Search results

In order to reach greenhouse gas emission reduction targets, atmospheric CO2 emissions from all industrial sectors need to be avoided. Globally, the cement production industry emits 2.4 Gt CO2 per year, or 7% of all CO2 emissions (IEA). While about a third of this could be reduced by using renewable energy sources, the remainder are process emissions from the calcination process. Lime or CaO is produced by heating limestone (CaCO3), emitting CO2. The Australian company Calix has developed a direct separation technology for capturing these process emissions; a pilot-scale installation is operational at the Lixhe cement plant in Belgium (Figure 1). The EU H2020-funded LEILAC2 project (Low Emission Intensity Lime and Cement 2: Demonstration Scale) upscaling and integrating a novel type of carbon capture technology. This technology aims to capture, at low cost, unavoidable process emissions from cement and lime plant. This large-scale capture plant will be installed at the Heidelberg Cement’s plant in Hannover, Germany, capturing 20% of a typical cement plant’s CO2 emission. Apart from the physical installation and operation of the capture unit, a business case will be developed for the downstream components of transport, use and geological storage for the captured CO2. In order to develop a business case, a very large number of options, combinations and scenarios for each these components need to be evaluated, taking into account the intricacies of for example dealing with geological data in economic calculations. The PSS suite of geo-techno-economic simulators has been developed by the Geological Survey of Belgium, specifically for creating forecasts on the deployment of CO2 capture and geological storage (CCS) technologies (Welkenhuysen et al., 2013). In PSS, investment decisions for the full CCS chain are simulated as a forecast in a non-deterministic way, considering uncertainty and flexibility. Especially for matching storage, these elements are essential. While capture in this demonstration project is a given, several scenarios will be analyzed: the current demo-scale, full-scale capture, and CO2-network integration. Due to its location, several CO2 transport options can be considered at the Hannover plant: from low-volume truck, railway or barge transport, up to ships and pipelines. Special attention is given to possible connections with ongoing and planned initiatives for infrastructure and hub development such as the Porthos project in the port of Rotterdam or the Northern Lights project offshore Norway. In the wider area around the capture location, North-Western Europe including the North Sea offshore area, there are many potential storage options available. Offshore storage options will be the primary targets for assessment, with many (nearly) depleted hydrocarbon fields and saline aquifers that are present in the southern North Sea. Storage aspects are treated as stochastic parameters, with for example storage capacity and injectivity of the reservoirs represented by probability density functions. In order to compare storage options, the degree of knowledge, uncertainty and economic and practical development feasibility of such a storage location needs to be assessed. An analysis of such storage classification systems is created by Tovar et al. (this conference). With the above-mentioned PSS method and CCS project development options, source-sink matching is performed to create forecasts on project and network development. Results will provide insight in the probability of preferred storage option development for steering exploration and development efforts, preferred transport modes and routes, the optimal timing of investments, and the influence of market parameters, such as the ETS price of CO2 emissions. Acknowledgments This research is carried out under the LEILAC2 project, which receives funding by the European Union’s Horizon 2020 research and innovation program under grant agreement number 884170. The LEILAC2 consortium consists of: Calix Europe SARL, HeidelbergCement AG, Ingenieurbüro Kühlerbau Neustad GmbH (IKN), Centre for Research and Technology Hellas (CERTH), Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Politecnico di Milano (POLIMI), Geological Survey of Belgium (RBINS-GSB), ENGIE Laborelec, Port of Rotterdam, Calix Limited, CIMPOR-Indústria de Cimentos SA and Lhoist Recherche et Development SA. References IEA, 2020. Energy Technology Perspectives 2020. https://www.iea.org/reports/energy-technology-perspectives-2020 Tovar, A., Piessens, K. & Welkenhuysen, K., this conference. Ranking CO2 storage capacities and identifying their technical, economic and regulatory constraints: A review of methods and screening criteria. Welkenhuysen K., Ramírez A., Swennen R. & Piessens K., 2013. Strategy for ranking potential CO2 storage reservoirs: A case study for Belgium. International Journal of Greenhouse Gas Control, 17, 431-449. http://dx.doi.org/10.1016/j.ijggc.2013.05.025

