scholarly journals Transient Simulations of Spouted Fluidized Bed for Coal-Direct Chemical Looping Combustion

2014 ◽  
Author(s):  
Zheming Zhang ◽  
Ramesh Agarwal
Keyword(s):  
Carbon Capture ◽  
Power Plants ◽  
High Efficiency ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Successful Implementation ◽  
Chemical Looping ◽  
Two Phase ◽  
Coal Particles ◽  
Fuel Reactor

Chemical-looping combustion holds significant promise as one of the next generation combustion technology for high-efficiency low-cost carbon capture from fossil fuel power plants. For thorough understanding of the chemical-looping combustion process and its successful implementation in CLC based industrial scale power plants, the development of high-fidelity modeling and simulation tools becomes essential for analysis and evaluation of efficient and cost effective designs. In this paper, multiphase flow simulations of coal-direct chemical-looping combustion process are performed using ANSYS Fluent CFD code. The details of solid-gas two-phase hydrodynamics in the CLC process are investigated by employing the Lagrangian particle-tracking approach called the discrete element method (DEM) for the movement and interaction of solid coal particles moving inside the gaseous medium created due to the combustion of coal particles with an oxidizer. The CFD/DEM simulations show excellent agreement with the experimental results obtained in a laboratory scale fuel reactor in cold flow conditions. More importantly, simulations provide important insights for making changes in fuel reactor configuration design that have resulted in significantly enhanced performance.

Multiphase CFD Modeling for a Chemical Looping Combustion Process (Fuel Reactor)

2008 ◽  
Vol 31 (12) ◽  
pp. 1754-1766 ◽  
Author(s):  
Z. G. Deng ◽  
R. Xiao ◽  
B. S. Jin ◽  
Q. L. Song ◽  
H. Huang
Keyword(s):  
Combustion Process ◽  
Cfd Modeling ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Fuel Reactor ◽  
Multiphase Cfd

Review of Computational Fluid Dynamics Studies on Chemical Looping Combustion

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Yali Shao ◽  
Ramesh K. Agarwal ◽  
Xudong Wang ◽  
Baosheng Jin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Flow Process ◽  
Gas Leakage ◽  
Fuel Reactor ◽  
Energy Penalty

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.

scholarly journals Thermodynamic Analysis of Chemical Looping Combustion Based Power Plants for Gaseous and Solid Fuels

2021 ◽  
Author(s):  
Sivaji Seepana ◽  
Aritra Chakraborty ◽  
Kannan Kaliyaperumal ◽  
Guruchandran Pocha Saminathan
Keyword(s):  
Power Plant ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Combustion Process ◽  
Rankine Cycle ◽  
Chemical Looping Combustion ◽  
Solid Fuels ◽  
Chemical Looping ◽  
Gaseous Fuels ◽  
The Difference

Abstract The chemical looping combustion (CLC) process is a promising technology for capturing CO2 at the source due to its inherent separation of flue gas from nitrogen. In this regard, the present study is focused on the development of various Rankine cycle based CLC power plant layouts for gaseous and solid fuels. To evaluate the performance of these CLC based cycles, a detailed thermodynamic analysis has been carried out with natural gas (NG)& synthesis gas as gaseous fuels and lignite as solid fuel. For lignite based power production, in-site gasification CLC (iG-CLC) for syngas generation and CLC based combustion process employed. The Energy analysis showed that NG based power plant has a net efficiency of 40.44% with CO2 capture and compression which is the highest among all cases while the same for syngas based power plant is 38.06%. The difference in net efficiency between NG and syngas power plants is attributed to the variation in CO2 compression cost. For lignite based iG-CLC power plant layout, the net efficiency of 39.64% is observed which is higher than syngas fuelledCLC power plant. This shows the potential of CLC technology for power generation applications with or without CO2 capture.

Computational Fluid Dynamics Modeling of Chemical Looping Combustion Process with Calcium Sulphate Oxygen Carrier

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Baosheng Jin ◽  
Rui Xiao ◽  
Zhongyi Deng ◽  
Qilei Song
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Combustion Products ◽  
Calcium Sulphate ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Dynamics Modeling ◽  
Fuel Reactor

To concentrate CO2 in combustion processes by efficient and energy-saving ways is a first and very important step for its sequestration. Chemical looping combustion (CLC) could easily achieve this goal. A chemical-looping combustion system consists of a fuel reactor and an air reactor. Two reactors in the form of interconnected fluidized beds are used in the process: (1) a fuel reactor where the oxygen carrier is reduced by reaction with the fuel, and (2) an air reactor where the reduced oxygen carrier from the fuel reactor is oxidized with air. The outlet gas from the fuel reactor consists of CO2 and H2O, while the outlet gas stream from the air reactor contains only N2 and some unused O2. The water in combustion products can be easily removed by condensation and pure carbon dioxide is obtained without any loss of energy for separation.Until now, there is little literature about mathematical modeling of chemical-looping combustion using the computational fluid dynamics (CFD) approach. In this work, the reaction kinetic model of the fuel reactor (CaSO4+ H2) is developed by means of the commercial code FLUENT and the effects of partial pressure of H2 (concentration of H2) on chemical looping combustion performance are also studied. The results show that the concentration of H2 could enhance the CLC performance.

