UKCCSRC Call 1 Project (C1-27) - 'Experimental investigation with PACT facility and CFD modelling of oxy-coal combustion on recycling real flue gas and vent gas of compression and purification units' - Methodologies and Data
This report describes the results of Task 5.1 in SACS2 Work Area 5 (Geophysics). The aim of the Task is to evaluate the applicability of microgravity surveys as a means of monitoring the future subsurface distribution and migration of the Sleipner CO2 bubble. The report can be downloaded from http://nora.nerc.ac.uk/511457/.
The aim of this project is to develop validated and computationally efficient shelter and escape models describing the consequences of a carbon dioxide (CO2) release from Carbon Capture and Storage (CCS) transport infrastructure to the surrounding population. The models will allow pipeline operators, regulators and standard setters to make informed and appropriate decisions regarding pipeline safety and emergency response. The primary objectives planned to achieve this aim are: 1.To produce an indoor shelter model, based on ventilation and air change theory, which will account for both wind and buoyancy driven CO2 ventilation into a building. The model will be capable of incorporating varying cloud heights, internal building divisions, internal and external temperature differences and impurities. 2.To create an external escape model that will determine the dosage received by an individual exposed to a cloud of CO2 outdoors. The model will be capable of incorporating multi-decision making by the individual in terms of the direction and speed of running, wind direction, the time taken to find shelter and the time required to make a decision, on becoming aware of the release. 3.To build a Computational Fluid Dynamics (CFD) model describing the effects of ingress of a CO2 cloud into a multicompartment building. 4.To validate the indoor shelter model and the CFD model against experimental test data for a CO2 release into a single compartment building. 5.To validate the indoor shelter model against further CO2 ingress scenarios modelled with CFD. 6.To conduct a sensitivity study using the shelter and escape models to calculate the dosage that an individual will be expected to receive under different conditions building height, window area, wind direction, temperature gradient, wind speed, atmospheric conditions, building size, running speed, direction of travel and reaction time. 7.To illustrate how the output from the models, in terms of dosage, can be used as input to Quantitative Risk Assessment (QRA) studies to determine safe distances between CO2 pipelines and population centres. 8.To demonstrate how the output from the models, in terms of dosage, can be used as input to the development of emergency response plans regarding the protection afforded by shelter and the likely concentrations remaining in a shelter after release. 9.To disseminate the findings of the research to relevant stakeholders through publication of academic journal papers as well as presentations at conferences, UKCCSRC meetings and relevant specialist workshops. Grant number: UKCCSRC-C2-179.
A sub-seabed release of carbon dioxide (CO2) was conducted to assess the potential impacts of leakage from sub-seabed geological CO2 Capture and Storage CCS) on benthic macrofauna. CO2 gas was released 12 m below the seabed for 37 days, causing significant disruption to sediment carbonate chemistry. Regular macrofauna samples were collected from within the area of active CO2 leakage (Zone 1) and in three additional reference areas, 25 m, 75 m and 450 m from the centre of the leakage (Zones 2, 3 and 4 respectively). Macrofaunal community structure changed significantly in all zones during the study period. However, only the changes in Zone 1 were driven by the CO2 leakage with the changes in reference zones appearing to reflect natural seasonal succession and stochastic weather events. The impacts in Zone 1 occurred rapidly (within a few days), increased in severity through the duration of the leak, and continued to worsen after the leak had stopped. Considerable macrofaunal recovery was seen 18 days after the CO2 gas injection had stopped. In summary, small short-term CCS leakage events are likely to cause highly localised impacts on macrofaunal communities and there is the potential for rapid recovery to occur, depending on the characteristics of the communities and habitats impacted. This is a publication in QICS Special Issue - International Journal of Greenhouse Gas Control, Stephen Widdicombe et. al. Doi:10.1016/j.ijggc.2015.01.003.
The data consists of a poster presented at 'The Fourth International Conference on Fault and Top Seals', Almeria, Spain, 20-24th September 2015. The poster describes work carried-out on behalf of the 'Fault seal controls on CO2 storage capacity in aquifers' project funded by the UKCCS Research Centre, grant number UKCCSRC-C1-14. The CO2-rich St. Johns Dome reservoir in Arizona provides a useful analogue for leaking CO2 storage sites, and the abstract describes an analysis of the fault-seal behaviour at the site as well as at the UK Fizzy and Oak CO2-rich gas Fields
Carbon capture and storage is a mitigation strategy that can be used to aid the reduction of anthropogenic CO2 emissions. This process aims to capture CO2 from large point-source emitters and transport it to a long-term storage site. For much of Europe, these deep storage sites are anticipated to be sited below the sea bed on continental shelves. A key operational requirement is an understanding of best practice of monitoring for potential leakage and of the environmental impact that could result from a diffusive leak from a storage complex. Here we describe a controlled CO2 release experiment beneath the seabed, which overcomes the limitations of laboratory simulations and natural analogues. The complex processes involved in setting up the experimental facility and ensuring its successful operation are discussed, including site selection, permissions, communications and facility construction. The experimental design and observational strategy are reviewed with respect to scientific outcomes along with lessons learnt in order to facilitate any similar future. This is a publication in QICS Special Issue - International Journal of Greenhouse Gas Control, Peter Taylor et. al. Doi:10.1016/j.ijggc.2014.09.007.