Numerous naturally CO2-rich mineral water springs, locally called ‘pouhons’, occur in southeast Belgium. These are oversaturated in CO2 (up to 4g/L) and have attracted economic, touristic and scientific interest for centuries. Water sources occur within Palaeozoic rocks of the Rhenohercynian deformation zone, a fold-and-thrust belt at the north of the Variscan orogeny in central Europe. Many occurrences are concentrated in the Cambro-Ordivician Stavelot-Venn massif. A widely accepted model, supported by H-O isotopic signatures, is that sources are primarily fed by meteoric water, which infiltrates through Quaternary sediments, then reaching Lower Palaeozoic rocks to meet the mineral and CO2 source at unknown depth. Different ideas for the origin of CO2 are grouped in two main hypotheses: a) generation by dissolution of carbonate rocks and/or nodules, and b) volcanic degassing related to the neighbouring Eifel area in Germany. These well-known interpretations are mostly based on geochemical studies that are dispersed and poorly accessible. These have now been gathered in the light of new sampling campaigns, allowing to revisit and compare the views of earlier authors. We also for the first time include the geotectonic setting of the region. Carbonate rocks in the region are represented by Lower Carboniferous and Middle Devonian limestones. Depending on the assumed structural evolution for this foreland fold-an-thrust belt, these may occur at >2 km depth below the Stavelot-Venn massif. Carbonate nodules are present in other formations, but their limited volume is unlikely to originate high and long-lived quantities of CO2. Springs enriched in CO2 are also common in the volcanic Eifel area, with presence of mantle CO2 well established. The supposed extension of the Eifel plume would allow for a magmatic CO2 source below the Stavelot-Venn massif from degassing of the plume (>50 km deep), or of an unknown shallower magmatic reservoir. Available stable and noble isotopes point to a mixed carbonate-magmatic origin. If considering the presence of limestones at depth, meteoric water should infiltrate at least 2 km. Known deep-rooted faults are thought to act as preferential groundwater pathways. However, such deep circulation is incompatible with the low temperatures of springs (~10oC), unless the ascent is slow enough to fully dissipate heat prior to resurfacing. Another possibility is that meteoric water does not infiltrate as deep, with CO2 being transported upwards to meet groundwaters at shallower depths. The presence of CO2 surface leaks, locally called ‘mofettes’, could be evidence of such relatively shallow availability of CO2. The evaluation of existing hypotheses highlights complex subsurface processes that involve water infiltration, CO2 assimilation and water resurfacing in southeast Belgium (Figure 1). As such, this review is an important guide for the newly launched sampling campaigns. Acknowledgements This work is part of two research projects: GeoConnect³d-GeoERA that has received funding by the European Union’s Horizon 2020 research and innovation programme under grant agreement number 731166, and ROSEAU project, as part of the Walloon program «Doctorat en Entreprise», co-funded by the SPW Région Wallonne of Belgium and the company Bru-Chevron S.A. (Spadel group), under grant number 7984. References Barros, R., Defourny, A., Collignon, A., Jobé, P., Dassargues, A., Piessens, K. & Welkenhuysen, K., 2021. A review of the geology and origin of CO2 in mineral water springs in east Belgium. Geologica Belgica, 24 (1-2), p.17-31. https://doi.org/10.20341/gb.2020.023

PSInSAR analyses across Belgium using ERS 1-2, ENVISAT, TerraSAR-X and Sentinel 1 allowed to follow several ground movements areas during the last three decades. Several areas of regional importance are affected by land subsidence processes that have been observed during this period (i.e. the alluvial plain of the Schelde estuary in Antwerpen, a large area in the West Flanders province and one around Merchtem area). Other land subsidence areas associated to old coal mining both in Flanders (Campine basin) and Wallonia (Hainaut and Liège province) are affected by progressive uplifting conditions linked to the mining aquifer piezometric rebound. It is extremely important to follow the spatio-temporal behavior of these phenomena to forecast their influences and their effects on the urban developments.

A land subsidence affecting several towns at the joining limits of the Belgian Provinces of East Flanders, Antwerp and Flemish Brabant is followed during the last three decades. ERS 1–2, ENVISAT, TerraSAR-X and Sentinel-1A satellites SAR scenes were processed from 1992 till October 2020 to map the land subsidence evolution. The subsidence corresponds to a surface area of 220 km 2 during the ERS 1/2 time interval distributed over three distinct subsidence bowls. During the ENVISAT and TerraSAR-X time interval, only one residual subsidence bowl was mapped affecting a surface area of about 70 km 2 . Several towns (Londerzeel and Steenhuffel) remained in the center of the subsidence bowl. The annual average negative velocity values range between −5.99 and −0.5 mm/year. During the Sentinel-1A period, the subsidence bowl has lost half of its surface reaching 36 km 2 . The LOS velocity values have also decreased during the period 2016–2020.