Effect of Fuel and Oxygen Carriers on the Hydrodynamics of Fuel Reactor in a Chemical Looping Combustion System

2013 ◽  
Author(s):  
Atal B. Harichandan ◽  
Tariq Shamim
Keyword(s):  
Oxygen Carrier ◽  
Bubble Formation ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Calcium Sulfide ◽  
Oxygen Carriers ◽  
Fuel Reactor ◽  
Gas Interactions ◽  
Kinetics Of ◽  
Good Agreement

The hydrodynamics of fuel reactor in a chemical looping combustion (CLC) system has been analyzed by using a multiphase CFD-based model with solid-gas interactions and chemical reactions. In this paper, the fuel reactors of two CLC systems are numerically simulated independently by using hydrogen with calcium sulfide as oxygen carrier, and methane with nickel as oxygen carrier in similar conditions. Kinetic theory of granular flow has been adopted. Conservation of mass, momentum and species equations, and reaction kinetics of oxygen carriers are used for the numerical calculation. The present results obtained are in good agreement with the experimental and numerical results available in open literature. The bubble hydrodynamics in both the fuel reactors are analyzed. The salient features of bubble formation, rise and burst are prominent in hydrogen-fueled reactor as compared to methane-fueled reactor. The fuel conversion rate is found to be larger in the case of hydrogen-fueled reactor.

Effect of Fuel and Oxygen Carriers on the Hydrodynamics of Fuel Reactor in a Chemical Looping Combustion System

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Atal Bihari Harichandan ◽  
Tariq Shamim
Keyword(s):  
Oxygen Carrier ◽  
Bubble Formation ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Fuel Reactor ◽  
Computational Fluid Dynamics Cfd ◽  
Gas Interactions ◽  
Kinetics Of ◽  
Good Agreement

The hydrodynamics of a fuel reactor in a chemical looping combustion (CLC) system is analyzed by using a multiphase two-dimensional computational fluid dynamics (CFD) model that involves solid–gas interactions and chemical reactions. The study compares the fuel reactors of two CLC systems numerically by using hydrogen with calcium sulfide as an oxygen carrier, and methane with nickel as an oxygen carrier in similar conditions. Kinetic theory of granular flow has been adopted. The model considers the conservation equations of mass, momentum and species, and reaction kinetics of oxygen carriers. The results obtained are in good agreement with the experimental and numerical results available in open literature. The bubble hydrodynamics in both the fuel reactors are analyzed. The salient features of the bubble formation, rise, and burst are more prominent in the hydrogen-fueled reactor as compared to the methane-fueled reactor. The fuel conversion rate is found to be larger for the hydrogen-fueled reactor.

Thermodynamic and Kinetic Analysis of Ca-Based Oxygen Carrier in Chemical-Looping Combustion

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Chang Jing ◽  
Cui Dejie
Keyword(s):  
Kinetic Analysis ◽  
Oxygen Carrier ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Calcium Sulfide ◽  
Oxygen Carriers ◽  
Thermo Gravimetric ◽  
Caso4 Oxygen Carrier ◽  
Carbon Dioxide Co2 ◽  
Gravimetric Apparatus

Chemical-looping combustion (CLC) is a promising technology to capture carbon dioxide (CO2) inherently and conveniently without the additional apparatus. At present, for some metal oxide oxygen carriers, the high costs and the positive hazards to the environment inhibit the developing of CLC systems. The feasibility of using CaSO4 oxygen carrier in the CLC system is studied in this paper. Through the thermodynamic analysis, the carbon deposition and the sulfur evolution are studied in the reaction between CaSO4 and a typical syngas. In addition, providing that hydrogen (H2) is fed as the gaseous fuel in the CLC system, the kinetic analysis is investigated on the reduction of CaSO4 by H2 and the oxidation of calcium sulfide (CaS) by oxygen (O2) through the thermo-gravimetric apparatus (TGA). The kinetic models are built on the reduction and the oxidation of the oxygen carrier. The results calculated from the models agree well with the experimental data. Finally, the possible reaction mechanisms for the reduction and the oxidation are explored.

