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11 pags., 9 figs., The formation of specific clathrate hydrates and their trans-formation at given thermodynamic conditions depends on theinteractions between the guest molecule/s and the host waterlattice. Understanding their structural stability is essential tocontrol structure-property relations involved in different tech-nological applications. Thus, the energetic aspects relative toCO2@sI clathrate hydrate are investigated through the compu-tation of the underlying interactions, dominated by hydrogenbonds and van der Waals forces, from first-principles electronicstructure approaches. The stability of the CO2@sI clathrate isevaluated by combining bottom-up and top-down approaches.Guest-free and CO2guest-filled aperiodic cages, up to thegradually CO2occupation of the entire sI periodic unit cellswere considered. Saturation, cohesive and binding energies forthe systems are determined by employing a variety of densityfunctionals and their performance is assessed. The dispersioncorrections on the non-covalent interactions are found to beimportant in the stabilization of the CO2@sI energies, with theencapsulation of the CO2into guest-free/empty cage/latticebeing always an energetically favorable process for most of thefunctionals studied. The PW86PBE functional with XDM orD3(BJ) dispersion corrections predicts a lattice constant inaccord to the experimental values available, and simultaneouslyprovides a reliable description for the guest-host interactions inthe periodic CO2@sI crystal, as well as the energetics of itsprogressive single cage occupancy process. It has been foundthat the preferential orientation of the single CO2in the large sIcrystal cages has a stabilizing effect on the hydrate, concludingthat the CO2@sI structure is favored either by considering theindividual building block cages or the complete sI unit cellcrystal. Such benchmark and methodology cross-check studiesbenefit new data-driven model research by providing high-quality training information, with new insights that indicate theunderlying factors governing their structure-driven stability,and triggering further investigations for controlling the stabili-zation of these promising long-term CO2storage materials., The authors acknowledge the “Centro de Calculo del IFF/SGAI”(CSIC) and CESGA-Supercomputingg centre for allocation ofcomputer time. This work has been supported by MINECO grantNo. FIS2017-83157-P, Comunidad de Madrid grant No. IND2017-AMB7696, “CSIC for Development“ (i-COOP) grant ref:ICOOPB20214, Hermes code:49572 (Universidad Nacional de Colombia) and COST Action CA18212(MD-GAS).

To meet the ambitious target set out in the Paris Agreement to keep the temperature rise well below 2°C, all the tools available for reducing CO2 emissions, including CO2 Capture, Utilisation and Storage (CCUS), are needed to meet the challenge. Global collaboration is key in advancing CCUS. CO2GeoNet, a pan-European scientific body on CO2 geological storage, has gained visibility and recognition in the European and global arenas, participating in research and providing scientific advice, training and capacity building, and information and communication. A summary of CO2GeoNet’s cooperation activities with countries outside Europe and with international bodies is given here. CO2GeoNet is open to further opportunities as the Association views global cooperation as critical to accelerating the development, recognition and deployment of CCUS as an important and flexible climate change mitigation technology.

The reduction of carbon emissions is a worldwide global challenge and represents the objective of many scientists that are trying to modify the role of carbon, turning a problem into an opportunity. The potential of CO2 capture and storage by vegetal species is significant because of their capacity to absorb exceeding carbon emission. The purpose of the present paper is to draw a picture of the role of vegetal ecosystems on carbon fixation by identifying the most significant scientific contributions related to the absorption by vegetal species. In particular the aim of this paper is to examine different forms of CO2 sequestration made by plants and crops involved in reducing greenhouse gas (GHG) emission. Results highlight the important role played by agricultural soils, forests, perennial plants, and algae, looking at the overall reduction of carbon emissions. In addition, results show that some bioenergy crops allow substantial storage of carbon dioxide, providing a significant contribution to climate change mitigation.

