Hydrodynamic simulation of fuel-reactor in chemical looping combustion process

Abstract A multiphase CFD-based model with gas–solid hydrodynamics and chemical reactions is used to model flow behavior of gas and particles in the fuel reactor of chemical looping combustion process. The granular kinetic theory model is used to model the interaction of particle collisions. The friction stress of particles is considered to account for strain rate fluctuations and slow relaxation of the assembly to the yield surface. The reaction kinetics model of the fuel reactor is presented. The instantaneous mass fractions of both reactant and products are predicted, and the time averaged distributions are calculated in the fuel reactor. Simulated fuel reactor flows reveal a high weight fraction of unburned methane fuel in the flue gas along with CO 2 and H 2 O. This behavior implies high fuel loss at the exit of the reactor and indicates the necessity to increase the residence time and improve mixing in the fuel reactor using circulating fluidized bed technology.

[1]  Prabhu R. Nott,et al.  Frictional–collisional equations of motion for participate flows and their application to chutes , 1990, Journal of Fluid Mechanics.

[2]  Ho-Jung Ryu,et al.  Effect of temperature on reduction reactivity of oxygen carrier particles in a fixed bed chemical-looping combustor , 2003 .

[3]  A. Lyngfelt,et al.  Gas leakage measurements in a cold model of an interconnected fluidized bed for chemical-looping combustion , 2003 .

[4]  Jesse Zhu,et al.  Hydrodynamics and scale-up of liquid–solid circulating fluidized beds: Similitude method vs. CFD , 2008 .

[5]  A. Munjiza,et al.  Development and testing of an interconnected multiphase CFD-model for chemical looping combustion , 2010 .

[6]  D. Gidaspow,et al.  Simulation and experiment of segregating/mixing of rice husk–sand mixture in a bubbling fluidized bed , 2005 .

[7]  Fariborz Taghipour,et al.  Computational fluid dynamics of high density circulating fluidized bed riser : Study of modeling parameters , 2008 .

[8]  S. Pannala,et al.  Multifluid Eulerian modeling of dense gas–solids fluidized bed hydrodynamics: Influence of the dissipation parameters , 2008 .

[9]  A. Almstedt,et al.  Experimental validation of CFD models for fluidized beds: Influence of particle stress models, gas phase compressibility and air inflow models , 2006 .

[10]  Jonghwun Jung,et al.  Multiphase CFD-based models for chemical looping combustion process: Fuel reactor modeling , 2008 .

[11]  S. Ergun.  Fluid flow through packed columns , 1952 .

[12]  D. Gidaspow.  Multiphase Flow and Fluidization: Continuum and Kinetic Theory Descriptions , 1994 .

[13]  M. Syamlal,et al.  MFIX documentation theory guide , 1993 .

[14]  Jianmin Ding,et al.  Numerical analysis of particle clustering effects on desulphurization and NO emission in a circulating fluidized bed combustor , 2008 .

[15]  H. Jakobsen,et al.  Practical validation of the two-fluid model applied to dense gas-solid flows in fluidized beds , 2007 .

[16]  Anuj Srivastava,et al.  Analysis of a frictional-kinetic model for gas-particle flow , 2003 .

[17]  Jam Hans Kuipers,et al.  Critical comparison of hydrodynamic models for gas-solid fluidized beds - Part I: bubbling gas-solid fludized beds operated with a jet , 2005 .

[18]  He Yurong,et al.  Computer simulations of gas–solid flow in spouted beds using kinetic–frictional stress model of granular flow , 2004 .

[19]  Guy T. Houlsby,et al.  The flow of granular materials—II Velocity distributions in slow flow , 1982 .

[20]  Wei Ge,et al.  CFD simulation of concurrent-up gas-solid flow in circulating fluidized beds with structure-dependent drag coefficient , 2003 .

[21]  Mohammad. M. Hossain,et al.  Chemical-looping combustion (CLC) for inherent CO2 separations—a review , 2008 .

[22]  R. Bagnold.  Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear , 1954, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[23]  S. Savage,et al.  Analyses of slow high-concentration flows of granular materials , 1998, Journal of Fluid Mechanics.

[24]  A. Lyngfelt,et al.  A fluidized-bed combustion process with inherent CO2 separation; Application of chemical-looping combustion , 2001 .

[25]  Donald L. Koch,et al.  Kinetic theory for a monodisperse gas–solid suspension , 1990 .

[26]  C. Wen.  Mechanics of Fluidization , 1966 .

[27]  Joachim Werther,et al.  CFD-simulation of a circulating fluidized bed riser , 2009 .

[28]  Dimitri Gidaspow,et al.  Hydrodynamics of fluidization using kinetic theory: an emerging paradigm: 2002 Flour-Daniel lecture , 2004 .

[29]  He Yurong,et al.  Numerical simulations of flow behavior of gas and particles in spouted beds using frictional-kinetic stresses model , 2009 .

[30]  Anders Lyngfelt,et al.  Natural minerals as oxygen carriers for chemical looping combustion in a dual circulating fluidized bed system , 2009 .

[31]  R. Jackson,et al.  Gas‐particle flow in a vertical pipe with particle‐particle interactions , 1989 .

[32]  David G. Schaeffer,et al.  Instability in the evolution equations describing incompressible granular flow , 1987 .

[33]  Jeong-Hoo Choi,et al.  Oxidation and reduction characteristics of oxygen carrier particles and reaction kinetics by unreacted core model , 2001, Korean Journal of Chemical Engineering.

[34]  Hermann Hofbauer,et al.  Operating experience with chemical looping combustion in a 120 kW dual circulating fluidized bed (DCFB) unit , 2009 .

[35]  Hamid Arastoopour,et al.  Numerical simulation and experimental analysis of gas/solid flow systems: 1999 Fluor-Daniel Plenary lecture , 2001 .

[36]  Dimitri Gidaspow,et al.  Hydrodynamic simulation of gas-solid flow in a riser using kinetic theory of granular flow , 2003 .

[37]  D. Gidaspow,et al.  A bubbling fluidization model using kinetic theory of granular flow , 1990 .

[38]  Christine M. Hrenya,et al.  Effects of particle‐phase turbulence in gas‐solid flows , 1997 .