COMPLETED BCIA PROJECTS
In 2013, BCIA announced $3.62 million in funding for nine world-class R&D projects as part of BCIA's competitive funding round for low emissions brown coal power generation technologies. The total leveraged value of the 2013 BCIA R&D projects was $14.69 million including research institute, industry and State and Commonwealth Government (via Australian National Low Emissions Coal R&D) contributions.
1. Low emissions value-added products from carbon resources
Blast Furnace Coke from Lignite
Submitted by Monash University in association with CSIRO, HRL, and Australian Char
The aim of this project was to investigate whether Victorian lignite can be heated and chemically treated to become similar to coking coal, which is used in the production of steel. Coking coal has become rarer and more expensive as global steel demand grows.
Blast furnace coke must be able to maintain its mechanical strength while it reacts with CO₂, to maintain the permeability of the reaction bed. The hard char produced by pyrolysis of Victorian brown coal is known to be too reactive, quickly breaking down to fines. Research efforts in this project were directed to production of hard, low reactivity cokes from Victorian lignite. Combinations of thermal coal treatments, binding agents and processing conditions were investigated. Briquettes were produced and tested for compressive strength and reactivity.
The project was successful in producing a briquetted product with acceptably low reactivity by using a combination of optimised processing conditions and a binder material derived from lignite. Opportunities to commercialise this valuable intellectual property are being explored.
Hydrogen Energy Supply Chain Development
Submitted by HRL Developments Pty Ltd in association with Kawasaki Heavy Industries Limited and HRL Technology Pty Ltd
Hydrogen produced from the gasification of lignite, linked with carbon capture and storage technology, can provide a valuable energy source with low CO₂ emissions. This project examined the process design and key infrastructure requirements for hydrogen production at both the pilot and commercial-scale using both commercially available and new technologies. The market potential for the product was examined and the cost effectiveness of the process was assessed against alternative means of production.
The project obtained information on the costs and performance of specific syngas processing steps. It also developed an overall model for the process, incorporating heat and mass balances, and utility requirements, as well as a financial model. Researchers evaluated and modelled a number of prospective alternative technologies to establish the most feasible. Designs were developed for pilot-scale and demonstration-scale hydrogen production plants, including considerations of hydrogen liquefaction and transport.
This project was the forerunner to the current Hydrogen Energy Supply Chain (HESC) pilot project, which aims to safely and efficiently produce and transport clean hydrogen from Victoria’s Latrobe Valley to Japan.
Advanced Lignite Gasification
Submitted by Monash University in association with AGL Loy Yang, GDF SUEZ Australian Energy and Energy Australia
The aim of the project was to experimentally demonstrate the gasification of Victorian lignite at low temperatures through high carbon conversion. This brief project involved preliminary investigations of two strategies for managing the removal of ash and impurities from the syngas produced by gasification of Victorian lignite. These were:
he use of inexpensive catalysts, based on lignite char or flyash, for syngas cleaning and conversion of CO to CO₂
development of a computer model for characterising the composition and phase state of ash
The project findings did not support the concept of producing effective catalysts from inexpensive local raw materials. The computer model that was developed showed that three different Latrobe Valley lignites would each behave differently, producing different ash components with unique properties. This was a positive outcome, but further work was recommended to validate the predictions experimentally.
Next Generation Lower Emissions Gasification Systems R&D – Power and Products
Submitted by HRL Technology Pty Ltd in association with Monash University and CO2CRC
The objective of the project was to develop a short-list of feasible products that could be produced by gasification of Victorian lignite, along with a conceptual design for a pilot plant facility suitable for undertaking further product development research. The work included reviews of: syngas technologies and products; alternative concepts for Victorian lignite gasification, gas treatment and use; pre-combustion CO₂ capture technologies; identification of research gaps and priorities; and pilot plant design.
Development of Entrained Flow Gasification Technology with Lignite for Generation of Power, Fuel and Chemicals
Submitted by Department of Chemical Engineering, Monash University in association with Mitsubishi Heavy Industries and the Institute for Energy and Climate Research in Jülich, Germany
This project aimed to develop an understanding of the flow characteristics of molten slag from Victorian lignite under gasification conditions. The project involved the design and construction of a sophisticated rheometer for high-temperature slag viscosity measurements at Monash University. This facility allowed the measurement of slag viscosity under different gas atmospheres, representative of both gasification and oxidation environments.
A model was developed for the slag viscosity of various Victorian lignites as a function of temperature, composition and gas-phase composition. The trace element composition of the slags was measured using existing equipment at Monash University and used to develop a model for simulation of trace element emissions. The measurements and models were calibrated against data obtained by Mitsubishi Heavy Industries from a commercial gasifier.
