Cardiff University engineers are leading a pan-European project to explore the feasibility of enhancing carbon dioxide (CO2) storage in European coal seams. Technology will be used to create a horizontal ‘well system’ at specialist research facilities in Mikolów, Poland, enabling engineers to monitor the rate of uptake of CO2 into the coal seams as well as assess and manage the environmental risks. The horizontal well system will be installed at approximately 50 m below the surface at the facility, enabling the team to pump between 1 – 10 t of CO2 into the coal seam throughout the project. The injected CO2 will be stored in the coal matrix for a long period of time via a process known as ‘physical adsorption’.
The storage of CO2 in deep-lying coal beds has been studied extensively by Cardiff University researchers in recent years. It is seen as a viable option to complement the mitigation of CO2 emissions, especially in areas that are rich in coal-deposits and where other forms of storage options, such as offshore saline aquifers and abandoned oil wells, are either not available or feasible.
Experiments will take place at the Experimental Mine ‘Barbara’, the only research facility in Europe with the capability to demonstrate CO2 injection in coal seams using the proposed technique in real underground conditions. The three-year project has received over €2 million funding from the European Union’s Research Fund for Coal and Steel (RFCS) programme, and will bring together academics from Wales, Germany and Poland.
The project will be led by FLEXIS (Flexible Integrated Energy Systems), a £24 million collaborative research programme comprising of the universities of Cardiff, Swansea and South Wales.
“This project is an excellent opportunity to take our research from the lab into a full-scale demonstration test site,” said Principal Investigator on the project Professor Hywel Thomas, from Cardiff University’s School of Engineering. “The existing network of underground tunnels in the Experimental Mine provides easy access to the targeted coal-seam and therefore does not require any vertical drilling. It is also well equipped with a system of pipelines that allow direct and safe supply of gas to the working area of the coal deposit.”
The in-situ tests will aim to overcome practical limitations and increase the amount of gas stored in coal reserves, whilst also undertaking a comprehensive cost analysis and environmental risk assessment.
The team will also select a potential large-scale commercial site for implementing the technology complying with the EU’s Carbon Capture and Sequestration (CCS) Directive.
“Our overall aim is to explore the effectiveness of a novel injection system to improve the rate of CO2 injection and storage, which will ultimately lead to new best practices for commercial application,” continued Professor Thomas. “As many European regions have significant rich coal deposits, partnerships such as this can play a pivotal role in meeting the EU’s carbon emission reduction targets.”
The project, entitled ‘Establishing a Research Observatory to unlock European Coal seams for Carbon dioxide Storage’ (ROCCS), will run for three years, starting on 1 September 2020.