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Go ES, Kim BS, Ling JLJ, Oh SS, Park HJ, Lee SH. In-situ desulfurization using porous Ca-based materials for the oxy-CFB process: A computational study. ENVIRONMENTAL RESEARCH 2023; 225:115582. [PMID: 36858302 DOI: 10.1016/j.envres.2023.115582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/18/2023] [Accepted: 02/25/2023] [Indexed: 06/18/2023]
Abstract
Within circulating fluidized bed (CFB) processes, gas and solid behaviors are mutually affected by operating conditions. Therefore, understanding the behaviors of gas and solid materials inside CFB processes is required for designing and operating those processes. In addition, in order to minimize the environmental impact, modeling to reduce pollutants such as SOx emitted from those processes is essential, and simulation reproduction is necessary for optimization, but little is known. In this study, the gas and solid behaviors in a pilot-scale circulating fluidized bed combustor were investigated by using computational particle fluid dynamics (CPFD) numerical simulation based on the multiphase particle-in-cell (MP-PIC) method under oxy-fuel combustion conditions. In particular, the combustion and in-situ desulfurization reactions simultaneously were considered in this CPFD model. Effect of fluidization number (ULS/Umf) was investigated through the comparison of particle circulation rates with regards to the loop seal flux plane and bed height in the standpipe. In addition, the effects of parameters (temperature, Ca/S molar ratio, and particle size distribution), sensitive indicators for the desulfurization efficiency of limestone, were confirmed. Based on the cycle of the thermodynamic equilibrium curve of limestone, it is suggested that direct and indirect desulfurization occur simultaneously under different operating conditions in CFB, creating an environment in which various reactions other than desulfurization can occur. Addition of the reaction equations (i.e., porosity, diffusion) to the established simple model minimizes uncertainty in the results. Furthermore, the model can be utilized to optimize in-situ desulfurization under oxy-CFB operating conditions.
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Affiliation(s)
- Eun Sol Go
- Department of Environment and Energy, Jeonbuk National University, 567, Baekje-daero, Jeonju-si, jeollabuk-do, 54896, Republic of Korea
| | - Beom-Sik Kim
- Hydrogen Research Center, Research Institute of Industrial Science and Technology, 67, Cheongam-ro, Nam-gu, Pohang-si, Gyeongsangbuk-do, 37673, Republic of Korea
| | - Jester Lih Jie Ling
- Department of Environment and Energy, Jeonbuk National University, 567, Baekje-daero, Jeonju-si, jeollabuk-do, 54896, Republic of Korea
| | - Seung Seok Oh
- Department of Environment and Energy, Jeonbuk National University, 567, Baekje-daero, Jeonju-si, jeollabuk-do, 54896, Republic of Korea
| | - Hyun Jun Park
- Department of Environment and Energy, Jeonbuk National University, 567, Baekje-daero, Jeonju-si, jeollabuk-do, 54896, Republic of Korea
| | - See Hoon Lee
- Department of Environment and Energy, Jeonbuk National University, 567, Baekje-daero, Jeonju-si, jeollabuk-do, 54896, Republic of Korea; Department of Mineral Resources Energy Engineering, Jeonbuk National University, 567, Baekje-daero, Jeonju-si, jeollabuk-do, 54896, Republic of Korea.
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Sano K, Koshiba Y, Ohtani H. Emergency shutdown of fluidized bed reaction systems. J Loss Prev Process Ind 2020. [DOI: 10.1016/j.jlp.2020.104277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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An Assessment of Drag Models in Eulerian–Eulerian CFD Simulation of Gas–Solid Flow Hydrodynamics in Circulating Fluidized Bed Riser. CHEMENGINEERING 2020. [DOI: 10.3390/chemengineering4020037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Accurate prediction of the hydrodynamic profile is important for circulating fluidized bed (CFB) reactor design and scale-up. Multiphase computational fluid dynamics (CFD) simulation with interphase momentum exchange is key to accurately predict the gas-solid profile along the height of the riser. The present work deals with the assessment of six different drag model capability to accurately predict the riser section axial solid holdup distribution in bench scale circulating fluidized bed. The difference between six drag model predictions were validated against the experiment data. Two-dimensional geometry, transient solver and Eulerian–Eulerian multiphase models were used. Six drag model simulation predictions were discussed with respect to axial and radial profile. The comparison between CFD simulation and experimental data shows that the Syamlal-O’Brien, Gidaspow, Wen-Yu and Huilin-Gidaspow drag models were successfully able to predict the riser upper section solid holdup distribution with better accuracy, however unable to predict the solid holdup transition region. On the other hand, the Gibilaro model and Helland drag model were successfully able to predict the bottom dense region, but the upper section solid holdup distribution was overpredicted. The CFD simulation comparison of different drag model has clearly shown the limitation of the drag model to accurately predict overall axial heterogeneity with accuracy.
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Gu J, Liu Q, Zhong W, Yu A. Study on scale-up characteristics of oxy-fuel combustion in circulating fluidized bed boiler by 3D CFD simulation. ADV POWDER TECHNOL 2020. [DOI: 10.1016/j.apt.2020.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Simulation of a Scaled down 250 MWe CFB Boiler Using Computational Particle Fluid Dynamics Numerical Model. CHEMICAL PRODUCT AND PROCESS MODELING 2020. [DOI: 10.1515/cppm-2019-0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Eulerian-Eulerian approach and conventional Eulerian-Lagrangian model are computationally exhaustive for modelling circulating fluidized bed (CFB) riser which has wide particle size distribution and billions of particles Alternatively, the relatively recent Eulerian- Lagrangian computational particle fluid dynamics (CPFD) model enables simulation of the CFB system with lesser computational resources. Most of the published studies on CPFD simulations of CFB risers deal with single grate system. The present study aimed to investigate the performance of the CPFD model for predicting solids distribution in a CFB riser with pant-leg structure (dual grate) and characteristics similar to a commercial boiler. Experiments conducted in a scaled down 250 MWe CFB facility according to Glicksman’s simplified similarity laws for fluidized beds were simulated using commercial code Barracuda. The bottom dense bed, upper lean solid phase, increase in bottom bed voidage with increasing fluidizing velocity and reducing solids inventory, decrease in bottom bed solids concentration with decrease in particle size and exchange of solids between the legs typically occurring in a CFB with pant-leg structure were successfully captured by the CPFD calculations. Simulation results showed that the upper solids concentration is hardly influenced by the solids inventory level in line with the experimental observation, therefore the amount of solids inventory can be optimized during actual operation. The predicted pressures varied from the average experimental pressure data within the range –10 to 39 %.
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Liu Q, Shi Y, Zhong W, Yu A. Co-firing of coal and biomass in oxy-fuel fluidized bed for CO2 capture: A review of recent advances. Chin J Chem Eng 2019. [DOI: 10.1016/j.cjche.2019.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lu Y, Zhou Y, Yang L, Hu X, Luo X, Chen H. Verification of optimal models for 2D-full loop simulation of circulating fluidized bed. ADV POWDER TECHNOL 2018. [DOI: 10.1016/j.apt.2018.07.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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