Earlier this month the IEA Clean Coal Centre welcomed around 230 delegates from around the world to Houston, Texas for our 9th International Conference on Clean Coal Technologies, or ‘CCT’. Traditionally held in Europe, this flagship event for the Centre made the journey across the pond for the first time at the invitation of the US Department of Energy’s (DOE) Office for Fossil Energy, who we were pleased to have as co-hosts.
As a city steeped in oil, Houston is not usually associated with the coal industry, though it is an oft-forgotten fact that Texas consumes more coal than any other US state. More importantly, the city offered an unrivalled opportunity for delegates to visit two world-renowned sites for carbon capture and storage (CCS) technology: the Petra Nova project, which is the largest demonstration of CCS on a coal plant, and NET Power’s large-scale test facility for the innovative ‘Allam Cycle’ – a new process with the potential to dramatically cut the cost of carbon capture.
The conference kicked-off appropriately with a keynote from our co-hosts, as Deputy Assistant Secretary Lou Hrkman of the US DOE detailed the government’s current strategy and research priorities for coal and CCS. The US has long been at the forefront of developing CCS, generously funding large-scale projects such as Petra Nova as well as emerging technologies, and the research programme continues to target a cost of $30/t for CO2 capture (compared to an estimated $60/t today).
New to this administration is the ‘Coal FIRST’ initiative, standing for ‘flexible, innovative, resilient, small, transformative’, which calls for an ambitious conceptual shift for coal plants towards smaller generating units which can rapidly respond to changing demand and are designed to be integrated with CCS.
Following this opening address, we heard from key representatives of the other two titans of the global coal industry – China and India. China Energy was formed last year from a merger between the state-owned energy companies Shenhua and Guodian, leaving it the largest power company in the world by generating capacity, of which 74% is coal. Vice President Mr Mi outlined the energy giant’s wide-ranging efforts in cleaning up its vast coal mining, power generation, and coal-to-liquids activities, including world-leading innovation in coal-to-hydrogen, coal syngas-fired fuel cells, and construction of a large CCS test project at Jinjie power plant. Mr Gopalakrishnan from India’s National Thermal Power Corporation (NTPC) described the country’s trend towards greater renewables deployment and steady modernisation of its coal fleet with higher-efficiency plant, treading a similar path to the one taken by China over the last two decades, but with the added challenge of India’s problematic high-ash coals.
CCT has three streams for break-out sessions, broadly divided into new power plant technologies, CCS, and other issues such as alternative uses for coal, coal waste, and CO2. Innovation in power plant design and optimisation came to the fore on day 1, with presentations on upgrading existing plant from major players such as Shenergy Power Technology (China), Mitsubishi Hitachi Power Systems (Japan), and Tata Consultancy Services (India). As in other areas of society, big data, digitalisation, and artificial intelligence have become central to the tricky balancing act required to achieve high efficiency and low emissions from coal plants. MHPS outlined how they exploit their substantial experience with plant operation to rationalise the vast variable space in boiler optimisation, as well as their vision for remote tuning of power plants from monitoring centres around the world. Shenergy’s potentially ground-breaking idea for improving the efficiency of existing, low-efficiency power plants is to increase the main steam temperature to as high as 600°C while retaining as much of the existing heat transfer surface as possible. This is currently being put into action at Xuzhou power plant, where the aim is to increase the efficiency of a 320 MW subcritical unit to at least 42.8% – above that of even some ultrasupercritical units.
For new coal power plants, the holy grail of higher efficiency has long been to increase steam temperatures to over 700°C using advanced nickel-based alloys. The Electric Power Research Institute (EPRI) provided an update on a US-based consortium’s efforts in this direction, where the current focus is on developing a supply chain to manufacture full-scale nickel components such as turbine rotors, steam headers, and piping. BHEL expanded on the Indian programme earlier introduced in NTPC’s keynote address, which began only in 2017, but is no less ambitious than the US initiative. An extensive programme of large-scale component manufacturing and testing in power plant steam loops is scheduled to conclude later this year, to be followed by the construction of an 800 MW demonstration plant if all goes well.