Catalytic Steam Gasification and Assessment of Dimethyl Ether Synthesis
Submitted by Monash University in association with CSIRO Energy Technology and HRL Technology
Dimethyl Ether (DME) is a non-toxic, environmentally benign fuel which is actively being developed as a diesel substitute for motor vehicles. It is currently produced by catalytic conversion of methanol, which is not an efficient process. Research efforts in this project were directed to production of DME by gasification of Victorian lignite and one-pot synthesis using bi-functional catalysts (hydrogenation plus methanol dehydration). DME was successfully produced at yields of 35-40%, using mixtures of commercial catalysts as well as three new bi-functional catalysts developed at Monash University. A detailed process design model was also developed.
This project successfully established the feasibility of efficient production of DME from Victorian brown coal. Monash University is continuing work to develop improved catalysts for this application.
Improved Handling of Lignite-Based Products
Submitted by Monash University; project participants include Environmental Clean Technologies Ltd; LawrieCo; Keith Engineering (Australia) Pty Ltd
Dried or de-watered lignite (brown coal) is prone to spontaneous combustion following exposure to air, making lignite-based products notoriously difficult to handle and transport. The objectives of this project were to establish effective processes for granulation of brown coal at both laboratory and pilot scales, and a method for safely drying the granules using superheated steam.
The project showed that the granule strength was dependent on both the drying rate and the drying method used. Laboratory scale drying experiments showed that air drying produces stronger, less porous granules than steam drying. Steam dried granules had larger average pore size, greater pore volume and had more visible surface cracks than granules air-dried at the same temperature.
This project demonstrated the feasibility of producing new products from lignite using a combination of granulation and superheated steam drying. Preliminary products were produced, including granulated lignite and granulated lignite plus organic/inorganic fertiliser. Further work is needed to optimise these products through selection of efficient and cost-effective binder materials.
Coal-Derived Additives: A Green Option for Improving Soil Carbon; Soil Fertility and Agricultural Productivity?
Submitted by Monash University. Project participants include Clean Coal Victoria; International Power; LawrieCo; Exergen Pty Ltd and Environmental Clean Technologies
Humic substances, specifically humic acids and fulvic acids derived from low-rank coals, have been widely reported to have beneficial effects on soil health and plant growth. Increased plant growth, improved soil properties and enhanced microbial activity are thought to create conditions in which a higher equilibrium level of carbon is maintained in the soil. The addition of humic substances to crops has the potential to enhance CO2 capture from the atmosphere through the increased photosynthesis resulting from better plant growth conditions.
The objectives of this project were to:
characterise the humic substance content of a range of commercial products
assess the effects of humic substance products on agricultural plants in glasshouses
evaluate the impact of humic substance products on degraded soils
undertake field assessments of humic substance products on agricultural productivity and soil carbon.
A number of laboratory and field studies were conducted on commercial humic substance products and as-mined Victorian lignite, based on standardised levels of humic substance content. Despite a range of plant growth investigations covering pasture (ryegrass and mixed pasture) cereals (wheat) and vegetables (leeks), responses to humic substance were spasmodic and no clear trend emerged. Where lignite itself was applied, soil properties were improved and carbon level increases were observed. Some of these plant growth studies were conducted in the field on operating farms and results communicated to local farmers through public information sessions.
Evaluation of Vortex Drying Technology with Victorian Lignite
Submitted by Ahrko Holdings Pty Ltd with support from the University of Melbourne
The energy penalty and capital cost associated with drying Victorian lignite is a major impediment to more efficient power production using this resource. Ahrko has a proprietary vortex drying technology that it claims can dry lignite at ambient temperature by entrainment in a high-velocity stream of air.
The vortex drying technology is currently at the proof-of-concept stage. A commercial-scale demonstration rig has been installed at Stable Engineering in Morwell. The University of Melbourne is developing a CFD model of the vortex drying process, which will be validated by the experimental trials in this project. The outcome will be a design tool for use in scale-up of the vortex drying technology.
Performance Evaluation of the Counter Flow Multi Baffle Dryer with Victorian Lignite
Submitted by Monash University in association with the Korean Institute of Energy Research
Efficient coal drying is essential for most next-generation brown coal technologies, whether it be briquettes for export, ultra-supercritical boilers, pyrolysis or gasification. The Counter Flow Multi Baffle dryer (COMBdry) plant was developed by the Korean Institute of Energy Research and is located at the Dangjin power plant owned by the Korea East-West Power Company.
The COMBdry process is a very attractive new drying option, using low temperature waste flue gas (rather than high temperature steam) in an efficient countercurrent design. The project involved a researcher from Monash University participating in trials with Victorian lignite at the Dangjin plant to evaluate the drying capability of COMBdry.
This project provided valuable engineering performance data for COMBdry with Victorian lignite, and will be followed up by a similar trial on a 10-fold larger test facility when construction is completed.
