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Chubukov BA, Rowe SC, Palumbo AW, Wallace MA, Weimer AW. Investigation of continuous carbothermal reduction of magnesia by magnesium vapor condensation onto a moving bed of solid particles. POWDER TECHNOL 2020. [DOI: 10.1016/j.powtec.2019.01.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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2
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CFD Steady Model Applied to a Biomass Boiler Operating in Air Enrichment Conditions. ENERGIES 2018. [DOI: 10.3390/en11102513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A numerical model is proposed to perform CFD simulations of biomass boilers working in different operating conditions and analyse the results with low computational effort. The model is based on steady fluxes that represent the biomass thermal conversion stages through the conservation of mass, energy, and chemical species in the packed bed region. The conversion reactions are combined with heat and mass transfer submodels that release the combustion products to the gas flow. The gas flow is calculated through classical finite volume techniques to model the transport and reaction phenomena. The overall process is calculated in a steady state with a fast, efficient, and reasonably accurate method, which allows the results to converge without long computation times. The modelling is applied to the simulation of a 30 kW domestic boiler, and the results are compared with experimental tests with reasonably good results for such a simple model. The model is also applied to study the effect of air enrichment in boiler performance and gas emissions. The boiler operation is simulated using different oxygen concentrations that range from 21% to 90% in the feeding air, and parameters such as the heat transferred, fume temperatures, and emissions of CO, CO2, and NOx are analysed. The results show that with a moderated air enrichment of 40% oxygen, the energy performance can be increased by 8%, CO emissions are noticeably reduced, and NOx remains practically stable.
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Characterization of high-turbulence zone in slowly moving bed slagging coal gasifier by a 3D mathematical model. POWDER TECHNOL 2017. [DOI: 10.1016/j.powtec.2016.10.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ismail TM, El-Salam MA. Parametric studies on biomass gasification process on updraft gasifier high temperature air gasification. APPLIED THERMAL ENGINEERING 2017; 112:1460-1473. [DOI: 10.1016/j.applthermaleng.2016.10.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Simplification of a Mechanistic Model of Biomass Combustion for On-Line Computations. ENERGIES 2016. [DOI: 10.3390/en9090735] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sahu PK, Schulze S, Nikrityuk P. 2-D approximation of a structured packed bed column. CAN J CHEM ENG 2016. [DOI: 10.1002/cjce.22531] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Pankaj Kumar Sahu
- Donadeo Innovation Centre for Engineering, Department of Chemical and Materials Engineering; University of Alberta; Edmonton AB T6G 1H9 Canada
| | - Sebastian Schulze
- Institute of Energy Process Engineering and Chemical Engineering; TU Bergakademie Freiberg; 09596 Freiberg Germany
| | - Petr Nikrityuk
- Donadeo Innovation Centre for Engineering, Department of Chemical and Materials Engineering; University of Alberta; Edmonton AB T6G 1H9 Canada
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Sun R, Ismail TM, Ren X, El-Salam MA. Influence of simulated MSW sizes on the combustion process in a fixed bed: CFD and experimental approaches. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 49:272-286. [PMID: 26750870 DOI: 10.1016/j.wasman.2015.12.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 12/03/2015] [Accepted: 12/21/2015] [Indexed: 06/05/2023]
Abstract
This work presents the effect of the simulated sizes of Municipal Solid Waste (MSW) on the combustion process in a fixed bed experimentally and numerically. The effect of temperature, gas emissions, flame front velocity and process rate are discussed for three different sizes of MSW: 10, 30, and 50 mm. The study found that for the operating conditions of the current model, when the diameter of particles is decreased, the bulk density of the material is increased, resulting in a decrease of convective heat transfer as well as combustion speed. As the diameter size of the material particles increase, the height of the post-combustion zone is increased, while the temperature in a high temperature area is decreased, due to the decrease in the material's bulk density and the excessive increase in porosity. Results also show that the average emission concentration of CO and CO2 decreases gradually with an increase in the particle diameter size.