Comparison of Chemical-Looping with Oxygen Uncoupling and Chemical-Looping Combustion Technology Reaction Mechanism

2014 ◽  
Vol 955-959 ◽  
pp. 2261-2266
Author(s):  
Xiao Ning Gao ◽  
Hui Min Xue ◽  
Yuan Li ◽  
Xue Feng Yin
Keyword(s):  
New Technologies ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
High Efficient ◽  
Direct Separation ◽  
Fuel Reactor ◽  
Combustion Technology

In order to reduce the emission of CO2and control the global greenhouse effect, the paper introduces and compares two new technologies named chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) that are both high-efficient and clean. Through comparative analysis, CLC has been widely studied because of its direct separation of CO2, reduction loss of the heat, improvement of energy efficiency and avoiding of the generation of fuel type NOxin the combustion process. Besides the current research for metal oxygen carrier, there are some scholars find various non-metal oxygen carriers that have the better performance in CLC. But the study on reactors of CLC is still not mature, especially the solid fuel reactor, which is different from CLOU. In a certain sense, CLOU is an improved technology based CLC, besides the bove advantages, it also can react with coal directly. Many scholars use coal as fuel in the fluidized bed by the technology of CLOU, and the results of them are feasible. So from this perspective, CLOU technology has more broad prospects than CLC in the China.

Optimizing the Fuel Reactor for Chemical Looping Combustion

2003 ◽  
Author(s):  
Juan Ada´nez ◽  
Francisco Garci´a-Labiano ◽  
Luis F. de Diego ◽  
Ainhoa Plata ◽  
Javier Celaya ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Oxygen Carrier ◽  
Bubble Diameter ◽  
Operating Conditions ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Solid Contact ◽  
Fuel Reactor ◽  
Contact Efficiency

A mathematical model for a bubbling fluidized bed has been developed to optimize the performance of the fuel reactor in chemical looping combustion systems. This model considers both the hydrodynamic of the fluidized bed (dense bed and freeboard) and the kinetics of the oxygen carrier reduction. Although the model is valid for any of the possible oxygen carriers and fuels, the present work has been focused in the use of a carrier, CuO-SiO2, and CH4 as fuel. The shrinking core model has been used to define the particle behavior during their reduction. The simulation of the fuel reactor under different operating conditions was carried out to set the operating conditions and optimize the process. The effect of different design or operating variables as the bed height, the oxygen carrier/fuel ratio, and the gas throughput was analyzed. Finally, a sensitivity analysis to the solid reactivity, the bubble diameter, and to the gas/solid contact efficiency in the freeboard was done. At vigorous fluidization, solid present in the freeboard can strongly contribute to the gas conversion in the fuel reactor. However, the gas/solid contact efficiency in this zone must be determined for each particular case.

scholarly journals Modeling of the Chemical Looping Combustion of Hard Coal and Biomass Using Ilmenite as the Oxygen Carrier

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5394
Author(s):  
Anna Zylka ◽  
Jaroslaw Krzywanski ◽  
Tomasz Czakiert ◽  
Kamil Idziak ◽  
Marcin Sosnowski ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Oxygen Carrier ◽  
Experimental Tests ◽  
Chemical Looping Combustion ◽  
Hard Coal ◽  
Chemical Looping ◽  
Simulation Accuracy ◽  
Energy Technologies ◽  
Fuel Reactor ◽  
Relative Errors

This paper presents a 1.5D model of a fluidized bed chemical looping combustion (CLC) built with the use of a comprehensive simulator of fluidized and moving bed equipment (CeSFaMB) simulator. The model is capable of calculating the effect of gas velocity in the fuel reactor on the hydrodynamics of the fluidized bed and the kinetics of the CLC process. Mass of solids in re actors, solid circulating rates, particle residence time, and the number of particle cycles in the air and fuel reactor are considered within the study. Moreover, the presented model calculates essential emissions such as CO2, SOX, NOX, and O2. The model was successfully validated on experimental tests that were carried out on the Fluidized-Bed Chemical-Looping-Combustion of Solid-Fuels unit located at the Institute of Advanced Energy Technologies, Czestochowa University of Technology, Poland. The model’s validation showed that the maximum relative errors between simulations and experiment results do not exceed 10%. The CeSFaMB model is an optimum compromise among simulation accuracy, computational resources, and processing time.

scholarly journals Kinetics of CuO/SiO2 and CuO/Al2O3 oxygen carriers for chemical looping combustion

2018 ◽  
Vol 175 ◽  
pp. 56-71 ◽  
Author(s):  
M.A. San Pio ◽  
M. Martini ◽  
F. Gallucci ◽  
I. Roghair ◽  
M. van Sint Annaland
Keyword(s):  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Kinetics Of
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