2. CO2 Capture Technologies
Pre-Combustion Carbon Dioxide Capture Technologies for Lignite Power Generation
Submitted by CO2CRC in association with HRL Developments Pty Ltd and researchers at The University of Melbourne and Monash University
The project involved an evaluation of the performance of CO2CRCs pilot-scale potassium carbonate absorption process (UNO Mk 1) using syngas from an air-blown pilot-scale gasifier. The overall objectives of this project were to:
valuate solvent, adsorbent and membrane pre-combustion capture techniques
reduce the technical risk and cost of capturing CO₂ from pre-combustion sources
identify the most cost-effective technologies for deployment in Victoria.
One of the most important findings from this work was that sulfur and nitrogen impurities in the syngas interact with the potassium carbonate solvent, altering the CO₂ capture properties. These interactions were incorporated into a simulation model for use in process design and optimisation.
An economic evaluation found that the CO2CRC potassium carbonate solvent incurred a lower CO₂ capture cost than either physical adsorption or membrane separation.
Latrobe Valley Post-Combustion Capture (LVPCC) Project – CSIRO Stream
Submitted by Loy Yang Power Management Pty Ltd in conjunction with CSIRO
CSIRO installed and commissioned a pilot plant for capture of CO₂ from flue gas at Loy Yang A Power Station, the first of its kind in the southern hemisphere. The objectives of this project were to:
evaluate four new solvents
investigate the use of two separate absorber columns
validate a simulation model for the absorber
understand the degradation kinetics of MEA solvent
Each of the four solvents was able to capture 80-90% of the CO₂ from the flue gas. One of the amine blends required significantly less heat duty in the stripper reboiler, while maintaining good CO₂ sorption/desorption kinetics, translating to an overall lower energy penalty for CO₂ capture. This result demonstrates the value of fine-tuning the solvent composition to achieve optimal performance with minimum energy penalty.
Latrobe Valley Post-Combustion Capture (LVPCC) Project – CO2CRC H3 Stream
Submitted by Cooperative Research Centre for Greenhouse Gas Technologies
The CO2CRC led a post-combustion capture project at the GDF-SUEZ Hazelwood power station, representing a world first in demonstrating post-combustion capture using three different separation technologies (solvents, membranes and adsorption) in parallel in a real power plant setting. The objective of the project was to reduce the technical risk and cost of post-combustion capture for Victorian coal-fired power stations by:
testing solvent, adsorbent and membrane post-combustion capture techniques with real power plant flue gas
reducing the technical risk and cost of capturing CO2 from post-combustion sources
identifying the most cost-effective capture technologies for use in Victoria
providing large scale designs for all capture technologies and comparing their technical and economic performance.
CO2CRC's Solvent-Based Carbon Capture Technology in Brown Coal Fired Power Plants – (CSCCT-BCFPP) Capture Demonstration for Cost Reduction
Submitted by CO2CRC Limited in association with GDF SUEZ Australian Energy; CO2CRC partners and Process Group
The objective of this project was to demonstrate CO2CRC’s UNO MK 3 CO₂ capture concept at pilot scale and develop a comprehensive process model to facilitate further scale-up. The project involved a series of campaigns in which different process modifications were evaluated. These included performance evaluation of alternative absorber configurations (Sulzer structured packing, WES frother absorber column and the TurboScrubber® system), as well as different solvent formulations.
Outcomes of this project included a comprehensive model to facilitate scale-up, along with designs for full-scale equipment items including contactors, exchangers and solids removal devices, ready for commercial development. Updated modelling of the UNO MK 3 process retrofitted to a 500 MW brown-coal-fired power station showed that it should be more cost effective than amine solvents. A life cycle assessment showed that UNO MK 3 is more environmentally benign than amines.
Following this project, the CO2CRC licensed UNO MK 3 for commercialisation to a spin-off company, UNO Technology.
Development of Contactor Internals for Application of the WES Froth Generator Gas / Liquid Absorption Technology
Submitted by Process Group Ltd in association with Westec Environmental Solutions LLC
Westec Environmental Solutions (WES), a US company, has developed a novel froth generator absorber which is a more efficient mass transfer device than conventional column packings. The WES froth generator absorber could substantially reduce the size and cost of equipment needed for CO₂ capture.
The objective of this project was to translate the WES froth generator absorber concept from laboratory scale to pilot plant scale for CO₂ capture from power station flue gas. Experiments in similar sized columns were run in parallel at the WES facility at Maui, Hawaii, using a model air/CO₂ gas mixture, and in the CO2CRC pilot plant at the GDF Suez Hazelwood power station. The aim was to validate the results obtained at Maui with real flue gas, and to develop a CFD model that could be used for subsequent scale-up.
