Engineering:CO2-Plume Geothermal
CO
2-Plume Geothermal (CPG) is a proposed technology that combines carbon capture and storage (CCS/CCUS) with geothermal energy extraction, utilising carbon dioxide (CO
2) itself as a geothermal energy extraction fluid.[1][2][3]
Technology
2-Plume Geothermal system
First, CO
2 would be injected in deep and naturally permeable reservoirs, as in CCS, where the CO
2 would be heated by the surrounding rock. At a nearby location, production wells would then extract the geothermally heated supercritical CO
2 back to the surface,[4] where it would be expanded in a turbine to generate electricity.[5] The CO
2 would then be cooled and condensed back to a dense phase and re-injected into the reservoir, closing the cycle and enabling all CO
2 to remain sequestered.[1] CPG has the potential to generate over twice the power of conventional, water-based geothermal systems for similar conditions:[6][obsolete source] while the specific heat capacity of CO
2 is less than that of water, the significantly lower dynamic viscosity of CO
2 would enable higher overall energy extraction rates.[7]
Over 14 peer reviewed publications have been published on CPG as of 2024 since its proposal by Martin Saar and Jimmy Randolph in 2011.[8][clarification needed]
Relation to CCS projects
As the subsurface reservoir cools due to geothermal heat extraction, the density of CO
2 in the subsurface increases, enabling a larger mass to be stored for a given formation.[9] Other identified impacts of CPG on CCS include increased control over CO
2 volumetric sweep, reduced carbon intensity of storage due to renewable energy production, additional monitoring data from production wells, flexibility to repurpose producer wells to injectors, avoiding injector downtime with associated halite deposition risks, and providing communities with power produced using CO
2.[9]
Research needs
While existing equipment from CO
2 enhanced oil recovery (EOR) and CCS projects could be repurposed for CPG, additional new equipment is required, primarily lower temperature supercritical turbines and high-pressure CO
2 cooling and condensing units.[5] Selecting suitable locations is a challenge.[10]
References
- ↑ 1.0 1.1 Randolph, Jimmy; Saar, Martin O. (9 April 2011). "Combining geothermal energy capture with geologic carbon dioxide sequestration". Geophysical Research Letters (John Wiley & Sons) 38 (10). 9 May 2011. doi:10.1029/2011GL047265. Bibcode: 2011GeoRL..3810401R.
- ↑ Norouzi, Amir Mohammad; Fatemeh, Rabbani; Fowler, Neil; Gluyas, Jon; Niasar, Vahid; Ezekiel, Justin; Babaei, Masoud (18 December 2022). "CO2-plume geothermal: Power net generation from 3D fluvial aquifers". Applied Energy (Elsevier) 332. 27 December 2022. doi:10.1016/j.apenergy.2022.120546. ISSN 0306-2619.
- ↑ Chen, Mingjie; Nikoo, Mohammad Reza; Al-Maktoumi, Ali; Izady, Azizallah; Rajabi, Mohammad Mahdi Rajabi (16 November 2022). "The impact of geological heterogeneity on coupled CO2 storage and geothermal extraction in inclined reservoirs". Journal of Hydrology (Elsevier) 617: part A. 17 December 2022. doi:10.1016/j.jhydrol.2022.128950. ISSN 0022-1694. Archived from the original on 2022-12-18. https://web.archive.org/web/20221218221513/www.sciencedirect.com/science/article/abs/pii/S0022169422015207. Retrieved 9 August 2024.
- ↑ Ezekiel, Justin; Adams, Benjamin M; Saar, Martin O.; Ebigbo, Anomie (6 October 2022). "Numerical analysis and optimization of the performance of CO2-Plume Geothermal (CPG) production wells and implications for electric power generation". Geothermics (Elsevier) 98. 17 October 2022. doi:10.1016/j.geothermics.2021.102270. ISSN 0375-6505.
- ↑ 5.0 5.1 Schifflechner, Christopher; de Reus, Adriaan Jasper; Schuster, Sebastian; Villasana, Andreas Corpancho; Brillert, Dieter; Saar, Martin O.; Spliethoff, Harmut (28 June 2024). "Paving the way for CO2-Plume Geothermal (CPG) systems: A perspective on the CO2 surface equipment". Energy (Elsevier) 305. 2 July 2024. doi:10.1016/j.energy.2024.132258. ISSN 0360-5442.
- ↑ Adams, Benjamin M.; Kuehn, Thomas H.; Bielicki, Jeffrey M.; Randolph, Jimmy B.; Saar, Martin O. (20 November 2014). "A comparison of electric power output of CO2 Plume Geothermal (CPG) and brine geothermal systems for varying reservoir conditions". Applied Energy (Elsevier) 140: 365–377. 20 December 2014. doi:10.1016/j.apenergy.2014.11.043. ISSN 0306-2619. https://www.sciencedirect.com/science/article/pii/S0306261914012124. Retrieved 9 August 2024.
- ↑ Brown, Donald W. (24-25 January 2000). "A hot dry rock geothermal energy concept utilizing supercritical CO2 instead of water". 25. Stanford, CA: Stanford University. pp. 233–238. Archived from the original on 2024-10-10. https://web.archive.org/web/20241010022316/pangea.stanford.edu/ERE/pdf/IGAstandard/SGW/2000/Brown.pdf.
- ↑ "CPG Consortium". ETH Zürich. n.d.. https://geg.cpg.ethz.ch.
- ↑ 9.0 9.1 Saar, Martin (24-25 January 2024). "How CCS can benefit from CO
2-Plume Geothermal (CPG)". 1st Caprock Integrity & Gas Storage Symposium 2024. St-Ursanne, Switzerland: Swisstopo. Archived from the original on 2024-06-20. https://web.archive.org/web/20240620223648/www.cigss.ch/wp-content/uploads/2024/01/CIGSS2024-extended-abstracts.pdf. Retrieved 15 May 2024. - ↑ Antoneas, George; Koronaki, Irene (6 January 2024). "Geothermal Solutions for Urban Energy Challenges: A Focus on CO2-Plume Geothermal Systems" (in en). Energies (MDPI) 17 (2). doi:10.3390/en17020294.
 |  |
