Last week I was in Spain for the 3rd Oxyfuel Combustion Conference to be organised by our sister organisation IEA GHG, researching for a forthcoming Clean Coal Centre report on this increasingly important carbon capture technology. The event was held in Ponferrada and hosted by the ‘Ciudad de la Energia’ (CIUDEN) research institute which operates a pioneering oxyfuel pilot project close to the town. The surrounding El Bierzo region in Spain’s North-West is rich in mining history dating from Roman times up to early coal mining activity which continues to this day. Testament to this history is Spain’s first ever coal power plant, found on the edge of Ponferrada, which in its new guise as a museum to thermal power provided a fitting venue for the opening event of the conference.
The keynote speeches and plenary sessions, held at the imposing Bergidum theatre in the town centre, focussed on the oxyfuel pilots currently operating and some of the larger demonstrations projects that may be close to realisation. A particular emphasis was naturally placed on the nearby CIUDEN facility, which features a 20 MWt PC boiler and a 30 MWt circulating fluidised bed boiler demonstrating Foster Wheeler ‘Flexiburn’ technology which is the largest of its kind. The ambitious plan for scale-up of this oxyCFB pilot to a 300 MW supercritical demonstration plant, outlined in detail by Endesa, is currently awaiting an investment decision from the EU and Spain. Closer to realisation is the Futuregen 2 project in the USA, a 168 MW oxyfuel retrofit of an existing boiler at Meredosia power plant which has already received funding from the US government and other backers, as well as winning public approval for the transport and storage of the CO2 in a nearby saline aquifer. This project, which is designed to achieve around 22% efficiency (higher heating value) looks set to become the world’s first oxyfuel demonstration plant upon commissioning scheduled for 2017. Results from other important pilots were also presented, including the Callide 30 MWe PC project in Australia, which is currently the world’s largest and the first to generate electricity for the grid. A keynote speech from Huazhong University provided an enlightening perspective on the rapid growth in carbon capture research in China, where a 35 MWt oxyfuel pilot is scheduled to be commissioned this year, and a demonstration plant proposed for 2018.
A wide array of conference technical sessions took place over three days in the atmospheric setting of the 12th century Templar castle at the heart of Ponferrada. The topics covered ranged from more detailed pilot results to fundamental research into rates of combustion, changes to emissions, and corrosion mechanisms under oxyfuel conditions. Also featuring heavily were the gas separation and purification technologies at the heart of the oxyfuel process; both the air separation unit for production of oxygen and compression and purification unit (CPU) for purification of emitted CO2 have undergone development by a number leading gas companies in an effort to reduce the significant energy penalty they impose. The design of the CPU in particular presents the challenge of removing the host of coal-derived and other impurities which remain in the flue gas even after scrubbing, but also the attractive possibility of incorporating these treatments into a single unit, producing liquid streams of acid as the gas is compressed and water condensed out. A look to the further future was provided by presentations on the next generation oxyfuel techniques such as chemical and carbonate looping, the use of ion transport membranes for oxygen production, pressurised and low temperature oxyfuel combustion, and integration of plant processes based on exergy analysis.
The closing session gave a platform to some leading figures in the field to speculate on the future of oxyfuel combustion, and whether it can make the step up to commercial reality in the next decade. The general consensus here echoed one heard throughout the conference and perhaps throughout the world of carbon capture and storage; that the technology itself presents few remaining challenges and achieving political and financial backing are the final and most significant hurdles to be overcome. Applied to a state-of-the-art supercritical plant, an achievable efficiency penalty for the process of around 8 percentage points could allow a competitive overall efficiency of 40%. However, investment costs will always be significant and implementation of a costing mechanism for carbon emissions will be required before books can be balanced. Opposition to onshore CO2 storage also presents an obstacle in many regions which only political willpower and the success of demonstrations such as Futuregen may be able to remove.
A visit to the CIUDEN research facility on the final day brought a climactic close to a conference in which so much had been heard about the project. Only operating since 2011, the spotless plant is an impressive showcase for oxyfuel combustion, featuring a biomass gasifier and a 3 km CO2 transport test rig in addition to the two boilers. As a non-profit facility open to research by any company or institution, the site will doubtless provide invaluable data for the scale-up of oxyfuel boilers and CPU.
On leaving the plant I used some remaining time to pay a visit to Las Medulas, a bizarre landscape carved out of nearby hills by the Romans, who mined for gold there by using pressurised water to split huge cracks in the rock. Struck by the resistance of the local geology, Pliny the Elder wrote “it is thought to be the hardest thing that exists, except for greed for gold, which is the most stubborn of all things”; perhaps a reminder from the past that the modern world’s own thirst for fossil energy is unlikely to leave even inaccessible resources untouched, and that carbon capture must therefore have a role to play in the future.
Added Comments by John Topper
I also attended OCC3 but in my capacity as CEO of the company operating the IEA Greenhouse Gas Programme rather than IEA Clean Coal Centre, but that doesn’t stop me adding something to Toby’s perspectives.
This was actually the 6th oxyfuel event run by the IEAGHG with the first workshop taking place as guests of Vattenfall in 2005. In the intervening 8 years technical solutions to all the issues have been found. This is not to say that further improvements will not be made, but rather that the world is technically ready to go to large scale demonstration; which is exactly what CIUDEN’s installation should facilitate. But commercial scale demonstration is expensive and in the current economic climate in Europe it will be difficult to get the necessary funding together. In an interview I gave to the local Leon newspaper I did point out that, given the same support that renewables have enjoyed in recent years, then it would be so much easier to get this important capture technology demonstrated at scale.
Against this background the CIUDEN management have to find further support from government and big corporates to keep what is a world-class facility running. I wish them every success.
My overall impression from the conference itself was that it was very successful in creating a family atmosphere across the oxyfuel community with excellent networking a strong feature. I was particularly impressed that out of the over 300 attendees, about 30% had travelled long haul to participate with a strong contingent from China amongst them.
Finally, a word of congratulation to Stanley Santos and Sian Twinning of IEAGHG and Pedro Otero, Sandra Ramos and the Ciuden team. Good job; well done.