A small pilot-scale WES absorber was operated successfully as part of the CO2CRC trial program, with trials on both the CO2CRC potassium carbonate solvent and sodium glycinate. The results achieved were consistent with those obtained in the Maui laboratory. This confirmed that the WES absorber is more efficient than conventional structured packing, and can effectively halve the required length of absorber column.
In the absence of a suitable modelling tool, it was not possible to progress the project to a larger scale, as originally intended. The project was abandoned by mutual consent. WES will continue to develop a suitable process design methodology at the Maui facility.
Combined Low-Cost Pre-Treatment of Flue Gas and Capture of CO₂ from Lignite-Fired Power Stations Using a Novel Integrated Process Concept – COCAPCO
Submitted by Loy Yang Power Management Pty Ltd in association with TRUenergy and CSIRO Energy Technology
The objective of this project was to develop a new absorber system to allow effective simultaneous capture of SO₂ and CO₂. This was intended to allow post-combustion capture to be implemented effectively in Australia without the need for an expensive preliminary desulfurisation step.
The research was undertaken in two parallel streams. The first involved a collaboration between CSIRO and the European Union iCap project consortium , to test a process developed by TNO, dubbed ‘CASPER’, at the CSIRO post-combustion capture pilot plant at the AGL Loy Yang power station. The CASPER process involves continuous precipitation of SO₂ in the form of K₂SO₄ from a bleed stream off the main amine solvent loop.
The second stream involved pilot scale testing of a novel amine-based solvent developed by CSIRO and a novel post-combustion capture process configuration, dubbed ‘CS-CAP’. In this patented process, both CO₂ and SO₂ are removed using a single column and a single solvent. CO₂ is absorbed using the bulk of the solvent in the upper section of the column while SO₂ is absorbed in a fraction of the solvent in the lower section of the column. The concentrated SO2 stream can be recycled, while the bulk of the solvent remains SO₂ free.
Both the TNO CASPER process and the CSIRO CS-CAP process were able to capture over 90% of the CO₂ in the flue gas and all of the SO₂, irrespective of the concentration in the flue gas. A model for the sulfur chemistry as a function of SO₂, CO₂ and absorbent composition was validated. Both technologies were shown to have the potential to capture SO₂ and CO₂ simultaneously, eliminating the need for a separate flue gas desulfurisation step.
A techno-economic assessment suggested that the CASPER process should represent a cost saving of about $200m for a 500 MW plant fitted with amine-based post-combustion capture.
Evaluation of Advanced Post Combustion Capture Process and Equipment with Two Advanced Liquid Absorbents for Application in Victorian Brown Coal-Fired Power Stations
Submitted by Commonwealth Scientific and Industrial Research Organisation (CSIRO) in association with IHI Corporation, Japan and AGL Loy Yang Power Pty Ltd
This research project is a major collaboration between internationally renowned technology provider, IHI Corporation, and Australia’s world-class research organisation; CSIRO. The collaboration is a world-first evaluation of a technology provider-developed PCC process in flue gases from Victorian lignite-fired power.
This project entailed a two-year evaluation of two advanced liquid absorbents, two advanced process designs and an advanced gas/liquid contactor. The combination of these three aspects represents a significant step forward in post-combustion capture technology application for Victorian lignite-fired power stations. These improvements were expected to deliver almost a 40% reduction in the absorbent energy requirement of the pilot plant compared to a standard amine process.
IHI’s amine-based technology was evaluated through a parametric study to determine the minimum thermal energy requirement for liquid absorbent regeneration for the two selected absorbents and two process configurations. This was followed by a similar study of an advanced liquid absorbent developed by CSIRO. Each of these studies involved continuous operation for 5,000 hours to assess the performance and robustness of the two liquid absorbents under lignite flue gas conditions.
Successful completion of the project is expected to enable scale-up of the next technology phase; most likely a demonstration project at a scale of between 100 and 1,000 kton CO₂ per year.
Carbon Materials for CO₂ Capture
Submitted by Monash University in association with Australian Char Pty Ltd and the University of Melbourne
The aim of this project was to investigate whether cheap carbon derived from Victorian lignite can be used to adsorb carbon captured from coal and gas-fired electricity generation ready for storage.
Research efforts in this project were directed to production of mesoporous adsorbents from brown coal for CO₂ capture, using organometallic catalysts. Mesoporous carbons were prepared using steam activation catalysed by cerium, lanthanum and yttrium, and some were modified further by surface impregnation with polyethyleneimine. All of the resulting mesoporous carbons exhibited a higher CO₂ adsorption capacity than a leading commercial activated carbon.
This project produced promising results, although further work is needed to improve the CO₂ adsorption capacity and physical stability of mesoporous adsorbents derived from brown coal.
