|An update on brown coal projects |
|By Dr David McManus, Research Investment Manager, BCIA|
|One of BCIA’s objectives in developing its research portfolio is to cultivate significant international collaborations that will create new opportunities for Victoria’s massive brown coal resource. This is exemplified by the projects currently being funded by BCIA, in the areas of efficient brown coal combustion and reduced cost carbon capture.|
Given the urgent need to rapidly reduce global greenhouse gas emissions, coal-fired power generation must be coupled with carbon capture and storage (CCS) technologies to remain relevant. To facilitate this, the current round of BCIA-funded power generation projects are targeted at (a) achieving higher efficiency power generation, to reduce the quantity of CO₂ produced; (b) reducing the cost of post-combustion carbon capture (PCC); and (c) combustion in oxygen rather than air, to produce a concentrated stream of CO₂ and eliminate the need for PCC equipment altogether.
In each of these areas, BCIA-funded projects are leveraging local expertise with the involvement of major international companies, to maximise the prospect of rapid commercial outcomes that will be of benefit in Victoria.
|Higher efficiency power generation|
|The ‘Victorian DICE Development’ project, led by CSIRO in Newcastle, aims to demonstrate that a 50:50 mixture of brown coal in water can be successfully used as a fuel in a large, two-stroke diesel test engine in Japan. Previous BCIA-funded research by CSIRO established the feasibility of this concept at laboratory scale, which attracted the commercial interest of MAN Diesel & Turbo SE, the world’s leading provider of large-bore diesel engines and turbomachinery for marine and stationary applications.|
MAN Diesel & Turbo is based in Augsburg, Germany, while its two-stroke engines are developed in Copenhagen, Denmark. These engines, ranging in capacity from 2MW to 87MW, are manufactured by international licensees for use in large container vessels, freighters and oil tankers.
MAN Diesel & Turbo is providing the technical expertise needed to develop new engine components capable of handling abrasive coal-based fuels. A successful outcome for the ‘Victorian DICE Development’ project will open a pathway to a new type of coal-fired power generation, with the potential for the efficient, flexible operation needed for integration with intermittent renewable energy sources.
|Reduced cost of PCC|
The ‘Evaluation of advanced PCC with two advanced liquid absorbents’ project is led by CSIRO in Newcastle. CSIRO is the lead developer of advanced PCC technologies in Australia, and for this project has partnered with IHI Corporation, of Japan.
|IHI Corporation is one of the major international manufacturers of coal-fired boilers, and has supplied 15 boilers for coal-fired power plants in Australia. IHI is actively developing two types of clean coal technologies, i.e. oxyfuel combustion and PCC to reduce the greenhouse gas emissions from coal-fired power. IHI Corporation was a partner in the demonstration of oxyfuel combustion technology at the Callide Oxyfuel Project, which was successfully completed in March 2015. IHI Corporation is now accelerating its efforts with PCC, and has developed a new liquid absorbent, an advanced packing system and an advanced PCC process.|
IHI Corporation, with technical support from CSIRO, has designed and constructed a new PCC pilot plant which is now successfully operating at the AGL Loy Yang power station. The PICA (derived from first letters of PCC, IHI, CSIRO, AGL) research plant is 21 metres high and is capable of operating around the clock, capturing 150 to 200 tonnes of CO₂ each year. Throughout the two-year program, researchers will study the energy efficiency of various CO₂ capture configurations and the effectiveness of two new CO₂ capture solvents.
This research program is targeting a 40 per cent reduction in the energy required for CO₂ capture, representing a substantial step toward the commercial implementation of PCC. IHI Corporation’s Executive Officer, Vice President of Energy and Plant Operations, Mr Yahagi has said, “Without doubt, this PICA project will be a great catalyst for the future of low-emissions technologies in both the Australian and Japanese coal and energy industries.”
Looking further into the future, BCIA is also funding a project that is being run jointly by Monash University and the University of Melbourne. This project, called “Development of carbon monoliths for capture of CO₂ by electrical swing absorption”, is an international collaboration involving five universities, two R&D institutes, three small to medium sized enterprises (SMEs) and two large industries.
The aim of this collaboration is to develop an innovative post-combustion capture technique called Electric Swing Adsorption (ESA), by using hybrid honeycomb monoliths to selectively remove CO₂ from flue gas streams. The hybrid honeycombs will be manufactured by combining an electrically conductive matrix with a surface coating of CO₂ adsorbent material. An electrical current and waste heat will be used to regenerate the adsorbent, releasing the CO₂ at high purity.
