Optimisation of Biomass/Coal Co-Firing Processes through Integrated Measurement and Computational Modelling

Lead Research Organisation: University of Kent
Department Name: Sch of Engineering & Digital Arts

Abstract

Co-firing biomass with coal at existing power plant is widely adopted as one of the main technologies for reducing CO2 emissions in the UK and the rest of the world. Despite various advances in developing the co-firing technology, a range of technological issues remain to be resolved due to the inherent differences in the physical and combustion properties between biomass and coal. Typical problems associated with co-firing include poor flame stability, low thermal efficiency, and slagging and fouling. This project aims to achieve the optimisation of biomass/coal co-firing processes through a combination of advanced fuel characterisation, integrated measurement and computational modelling. In the area of fuel characterisation, both thermo-gravimetric analysis and automated image analysis techniques in conjunction with conventional fuel analysis methods will be combined to achieve comprehensive characterisation of biomass and biomass/coal blends from a wide range of sources. Because of the physical differences between biomass and coal the fluid dynamics of the biomass/coal/air three-phase flow in the fuel lines feeding the burners is rather complex and very little is known in this area of science. It is proposed in this project to develop an instrumentation technology capable of measuring the basic parameters of the biomass/coal particles in the fuel lines on an on-line continuous basis. The system will allow the monitoring and optimisation of the fuel delivery to the burners. The instrumentation technology combines novel electrostatic sensing and digital imaging principles and embedded system design methodology. The flow parameters to be measured include particle size distribution, velocity and concentration of biomass/coal particles as well as biomass proportion in the blend. It is known that biomass addition and variations in coal diet can have a significant impact on combustion stability and co-firing efficiency. As part of this project, a system incorporating digital imaging devices and solid state optical detectors will be developed for the continuous monitoring of the burner conditions and flame stability under co-firing conditions. Computational modelling provides a powerful supplementary tool to experimental measurement in the studies of three-phase flow and combustion flame characteristics. Computational Fluid Dynamic (CFD) modelling techniques will be applied in this project to investigate the dynamic behaviours of irregular biomass particles and their blends with pulverised coal in the fuel lines and associated combustion characteristics particularly flame stability. CFD modelling techniques will also be applied to study the impact of biomass addition on ash deposition and formation of slagging and fouling. The measurements from the flow metering and flame monitoring systems will be integrated to establish and validate the CFD models. Meanwhile, the modelling results will be used to interpret the practical measurements under a wide range of conditions.The project consortium comprises three academic centres of expertise including Kent, Leeds and Nottingham. Collaborative arrangements with three leading research centres in China have been established in addition to support from power generation organizations in the UK and China. Following the design and implementation of the instrumentation systems and computational modeling work, experimental work will be performed on combustion test rigs in both countries. The instrumentation systems and computational models will then be scaled up for full scale power stations. Demonstration trials will be undertaken to assess the efficacy of the advanced fuel characterisation techniques, the performance and operability of the instrumentation systems, and the validity of the computational models under a range of co-firing conditions. Recommendations for the optimization of co-firing processes at existing power plant and on the design of new plant will be reported.

Publications

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Jiaqing Shao (2010) Velocity Measurement of Pneumatically Conveyed Particles Using Intrusive Electrostatic Sensors in IEEE Transactions on Instrumentation and Measurement

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Yonghui Hu (2015) On-line Sizing of Pneumatically Conveyed Particles Through Acoustic Emission Detection and Signal Analysis in IEEE Transactions on Instrumentation and Measurement

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Zhang W (2016) Measurement of Flow Characteristics in a Bubbling Fluidized Bed Using Electrostatic Sensor Arrays in IEEE Transactions on Instrumentation and Measurement

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Zhang W (2017) Measurement of Charge Distributions in a Bubbling Fluidized Bed Using Wire-Mesh Electrostatic Sensors in IEEE Transactions on Instrumentation and Measurement

 
Description 1. As a result of this project a new instrumentation technology has been developed for the in-line continuous measurement of the basic parameters of the biomass/coal particles in the fuel pipes. The instrumentation technology combines novel electrostatic sensor arrays, piezoelectric sensors, digital imaging devices and associated digital signal and image processing algorithms. Prototype systems operating on the technology were developed and evaluated on to measure a range of flow parameters including particle size distribution, particle shape distribution, velocity and concentration of biomass and coal particles. Trials were undertaken on industrial-scale combustion facilities in the UK and China.