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Affiliation(s)
- Rui Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001, PR China
| | - Tamer M Ismail
- Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
| | - Xiaohan Ren
- School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001, PR China
| | - M Abd El-Salam
- Department of Basic Science, Cairo University, Giza, Egypt
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Sun R, Ismail TM, Ren X, Abd El-Salam M. Effect of ash content on the combustion process of simulated MSW in the fixed bed. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 48:236-249. [PMID: 26476592 DOI: 10.1016/j.wasman.2015.10.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/27/2015] [Accepted: 10/06/2015] [Indexed: 06/05/2023]
Abstract
This paper experimentally and numerically investigates the effects of ash content on the combustion process of simulated Municipal Solid Waste (MSW). A fixed-bed experimental reactor was utilized to reveal the combustion characteristics. Temperature distributions, ignition front velocity, and the characteristics of gas species' release were measured and simulated during the combustion process. In the present work, the two-dimensional unsteady mathematical heterogeneous model was developed to simulate the combustion process in the bed, including the process rate model as well as NOx production model. The simulation results in the bed are accordant with the experimental results. The results show that as ash content increases, the lower burning rate of fuel results in char particles leaving the grate without being fully burned, causing a loss of combustible material in the MSW in a fixed bed and therefore reducing the combustion efficiency and increasing the burning time of the MSW.
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Affiliation(s)
- Rui Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001, PR China.
| | - Tamer M Ismail
- Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
| | - Xiaohan Ren
- School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001, PR China
| | - M Abd El-Salam
- Department of Basic Science, Cairo University, Giza, Egypt
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Soria J, Gauthier D, Flamant G, Rodriguez R, Mazza G. Coupling scales for modelling heavy metal vaporization from municipal solid waste incineration in a fluid bed by CFD. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 43:176-187. [PMID: 26050934 DOI: 10.1016/j.wasman.2015.05.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/12/2015] [Accepted: 05/14/2015] [Indexed: 06/04/2023]
Abstract
Municipal Solid Waste Incineration (MSWI) in fluidized bed is a very interesting technology mainly due to high combustion efficiency, great flexibility for treating several types of waste fuels and reduction in pollutants emitted with the flue gas. However, there is a great concern with respect to the fate of heavy metals (HM) contained in MSW and their environmental impact. In this study, a coupled two-scale CFD model was developed for MSWI in a bubbling fluidized bed. It presents an original scheme that combines a single particle model and a global fluidized bed model in order to represent the HM vaporization during MSW combustion. Two of the most representative HM (Cd and Pb) with bed temperatures ranging between 923 and 1073K have been considered. This new approach uses ANSYS FLUENT 14.0 as the modelling platform for the simulations along with a complete set of self-developed user-defined functions (UDFs). The simulation results are compared to the experimental data obtained previously by the research group in a lab-scale fluid bed incinerator. The comparison indicates that the proposed CFD model predicts well the evolution of the HM release for the bed temperatures analyzed. It shows that both bed temperature and bed dynamics have influence on the HM vaporization rate. It can be concluded that CFD is a rigorous tool that provides valuable information about HM vaporization and that the original two-scale simulation scheme adopted allows to better represent the actual particle behavior in a fluid bed incinerator.
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Affiliation(s)
- José Soria
- Institute for Research and Development in Process Engineering, Biotechnology and Alternative Energies (PROBIEN, CONICET - UNCo), 1400 Buenos Aires St., 8300 Neuquén, Argentina.
