Utility of peridotite host rocks for sequestering atmospheric carbon dioxide
Utility of peridotite host rocks for sequestering atmospheric carbon dioxide
Weathering is a natural geological process whereby atmospheric CO2 dissolved in rainwater attacks rocks, partly dissolving them. The CO2 is converted into alkalinity or carbonate minerals that securely store carbon on timescales of >10,000 years. Modelling studies show that if weathering rates can be increased (by selecting the most reactive rocks, increasing reactive surface area), up to an additional 2 Gt CO2 yr-1 could be removed from the atmosphere, ~40% of the amount required by 2100 to meet the Paris Agreement target.
The mining industry extracts gigatonnes of rock each year, generating large amounts of freshly exposed, reactive surface area that could be used as a feedstock for enhanced weathering. Ore deposits with the highest CO2 removal capacity are those mined in high quantities that have an abundance of calcium- and magnesium-bearing silicate minerals [1]. Here, we report the results of an investigation into the reactivity of serpentinised peridotite samples from the Sakatti Cu-Ni-PGE deposit (Finland). The deposit consists of both disseminated and massive sulphides hosted within a large olivine-cumulate body [2]. The material consists primarily of serpentine [Mg3Si2O5(OH)4] and olivine [Mg2SiO4] minerals that have a high potential for CO2 removal via enhanced weathering.
We have conducted a series of laboratory experiments whereby crushed peridotite samples were reacted with CO2-enriched solutions at 25 °C and 50 °C, and 1 bar CO2 (100% CO2). Surface area normalised dissolution rates were determined for various grain sizes, temperatures, mineral compositions (degree of serpentinization) and solution chemistry (with/without a chelating agent).
Shannon, Jo
403e75fb-9a07-47cc-b43a-405c90e3a38b
Matter, Juerg
abb60c24-b6cb-4d1a-a108-6fc51ee20395
Teagle, Damon
396539c5-acbe-4dfa-bb9b-94af878fe286
James, Rachael
79aa1d5c-675d-4ba3-85be-fb20798c02f4
Duret, Manon T.
7aa9476b-d178-4f09-b089-02c7e9943eba
Newman, Phil
453bb69f-5101-4edb-acb4-4ee7a22a9be8
Plint, Neville
a25ebf24-53d6-4a8e-9bf0-8ad0b1db0713
11 December 2023
Shannon, Jo
403e75fb-9a07-47cc-b43a-405c90e3a38b
Matter, Juerg
abb60c24-b6cb-4d1a-a108-6fc51ee20395
Teagle, Damon
396539c5-acbe-4dfa-bb9b-94af878fe286
James, Rachael
79aa1d5c-675d-4ba3-85be-fb20798c02f4
Duret, Manon T.
7aa9476b-d178-4f09-b089-02c7e9943eba
Newman, Phil
453bb69f-5101-4edb-acb4-4ee7a22a9be8
Plint, Neville
a25ebf24-53d6-4a8e-9bf0-8ad0b1db0713
Shannon, Jo, Matter, Juerg, Teagle, Damon, James, Rachael, Duret, Manon T., Newman, Phil and Plint, Neville
(2023)
Utility of peridotite host rocks for sequestering atmospheric carbon dioxide.
AGU Fall Meeting 2023, Moscone Center, San Francisco, United States.
11 - 15 Dec 2023.
(doi:10.22541/au.170319490.09706364/v1).
Record type:
Conference or Workshop Item
(Poster)
Abstract
Weathering is a natural geological process whereby atmospheric CO2 dissolved in rainwater attacks rocks, partly dissolving them. The CO2 is converted into alkalinity or carbonate minerals that securely store carbon on timescales of >10,000 years. Modelling studies show that if weathering rates can be increased (by selecting the most reactive rocks, increasing reactive surface area), up to an additional 2 Gt CO2 yr-1 could be removed from the atmosphere, ~40% of the amount required by 2100 to meet the Paris Agreement target.
The mining industry extracts gigatonnes of rock each year, generating large amounts of freshly exposed, reactive surface area that could be used as a feedstock for enhanced weathering. Ore deposits with the highest CO2 removal capacity are those mined in high quantities that have an abundance of calcium- and magnesium-bearing silicate minerals [1]. Here, we report the results of an investigation into the reactivity of serpentinised peridotite samples from the Sakatti Cu-Ni-PGE deposit (Finland). The deposit consists of both disseminated and massive sulphides hosted within a large olivine-cumulate body [2]. The material consists primarily of serpentine [Mg3Si2O5(OH)4] and olivine [Mg2SiO4] minerals that have a high potential for CO2 removal via enhanced weathering.
We have conducted a series of laboratory experiments whereby crushed peridotite samples were reacted with CO2-enriched solutions at 25 °C and 50 °C, and 1 bar CO2 (100% CO2). Surface area normalised dissolution rates were determined for various grain sizes, temperatures, mineral compositions (degree of serpentinization) and solution chemistry (with/without a chelating agent).
Text
694906
- Version of Record
More information
Published date: 11 December 2023
Venue - Dates:
AGU Fall Meeting 2023, Moscone Center, San Francisco, United States, 2023-12-11 - 2023-12-15
Identifiers
Local EPrints ID: 504931
URI: http://eprints.soton.ac.uk/id/eprint/504931
PURE UUID: 1cbc17a3-c832-4a9e-b583-35c9ca29d7a2
Catalogue record
Date deposited: 22 Sep 2025 16:57
Last modified: 23 Sep 2025 02:11
Export record
Altmetrics
Contributors
Author:
Jo Shannon
Author:
Manon T. Duret
Author:
Phil Newman
Author:
Neville Plint
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