CO2 Sequestration Through Combining Clay Minerals and Construction By-products

Abstract

The rising global temperatures, driven by anthropogenic CO2 emissions, call for urgent climate mitigation strategies. Enhanced weathering is a promising Carbon Dioxide Removal (CDR) method that accelerates natural weathering processes to sequester CO2 in soils. This study focuses on utilising clay minerals, waste clays, and construction by-products to enhance CO2 sequestration potential, addressing both waste management and climate change. By exploring the synergies between these materials, this research provides a sustainable solution to carbon capture, supporting both the scientific community and public stakeholders such as farmers.
This thesis takes a comprehensive approach, including experimental investigations, a process-based life cycle assessment (LCA), and field trials. New methodologies, such as modifications to previous pressurized, slurry, and incubator carbonation experiments, were introduced to assess the CO2 sequestration potential of waste clays, recycled aggregates, and Redcar mudstone. A field study with 30 trial pits was conducted to monitor CO2 sequestration under real-world conditions, measuring parameters such as soil pH, moisture content, and carbonate formation. The process based LCA quantifies the environmental impact of enhanced weathering, marking the
first assessment of these materials. The findings show that combining waste clays and construction by-products significantly increases carbonate content, optimising CO2 sequestration. The field trials demonstrated substantial increases in carbonate content in pits filled with waste clay mixtures, validating the practical application of enhanced weathering. The process based LCA results reveal that with an application rate of 11.2 t/ha, these materials can capture between 0.77 and 1.62 Mt CO2eq, aligning with circular economy principles. This study advances the understanding of waste valorisation and CO2 capture and contributes directly to the United Nations' Sustainable Development Goals
(SDGs), particularly SDG 13 (Climate Action), SDG 12 (Responsible Consumption and Production), SDG 9 (Industry, Innovation, and Infrastructure), and SDG 11
(Sustainable Cities and Communities).

Date of Award	11 Dec 2024
Original language	English
Awarding Institution	Teesside University
Supervisor	Sina Rezaei Gomari (Supervisor), Tannaz Pak (Supervisor) & David Hughes (Supervisor)