Power Generation from Coal: Ongoing Developments and Outlook

Coal is an important source of energy for the world, particularly for power generation. To meet the growth in demand for energy over the past decade, the contribution from coal has exceeded that of any other energy source. Additionally, coal has contributed almost half of total growth in electricity over the past decade. As a result, CO2 emissions from coal-fired power generation have increased markedly and continue to rise. More than 70% of CO2 emissions that arise from power generation are attributed to coal. To play its role in a sustainable energy future, its environmental footprint must be reduced; using coal more efficiently is an important first step. Beyond efficiency improvement, carbon capture and storage (CCS) must be deployed to make deep cuts in CO2 emissions. This report focuses mainly on developments to improve the performance of coal-based power generation technologies, which should be a priority – particularly if carbon capture and storage takes longer to become established than currently projected. A close look is taken of the major ongoing developments in process technology, plant equipment, instrumentation and control. The need for energy and the economics of producing and supplying it to the end-user are central considerations in power plant construction and operation. Economic and regulatory conditions must be made consistent with the ambition to achieve higher efficiencies and lower emissions. In essence, clean coal technologies must be more widely deployed.

The IEA CCS Technology Roadmap: One Year On

AbstractIn October 2009, the International Energy Agency’s CCS Technology Roadmap was launched at the Carbon Sequestration Leadership forum (CSLF) Ministerial Meeting in London. The Roadmap builds on the IEA BLUE Map scenario that leads to the stabilisation of CO2 emissions at 450 ppm by 2050. Achieving this scenario will require an energy technology revolution involving a portfolio of solutions: greater energy efficiency, increased renewable energy technologies and nuclear power, and the near decarbonisation of fossil fuel-based power generation via carbon capture and storage (CCS). In this scenario CCS contributes almost 20% to the total emissions reductions required in 2050. Recommendations are made in the IEA CCS Roadmap on what is required to achieve this level of deployment not only technically, but also from a financial and regulatory point of view as well as in terms of public engagement and international collaboration, including the sharing of knowledge. This paper looks at progress made against these recommendations in the 12 months since the release of the roadmap. •Analysis undertaken by the IEA consistently identifies a significant role for CCS in mitigating global CO2 emissions. IEA analysis suggests that there will be a need to capture and store 10 Gt CO2 per year in 2050, from 3400 projects globally to achieve the BLUE Map emissions reduction targets.•Significant progress is being made to launch large-scale demonstration facilities across the globe, with some 80 large-scale integrated demonstration projects identified. As of April 2010, public funding commitments were in the range of USD 26.6 billion to USD 36.1 billion.•While 5500 km of CO2 pipelines already exist and further infrastructure development is planned, it is however clear that to enable large-scale deployment of CCS, more joint planning of CO2 transportation infrastructure is required globally.•The status and availability of data on CO2 storage varies significantly around the world and is potentially a major constraint to rapid, widespread CCS deployment. In regions with the potential to store large volumes of CO2, a concerted effort will be required to characterise the basins in sufficient detail.•Much progress has been achieved in the legal and regulatory area. The first movers in establishing legal frameworks have generally been OECD countries. It is now important that the large emerging economies start developing their legal and regulatory frameworks.•Public awareness and acceptance is a key element in making CCS possible. Public concerns are legitimate and require a close dialogue and sharing of information with the local population. While companies developing transport and storage will need to lead on the engagement processes, governments and politicians have a vital role to play.•Several initiatives are in place for international dialogue and collaboration on the development and deployment of CCS.•While much progress has been made, many challenges still remain if CCS is to deliver at the scale required. The challenges are well-known and require concerted action by industry, governments, international organisations and civil society. Continued political leadership remains absolutely essential

Storage capacity and containment issues for carbon dioxide capture and geological storage on the UK continental shelf

Carbon dioxide (CO2) can be stored in geological formations beneath the UK continental shelf (UKCS) as a greenhouse gas mitigation option. It can be trapped in subsurface reservoirs in structural or stratigraphic traps beneath cap rocks, as a residual CO2 saturation in pore spaces along the CO2 migration path within the reservoir rock, by dissolution into the native pore fluid (most commonly brine), by reaction of acidified groundwater with mineral components of the reservoir rock, or by adsorption onto surfaces within the reservoir rock, e.g. onto the carbonaceous macerals that are the principal components of coal. Estimates of the CO2 storage capacity of oil and gas fields on the UKCS suggest that they could store between 1200 and 3500×106 t of CO2 and up to 6100×106 t CO2, respectively. Estimating the regional CO2 storage potential of saline water-bearing sedimentary rocks is resource-intensive and no UK estimates have yet taken into account all the factors that should be considered. Existing studies estimate the pore volume and the likely CO2 saturation in the closed structures in a potential reservoir formation but do not take account of the potentially limiting regional pressure rise likely to occur as a result of the very large-scale CO2 injection that would be necessary to make an impact on national emissions. There is undoubtedly great storage potential in the saline water-bearing reservoir rocks of the basins around the UK, but the real challenge for studies of aquifer CO2 storage capacity in the UK is perhaps not to estimate the total theoretical CO2 storage capacity, as this is not a particularly meaningful number. Rather it is to thoroughly investigate selected reservoirs perceived to have good storage potential to a standard where there is scientific consensus that the resulting storage capacity estimates are realistic. This will allow it to be considered as closer to the status of a reserve rather than a resource and will help define the scope for CO2 capture and storage in the UK

An initial assessment of the potential environmental impact of CO2 escape from marine carbon capture and storage systems

If carbon capture and storage is to be adopted as a CO2 mitigation strategy, it is important to understand the associated risks. The risk analysis consists of several elements such as leakage probability, assessing the trength of environmental perturbation, and quantifying the ecological, economic, and social impacts. Here, the environmental perturbation aspect is addressed by using a marine system model of the North West European Shelf seas to simulate the consequences of CO2 additions such as those that could arise from a failure of geological sequestration schemes. Little information exists to guide the choice of leak scenario and many assumptions are required; for consistency the assumptions err towards greater impact and what would be in likelihood extreme scenarios. The simulations indicate that only the largest leakage scenarios tested are capable of producing perturbations that are likely to have environmental consequences beyond the locality of a leak event. It is shown that, given the available evidence, the chemical perturbation of a sequestration leak, regionally integrated, is likely to be insignificant when compared with that from continued non-mitigated atmospheric CO2 emissions and the subsequent acidification of the marine system. The potential ecological impacts of a large environmental CO2 perturbation are reviewed, indicating that the biogeochemical functioning and biodiversity are sensitive. The key unknowns that must be addressed in future research are identified; namely, the fine scale dispersion of CO2 and the ability of ecological systems to recover from perturbation

Public acceptance of carbon dioxide capture and storage in a proposed demonstration area

With the rising levels of CO2 in the atmosphere, low-emission technologies with carbon dioxide capture and storage (CCS) provide one option for transforming the global energy infrastructure into a more environmentally, climate sustainable system. However, like many technology innovations, there is a social risk to the acceptance of CCS. This article presents the findings of an engagement process using facilitated workshops conducted in two communities in rural Queensland, Australia, where a demonstration project for IGCC with CCS has been announced. The findings demonstrate that workshop participants were concerned about climate change and wanted leadership from government and industry to address the issue. After the workshops, participants reported increased knowledge and more positive attitudes towards CCS, expressing support for the demonstration project to continue in their local area. The process developed is one that could be utilized around the world to successfully engage communities on the low carbon emission technology options