Evaluation of Carbon Monoliths for Capture of CO₂ by Electrical Swing Adsorption
Submitted by Monash University and the University of Melbourne, in collaboration with the international MATESA consortium
This project focused on the development of carbonaceous adsorbent monolithic solids that can be used to capture CO₂ in a process known as Electrical Swing Adsorption (ESA). With this approach, the monolith adsorbs or ‘grabs’ the CO₂ from the flue gas stream as it passes through. The monolith must be electrically conductive so that the CO₂ can be recovered (desorbed) in a concentrated form by applying electrical current. This work was conducted as part of the international MATESA consortium that involves collaboration by recognised experts from industry (both large and small), government laboratories and universities both in Europe and Australia (http://www.sintef.no/Projectweb/MATESA/).
In this project, a method was developed to prepare robust honeycomb monolith carbons from Victorian lignite. The products were mechanically strong, electrically conductive and had high surface areas. The materials have a multitude of potential applications in gas phase adsorption, liquid phase adsorption, catalysis, etc.
It was found that the honeycomb monolith carbons are good, selective CO₂ adsorbents in their own right. Efforts to improve the CO₂ adsorption capacity by adding a surface coating of a metal oxide framework or polyethyleneimine were technically successful but in each case the overall CO₂ adsorption capacity was decreased.
A process model for the electrical swing adsorption process was developed and validated using a commercial activated carbon monolith.
Dispersion Modelling for CO2 Pipelines: Fit for Purpose and Best Practice Techniques
Submitted by Sherpa Consulting with support from ENVIRON Australia and Hanna Consultants
This project was undertaken to inform the future development of CO₂ pipelines in Australia, as part of an integrated CO₂ capture and storage infrastructure. The aim of the project was to create a reference point for national and international best practice in modelling CO₂ emissions and dispersion, for use in pipeline route selection, risk management and emergency response planning.
A range of dense gas dispersion models were investigated, including empirical correlations, integral models, Lagrangian particle and plume dispersion models and computational fluid dynamics (CFD) models. Selected models were reviewed and evaluated against the various criteria to determine if they could be considered ‘fit for purpose’.
One of the main conclusions from this project was that sufficient information and modelling tools are available to allow a new CO₂ pipeline to be designed in accordance with Australian Standard 2885.
The project deliverable was a comprehensive report that provides guidance on the current international best practice in modelling CO₂ dispersion, and identifies appropriate, fit-for-purpose modelling tools that can be used at different stages in the pipeline design process. It can be accessed online HERE.
3. Low emissions power from lignite
Advanced Materials Assessment
Submitted by HRL Technology Pty Ltd in association with Monash University, with significant contributions from the main Latrobe Valley power generators: GDF SUEZ – Loy Yang B, GDF SUEZ – Hazelwood, AGL Loy Yang and Energy Australia Yallourn
Modern ultra-supercritical power stations use higher temperature boilers to deliver greater efficiency, and reduced greenhouse gas emissions. The higher temperatures require the use of different metal alloys from those currently used in Victoria. Local knowledge of how these alloys operate under the conditions that might exist in a new ultra-supercritical brown coal power stations is lacking, and this research program aimed to fill some of the gaps.
The project was undertaken in four strands, each addressing different aspects of the evaluation of advanced steel alloys:
Overall, this project delivered a number of significant benefits:
new oxide thickness measurement equipment and an improved protocol for interpreting apparent maximum metal temperature from measurements of oxide thickness
a technique to accelerate testing to determine the remaining creep life of high temperature components, with assessments available from around 1,000 hours of testing rather than from a year
improved assessment techniques to determine fitness for service of aged materials
data to suggest that flux-core welding could be a suitable alternative to conventional manual metal arc welding in some instances, although further evaluation is required
more information on the risks of weld cracking in CMV steel (widely used in the Latrobe Valley) as components exceed 200,000 hours of service, and of appropriate methods to manage risk
an opportunity for Latrobe Valley power generators to discuss problems and share technical information.
This project contributed significantly to the professional development of young engineers associated with the Latrobe Valley power industry. Three graduate engineers were directly involved for a large proportion of their time, and one transferred from a Master of Engineering Science to a Doctor of Philosophy to undertake research on oxidation.
Laser Based O₂ and CO Monitoring
Submitted by HRL Technology Pty Ltd with support from EnergyAustralia, Siemens Ltd, AGL Loy Yang Pty Ltd, GDF SUEZ Australian Energy, Macquarie Generation, Intergen – MOC, Origin Eraring, CS Energy, Alinta Energy and a number of other Australian power industry participants
Improvements in on-line monitoring of power station outputs, such as monitoring the composition of the flue gas, can enable better control of boiler operation. This in turn can deliver reductions in CO₂ emissions and lower cost of operations. A challenge for Australian coal-fired power stations has been the accurate monitoring of oxygen and carbon monoxide – currently used gas probes monitor only at a single point, and so give only part of the picture.
