An Eulerian Approach to Computational Fluid Dynamics Simulation of a Chemical-Looping Combustion Reactor With Chemical Reactions

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Subhodeep Banerjee ◽  
Ramesh K. Agarwal

Chemical-looping combustion (CLC) is a next-generation combustion technology that shows great promise in addressing the need for high-efficiency low-cost carbon capture from fossil fueled power plants. Although there have been a number of experimental studies on CLC in recent years, computational fluid dynamics (CFD) simulations have been limited in the literature. In this paper, simulation of a CLC reactor is conducted using the Eulerian approach in the commercial CFD solver ansys fluent based on a laboratory-scale experiment with a dual fluidized bed CLC reactor. The solid phase consists of a Fe-based oxygen carrier while the gaseous fuel used is syngas. The salient features of the fluidization behavior in the air reactor and fuel reactor beds representing a riser and a bubbling bed, respectively, as well as the down-comer, are accurately captured in the simulation. This work is among the few CFD simulations of a complete circulating dual fluidized bed system for CLC in 3D in the literature. It highlights the importance of 3D simulation of CLC systems and the need for more accurate empirical reaction rate data for future CLC simulations.

2011 ◽  
Vol 4 ◽  
pp. 433-440 ◽  
Author(s):  
A.R. Bidwe ◽  
F. Mayer ◽  
C. Hawthorne ◽  
A. Charitos ◽  
A. Schuster ◽  
...  

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Yali Shao ◽  
Ramesh K. Agarwal ◽  
Xudong Wang ◽  
Baosheng Jin

Abstract Chemical looping combustion (CLC) is an attractive technology to achieve inherent CO2 separation with low energy penalty. In CLC, the conventional one-step combustion process is replaced by two successive reactions in two reactors, a fuel reactor (FR) and an air reactor (AR). In addition to experimental techniques, computational fluid dynamics (CFD) is a powerful tool to simulate the flow and reaction characteristics in a CLC system. This review attempts to analyze and summarize the CFD simulations of CLC process. Various numerical approaches for prediction of CLC flow process are first introduced and compared. The simulations of CLC are presented for different types of reactors and fuels, and some key characteristics including flow regimes, combustion process, and gas-solid distributions are described in detail. The full-loop CLC simulations are then presented to reveal the coupling mechanisms of reactors in the whole system such as the gas leakage, solid circulation, redox reactions of the oxygen carrier, fuel conversion, etc. Examples of partial-loop CLC simulation are finally introduced to give a summary of different ways to simplify a CLC system by using appropriate boundary conditions.


Fuel ◽  
2014 ◽  
Vol 127 ◽  
pp. 178-185 ◽  
Author(s):  
Stefan Penthor ◽  
Karl Mayer ◽  
Stefan Kern ◽  
Hannes Kitzler ◽  
David Wöss ◽  
...  

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Kamil Idziak ◽  
Tomasz Czakiert ◽  
Jaroslaw Krzywanski ◽  
Anna Zylka ◽  
Wojciech Nowak

Abstract The results of investigations on solids flow in a cold model of the dual fluidized bed reactor designed for chemical looping combustion of solid fuels (DFB-CLC-SF) are presented in this paper. The constructed unit consists of two interconnected reactors. The first one, so-called fuel reactor (FR), is operated under bubbling fluidized bed (BFB) conditions, whereas the second one, so-called air reactor (AR), is structurally divided into two sections. The bottom part of AR works under BFB while the upper part, i.e., the riser, is operated in the fast fluidized bed (FFB) regime. In these studies, the air was used for fluidization process in all parts of the DFB-CLC-SF reactor. The glass beads with similar parameters to oxygen carriers (OCs) used in the CLC process were utilized as an inventory. The fluidization conditions are controlled by using the sets of pressure sensors installed around the circulation loop. The experimental data acquired in the tests are further employed to the analysis of solids behavior in a cold model of the DFB-CLC-SF reactor. The main goal of these studies was to establish the conditions for smooth fluidization, which concurrently provide the required residence time of solids in both reactors that is one of the most crucial factors in the CLC process. It was found that the fluidizing gas velocity in reactors has a significant impact on solids behavior and the investigated parameters. However, what is the most important, it was confirmed that the operation condition of the DFB-CLC-SF reactor can be adjusted to meet the requirements resulting from the properties of OCs.


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