Reduced order modeling of a short-residence time gasifier

Sahraei, M. Hossein; Duchesne, Marc; Yandon, Robert; Majeski, Adrian; Hughes, Robin W.; Ricardez‐Sandoval, Luis A.

doi:10.1016/j.fuel.2015.07.096

Cited by 24 publications

(32 citation statements)

References 23 publications

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“…Around 90 % of the reactor volume was divided between the flame zone and the main gasification zone, with the remaining 10 % reserved for the recirculation zone on the basis of visual interpretation of CFD results for black liquor gasification and camera observations of the PEBG pilot‐scale reactor . The volumes are in approximate agreement with a 15 % recirculation zone volume used for entrained flow petcoke gasification . This limits the reactions occurring in the recirculation zone.…”

Section: Methodsmentioning

confidence: 99%

“…[24] Thev olumes are in approximate agreement with a1 5% recirculation zone volume used for entrained flow petcoke gasification. [33] This limits the reactions occurring in the recirculation zone.R esults from as ensitivity study (not shown) indicate that the results are not sensitive to changing the different zone volumes in AE 5% units.…”

Section: Thermodynamic Equilibriummentioning

confidence: 99%

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Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier: Model Description and Validation

et al. 2017

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This paper describes the development of a multiscale equivalent reactor network model for pressurized entrained flow biomass gasification to quantify the effect of operational parameters on the gasification process, including carbon conversion, cold gas efficiency, and syngas methane content. The model, implemented in the commercial software Aspen Plus, includes chemical kinetics as well as heat and mass transfer. Characteristic aspects of the model are the multiscale effect caused by the combination of transport phenomena at particle scale during heating, pyrolysis, and char burnout, as well as the effect of macroscopic gas flow, including gas recirculation. A validation using experimental data from a pilot‐scale process shows that the model can provide accurate estimations of carbon conversion, concentrations of main syngas components, and cold gas efficiency over a wide range of oxygen‐to‐biomass ratios and reactor loads. The syngas methane content was most difficult to estimate accurately owing to the unavailability of accurate kinetic parameters for steam methane reforming.

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Section: Methodsmentioning

confidence: 99%

Section: Thermodynamic Equilibriummentioning

confidence: 99%

Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier: Model Description and Validation

et al. 2017

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“…While there are a variety of computationally efficient linear [11,37,38] and nonnlinear [10,[39][40][41][42] MOR techniques available, in this work, we developed a reduced-order model (ROM) based on multivariate output error state space (MOESP) algorithm using the simulation results from the high-fidelity model as described in [8]. The developed ROM is presented as follows:…”

Section: Simulation Of Sub-optimal Control Policies For Adpmentioning

confidence: 99%

Approximate Dynamic Programming Based Control of Proppant Concentration in Hydraulic Fracturing

2018

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Abstract:Hydraulic fracturing has played a crucial role in enhancing the extraction of oil and gas from deep underground sources. The two main objectives of hydraulic fracturing are to produce fractures with a desired fracture geometry and to achieve the target proppant concentration inside the fracture. Recently, some efforts have been made to accomplish these objectives by the model predictive control (MPC) theory based on the assumption that the rock mechanical properties such as the Young's modulus are known and spatially homogenous. However, this approach may not be optimal if there is an uncertainty in the rock mechanical properties. Furthermore, the computational requirements associated with the MPC approach to calculate the control moves at each sampling time can be significantly high when the underlying process dynamics is described by a nonlinear large-scale system. To address these issues, the current work proposes an approximate dynamic programming (ADP) based approach for the closed-loop control of hydraulic fracturing to achieve the target proppant concentration at the end of pumping. ADP is a model-based control technique which combines a high-fidelity simulation and function approximator to alleviate the "curse-of-dimensionality" associated with the traditional dynamic programming (DP) approach. A series of simulations results is provided to demonstrate the performance of the ADP-based controller in achieving the target proppant concentration at the end of pumping at a fraction of the computational cost required by MPC while handling the uncertainty in the Young's modulus of the rock formation.

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“…They require less computational time and power; simulation typically requires several minutes on a standard work station. The reduced computational time is amenable to studying detailed reaction kinetics and the transient performance of gasifiers [5][6][7]. ROMs function on a basis of a reactor network that emulates the geometry and fluid dynamics of the gasifier.…”

Section: Introductionmentioning

confidence: 99%

“…Sahraei et al proposed a ROM for an entrained flow gasification unit located at CanmetENERGY in Ottawa, Canada [5,6,8,9]. Their reactor network model consists of three plug-flow reactors (PFR) and two continuous-stirred tank reactors (CSTR).…”

Section: Introductionmentioning

confidence: 99%

Dry Fuel Jet Half-Angle Measurements and Correlation for an Entrained Flow Gasifier

et al. 2018

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Reduced order models (ROMs) are increasingly applied to entrained flow gasification development due to reduced computational requirements relative to computational fluid dynamics (CFD) models. However, they require greater a posteriori knowledge of the reactor physics. A significant parameter influencing ROM outputs is the jet half-angle of the solid fuel and oxidant mixture in the gasifier. Thus, it is important to understand the geometry of the jet in the gasifier, and how it is dependent on operating parameters, such as solid and carrier gas flow rates. In this work, an existing model for jet half-angles, which considers the ratio of surrounding gas density to jet core density, is extended to a dry solids jet with impinging gas. The model is fitted to experimental jet half-angles. The jet half-angle of a non-reactive flow was measured using laser-sheet imaging for solid fluxes in the range of 460–880 kg/m2·s and carrier gas fluxes in the range of 43–90 kg/m2·s at the transport line outlet. Jet half-angles ranged from 5.6° to 11.3°, increasing with lower solid/gas loading ratios. CFD simulations of two reactive conditions, with solid and gas fluxes similar to experiments, were used to test the applicability of the proposed jet half-angle model.

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Reduced order modeling of a short-residence time gasifier

Cited by 24 publications

References 23 publications

Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier: Model Description and Validation

Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier: Model Description and Validation

Approximate Dynamic Programming Based Control of Proppant Concentration in Hydraulic Fracturing

Dry Fuel Jet Half-Angle Measurements and Correlation for an Entrained Flow Gasifier

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