Laser instrumentation is not currently used in Australian coal-fired power stations. It is too expensive to purchase, install and calibrate a laser analyser for an equipment trial at an individual power station, particularly when the effectiveness of the instrument is unknown. Accordingly, the BCIA-funded project was undertaken as a collaboration between both brown- and black-coal-fired power stations, so that the project outcomes could be available to power stations across Australia.
This project involved long-term trials of two Siemens SITRANS-SL Tuneable Laser Diode Spectroscopy (TLDS) gas analysers, one measuring O₂ and one measuring CO. Each instrument included a laser transmitter and receiver, located on opposite sides of the gas duct, allowing measurement of the average gas concentration along the path of the laser beam.
HRL Technology concluded that the Siemens SITRANS-SL laser gas analyser is robust enough to withstand the heat and vibration in a power station, and has the potential to provide more accurate and reliable concentration measurements than the O₂ and CO instruments currently in use.
The CO laser can be purged using compressed air, which is readily available, and can be used to trim the excess air and make substantial reductions in power requirements and greenhouse gas emissions. The project concluded that the revenue raised from increased power sales would justify the purchase price of the CO monitor.
Use of the laser O₂ monitor for boiler control would deliver more accurate results than current O₂ probes, but requires installation of an on-site nitrogen generator to produce the necessary purge gas for accurate results.
Oxy-Fuel Combustion of Victorian Lignite
Submitted by Monash University in association with HRL Technology Pty Ltd
Oxy-fuel combustion is a promising new technology that could enable efficient production of power from Victorian brown coal with little to no greenhouse gas emissions. Indeed, the research and modelling to date shows that oxy-fuel combustion, in combination with CO₂ storage, could deliver power with near-zero emissions at almost zero net efficiency penalty compared to today’s Victorian brown coal plants.
In this project, Monash University and HRL Technology conducted two separate but similar studies in collaboration with local power generators. One study examined the feasibility of retrofitting oxy-fuel combustion and CO₂ capture to Unit 7 at International Power Hazelwood, while the other focussed on Unit B at Loy Yang International Power.
Both studies suggested that oxy-fuel combustion could be cost-competitive with post-combustion CO₂ capture for producing low-emissions power, especially when waste heat is efficiently used. The single largest barrier to cost-effective implementation of oxy-fuel combustion is the large energy penalty associated with producing the huge volumes of pure oxygen required. The conclusion was that further work to develop oxy-fuel combustion technology for deployment in Victoria is justified.
Pilot-Scale Oxy-Fuel Combustion of Victorian Lignite
Submitted by Monash University; project participants include Shanghai Boiler Works Limited, Chubu University, Shanghai Jiao Tong University, GDF SUEZ Australian Energy, International Power Loy Yang B, TRUenergy
Following the positive outcomes from the techno-economic evaluations, BCIA supported a second oxy-fuel combustion project, completed in March 2014, with funding from ANLEC R&D. The objective of this project was to investigate oxy-fuel combustion at pilot-scale and develop a computational fluid dynamics (CFD) model for the process. These CFD models are vital to understanding the challenges and opportunities in scale-up of such technologies.
As suitable pilot-scale facilities do not exist in Australia, the trials were conducted using a 3MWth oxy-fired boiler at Shanghai Boiler Works Ltd (SBWL) in Shanghai, China. SBWL is the second-largest boiler manufacturer in China, and has already commercialised oxy-fuel boilers for black coal. The project also involved two local power companies (Energy Australia and GDF SUEZ Australian Energy) and universities in China and Japan.
A series of trials at the 3MWth oxy-fired boiler established the feasibility of oxy-fuel combustion of Victorian lignite that had been dried to moisture contents ranging from 12% to 40%. The research established a range of outcomes including the stable and faster combustion of Victorian lignite under oxy-fuel conditions, production of high purity CO₂ (up to 80 per cent) in flue gases, and led to a greater understanding of the distinct slagging/fouling propensities of Victorian lignite in oxy-fuel mode.
The knowledge gained at both laboratory and pilot scales was used to develop and validate new CFD modelling codes to account for: the radiation properties of CO₂ and steam; the higher char-CO2 and char-steam reactivity of Victorian lignite; and the reaction rates for volatiles under oxy-firing conditions. Monash University has licensed these codes to Shanghai Boiler Works Co Ltd for application in commercial design of oxy-fuel boilers.
Accelerating the Deployment of Oxy-Fuel Combustion Technology for Victorian Lignite
Submitted by Department of Chemical Engineering, Monash University. Project participants include Shanghai Boiler Works; Energy Australia; GDF Suez Australian Energy; Chubu University, Japan and Shanghai Jiao Tong University (University of Electric Power), China
This project investigated the ash fouling and water tube corrosion that occur under optimised oxy-firing conditions. Understanding the lignite-specific factors that control fouling and corrosion is essential for commercial boiler design.
