title: CO2 transport and geological storage under supercritical conditions: preliminary study of the integration with renewable electrothermal energy storage
Creators: name: Carro, Andrés
name: Carneiro, Julio
name: Unger, Sebastian
name: Mesquita, Paulo
name: Fogel, Stefan
name: Chacartegui, Ricardo
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2025
Subjects: subject: transcritical CO2 cycles
subject: energy storage
subject: CO2 geological storage
subject: Carbon Capture
subject: CO2 transport
subject: 620

description: The European Commission promotes technologies that support economic growth decoupled from the use of fossil fuels and promote carbon emissions mitigation. Its objectives for 2050 include the achievement of greenhouse gas neutrality, energy transition towards renewable and sustainable sources (e.g. solar, wind, hydro, etc.) and replacement of fossil fuels and feedstocks. These ambitious goals should be achieved by promoting research and technological development in clean energy, industrial efficiency and innovative technologies. One promising technology addressing these challenges is a large-scale CO2-based electrothermal energy and geological storage system. When excess renewable energy is available, the system acts as a heat pump, storing electrical energy in the form of heat at two temperature levels and as mechanical energy in CO2 injected in geological formations. The trigeneration system allows flexible coverage of electricity, heating or cooling demand, compensating for the temporary mismatch between renewable energy supply and demand. The use of CO2 as a working fluid makes the system potentially integrable in carbon capture, utilisation and storage (CCUS) processes. The pressure (30-200 bar) and low-temperature conditions of transcritical CO2 cycles are compatible with the transport of captured CO2 under supercritical conditions. This work analyses different integration options for transporting and conditioning CO2 captured in stationary sources to conditions suitable for injection in geological formations. Options for transport as liquid CO2 in storage tanks and supercritical CO2 by pipeline are considered. Different scenarios where the CEEGS system could complement the process are studied, and the cycle behaviour and impact are evaluated. CEEGS system is positioned as a suitable technology in the process of using and conditioning the captured CO2 to transport as well as geological injection conditions. The energy storage concept of CEEGS can present strong synergies with the implementation process of carbon capture plants, allowing the captured CO2 to be conditioned through a cycle of energy storage and power production from renewable sources with roundtrip efficiencies higher than 50%, and the flexible coverage of electrical or thermal demands (heating and cooling). Renewable energy could be used for the energy needs of the entire process of conditioning and transporting the captured CO2.
description: Conference Proceedings of the European sCO2 Conference6th Edition of the European Conference on Supercritical CO2 (sCO2) for Energy Systems: April 09–11, 2025, Delft, The Netherlands, p. 232