2. A new flame monitoring technology, incorporating imaging devices, solid-state optical detectors, image fibre bundles and optical spectroscopic components, have been developed for the continuous monitoring of flame temperature distribution, oscillation frequency and radiative profiles of free radicals as well as flame stability. Prototype systems based this technology has been evaluated on full-scale coal, biomass and heavy oil fired power stations in the UK, China and Saudi Arabia.

3. We have found that adding biomass to pulverised coal at existing coal fired power stations can have significant impact on the operation of the power plant in terms of fuel handling and flame stability. The presence of large and irregular biomass particles in the fuel affects the flow characteristics in the fuel injection pipeline and, more significantly, the stability and properties of the flame.

4. Significant further research is required to study the characteristics of biomass flow and biomass fired flames as many coal to coal/biomass fired power plants are being converted to 100% biomass combustion. Because of the physical differences between biomass and coal the fluid dynamics of the biomass/air two-phase flow in the fuel pipes is rather complex and very little is known.
Exploitation Route The design of new instruments for pulverised fuel flow metering and advanced flame monitoring and associated experimental results have been published in a range of journals and presented at leading international conferences in the field. Three one-day workshops were held over the project period, two in China and one in the UK. The workshops were attended by both academics and industrialists across the UK and China. The results have helped the industrial partners, in particular, Drax Power, RWE npower, E.ON, Alstom Power and China Datang Corporation, to optimise their coal and biomass fired power plants, leading to improved plant efficiency and reduced pollutant emissions. The findings are also beneficial to academic researchers and practitioners working in particle technology, fluid mechanics, multiphase flow, material sciences, computational modelling, sensors and measurement sciences. The technology has been used by several coal fired power stations in China.
Sectors Electronics,Energy,Environment

 
Description The technology has been used by coal fired power generation industry.
First Year Of Impact 2015
Sector Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment
Impact Types Societal,Economic

 
Description British Coal Utilisation Res Assoc BCURA
Amount £50,000 (GBP)
Funding ID No.2 
Organisation British Coal Utilisation Research Association (BCURA) 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2010 
End 06/2014
 
Description EPSRC-E.ON Strategic Partnership, Carbon Capture and Storage
Amount £169,067 (GBP)
Funding ID EP/G062153/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 07/2009 
End 07/2014
 
Description Graduate Fellowship Award
Amount $15,000 (USD)
Organisation The IEEE Instrumentation and Measurement Society 
Sector Charity/Non Profit
Country United States
Start 07/2016 
End 06/2018
 
Description Imaging of coal fired flames
Amount £10,190 (GBP)
Organisation Doosan Babcock 
Sector Private
Country United Kingdom
Start 04/2017 
End 11/2017
 
Description Imaging of special coal flames
Amount £11,952 (GBP)
Organisation Doosan Babcock 
Sector Private
Country United Kingdom
Start 11/2017 
End 04/2018
 
Description Industrial Consultancy - IIT Ltd
Amount £4,174 (GBP)
Organisation International Innovative Technologies 
Sector Private
Country United Kingdom
Start 03/2013 
End 09/2013
 
Description KIE - Innovation and Enterprise
Amount £4,925 (GBP)
Funding ID F302 002 
Organisation University of Kent 
Department Innovation and Enterprise
Sector Private
Country United Kingdom
Start 08/2009 
End 03/2010
 
Description KIE - Innovation and Enterprise
Amount £4,858 (GBP)
Funding ID F4F 
Organisation University of Kent 
Department Kent Innovation and Enterprise
Sector Academic/University
Country United Kingdom
Start 02/2010 
End 07/2010
 
Description KIE Innovation and Enterprise
Amount £9,515 (GBP)
Funding ID F8T 
Organisation University of Kent 
Department Innovation and Enterprise
Sector Private
Country United Kingdom
Start 01/2011 
End 11/2011
 
Description Newton International Fellowship
Amount £99,000 (GBP)
Funding ID NF141121 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 01/2015 
End 01/2017
 
Description RCUK China-UK Summer School
Amount £12,000 (GBP)
Funding ID SS08-025 
Organisation Research Councils UK (RCUK) 
Department RCUK-China
Sector Public
Country China
Start 06/2008 
End 10/2008
 
Description Royal Academy of Engineering
Amount £97,500 (GBP)
Funding ID 35131 
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 01/2011 
End 01/2013
 
Description Royal Academy of Engineering
Amount £14,650 (GBP)
Funding ID 5502 
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 07/2009 
End 12/2010
 