The focus of the project was on oxy-fuel combustion of dried Victorian lignite under supercritical and ultra-supercritical conditions. The project involved long-term ash exposure experiments in the 3 MWth SBWL boiler, and the development of advanced modelling tools for the prediction of lignite ash slagging/fouling and water tube corrosion propensities in an industrial oxy-fired boiler.
The project established that water tube corrosion is always enhanced under oxy-fuel conditions, irrespective of the tube material and fly ash type. The extent of corrosion can be reduced by adding clay to the lignite during combustion. Detailed mapping of the elemental composition within the corrosion layer led to the identification of advanced steel alloys that are suitable for construction of water tubes for oxy-fired boilers using Victorian brown coal. A CFD model was developed for predicting the composition of flue gas, ash and slag within a boiler under oxy-firing conditions.
Read project funding article…
Development of Chemical Looping Process for Fuels Production and CO₂ Capture from Victorian Lignites
Submitted by Monash University in association with TRUenergy; CSIRO Process Science and Engineering and leading European universities engaged in chemical looping research – Chalmers University of Technology Gothenburg, Sweden and Technical University of Darmstadt, Germany
Chemical looping combustion (CLC) is an emerging technology to facilitate capture of CO₂ at a lower energy and cost penalty. In CLC, the oxygen for combustion of the fuel is provided by a recyclable metal oxide as oxygen carrier instead of using gaseous oxygen. Direct contact between air and the lignite is avoided, creating a flue gas that is rich in CO₂. By condensing the associated water vapour, the CO₂ can be recovered in pure form ready for compression and transport for geological sequestration.
Chemical looping has been widely studied for the combustion of natural gas but research into its application for solid fuels commenced only in recent years. Victorian brown coal is low in slag-forming ash and thus should be suitable for use in a fluidised bed combustion system. However, the performance characteristics of Victorian lignite in a chemical looping system are unknown.
The objective of this project was to generate new and critical technical information relating to the effect of the unique properties of Victorian lignite (low ash, high reactivity, inherent minerals) on the CLC process, including:
stability of the oxygen carrier
ash mineral and oxygen carrier interactions
kinetic modelling for process optimisation
The CLC process was investigated though fundamental studies using thermogravimetric analysis and a custom-built 500 Wth bench scale chemical looping rig. This work was supported by the technical expertise in CLC technology of the international project participants, Chalmers University of Technology and Technical University of Darmstadt.
The project systematically assessed various oxygen carriers for use with Victorian and international lignite samples and found that the high reactivity and high oxygen content of Victorian lignite is particularly suited to CLC. The low ash content minimises the potential for deactivation of the oxygen carrier.
A new laboratory-scale 10 kWth fluidised bed reactor was designed and constructed in the Department of Chemical Engineering at Monash University. Carbon conversion efficiencies of greater than 92% were achieved in this reactor, producing flue gas containing more than 82% CO₂. Efficiencies improved with increasing scale, so better results may be expected at pilot scale.
Advanced Chemical Looping Combustion Technology for Victorian Lignite
Submitted by Monash University in association with Commonwealth Scientific and Industrial Research Organisation (CSIRO); Alstom Boiler, France; Energy Australia; VITO, Belgium (oxygen carrier manufacturer); and Lycopodium Process Industries Australia (engineering consultancy); Southeast University, China and University of Alberta, Canada
This project extended the previous CLC research through bench-scale research and experiments using a Victorian purpose-built, compact fully looped and continuously fed reactor system. The research objectives of the project were to examine the feasibility of the CLC process in the continuously looping reactor, establish the techno-economics of a commercial scale lignite CLC and develop a detailed process model for a commercial scale CLC plant.
The project established that Victorian lignite is an ideal fuel for CLC in combination with abundant, low-cost ore such as ilmenite as an oxygen carrier. The high reactivity and low ash content of Victorian lignite makes it eminently suitable for CLC and is key for the technical and economic feasibility of the process.
A techno-economic study of a 550 MWe CLC plant using Victorian lignite was completed. The HHV, net efficiency was estimated as 35%, including the energy required for CO₂ compression. The total plant cost was estimated as A$4,200 per net kW. At a capacity factor of 85%, the levelised cost of electricity (LCOE) was estimated as approximately $150/MWh. This is similar to the estimated 2020 LCOE for supercritical pulverised coal combustion of Victorian brown coal (with CCS) reported in the Australian Energy Technology Assessment 2012.
