CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels

Handle URI:
http://hdl.handle.net/10754/597748
Title:
CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels
Authors:
Kumar, Mayank; Zhang, Cheng; Monaghan, Rory F. D.; Singer, Simcha L.; Ghoniem, Ahmed F.
Abstract:
In this work, we use a CFD package to model the operation of a coal gasifier with the objective of assessing the impact of devolatilization and char consumption models on the accuracy of the results. Devolatilization is modeled using the Chemical Percolation Devolitilization (CPD) model. The traditional CPD models predict the rate and the amount of volatiles released but not their species composition. We show that the knowledge of devolatilization rates is not sufficient for the accurate prediction of char consumption and a quantitative description of the devolatilization products, including the chemical composition of the tar, is needed. We incorporate experimental data on devolatilization products combined with modeling of the tar composition and reactions to improve the prediction of syngas compositions and carbon conversion. We also apply the shrinking core model and the random pore model to describe char consumption in the CFD simulations. Analysis of the results indicates distinct regimes of kinetic and diffusion control depending on the particle radius and injection conditions for both char oxidation and gasification reactions. The random pore model with Langmuir-Hinshelwood reaction kinetics are found to be better at predicting carbon conversion and exit syngas composition than the shrinking core model with Arrhenius kinetics. In addition, we gain qualitative and quantitative insights into the impact of the ash layer surrounding the char particle on the reaction rate. Copyright © 2010 by ASME.
Citation:
Kumar M, Zhang C, Monaghan RFD, Singer SL, Ghoniem AF (2009) CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels. Volume 3: Combustion Science and Engineering. Available: http://dx.doi.org/10.1115/imece2009-12982.
Publisher:
ASME International
Journal:
Volume 3: Combustion Science and Engineering
Issue Date:
2009
DOI:
10.1115/imece2009-12982
Type:
Conference Paper
Sponsors:
This research is funded by the BP-MIT ConversionResearch Program. Mayank Kumar was supported byMASDAR. The computational facilities were supported inpart by KAUST.
Appears in Collections:
Publications Acknowledging KAUST Support

Full metadata record

DC FieldValue Language
dc.contributor.authorKumar, Mayanken
dc.contributor.authorZhang, Chengen
dc.contributor.authorMonaghan, Rory F. D.en
dc.contributor.authorSinger, Simcha L.en
dc.contributor.authorGhoniem, Ahmed F.en
dc.date.accessioned2016-02-25T12:56:01Zen
dc.date.available2016-02-25T12:56:01Zen
dc.date.issued2009en
dc.identifier.citationKumar M, Zhang C, Monaghan RFD, Singer SL, Ghoniem AF (2009) CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels. Volume 3: Combustion Science and Engineering. Available: http://dx.doi.org/10.1115/imece2009-12982.en
dc.identifier.doi10.1115/imece2009-12982en
dc.identifier.urihttp://hdl.handle.net/10754/597748en
dc.description.abstractIn this work, we use a CFD package to model the operation of a coal gasifier with the objective of assessing the impact of devolatilization and char consumption models on the accuracy of the results. Devolatilization is modeled using the Chemical Percolation Devolitilization (CPD) model. The traditional CPD models predict the rate and the amount of volatiles released but not their species composition. We show that the knowledge of devolatilization rates is not sufficient for the accurate prediction of char consumption and a quantitative description of the devolatilization products, including the chemical composition of the tar, is needed. We incorporate experimental data on devolatilization products combined with modeling of the tar composition and reactions to improve the prediction of syngas compositions and carbon conversion. We also apply the shrinking core model and the random pore model to describe char consumption in the CFD simulations. Analysis of the results indicates distinct regimes of kinetic and diffusion control depending on the particle radius and injection conditions for both char oxidation and gasification reactions. The random pore model with Langmuir-Hinshelwood reaction kinetics are found to be better at predicting carbon conversion and exit syngas composition than the shrinking core model with Arrhenius kinetics. In addition, we gain qualitative and quantitative insights into the impact of the ash layer surrounding the char particle on the reaction rate. Copyright © 2010 by ASME.en
dc.description.sponsorshipThis research is funded by the BP-MIT ConversionResearch Program. Mayank Kumar was supported byMASDAR. The computational facilities were supported inpart by KAUST.en
dc.publisherASME Internationalen
dc.titleCFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodelsen
dc.typeConference Paperen
dc.identifier.journalVolume 3: Combustion Science and Engineeringen
dc.contributor.institutionMassachusetts Institute of Technology, Cambridge, United Statesen
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.