Investigation of the liquid recycle in the reactor cascade of an industrial scale ebullated bed hydrocracking unit

Manek, Eduard; Haydary, Juma

doi:10.1016/j.cjche.2018.06.023

Cited by 8 publications

(3 citation statements)

References 9 publications

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“…In an earlier attempt to lessen gas hold, a recycling pan was installed at the head of the ebullated bed reactor's internal recycle line [5]. This layout was introduced in the freeboard area of the reactor to improve gas disengagement above the catalyst bed [6].…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Gas Hold-Up of Two-Phase Ebullated Bed Reactor

Almukhtar,

Yahya,

Mahdy

et al. 2023

ChemEngineering

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Due to the significant increase in heavy feedstocks being transported to refineries and the hydrocracking process, the significance of adopting an ebullated bed reactor has been reemphasized in recent years. The predictive modelling of gas hold-up in an ebullated two-phase reactor was performed using 10 machine learning methods based on support vector machine (SVM) and Gaussian process regression (GPR) in this study. In an ebullated bed reactor, the impacts of three features, namely liquid velocity, gas velocity, and recycling ratio, on the gas hold-up were examined. The liquid velocity has the most impact on the predicted gas hold-up, according to the feature significance analysis. The rotational-quadratic, squared-exponential, Matern 5/2, and exponential kernel functions integrated with the GPR models and the linear, quadratic, cubic, fine, medium, and coarse kernel functions integrated with the SVM model performed well during training and testing, with the exception of the fine SVM model, whose R2 is very low. According to the R2 > 0.9 and low RMSE and MAE values, the rotational-quadratic, squared-exponential, and Matern 5/2 GPR models performed the best.

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Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Gas Hold-Up of Two-Phase Ebullated Bed Reactor

Almukhtar,

Yahya,

Mahdy

et al. 2023

ChemEngineering

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show abstract

“…Manek and Haydary 19 developed a simplified block model of a cascade of three ebullated bed hydroprocessors in Aspen Plus to investigate the impact of liquid recycle (without gas) on ebullated bed characteristics. Measurements from an industrial scale hydrocracking unit were used as inputs to the Aspen Plus model.…”

Section: Introductionmentioning

confidence: 99%

“…Previous studies on ebullated bed hydroprocessors focused on the scaling of bed fluid dynamics, − simulation of gas–liquid separation at the recycle pan, , modeling of overall reactor fluid dynamics, − and the impact of gas–liquid distribution system on bubble dynamics and properties. − Building on the works of Safoniuk et al and Macchi et al, , Pjontek et al proposed a scaling approach for bed fluid dynamics. The proposed scaling required matching of five dimensionless groups ( U g / U l , ρ g / ρ l , ρ l / ρ s , Ar L – S , and Re L – S ) and bubble coalescence behavior.…”

Section: Introductionmentioning

confidence: 99%

Fluid Dynamics Modeling of a Commercial Ebullated Bed Hydroprocessor

Mach

Donaldson

Haelssig

et al. 2020

Ind. Eng. Chem. Res.

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A new multiphase fluid dynamics model for a commercial ebullated bed hydroprocessor was developed. The impact of the gas–liquid distribution system is now explicitly included through new submodels for bubble size distribution and drag coefficients. The size distribution submodel is coupled with the existing gas–liquid separation submodel to better predict recycled gas and liquid flow rates. Either the mass of the catalyst inventory or recycle pump curve can be specified as inputs to converge the model; the former is not always well known during operation in which case the latter can be used after making a few assumptions. A sensitivity analysis was performed to study the impact of fresh treat gas velocity, catalyst mass, phase properties, and reactor internals on recycled gas and liquid flow rates, bubble size distribution, and bed liquid holdup. A 0.2 mm shift in bubble size distribution toward larger sizes was found to significantly increase bed liquid holdup, suggesting that distributor modification/redesign could help improve the capacity of the hydroprocessor.

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Dynamic Impacts of Catalyst Management on Self-fluidized Pump-Free Ebullated-Bed Reactor

Chen

Meng

et al. 2019

Computational and Experimental Simulations in Engineering

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Investigation of the liquid recycle in the reactor cascade of an industrial scale ebullated bed hydrocracking unit

Cited by 8 publications

References 9 publications

Numerical Analysis of Gas Hold-Up of Two-Phase Ebullated Bed Reactor

Numerical Analysis of Gas Hold-Up of Two-Phase Ebullated Bed Reactor

Fluid Dynamics Modeling of a Commercial Ebullated Bed Hydroprocessor

Dynamic Impacts of Catalyst Management on Self-fluidized Pump-Free Ebullated-Bed Reactor

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