In this thesis we want to model all steps of a CO2 injection in deep saline aquifers, from the injection to the monitoring by means of seismic methods. After outlining the main physical and chemical processes which allow the CO2 to be trapped for very long periods of time, we present two numerical examples. In the first one, CO2 is injected in a complex aquifer, part of an anticlinal structure, with characteristics resembling those of the Sleipner field. The injection is monitored via an active cross-hole seismic experiment; in particular, we perform a tomographic inverion of the direct arrivals. In the second example, CO2 is injected at a constant rate for one hour in a homogenous aquifer. It is then monitored with a passive seismic method. In fact, the overpressure caused by the injection, may lead to the formation of microcracks and therefore to the emission of seismic waves. We approximate the position of the CO2 plume by finding these emitting points by means of a reverse-time migration algorithm.

CCS communication has proven a tough challenge, particularly for the difficulty in raising interest for the technology, which is still unknown to the majority of the population, and for the complexity of conveying information about its potential for reducing emissions. In this paper we present a research based effort for bringing CCS nearer to people, through visual material developed taking into account emotional needs related to the technology. The production of a short introductory film on CCS is illustrated and its testing with a sample of 700 high school students.

To meet the ambitious EC target of an 80% reduction in greenhouse gas emissions by 2050, CO2 Capture and Storage (CCS) needs to move rapidly towards full scale implementation with geological storage solutions both on and offshore. Onshore storage offers increased flexibility and reduced infrastructure and monitoring costs. Enabling onshore storage will support management of decarbonisation strategies at territory level while enhancing security of energy supply and local economic activities, and securing jobs across Europe. However, successful onshore storage also requires overcoming some unique technical and societal challenges. ENOS will provide crucial advances to help foster onshore CO2 storage across Europe through: 1. Developing, testing and demonstrating in the field, under “real-life conditions”, key technologies specifically adapted to onshore storage. 2. Contributing to the creation of a favourable environment for onshore storage across Europe. The ENOS site portfolio will provide a great opportunity for demonstration of technologies for safe and environmentally sound storage at relevant scale. Best practices will be developed using experience gained from the field experiments with the participation of local stakeholders and the lay public. This will produce improved integrated research outcomes and increase stakeholder understanding and confidence in CO2 storage. In this improved framework, ENOS will catalyse new onshore pilot and demonstration projects in new locations and geological settings across Europe, taking into account the site-specific and local socio-economic context. By developing technologies from TRL4/5 to TRL6 across the storage lifecycle, feeding the resultant knowledge and experience into training and education and cooperating at the pan-European and global level, ENOS will have a decisive impact on innovation and build the confidence needed for enabling onshore CO2 storage in Europe. ENOS is initiating strong international collaboration between European researchers and their counterparts from the USA, Canada, South Korea, Australia and South Africa for sharing experience worldwide based on real-life onshore pilots and field experiments. Fostering experience-sharing and research alignment between existing sites is key to maximise the investment made at individual sites and to support the efficient large scale deployment of CCS. ENOS is striving to promote collaboration between sites in the world through a programme of site twinning, focus groups centered around operative issues and the creation of a leakage simulation alliance.

tGeochemical modeling was used to assess the impact of sulfur dioxide (SO2) in impure carbon dioxide(CO2) streams on fluid–rock interaction during storage in siliciclastic rocks of Permian age (Rotliegend).We focused on the impact of SO2on the porosity evolution, as well as on the trapping of CO2as solidmineral phase. Due to the lack of a validated approach to calculate SO2solubility in highly saline brineat CO2storage conditions, different calculation approaches were tested against experimental literaturedata. Our novel approach employs a pressure and temperature adjusted Henry’s constant with salinitycorrection. Depending on the solubility calculation approach and on the consecutive reactions of dissolvedSO2, different SO2concentrations in the brine were calculated. Based on the results of these solubilitycalculations, a low and a high SO2concentration case were defined for geochemical modeling to assess theimpact of different SO2concentrations on fluid–rock interactions in a CO2storage reservoir. An exemplaryRotliegend sandstone composition was chosen reflecting compositions of potential target horizons inthe North German Basin. Short-term dissolution of carbonates and, in the presence of SO2, subsequentprecipitation of sulfur-bearing minerals results in a decrease in porosity. A precipitation of sulfates nearthe injection well may lower injectivity. With time, dissolution of alumosilicates further provides cationsto the aqueous solution for a precipitation of secondary carbonates. The presence of SO2modifies thislong-term interplay between silicate and carbonate minerals. The higher the SO2concentration in thebrine, the lower the amounts of newly formed carbonates, i.e. the mineral trapping of CO2, and thelower the overall porosity decrease. Hence, the assessment of SO2dissolution in the formation brine atsubsurface conditions is crucial for predicting mineral reactions and porosity evolution during geologicalstorage of impure CO2