| | - Daniel Gauthier
- Processes, Materials and Solar Energy Laboratory (PROMES-CNRS, UPR 8521), 7 Four Solaire Street, Odeillo, 66120 Font-Romeu, France
| | - Gilles Flamant
- Processes, Materials and Solar Energy Laboratory (PROMES-CNRS, UPR 8521), 7 Four Solaire Street, Odeillo, 66120 Font-Romeu, France
| | - Rosa Rodriguez
- Chemical Engineering Institute, National University of San Juan, 1109 Libertador (O) Avenue, 5400 San Juan, Argentina
| | - Germán Mazza
- Institute for Research and Development in Process Engineering, Biotechnology and Alternative Energies (PROBIEN, CONICET - UNCo), 1400 Buenos Aires St., 8300 Neuquén, Argentina
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Ismail T, El-Salam MA. Numerical and experimental studies on updraft gasifier HTAG. RENEWABLE ENERGY 2015; 78:484-497. [DOI: 10.1016/j.renene.2015.01.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Sun R, Ismail TM, Ren X, Abd El-Salam M. Numerical and experimental studies on effects of moisture content on combustion characteristics of simulated municipal solid wastes in a fixed bed. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 39:166-178. [PMID: 25746177 DOI: 10.1016/j.wasman.2015.02.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/30/2015] [Accepted: 02/10/2015] [Indexed: 06/04/2023]
Abstract
In order to reveal the features of the combustion process in the porous bed of a waste incinerator, a two-dimensional unsteady state model and experimental study were employed to investigate the combustion process in a fixed bed of municipal solid waste (MSW) on the combustion process in a fixed bed reactor. Conservation equations of the waste bed were implemented to describe the incineration process. The gas phase turbulence was modeled using the k-ε turbulent model and the particle phase was modeled using the kinetic theory of granular flow. The rate of moisture evaporation, devolatilization rate, and char burnout was calculated according to the waste property characters. The simulation results were then compared with experimental data for different moisture content of MSW, which shows that the incineration process of waste in the fixed bed is reasonably simulated. The simulation results of solid temperature, gas species and process rate in the bed are accordant with experimental data. Due to the high moisture content of fuel, moisture evaporation consumes a vast amount of heat, and the evaporation takes up most of the combustion time (about 2/3 of the whole combustion process). The whole bed combustion process reduces greatly as MSW moisture content increases. The experimental and simulation results provide direction for design and optimization of the fixed bed of MSW.
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Affiliation(s)
- Rui Sun
- School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001, PR China.
| | - Tamer M Ismail
- Department of Mechanical Engineering, Suez Canal University, Ismailia, Egypt.
| | - Xiaohan Ren
- School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001, PR China
| | - M Abd El-Salam
- Department of Basic Science, Cairo University, Giza, Egypt
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Jin G. Multiscale Coupling Framework for Modeling of Large-Size Biomass Particle Gasification in Fluidized Beds. Ind Eng Chem Res 2013. [DOI: 10.1021/ie400420p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guodong Jin
- LNM, Institute
of Mechanics, Chinese Academy of Sciences, Beijing 100190, P. R. China
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13
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Hallett W, Green B, Machula T, Yang Y. Packed bed combustion of non-uniformly sized char particles. Chem Eng Sci 2013. [DOI: 10.1016/j.ces.2013.02.070] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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14
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Soria J, Gauthier D, Falcoz Q, Flamant G, Mazza G. Local CFD kinetic model of cadmium vaporization during fluid bed incineration of municipal solid waste. JOURNAL OF HAZARDOUS MATERIALS 2013; 248-249:276-84. [PMID: 23410804 DOI: 10.1016/j.jhazmat.2013.01.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 05/11/2023]
Abstract
The emissions of heavy metals during incineration of Municipal Solid Waste (MSW) are a major issue to health and the environment. It is then necessary to well quantify these emissions in order to accomplish an adequate control and prevent the heavy metals from leaving the stacks. In this study the kinetic behavior of Cadmium during Fluidized Bed Incineration (FBI) of artificial MSW pellets, for bed temperatures ranging from 923 to 1073 K, was modeled. FLUENT 12.1.4 was used as the modeling framework for the simulations and implemented together with a complete set of user-defined functions (UDFs). The CFD model combines the combustion of a single solid waste particle with heavy metal (HM) vaporization from the burning particle, and it takes also into account both pyrolysis and volatiles' combustion. A kinetic rate law for the Cd release, derived from the CFD thermal analysis of the combusting particle, is proposed. The simulation results are compared with experimental data obtained in a lab-scale fluidized bed incinerator reported in literature, and with the predicted values from a particulate non-isothermal model, formerly developed by the authors. The comparison shows that the proposed CFD model represents very well the evolution of the HM release for the considered range of bed temperature.
