Such is the work published by Edge et al. [54] and Fei et al. [55]. Co‐simulation is the object of the Section 2.8, where it will be discussed further because it can give way to enhanced numerical predictions with implications also in control engineering.

Authors Aspect studied Short comment on findings
Gharebaghi et al. [51] Single‐phase combustion simulation for a test facility Comparison between turbulence modeling strategies, i.e. large eddy simulation (LES) and Reynolds averaged Navier–Stokes (RANS), and experimental data
Mayr et al. [52] 3‐D steady‐state simulation of a natural gas furnace including radiation models and the eddy dissipation concept (EDC) model. Effect of O2/N2 ratios on furnace efficiency To increase the O2‐to‐N2 ratio resulted in better furnace efficiency. Good matching between simulated and experimental results
Bhuiyan and Naser [50] Co‐firing biomass + coal using the Eulerian–Lagrangian approach The authors included factors describing the irregular shape of the biomass particles. The effect of changing the fuel ratio combustion atmosphere in the performance parameters of the furnace
Carrasco‐Maldonado et al. [53] Single‐phase approach to simulate the effect of integrating oxy‐fuel technologies in a cement production plant Validation against experimental data accomplished. The k–ω turbulence model gave way to the best results
Wu et al. [49] Study of oxy‐fuel combustion in a circulating fluidized bed (CFB). The model uses the Eulerian approach and thus this is a multiphase case that deviates from common oxy‐fuel CFD studies in the literature Detailed profiles of temperature and hydrodynamic variables are obtained, which match the experimental results. Gas hold‐up is also studied, resulting in identification of gas accumulation spots
Schematic illustration of the (a) Details of the volume fraction map describing the liquid flow within the porous medium. (b) Details of the pore geometry considered.

      Source: Dezfully et al. [57]. © Trans Tech Publication.

      (b) Details of the pore geometry considered.

      Source: Gharibshahi et al. [58]. © Elsevier.

      A reaction of particular importance in carbon dioxide utilization with chemical conversion is the Sabatier reaction, whereby COx is converted to methane by hydrogenation and subsequently introduced into the gas grid:

      (2.3)upper C upper O 2 plus 4 normal upper H 2 right-arrow upper C upper H 4 plus 2 normal upper H 2 normal upper O

      CFD simulations of the Sabatier reaction are single phase, which is an advantage from the perspective of the computational resources needed, although they require a multispecies approach and a careful selection of the turbulence model in those cases where the Reynolds number is high. CFD can play an important role in research oriented towards the implementation of different catalysts to accelerate the production of methane. The general approach followed in that case is to obtain experimental data on the reaction kinetics first and introduce them subsequently into the simulation set‐up.

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