Greenhouse Gas Removal in the Iron and Steel Industry

Lead Research Organisation: Heriot-Watt University
Department Name: Sch of Engineering and Physical Science

Abstract

This is a GGR Topic-specific proposal

Up to 200 billion tonnes of slag may be produced over the next century as a by-product of the iron and steel industry, which could theoretically sequester up to 90 to 155 billion tonnes of CO2 through enhanced weathering. This proposal explores the exciting possibility of realising an economic greenhouse gas removal technology within an existing industry through the novel management of waste material. We will do this by exploring the internal chemistry of historic slag deposits to understand the long-term constraints on CO2 sequestration, and undertake field trials of CO2 injection into large controlled reactors.

Iron and steel slags are a glass/semi-crystalline material rich in silicate and oxide minerals, which dissolve 4-5 orders of magnitude more rapidly compared to their naturally occurring counterparts. These wastes are found as large deposits at current and former steelworks, and represent a considerable environmental liability for producers. By accelerating the weathering of slag, it may be possible to reduce this environmental burden. It also offers a mechanism by which the CO2 intensive steel industry could begin to decarbonise, and ultimately become net negative, if combined with extensive emissions reduction at source.

Previous research has demonstrated unintentional atmospheric CO2 sequestration over multiple decades in the drainage waters emerging from slag heaps, and small scale engineered systems have been proposed to carbonate slag under elevated temperatures and pressures. What remains unclear is the feasibility and efficacy of engineering approaches to accelerate ambient weathering to occur in a policy-relevant time period at a relevant scale. This research aims to bridge this gap by demonstrating how such engineering interventions can accelerate the natural weathering processes and provide a means for these industrial residues to act as a major atmospheric CO2 sink.

Planned Impact

Accelerated weathering of slag has exciting potential as a new option for climate change mitigation, with far reaching impact into climate change policy, waste management, environmental regulation, carbon infrastructure, energy production, mineral extraction, and land use.

Economic Impact: The economic impact of climate change mitigation technologies is the relative contribution of preventing the potential 5- 20% (e.g. Stern Review) economic reduction the economy due to climate change ($135-540 billion per year on current economy figures). Even if a technology were only able to contribute to mitigating a small fraction of this cost, the value could still be in multi-billions per year. To realise these big-picture economic impacts, the project will 1) demonstrate the technology at a pilot scale and create a robust assessment of larger operation, 2) address key uncertainties about environmental impact, 3) identify a road map for future research, and 4) work with industrial partners to identify intellectual property and market value specific to slag weathering.

Societal impact: Progress in shifting to a low carbon economy has important society impacts. Storage of carbon as alkalinity raises issues of environmental impact, global governance, and public perception. We will work closely with the Understanding Risk Group at Cardiff University to spin out projects that question public perception of this technology, the necessary conditions for a social license to operate. Presently, the London Convention/Protocol is being amended to consider ocean carbon storage, for which the PI was invited to supply evidence in 2015, and the results of this project will directly inform subsequent considerations. Questions of governance and policy will be explored further with collaborators (e.g. through existing collaborations with Oxford University). The results of this project will be disseminated widely through trade/popular publications, our website, a series of short online videos, and as a presentation at Cardiff's regular public lectures. We will work with local authorities who manage the environmental liability of the steel industry (see LoS from Redcar and Cleveland Council) to recognise the remediation co-benefits of accelerated weathering of slag.

Training and People: The project will develop the research group of an Early Career Scientist. The PDRA will receive training and skills that combine exploration and experimental geochemistry with engineering (carbonate system chemistry, reactor modelling, and techno-economic analysis). They will have access to the extensive staff training programme at Cardiff University, close contact with expertise in the School of Earth and Ocean Sciences, and additional external training will be completed as needed. The PI will attend a Residential Communication and Media skills training at the Royal Society. Finally, the knowledge associated with the project will be integrated into teaching in the school as part of student projects (+5-10 per year) and lecture courses (90 students per year).