This poster on the UKCCSRC Call 2 project Shelter and Escape in the Event of a Release of CO2 from CCS Infrastructure (S-CAPE) was presented at the UKCCSRC Manchester Biannual Meeting, 13.04.2016. Grant number: UKCCSRC-C2-179.
The UK is committed to meeting stringent carbon dioxide emission targets over the next 35 years. One potentially valuable technology in achieving this target is the development of Carbon Capture and Storage (CCS) technologies, where carbon dioxide is captured during power generation and, instead of being released into the atmosphere, is injected into porous rocks underground. Porous rocks, such as sandstone, can act as a 'reservoir' for CO2, which can potentially be stored at depth over long periods of time and kept isolated from the rocks above by a much less porous 'caprock'. The UK has a large 'porosity resource', currently estimated to be of sufficient capacity to store the necessary 2-5 billion tonnes of CO2 to meet 2050 CO2 emission targets. It has been estimated that up to 9 billion tonnes of UK storage capacity come from reservoirs that previously contained hydrocarbons, which have been extracted by the oil and gas industry. This form of CO2 storage has a number of benefits, as the rocks are generally well characterised and there may be pre-existing infrastructure (such as pipelines) suitable for adaption to CO2 injection. However, the process of hydrocarbon extraction, or 'depletion', can significantly impact both the reservoir involved and the surrounding rocks. These activities can potentially cause deformation, movement on faults and/or damage to infrastructure. However, the long term impacts of these activities, particularly when the reservoir is 're-inflated' during injection of CO2, are not well understood and there is limited physical data for specific rock types and scenarios. In order for depleted reservoirs to become a viable national resource, these uncertainties must be addressed. As such, this project is focussed on providing a better understanding of the impact of depletion and reinflation on reservoir and caprock material. It will involve a combined approach, using both laboratory experiments and computer simulation to improve our understanding of this aspect of storage site behaviour. The project seeks to address this key area with a focussed programme of work that will generate a much-needed and unique data-set, new modelling tools and a fuller understanding of the processes involved. The findings will inform regulators and aid operators in reducing the financial and environmental risks of CCS, for depleted storage sites, making the technology more likely to happen. In addition, work will be carried out to examine effective communication with the public, relating to this new technology. Social acceptability represents a major potential barrier to CCS developments, as indicated by protests and moratoria in several countries. It is therefore critical to understand public attitudes and the bases of concern about CCS, and work as effectively as possible to improve understanding and engagement. Work within this project will explore the factors that determine public and stakeholder understanding and acceptability of CCS storage proposals. The lessons and knowledge derived from this work will be summarised in an outreach and engagement toolkit, which will be disseminated to regulators, operators and communication specialists. Grant number: EP/K036025/1.
It is now generally accepted that anthropogenic CO2 emissions are contributing to the global rise in atmospheric CO2 concentrations. One possibility for reducing carbon dioxide emissions is to remove it from the flue gases of coal-fired power stations and dispose of it in underground geological reservoirs, possibly offshore in the North Sea. The feasibility of this option has been studied in detail by a consortium of European partners. As part of this study, natural occurrences of carbon dioxide were identified and preliminary information from these was obtained. The best characterised are found in the United States where the carbon dioxide reserves are exploited for use in tertiary enhanced oil recovery (EOR) programs in the Texas oilfields. The carbon dioxide reserves occur in geological structures and lithologies which are similar to those present in the North Sea. As such, these fields offer an ideal natural analogue for the disposal of carbon dioxide, since the interactions with groundwaters and reservoir lithologies have occurred on both spatial and temporal scales relevant to geological processes. Those carbon dioxide fields currently being exploited have already been studied to a limited extent by the oil companies involved. However, further study is required to provide information on the potential effects that disposing of large quantities of carbon dioxide might have on groundwaters and reservoir quality. In addition, more detailed information will be obtained on the interactions which occur during EOR using carbon dioxide. This paper presents data on some of the natural carbon dioxide fields, and compares the effects of these natural fluid-rock interactions with those observed in laboratory experiments performed to establish what reactions occur during the geological disposal of carbon dioxide. doi:10.1016/0196-8904(95)00309-6. http://www.sciencedirect.com/science/article/pii/0196890495003096.
The solubility of water (H2O) in carbon dioxide (CO2) and nitrogen (N2) mixtures (xN2 = 0.050 and 0.100, mole fraction) has been investigated at 25 and 40 degrees C in the pressure range between 8 and 18 MPa. The motivation for this work is to aid the understanding of water solubility in complex CO2-based mixtures, which is required for the safety of anthropogenic CO2 transport via pipeline for carbon capture and storage (CCS) technology. The measurements have been performed using an FTIR spectroscopic approach and demonstrate that this method is a suitable technique to determine the concentration of water in both pure CO2 and CO2 + N2 mixtures. The presence of N2 lowers the mole concentration of water in CO2 by up to 42% for a given pressure in the studied conditions and this represents important data for the development of pipelines for CCS. This work also provides preliminary indications that the key parameters for the solubility of H2O in such CO2 + N2 mixtures are the temperature and the overall density of the fluid mixture and not solely the given pressure of the CCS mixture. This could have implications for understanding the parameters required to be monitored during the safer transportation of CO2 mixtures in CCS pipelines. The paper is available at http://www.sciencedirect.com/science/article/pii/S1750583615000444, DOI: 10.1016/j.ijggc.2015.02.002. UKCCSRC Grants UKCCSRC-C1-21 and UKCCSRC-C2-185.