tGeochemical modeling was used to assess the impact of sulfur dioxide (SO2) in impure carbon dioxide(CO2) streams on fluid–rock interaction during storage in siliciclastic rocks of Permian age (Rotliegend).We focused on the impact of SO2on the porosity evolution, as well as on the trapping of CO2as solidmineral phase. Due to the lack of a validated approach to calculate SO2solubility in highly saline brineat CO2storage conditions, different calculation approaches were tested against experimental literaturedata. Our novel approach employs a pressure and temperature adjusted Henry’s constant with salinitycorrection. Depending on the solubility calculation approach and on the consecutive reactions of dissolvedSO2, different SO2concentrations in the brine were calculated. Based on the results of these solubilitycalculations, a low and a high SO2concentration case were defined for geochemical modeling to assess theimpact of different SO2concentrations on fluid–rock interactions in a CO2storage reservoir. An exemplaryRotliegend sandstone composition was chosen reflecting compositions of potential target horizons inthe North German Basin. Short-term dissolution of carbonates and, in the presence of SO2, subsequentprecipitation of sulfur-bearing minerals results in a decrease in porosity. A precipitation of sulfates nearthe injection well may lower injectivity. With time, dissolution of alumosilicates further provides cationsto the aqueous solution for a precipitation of secondary carbonates. The presence of SO2modifies thislong-term interplay between silicate and carbonate minerals. The higher the SO2concentration in thebrine, the lower the amounts of newly formed carbonates, i.e. the mineral trapping of CO2, and thelower the overall porosity decrease. Hence, the assessment of SO2dissolution in the formation brine atsubsurface conditions is crucial for predicting mineral reactions and porosity evolution during geologicalstorage of impure CO2

Since its inception in 1996, the CO2 injection operation at Sleipner has been monitored by 3D time-lapse seismic surveys. Striking images of the CO2 plume have been obtained, showing a multi-tier feature of high reflectivity, interpreted as arising from a number of thin layers of CO2 trapped beneath thin, intra-reservoir mudstones. The topmost layer of the CO2 plume can be characterized most accurately, and its rate of growth quantified. From this the CO2 flux arriving at the reservoir top can be estimated. This is mostly controlled by pathway flow through the intra-reservoir mudstones. Flow has increased steadily with time suggesting that pathway transmissivities are increasing with time, and/or the pathways are becoming more numerous. Detailed 3D history-matching of the topmost layer cannot easily reproduce the observed rate of lateral spreading. Very high reservoir permeabilities seem likely, possibly with a degree of anisotropy. Other modelling variables under investigation include topseal topography, the number of feeder pathways and CO2 properties. Detailed studies such as this will provide important constraints on longer-term predictive models of plume evolution. © 2009 Natural Environment Research Council.

Since its inception in 1996, the CO2 injection operation at Sleipner has been monitored by 3D time-lapse seismic surveys. Striking images of the CO2 plume have been obtained, showing a multi-tier feature of high reflectivity, interpreted as arising from a number of thin layers of CO2 trapped beneath thin, intra-reservoir mudstones. The topmost layer of the CO2 plume can be characterized most accurately, and its rate of growth quantified. From this the CO2 flux arriving at the reservoir top can be estimated. This is mostly controlled by pathway flow through the intra-reservoir mudstones. Flow has increased steadily with time suggesting that pathway transmissivities are increasing with time, and/or the pathways are becoming more numerous. Detailed 3D history-matching of the topmost layer cannot easily reproduce the observed rate of lateral spreading. Very high reservoir permeabilities seem likely, possibly with a degree of anisotropy. Other modelling variables under investigation include topseal topography, the number of feeder pathways and CO2 properties. Detailed studies such as this will provide important constraints on longer-term predictive models of plume evolution. © 2009 Natural Environment Research Council.