Publications

10 25 50

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McQueen N (2020) Ambient weathering of magnesium oxide for CO2 removal from air. in Nature communications

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Pullin H (2019) Atmospheric Carbon Capture Performance of Legacy Iron and Steel Waste in Environmental Science & Technology

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Renforth P (2019) The negative emission potential of alkaline materials. in Nature communications

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Renforth P (2019) Specialty Grand Challenge: Negative Emission Technologies in Frontiers in Climate

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Renforth P (2021) The role of soils in the regulation of ocean acidification. in Philosophical transactions of the Royal Society of London. Series B, Biological sciences

Related Projects

Project Reference Relationship Related To Start End Award Value
NE/P019943/1 31/07/2017 31/12/2018 £243,670
NE/P019943/2 Transfer NE/P019943/1 25/01/2019 29/06/2022 £305,916
 
Title Slag and CO2 Painting and video work by Roger McNulty 
Description The artist (Roger McNulty) approached the Principal Investigator and invited to accompany the research team on location drilling for slag samples, to observe their work and that of their technical support teams and associate scientist from Hull and Leeds Universities, and later in the laboratory at Cardiff. Roger McNulty has a background in engineering and steelmaking. An engineering apprentice in Motherwell he was surrounded by Iron and steelmaking plants and their waste products. Subsequently working for British Steel in Industrial Relations gave him close quarter experience of iron and steelmaking processes. His art practice almost inevitably focuses on industrial and urban issues, their people, work and borderlands. His work normally involves landscape although in this project he has also used portraits to highlight concentration and strength. Roger studied art at Glasgow School of Art, Havering College and Central Saint Martins School of Art (UAL). His work has been exhibited in Europe and Asia and he has received several international awards. 
Type Of Art Artistic/Creative Exhibition 
Year Produced 2019 
Impact Awareness raising in Consett (a post-industrial town in North East England) about the possibility of CO2 sequestration in legacy waste. Exhibited at Willesden Gallery, London in 2019, Steel Club at Consett in 2019, POSK Gallery (section), Hammersmith in 2018 Comments from gallery visitors "Absolutely stunning, very thought-provoking thank you for such powerful work" "Marvellous I enjoyed the work very much. Captures the essence of both climate and how it impacts on the environment. I loved the title! Slag, & steel & co2" "A worthy cause - climate/environmental issues -raised to awareness in paintings. Thank you." 
URL http://www.rogermcnulty.com
 
Description Significant new knowledge generated: Through the quantification of carbon in a legacy deposit of steel work slag we have shown that only a small fraction of the material have realised its carbon capture potential (reported in Mayes et al., 2018 doi 10.1021/acs.est.8b01883 and Pullin et al., 2019 doi 10.1021/acs.est.9b01265). These results suggest that management practices are needed to maximise uptake potential.

We have created projections of alkaline material production in the future, showing that these materials may contribute considerable potential to CO2 removal of 3-7 GtCO2/yr by 2100 (Renforth 2019 doi: 10.1038/s41467-019-09475-5) and that there is asymmetrical distribution of these legacy resources in the UK but that they may have a cumulative removal potential of 60-140 Mt CO2 (Riley et al., 2020 doi: 10.1016/j.gexplo.2020.106630). The chemical composition of this slag resource is potentially variable, as considered by an exploration of material in S. Wales (Esele et al., 2021 doi 10.1016/j.mineng.2021.107232).
Exploitation Route The carbonation potential of slag may be used to justify investment into CO2 removal by slag producers/steelworks. Legacy deposits may still retain a considerable CO2 uptake potential, and our work justifies the exploration of methods for optimising their future processing
Sectors Environment,Government, Democracy and Justice,Manufacturing, including Industrial Biotechology

 
Description Contribution to EFI reports on GGR ("Unchartered Waters" + "Rock Solid")
Geographic Reach North America 
Policy Influence Type Membership of a guideline committee
Impact Has impacted legislation in the US around GGR including the upcoming American Energy Innovation Act. This will result in a projected total of $727 million dedicated to GGR research, development, and demonstration activities for FY2022 - FY 2031.
URL https://energyfuturesinitiative.org/efi-reports
 
Description Greenhouse Gas Removal Technologies - approaches and implementation pathways in Scotland
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Implementation circular/rapid advice/letter to e.g. Ministry of Health
URL https://www.climatexchange.org.uk/media/3749/greenhouse-gas-removal-technologies.pdf
 