The focus of day 2 spotlight sessions was very much on CCS, and the tone was set early on by a keynote from Petra Nova’s project manager Greg Kennedy. Operating on a 640 MW coal unit at the WA Parish power plant, this pioneering project was the second CCS demonstration on coal power in the world when it opened in January in 2017, and remains the largest. Using MHI’s solvent-based CO2 capture technology, over a third (240 MW equivalent) of the unit’s flue gas is treated and the resulting pure CO2 sent to a nearby oil field for enhancing oil recovery. An informative overview highlighted the many unique challenges encountered with first-of-a-kind projects such as this, the strong impact of commodity prices on project economics, and NRG’s supportive stance on CCS-driving policy developments such as the 45Q tax credit, but a cautious approach to potential future projects. Later in the day we heard about MHI’s new and improved CO2 capture technology which can reduce capital costs by 30%, through advances such as reduced equipment size, less conservative design margins, and a more compact, modular design. Lower operating costs are also derived from the newly developed ‘KS-21’ amine-based solvent, whose significantly higher thermal stability helps reduce consumption rates and allows regeneration at higher pressures, thus minimising the cost of CO2 compression. In a similar vein were a couple of presentations from the International CCS Knowledge Centre, a Saskatchewan-based group which harnesses expertise from the Boundary Dam CCS project – the first full-scale demonstration on a coal plant. While one presentation reviewed the ongoing operations at Boundary Dam, where Shell Cansolv capture technology is used, the second detailed the findings of the Centre’s recent assessment of retrofitting CCS to a larger, newer plant in the same province, this time using the MHI process. Again, the potential for major cost reductions (to $45/t of CO2) compared to the demonstration plant were highlighted, mostly derived from lessons learned from Boundary Dam, large-scale, modular construction and better opportunities for integrating the power plant and capture plant.
The US is a Mecca for carbon capture research, and alongside these large-scale projects are a number of smaller, but still significant pilot-scale facilities, including the National Carbon Capture Center in Alabama, the University of North Dakota’s Energy and Environmental Research Center, and the University of Wyoming’s new Integrated Test Facility at Dry Fork power plant, all of which presented their recent projects.
These medium-sized test facilities for post-combustion capture on real coal flue gases play a crucial role in scaling up new technologies from the laboratory to full-scale power plant applications. However, research funding can only go part of the way to driving CCS deployment, and bankable policy incentives for storing CO2 are needed to make the technology truly commercial. The expansion of the 45Q tax credit in the US last year, which rewards projects for each tonne of CO2 stored, has therefore caused much buzz within the industry, and was the main focus of our plenary panel session with experts from Peabody, the DOE, Occidental Petroleum, and the Carbon Utilization Research Council. There is now real optimism for new large-scale CCS deployment in the US, mostly driven by EOR operators such as Occidental, and much of it directed at sources other than power plants, but many other projects seem to be waiting for details of the new credit to be finalised by the Internal Revenue Service. Illustrating the effect of the new policy landscape, ION Engineering had earlier presented a plan to scale up their innovative low-water-content solvent to a 700 MW coal unit in Nebraska, currently completing a pre-FEED stage and factoring in the new credits as an essential component of the business plan. On the other hand, the timescale to receive the incentive is tight (construction must start by 2024), and seems to have contributed to NRG’s reticence in launching another Petra Nova.
The aim of day 3 of the conference was to look to the future for the coal sector, featuring a panel session with R&D programme leaders from around the world plotting a course for coal research to 2050. Other sessions looked at entirely new power plant concepts, such as the use of supercritical CO2 turbines in place of steam, and beyond technology to the over-riding challenge of social acceptance.
The day was launched by an engaging address from Dave Begley, managing director for steam power in the Americas for GE, who are now a dominant force in global coal plant manufacturing and active promoters of state-of-the-art high-efficiency coal plant. Despite many negative outlooks for the coal sector, GE are confident that consumption will continue to grow, and will still represent 37% of global power generation in 2029.
Like MHPS and others, GE have embraced digitalisation of its plants, promising at least a 1.5% increase in efficiency through real-time monitoring and optimisation, as well as higher availability and extended lifetime through intelligent maintenance.
The conference closed with some perspectives of coal’s place in the global energy sector from two leading experts in the field, Ken Medlock of Houston’s Baker Institute for Public Policy, and Barry Worthington of the US Energy Association – an organisation which also played a vital support role in the smooth running of the event.
The central message of these talks echoed GE’s assertion that reports of coal’s impending demise have been exaggerated, with its market share of primary energy demand remaining constant over the last three decades. Yet it is clear that coal’s role in the energy mix will become increasingly fragile unless the industry can embrace the suite of technologies now available to minimise its environmental impact.
I’ve only been able to give a snapshot of all the great research covered at CCT this year, as there is far too much to cover in one blog. Further reports from my colleagues should cover some of the other session themes, many of which were new to the conference and generated considerable interest, such as alternative uses of coal, water consumption issues, and CO2 utilisation. Delegates are able to access all the presentation slides from the programme page of the conference website, and these will be made generally available in six months. We look forward to another great conference in 2021.