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Affiliation(s)
- J Soria
- Instituto Multidisciplinario de Investigación y Desarrollo de la Patagonia Norte (IDEPA, CONICET-UNCo) y Facultad de Ingeniería, Universidad Nacional del Comahue, Buenos Aires 1400, 8300 Neuquén, Argentina
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Razuan R, Chen Q, Zhang X, Sharifi V, Swithenbank J. Pyrolysis and combustion of oil palm stone and palm kernel cake in fixed-bed reactors. BIORESOURCE TECHNOLOGY 2010; 101:4622-4629. [PMID: 20153960 DOI: 10.1016/j.biortech.2010.01.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 01/15/2010] [Accepted: 01/20/2010] [Indexed: 05/28/2023]
Abstract
The main objective of this research was to investigate the main characteristics of the thermo-chemical conversion of oil palm stone (OPS) and palm kernel cake (PKC). A series of combustion and pyrolysis tests were carried out in two fixed-bed reactors. The effects of heating rate at the temperature of 700 degrees C on the yields and properties of the pyrolysis products were investigated. The results from the combustion experiments showed that the burning rates increased with an increase in the air flow rate. In addition, the FLIC code was used to simulate the combustion of the oil palm stone to investigate the effect of primary air flow on the combustion process. The FLIC modelling results were in good agreement with the experimental data in terms of predicting the temperature profiles along the bed height and the composition of the flue gases.
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Affiliation(s)
- R Razuan
- SUWIC, Department of Chemical and Process Engineering, Sheffield University, Sheffield, UK
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Wang S, Lu H, Zhao Y, Mostofi R, Young Kim H, Yin L. Numerical study of coal particle cluster combustion under quiescent conditions. Chem Eng Sci 2007. [DOI: 10.1016/j.ces.2007.04.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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Ryu C, Phan AN, Yang YB, Sharifi VN, Swithenbank J. Ignition and burning rates of segregated waste combustion in packed beds. WASTE MANAGEMENT (NEW YORK, N.Y.) 2007; 27:802-10. [PMID: 16790338 DOI: 10.1016/j.wasman.2006.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 02/20/2006] [Accepted: 04/24/2006] [Indexed: 05/10/2023]
Abstract
Recent developments in national recycling and re-use programmes for municipal waste have led to segregation of an increasing proportion of waste to enhance material recovery. Several of the segregated streams contain materials that can not viably be re-used or recycled but can be used for energy recovery. In this study, the combustion of cardboard and waste wood was investigated in a small-scale packed bed reactor in order to provide fundamental data for the design/operation of moving bed furnaces. Key parameters of combustion including the ignition and burning rates were evaluated for various air flowrates and compared to the modelling results. Two successive stages of combustion were identified for both samples: the propagation of ignition front into the bed and combustion of the fuel above the ignition front. The burning rate of cardboard reached a peak of about 300 kg/m(2)h at the air flowrate of 936 kg/m(2)h and decreased at higher air flowrates. For waste wood, both the ignition and burning rates increased in the tested range of the air flowrate up to 702 kg/m(2)h, of which the values were very close to those for the cardboard. The model prediction was in good agreement with the test results for waste wood. However, the burning rate for cardboard was under-predicted due to strongly irregular shapes of the fuel.
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Affiliation(s)
- Changkook Ryu
- Department of Chemical and Process Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD, UK.
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Wurzenberger JC, Wallner S, Raupenstrauch H, Khinast JG. Thermal conversion of biomass: Comprehensive reactor and particle modeling. AIChE J 2006. [DOI: 10.1002/aic.690481029] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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