High Efficiency Power from Victorian Lignite
Submitted by CSIRO Advanced Coal Technology, in association with Exergen Pty Ltd and Ignite Energy Resources Pty Ltd
The direct injection carbon engine (DICE) uses a mixture of refined and micronised coal suspended in water as a fuel for stationary diesel engines, which can be used to generate electricity. Victorian lignite has the potential to make an excellent fuel for DICE engines, as it has low mineral content, high moisture and high reactivity.
Counterintuitively, a diesel engine operated on a coal-water fuel is inherently more energy-efficient and has far lower capital cost than a conventional coal-fired boiler. CSIRO has calculated that micronised and refined coal water fuel (micronised refined carbon (MRC)) produced from processed Victorian lignite should be capable of fuel cycle efficiencies of 48-50%, producing greenhouse gas emissions of less than 700kg CO₂/MWh.
This project involved fundamental studies to establish methodology for producing high quality MRC fuel from Victorian lignite and evaluate its likely performance in a diesel engine. The project involved a series of theoretical and laboratory-scale investigations to:
establish the procedures required to manufacture a stable, high quality MRC fuel from Victorian lignite
evaluate the atomisation and combustion performance of the MRC fuel
investigate the likely effects of coal ash on engine components
develop a business case to attract the interest of a major diesel engine manufacturer
This project demonstrated that high quality MRC fuels can successfully be produced from Victorian lignite and upgraded lignite products, and that these fuels can successfully be atomised and combusted at bench scale in CSIRO’s high efficiency coal test apparatus. Wear studies were conducted with the resulting ash, indicating that lignite ash appears to be generally less abrasive than ash from bituminous coal.
A key achievement of the project was a techno-economic model for the DICE technology, which included mass and energy flow models for the entire fuel cycle, as well as likely capital and operating costs. The modelling suggested that it should be possible to achieve a fuel cycle efficiency of 48%, including the process energy penalty associated with hydrothermal treatment of the lignite. The capital cost for DICE is likely to be $1,200-2,000/kW, which is about half the anticipated cost of supercritical pf plants. Added advantages of DICE are that it can be installed progressively as discrete power modules, spreading the load of the capital investment, and that it is a complementary generation partner for load variable and distributed renewable energy sources.
Victorian Direct Injection Carbon Engine (DICE) Development – Derisking and Small Scale Development
Submitted by CSIRO Energy Technology. Project participants include MAN Diesel & Turbo Australia Pty Ltd, Exergen Pty Ltd, Ignite Energy Resources Pty Ltd, AGL Loy Yang Pty Ltd and Energy Australia
This project formed part of a national collaboration between bituminous coal and lignite industry groups and a major international diesel engine manufacturer, MAN Diesel & Turbo. The aim of the project was to undertake demonstration-scale proof-of-concept trials using a test engine in Japan. The broad objectives of the national program were to:
Undertake proof-of-concept trials of both lignite and bituminous coal MRC fuels in a test engine in Japan.
Create sufficient data to allow an engine manufacturer to implement a development program.
Define the specification parameters and initial acceptable ranges for both lignite- and bituminous-coal-derived MRC fuels.
Undertake sufficient tests to confirm (or otherwise) that risks associated with the supply and combustion of MRC fuel in a contemporary low- or medium-speed diesel engine are acceptably low.
In the course of the project, it was found that high quality MRC fuels could be produced from both lignite and bituminous coal. However, the main limiting factor proved to be the abrasion resistance of the fuel injector for the engine. It became clear that a separate research program would be required to identify suitably hardened materials for the injector nozzle, and that this was beyond the scope and budget of the present project. The project was terminated because the risks involved in progressing to a test engine trial were unacceptable.
Feasibility Study for Direct Carbon Fuel Cell Operation on Victorian Brown Coal
Submitted by CSIRO
The direct carbon fuel cell (DCFC) is an emerging technology that has the potential to increase the efficiency of power generation from lignite to 65-70%. This is higher than any other carbon fuel technology, and would lead to a significant reduction in the production of CO₂ per MW of electricity generated. DCFCs achieve such high efficiency by directly converting solid high-carbon fuels (such as lignite and biomass) into electricity through electrochemical oxidation.
The main objective of this project was to determine the best way to use lignite in DCFC, taking into account the presence of ash-forming impurities, and to explore critical steps such as continuous feeding of the fuel. The project was predominantly a desk-top study, supplemented by limited experimental work using CSIRO’s lab-scale electrolyte-supported tubular DCFC. This was intended to assist in prioritising future research needs.
It was found that anode materials were degraded through reaction with coal minerals. The cell design was changed to avoid this problem, resulting in an increase in performance of over 40%. Lignites from the Morwell and Yallourn regions present the most attractive options for DCFCs, due to the presence of a number of beneficial elements, such as iron and calcium.
Overall this study found that Victorian lignite is an attractive feedstock for fuel cells. The results are being used to guide the further development of direct carbon fuel cell technology at CSIRO.