The University of Southampton
University of Southampton Institutional Repository

Geological storage of carbon dioxide in oceanic crust

Geological storage of carbon dioxide in oceanic crust
Geological storage of carbon dioxide in oceanic crust
The rise of atmospheric carbon dioxide (CO2), due to decades of burning of fossil fuels, is a key driver of anthropogenic climate change. Carbon Capture and Storage (CCS) is one of the most promising mitigation strategies for long-term sequestration of CO2.
Unlike most conventional CCS investigations targeting deep saline aquifers, this thesis focuses on the potential of the uppermost oceanic crust, inspired by the strong evidence that basaltic seafloor has acted, in the past, as a major sink for CO2.
The study of temperature, pressure, and density of CO2 and seawater at the sediment-basement interface for the whole seafloor highlights the influence of water depth, sediment thickness, and oceanic crustal age on the relative gravitational stability of CO2. Consequently, 8% of the entire oceanic crust is recognised as suitable for gravitational and physical trapping of CO2 injected into the basement. Five potential targets are proposed, and even the smallest of these provides sufficient carbon dioxide sequestration capacity for the next centuries.
Batch experiments on the mineral dissolution of submarine mafic rocks and ophiolitic gabbro, in CO2-rich solutions, contribute to improve the fundamental understanding of geochemical reactions at mid-ocean ridge flank temperatures (40 ?C). Concentrations of silicon and calcium in solution, and particle size are identified as the key factors to quantify the rock reactivity. Ca dissolution rates suggest calcite, plagioclase and amphibole are the principal sources of calcium at pH ~5.
The attempted estimation of costs related to the transport and storage of 20 Mt/yr of CO2 in deep-sea basalts, as a function of distance from the shore, injection rate, and water depth, shows the economic feasibility of potential offshore CCS projects. Overall, the expenditures are dominated by the number of ships and wells required to deliver large volumes of CO2 to reservoirs located far from the coast, rather than by the water depth. These financial considerations could potentially improve if the CCS strategies conquered a significant place in the global market.
Marieni, Chiara
3b6d4e99-c548-46c1-80a6-e849050f55f0
Marieni, Chiara
3b6d4e99-c548-46c1-80a6-e849050f55f0
Teagle, Damon
396539c5-acbe-4dfa-bb9b-94af878fe286

Marieni, Chiara (2016) Geological storage of carbon dioxide in oceanic crust. University of Southampton, Ocean & Earth Science, Doctoral Thesis, 223pp.

Record type: Thesis (Doctoral)

Abstract

The rise of atmospheric carbon dioxide (CO2), due to decades of burning of fossil fuels, is a key driver of anthropogenic climate change. Carbon Capture and Storage (CCS) is one of the most promising mitigation strategies for long-term sequestration of CO2.
Unlike most conventional CCS investigations targeting deep saline aquifers, this thesis focuses on the potential of the uppermost oceanic crust, inspired by the strong evidence that basaltic seafloor has acted, in the past, as a major sink for CO2.
The study of temperature, pressure, and density of CO2 and seawater at the sediment-basement interface for the whole seafloor highlights the influence of water depth, sediment thickness, and oceanic crustal age on the relative gravitational stability of CO2. Consequently, 8% of the entire oceanic crust is recognised as suitable for gravitational and physical trapping of CO2 injected into the basement. Five potential targets are proposed, and even the smallest of these provides sufficient carbon dioxide sequestration capacity for the next centuries.
Batch experiments on the mineral dissolution of submarine mafic rocks and ophiolitic gabbro, in CO2-rich solutions, contribute to improve the fundamental understanding of geochemical reactions at mid-ocean ridge flank temperatures (40 ?C). Concentrations of silicon and calcium in solution, and particle size are identified as the key factors to quantify the rock reactivity. Ca dissolution rates suggest calcite, plagioclase and amphibole are the principal sources of calcium at pH ~5.
The attempted estimation of costs related to the transport and storage of 20 Mt/yr of CO2 in deep-sea basalts, as a function of distance from the shore, injection rate, and water depth, shows the economic feasibility of potential offshore CCS projects. Overall, the expenditures are dominated by the number of ships and wells required to deliver large volumes of CO2 to reservoirs located far from the coast, rather than by the water depth. These financial considerations could potentially improve if the CCS strategies conquered a significant place in the global market.

PDF
Marieni, Chiara_final_PhD_Oct_16.pdf - Other
Restricted to Repository staff only until 24 October 2021.

More information

Accepted/In Press date: 24 October 2016
Organisations: University of Southampton, Geochemistry

Identifiers

Local EPrints ID: 402631
URI: https://eprints.soton.ac.uk/id/eprint/402631
PURE UUID: 18b58dca-4b4f-4b03-a105-2d1d8bd84f79
ORCID for Damon Teagle: ORCID iD orcid.org/0000-0002-4416-8409

Catalogue record

Date deposited: 15 Nov 2016 16:58
Last modified: 06 Jun 2018 12:52

Export record

Contributors

Author: Chiara Marieni
Thesis advisor: Damon Teagle ORCID iD

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×