Parametric analysis of internal gas separation within an ebullated bed reactor

Lane, Chris; McKnight, Craig A.; Wiens, Jason; Reid, Kevin; Donaldson, Adam

doi:10.1016/j.cherd.2015.10.043

Cited by 13 publications

(20 citation statements)

References 17 publications

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“…Much greater errors (22% on average) are, however, observed for co‐current flow. Since in neither flow regime can the appropriate bubble size be known a priori, Euler–Euler models are likely to require quantitative calibration in simple systems, such as the one investigated here, before they can be used to investigate industrial systems of greater geometric complexity (e.g., ).…”

Section: Resultsmentioning

confidence: 99%

On the prediction of gas hold‐up in two‐phase flow systems using an Euler–Euler model

et al. 2020

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We quantify the ability of the two-fluid Euler-Euler model to predict the overall gas hold-up during two-phase flow in vertical columns using a combination of experiments and simulations. Gas hold-up in a bubble column and gas hold-up in the less-frequently studied co-current flow are investigated. For homogeneous flow characterized by nearly uniform bubble size, Euler-Euler model predictions are within 10% of the experimental values for both modes of operation, if the bubble diameter supplied as input to the model is the average bubble diameter in the physical system. This also holds true for heterogeneous flow in bubble columns despite the presence of a broad distribution of bubble sizes, if turbulence and bubble swarm effects on momentum exchange between phases are properly accounted for. Swarm corrections adequate for bubble columns, are less successful for co-current heterogeneous flow, for which gas hold-up predictions are least accurate (average error of 22%). K E Y W O R D S churn-turbulent flow regime, dispersed flow regime, experimental validation, gas-liquid flow, two-fluid Euler-Euler model

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Section: Resultsmentioning

confidence: 99%

On the prediction of gas hold‐up in two‐phase flow systems using an Euler–Euler model

et al. 2020

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“…Industrial chemical engineering processes such as bubble columns (Jakobsen et al, 2005;Joshi, 2001;Ekambara et al, 2005;Krishna and van Baten, 2001), reactors (Becker et al, 1994;Sokolichin and Eigenberger, 1994) and separators (Lane et al, 2016) involve two or more fluids. To better design and operate these processes, an understanding of the hydrodynamics of the system is essential.…”

Section: Introductionmentioning

confidence: 99%

Diffuse-interface blended method for the imposition of physical boundaries in two-fluid flows

Treeratanaphitak,

Abukhdeir

2021

Preprint

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Multiphase flows are commonly found in chemical engineering processes such as distillation columns, bubble columns, fluidized beds and heat exchangers. Physical boundaries in numerical simulations of multiphase flows are generally defined by a mesh that conforms to the physical boundaries of the system. Depending on the complexity of the physical system, generating the conformal mesh can be time-consuming and the resulting mesh could potentially contain a large number of skewed elements, which is undesirable. The diffuse-interface approach allows for a structured mesh to be used while still capturing the desired solid-fluid boundaries. In this work, a diffuse-interface method for the imposition of physical boundaries is developed for two-fluid incompressible flow systems. The diffuse-interface is used to define the physical boundaries and the boundary conditions are imposed by blending the conservation equations from the twofluid model with that of the solid. The results from the diffuse-interface method and mesh-defined boundaries are found to be in good agreement at small diffuse-interface widths.

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“…Two-phase gas-liquid flow systems are prevalent in industrial processes and, consequently, the hydrodynamic behavior of gas-liquid systems is of great interest. Examples of gas-liquid flow systems include bubble columns (Jakobsen et al, 2005;Joshi, 2001;Rollbusch et al, 2015;Shaikh and Al-Dahhan, 2013;Shah et al, 1982), loop reactors (Becker et al, 1994), cyclones (Erdal et al, 1997), hydrocarbon pipelines (Issa and Kempf, 2003;Issa et al, 2006) and disengagers (Lane et al, 2016). The hydrodynamical behavior of gas-liquid systems is complicated and is dependent on factors such as operating conditions, physical properties, equipment type, etc.…”

Section: Introductionmentioning

confidence: 99%

Phase-bounded finite element method for two-fluid incompressible flow systems

Treeratanaphitak,

Abukhdeir

2021

Preprint

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An understanding of the hydrodynamics of multiphase processes is essential for their design and operation. Multiphase computational fluid dynamics (CFD) simulations enable researchers to gain insight which is inaccessible experimentally. The model frequently used to simulate these processes is the two-fluid (Euler-Euler) model where fluids are treated as inter-penetrating continua. It is formulated for the multiphase flow regime where one phase is dispersed within another and enables simulation on experimentally relevant scales. Phase fractions are used to describe the composition of the mixture and are bounded quantities. Consequently, numerical solution methods used in simulations must preserve boundedness for accuracy and physical fidelity. In this work, a numerical method for the two-fluid model is developed in which phase fraction constraints are imposed through the use of an nonlinear variational inequality solver which implicitly imposes inequality constraints. The numerical method is verified and compared to an established explicit numerical method.

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Parametric analysis of internal gas separation within an ebullated bed reactor

Cited by 13 publications

References 17 publications

On the prediction of gas hold‐up in two‐phase flow systems using an Euler–Euler model

On the prediction of gas hold‐up in two‐phase flow systems using an Euler–Euler model

Diffuse-interface blended method for the imposition of physical boundaries in two-fluid flows

Phase-bounded finite element method for two-fluid incompressible flow systems

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