Description Submission in a Call for Evidence on Greenhouse Gas Removals (GGRs) - Department for Business, Energy & Industrial Strategy
Geographic Reach Local/Municipal/Regional 
Policy Influence Type Gave evidence to a government review
 
Description Industrial Decarbonisation Research and Innovation Centre (IDRIC)
Amount £19,903,412 (GBP)
Funding ID EP/V027050/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 03/2021 
End 03/2024
 
Title Borehole logs from a site investigation of slag deposits in Consett Co. Durham, UK (NERC Grant NE/P019943/2) 
Description Three borehole logs are presented that describe the material excavated from a slag deposit in Consett Co. Durham (ad pdf files). The boreholes were created by GeoSonic Ltd commissioned by Cardiff University in September 2017 as part of a UKRI funded project that explores CO2 uptake in slag. The drilling penetrated through 20 and 25m of material representing the extent of the heap to underlying natural ground. The methods used and samples recovered are described in Pullin et al., 2019 Environmental Science and Technology. 53 (16) 9502-9511. DOI: 10.1021/acs.est.9b01265. The deposited data include photographs of recovered material from one of the boreholes. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
Impact None yet 
URL https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item172089
 
Description Partnership with Darlow Lloyd Ltd 
Organisation Darlow Lloyd & Sons Ltd
Country United Kingdom 
Sector Private 
PI Contribution Darlow Lloyd are a slag management company. Partnership currently involves scoping future work and submission of joint funding proposals
Collaborator Contribution Supply of materials, materials handling advice
Impact No outcomes yet
Start Year 2020
 
Description Partnership with Origen Power 
Organisation Origen Power Ltd
Country United Kingdom 
Sector Private 
PI Contribution Using our experience gained through the GGR project on the geochemical behaviour of alkaline materials, we have designed a series of experiments to test the carbonation behaviour of products from Origen Power. Work is ongoing.
Collaborator Contribution Origen Power have developed pilot scale testing facilities at Heriot-Watt that can carbonate large volume of mineral materials.
Impact Currently testing facilities are being developed by Origen Power to carbonate alkaline materials at pilot scale. Work is still ongoing.
Start Year 2019
 
Description Partnership with Tarmac Ltd 
Organisation Tarmac Ltd
Country United Kingdom 
Sector Private 
PI Contribution We have assessed through geochemical characterisation and modelling the potential of some of Tarmac's products for carbon sequestration.
Collaborator Contribution Worked with us to interpret the practical implications of the results of our work
Impact No outputs to date, but work is ongoing.
Start Year 2019
 
Title Systems and Methods For Enhanced Weathering and Calcining for CO2 Removal from Air 
Description Methods for removing CO2 from the atmosphere via oxide looping 
IP Reference 63/043,038 
Protection Patent granted
Year Protection Granted 2020
Licensed Commercial In Confidence
Impact No impacts yet
 
Description UKSIF Edinburgh Analyst e-Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Virtual presentation at an investment conference
Year(s) Of Engagement Activity 2020
 
Description Civil Service Environment Network 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact A presentation to Civil Service Environment Network on carbon dioxide removal
Year(s) Of Engagement Activity 2021
 
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Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
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Year(s) Of Engagement Activity 2021
 
Description Presentation - Engineering Geologists Special Interest Group 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact A recorded presentation to the Engineering Group of the Geological Society. Attending by ~50. Additional views online. General awareness raising to targeted industry. Follow up invitation to deliver training course at annual conference in March 2020
Year(s) Of Engagement Activity 2019
URL https://www.youtube.com/watch?v=_siZYhVGtIg&t=1s
 
Description Presentation to the Applied Group of the Mineralogical Society 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentation to the applied mineralogy group of the mineralogical society
Year(s) Of Engagement Activity 2020
 
Description Round table British - German Cooperation to Study Climate Change and Adaptation Options 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
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Year(s) Of Engagement Activity 2020
 
Description Seminar Series on Carbon and Climate 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact A seminar series given to Yale University A virtual lecture series hosted by the Departments of Earth and Planetary Sciences and Chemistry, the School of Engineering and Applied Science and the School of the Environment.
Year(s) Of Engagement Activity 2021
 
Description Seminar at Harvard University 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact Delivered a presentation to a seminar at Harvard University, specifically the implications of enhanced weathering for landscape architecture
Year(s) Of Engagement Activity 2020