In this project, researchers at Monash University and the University of Melbourne are working in collaboration with two major European companies, Linde Engineering and Corning SAS. Linde Engineering is a world leader in cryogenic technology, with expertise in CO₂ purification and liquefaction. Corning SAS has expertise in fabrication of complex cellular ceramic substrates and particulate filters that form the core of pollution control systems used worldwide in cars, trucks, construction equipment and power plants. The project also involves Biokol KB, a Swedish company, with expertise in fabricating porous carbon-based materials.
Researchers at Monash University and the University of Melbourne are leveraging the expertise of these project partners to fabricate an electrically-conductive honeycomb material from Victorian brown coal, coat it with a polymer that can selectively adsorb CO₂, demonstrate the use of this material in an innovative ESA process, and develop a process model to aid in system design. If successful, this work will pave the way for a new generation of cost-effective CO₂ capture technologies.
|Combustion in oxygen to produce concentrated CO₂|
|The "Accelerating the deployment of oxyfuel combustion technology project", led by Monash University, involves a close collaboration with Shanghai Boiler Works Limited (SBWL), the largest boiler manufacturer in China. SBWL has established expertise in ultra-supercritical combustion boilers and integrated gasification combined cycle (IGCC), and is collaborating with Monash University to develop oxyfuel combustion technology. |
In oxyfuel combustion, coal is burned in pure oxygen instead of air. Separating the nitrogen from the air before combustion creates a flue gas that is highly concentrated in CO₂. This facilitates capture of the CO₂ without the need for expensive PCC equipment. A previous BCIA-funded project established the feasibility of oxyfuel combustion of brown coal at pilot scale in Shanghai. The current project extends this work to provide a detailed understanding of ash deposition and slag-forming behaviour, and is helping to identify appropriate steel alloys to withstand corrosion by the ash.
This project could not proceed without a significant investment by SBWL in modifying its 3MW pilot boiler. Monash University has licensed its detailed process modelling codes to SBWL for use in commercial boiler design. SBWL is using the knowledge gained through this collaboration to progressively scale up oxyfuel combustion as a commercial process, through retrofit of a 30MW steam boiler in Xinjiang Province, to be followed by a new design 300MW oxyfuel power plant in Shanxi Province. SBWL has already completed a techno-economic study for an oxyfuel power station in the Latrobe Valley, demonstrating the feasibility of the technology produced through this collaboration to reduce the greenhouse gas footprint of power generation in Victoria.
The main disadvantage of oxyfuel combustion is the need for an expensive air separation unit (ASU) to produce a stream of pure oxygen for burning coal. Exciting new developments are emerging in improved ASU design, which are likely to substantially reduce costs. In the meantime, BCIA has supported the development of an alternative oxyfuel combustion process, known as chemical looping combustion (CLC).
The "Advancing Chemical Looping Combustion Technology" project, led by Monash University, builds upon an earlier project which established that Victorian brown coal is an excellent fuel for use with CLC. The current project involves scaling up the CLC process using a custom-built continuous-flow reactor at CSIRO in Clayton, which is described by Seng Lim in an article on page 2 of this newsletter. The project has attracted the interest of GE-Alstom of France, a major international power generation technology provider.
GE-Alstom believes that CLC represents the lowest cost option for coal power generation with CCS, and is working to develop two different CLC technologies. In Europe, research is focused on developing metal-oxide based CLC, while limestone-based CLC is being developed in the USA.
The current BCIA funded CLC project involves the use of metal oxides as a carrier of oxygen for combustion of Victorian brown coal, with the metallic oxygen carrier being continually regenerated in an air-blown reactor. This process allows the combustion of brown coal with pure oxygen, without the need for an expensive ASU. GE-Alstom is providing technical and commercial expertise in the development of an appropriate techno-economic model for CLC. This will enable the publication of the first credible techno-economic assessment of metal-oxide based CLC in the public domain.
|BCIA research collaborations involve major technology providers from Europe, Japan and China, and aim to cost-effectively capture the CO₂ produced from brown coal-fired power stations in Victoria. The Andrews Labor government has recently pledged to eliminate greenhouse gas emissions from power generation in Victoria by 2050. The only practical way to achieve this is to develop new coal-fired power technologies with affordable CO₂ capture. By leveraging local expertise with the active involvement of major international companies, BCIA is laying the necessary groundwork for this goal to be achieved.|