Investigating methods to improve the co-firing of biomass with coal using CFD simulations
department or school: Applied Science, Faculty of
department or school: Chemical and Biological Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Mohammed Redha, Adel
issued: 2021-06-23T22:48:40Z
issued: 2021
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Biomass as a renewable energy source can be burnt with coal in a coal-fired plant to reduce the impact of fossil fuel on the environment. The aim of this research is to investigate methods that can improve the co-firing of biomass with coal. Initially, a CFD model was validated by comparison with experimental data reported in the literature. Three mesh sizes were tested to prove that simulation results are mesh independent. The model was then applied to simulate the co-firing process with a 3:2 biomass-to-coal mixing ratio. Unsophisticated modifications of the furnace geometry near the inlet and the swirl angle were introduced to study their effect on co-firing. CFD simulations were extended to study the influence of particle shrinkage on co-firing due to biomass pelletization. Furthermore, fine coal tailings generated from coal processing (CT), raw biomass (RB), and torrefied biomass (TB) were characterized for subsequent CFD investigation on mono-firing and co-firing of the different fuels. Simulation results show that the modified furnace geometry with gradual expansion and a larger swirl angle leads to uniform temperature distribution (1650-1720 K) in the furnace vs. a more variant temperature profile (950-1500 K) for the original furnace geometry. Besides, an increase in the tangential component of gas velocity near the center from 1 m/s to 3 m/s with the modified furnace geometry results in a longer residence time of the particles and further reduction of unburnt fixed carbon by 55% from coal at the exit. With biomass pelletization, simulation outputs show that the compressed particles with particle density 1000 kg/m³ have slower volatilization rate and surface reaction, as well as a shorter residence time. This in turns causes a higher percentage of unburnt fixed carbon at the exit though NO emission is slightly lower. As for the co-firing of biomass with fine coal tailings, results indicate that CT alone, CT+TB, and CT+RB blended fuel are associated with 13%…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/78784
note: INVESTIGATING METHODS TO IMPROVE THE CO-FIRING OF BIOMASS WITH COAL USING CFD SIMULATIONS by Adel Mohammed Redha B.Sc., University of Baghdad, 1993 M.Sc., University of Baghdad 1997 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Doctor of Philosophy in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemical and Biological Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) June 2021 © Adel Mohammed Redha, 2021 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: INVESTIGATING METHODS TO IMPROVE THE CO-FIRING OF BIOMASS WITH COAL USING CFD SIMULATIONS submitted by Adel Mohammed Redha in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemical and Biological Engineering Examining Committee: Dr. Anthony Lau, Professor, Chemical and biological Engineering, UBC Co-supervisor Dr. Maria Holuszko, Professor, Mining engineering, UBC Co-supervisor Dr. William Kendal Bushe, Professor, Mechanical engineering, UBC University Examiner Dr. Fariborz Taghipour, Professor, Chemical and biological engineering, UBC University Examiner Additional Supervisory Committee Members: Dr. Ali Vakil, Adjunct Professor, Mechanical engineering, UBC Supervisory Committee Member Dr. Shahabaddine Sokhansanj, Professor, Chemical and biological Engineering, UBC Supervisory Committee Member iii Abstract Biomass as a renewable energy source can be burnt with coal in a coal-fired plant to reduce the impact of fossil fuel on the environment. The aim of this research is to investigate methods that can improve the co-firing of biomass with coal. Initially, a CFD model was validated by comparison with experimental data reported in the literature. Three mesh sizes were tested to prove that simulation results are mesh independent. The model was then applied to simulate the co-firing process with a 3:2 biomass-to-coal mixin…
has type: Thesis/Dissertation
date issued: 2021-11
is shown at: 10.14288/1.0398511
language: eng
degree discipline: Chemical and Biological Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Lau, Anthony
contributor: Holuszko, M. E.
type: Text
identifier URI: http://hdl.handle.net/2429/78784