Description Royal Academy of Engineering Major Award for Research Exchanges with China
Amount £15,800 (GBP)
Funding ID 12/13RECI046 
Organisation Royal Academy of Engineering 
Sector Learned Society
Country United Kingdom
Start 07/2013 
End 11/2014
 
Description Alstom Power UK Ltd 
Organisation Alstom
Department Alstom UK
Country United Kingdom 
Sector Private 
PI Contribution Access to the research results arising from the project.
Collaborator Contribution Guidance on co-firing and attendance of project meetings.
Impact Papers
Start Year 2008
 
Description Datang Group 
Organisation Datang Weihe Power Station
Country China 
Sector Private 
PI Contribution Access to the research results arising from the project.
Collaborator Contribution Attendance of project review meetings and research workshop; Technical advice on the research team on fuels, fuel handling and combustion; Data analysis of the results from the project.
Impact Papers.
Start Year 2008
 
Description Drax Power 
Organisation Drax Group
Country United Kingdom 
Sector Public 
PI Contribution Diagnosis of coal and biomass flames on Drax Power Station with the flame monitoring system developed by the Kent team.
Collaborator Contribution Drax made their power station available for on-plant trials of the flame monitoring system.
Impact Papers and reports
Start Year 2009
 
Description E.ON 
Organisation E ON
Country Germany 
Sector Private 
PI Contribution Access to the research results arising from the project.
Collaborator Contribution Attendance of project review meetings and research workshop Technical advice on the research team on fuels, fuel handling and combustion; Data analysis of the results from the project.
Impact Papers.
Start Year 2008
 
Description North China Electric Power University 
Organisation North China Electric Power University
Country China 
Sector Academic/University 
PI Contribution Expertise in sensors and instrumentation
Collaborator Contribution Researchers and test facilities
Impact Joint papers and best paper prizes.
Start Year 2011
 
Description Nottingham University 
Organisation University of Nottingham
Country United Kingdom 
Sector Academic/University 
PI Contribution Project partner in this EPSRC funded project.
Collaborator Contribution Expertise and experience in fuel characterisation.
Impact Joint papers.
Start Year 2008
 
Description RWE nPower 
Organisation RWE AG
Department RWE nPower
Country United Kingdom 
Sector Private 
PI Contribution Availability of prototype systems for on-line particle sizing of pulverised fuel (biomass and coal) including wood pellets. Availability of oxycoal flame data.
Collaborator Contribution RWE npower made their Tilbury Power Station available to the research team. Advice on oxycoal combustion.
Impact Several joint research papers.
Start Year 2008
 
Description Tianjin University 
Organisation Tianjin University
Country China 
Sector Academic/University 
PI Contribution Share of research results from the project.
Collaborator Contribution Advice on sensor design and attendance of project review meetings and workshops.
Impact Joint papers.
Start Year 2008
 
Description University of Leeds 
Organisation University of Leeds
Country United Kingdom 
Sector Academic/University 
PI Contribution Academic partner in EPSRC funded projects.
Collaborator Contribution Expertise and experience in computational modelling and simulation of fuels and flames.
Impact Joint papers
Start Year 2008
 
Description University of Nottingham 
Organisation University of Nottingham
Department School of Physics and Astronomy
Country United Kingdom 
Sector Academic/University 
PI Contribution Particle imaging techniques
Collaborator Contribution Fuel particle combustion and drop tube furnace.
Impact Joint papers.
Start Year 2015
 
Description Xi'an Jiaotong University 
Organisation Xi'an Jiaotong University
Country China 
Sector Academic/University 
PI Contribution Share of the research data from the project.
Collaborator Contribution Advice on flow meter design and attendance of project review meetings and workshops.
Impact Joint papers.
Start Year 2008
 
Description Zhejiang University 
Organisation Zhejiang University
Country China 
Sector Academic/University 
PI Contribution Availability of prototype instruments for coal and biomass flow metering, on-line particle sizing and flame monitoring.
Collaborator Contribution Access to their 3MW Combustion Test Facility for trials. Advice and attendance of project review meetings and workshops.
Impact Several joint papers
Start Year 2008
 
Company Name GreenTech Automation Ltd 
Description Design, construction and evaluation of instruments for power plant applications. 
Year Established 2015 
Impact Advanced flame monitors are helping power plant operators to optimise the operation of coal and biomass fired power stations in terms of process efficiency and pollutant emissions.