scholarly journals Fuel Reactor CFD Multiscale Modelling in Syngas-Based Chemical Looping Combustion with Ilmenite

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6059
Author(s):  
Vlad-Cristian Sandu ◽  
Ana-Maria Cormos ◽  
Calin-Cristian Cormos
Keyword(s):  
Mass Transfer ◽  
Carbon Capture ◽  
Alternative Energy ◽  
Power Plants ◽  
Fossil Fuel ◽  
Transition Period ◽  
Chemical Looping Combustion ◽  
Particle Model ◽  
Chemical Looping ◽  
Transfer Effects

As global power generation is currently relying on fossil fuel-based power plants, more anthropogenic CO2 is being released into the atmosphere. During the transition period to alternative energy sources, carbon capture and storage seems to be a promising solution. Chemical-looping combustion (CLC) is an energy conversion technology designed for combustion of fossil fuel with advantageous carbon capture capabilities. In this work, a 1D computational fluid dynamics (CFD) multiscale model was developed to study the reduction step in a syngas-based CLC system and was validated using literature data (R=0.99). In order to investigate mass transfer effects, flow rate and particle dimension studies were carried out. Sharper mass transfer rates were seen at lower flow rates and smaller granule sizes due to suppression of diffusion limitations. In addition, a 3D CFD particle model was developed to investigate in depth the reduction within an ilmenite particle, with focus on heat transfer effects. Minor differences of 1 K were seen when comparing temperature changes predicted by the two models during the slightly exothermic reduction reaction with syngas.

An Innovative Gas Turbine Cycle With Methanol-Fueled Chemical-Looping Combustion

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Hongguang Jin ◽  
Xiaosong Zhang ◽  
Hui Hong ◽  
Wei Han
Keyword(s):  
Low Temperature ◽  
Gas Turbine ◽  
Carbon Capture ◽  
Power Plants ◽  
Waste Heat ◽  
Carbon Capture And Storage ◽  
Chemical Looping Combustion ◽  
Inlet Temperature ◽  
Chemical Looping ◽  
Gas Turbine Cycle

In this paper, a novel gas turbine cycle integrating methanol decomposition and the chemical-looping combustion (CLC) is proposed. Two types of methanol-fueled power plants, including the new gas turbine cycle with CLC combustion and a chemically intercooled gas turbine cycle, have been investigated with the aid of the T-Q diagram. In the proposed system, methanol fuel is decomposed into syngas mainly containing H2 and CO by recovering low-temperature thermal energy from an intercooler of the air compressor. After the decomposition of methanol, the resulting product of syngas is divided into two parts: the part reacting with Fe2O3 is sent into the CLC subsystem, and the other part is introduced into a supplement combustor to enhance the inlet temperatures of the gas turbine to 1100–1500°C. As a result, the new methanol-fueled gas turbine cycle with CLC had a breakthrough in thermodynamic and environmental performance. The thermal efficiency of the new system can achieve 60.6% with 70% of CO2 recovery at a gas turbine inlet temperature of 1300°C. It would be expected to be at least about 10.7 percentage points higher than that of the chemically intercooled gas turbine cycle with the same recovery of CO2 and is environmentally superior due to the recovery of CO2. The promising results obtained here indicated that this novel gas turbine cycle with methanol-fueled chemical-looping combustion could provide a promising approach of both effective use of alternative fuel and recovering low-temperature waste heat and offer a technical probability of blending a combination of the chemical-looping combustion and the advanced gas turbine for carbon capture and storage.

Transient Reacting Flow Simulation of Spouted Fluidized Bed for Coal-Direct Chemical Looping Combustion

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Subhodeep Banerjee ◽  
Ramesh K. Agarwal
Keyword(s):  
Chemical Reactions ◽  
Power Plants ◽  
High Efficiency ◽  
Oxygen Carrier ◽  
Laboratory Scale ◽  
Industrial Scale ◽  
Chemical Looping Combustion ◽  
Great Promise ◽  
Reacting Flow ◽  
Chemical Looping

Coal-direct chemical-looping combustion (CD-CLC) is a next generation combustion technology that shows great promise as a solution for the need of high-efficiency low-cost carbon capture from fossil fueled power plants. To realize this technology on an industrial scale, the development of high-fidelity simulations is a necessary step to develop a thorough understanding of the CLC process. In this paper, simulations for multiphase flow of the CD-CLC process with chemical reactions are performed using ANSYS Fluent computational fluid dynamics (CFD) software. The details of the solid–gas two-phase hydrodynamics in the CLC process are investigated using the Lagrangian particle-tracking approach called the discrete element method (DEM) for the movement and interaction of the solid oxygen carrier particles with the gaseous fuel. The initial CFD/DEM simulation shows excellent agreement with the experimental results obtained in a laboratory scale fuel reactor in cold-flow conditions at Darmstadt University of Technology. Subsequent simulations using 60% Fe2O3 supported on MgAl2O4 reacting with gaseous CH4 demonstrate successful integration of chemical reactions into the CFCD/DEM approach. This work provides a strong foundation for future simulations of CD-CLC systems using solid coal as fuel, which will be crucial for successful deployment of CD-CLC technology from the laboratory scale to pilot and industrial scale projects.

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.

Sign in / Sign up

Export Citation Format

Share Document