Carbon-Negative Waste Treatment Through Smouldering with Ultramafic Rocks
Lead Research Organisation:
UNIVERSITY OF NOTTINGHAM
Abstract
Carbon-negative innovations are urgently needed to improve the sustainability of global waste management systems.
This project will provide the scientific basis needed to scale-up carbon-negative smouldering, a new carbon-negative waste treatment technology that integrates smouldering combustion with carbon sequestration via thermal activation of ultramafic rock. This integration will directly harness energy from waste to drive carbon sequestration.
Current waste management systems release 0.1 to 2 kg CO2-equivalent per kg waste. In contrast, our proof-of-concept research suggests that carbon-negative smouldering may sequester up to 7 kg CO2 per kg waste. Given the novel state of this technology, key knowledge gaps related to geochemistry, heat and mass transfer dynamics, and economic and sustainability success factors must be addressed to advance from proof-of-concept to large-scale operation. Tarek Rashwan, Phil Renforth, Christine Switzer, José Torero, and Katherine Dobson will address these knowledge gaps alongside an international team of industry partners.
Carbon-intensive waste management is a major societal challenge. Globally, over 2 billion tonnes of municipal solid waste are generated annually, and traditional waste management systems currently output ~5% of global CO2 emissions. These emissions are tough to abate. By 2050, global waste generation is projected to increase to 3.4 billion tonnes per year and will require management systems that output 2.6 GT CO2-equivalent annually. In the UK, major national commitments recognise waste management challenges and aim to maximise resource circularity and minimise environmental pollution, while also pursuing low-carbon solutions needed to reach net zero targets by 2050.
Carbon-negative smouldering can improve waste treatment systems, addressing global waste management challenges and contributing positively to the UK’s environmental goals and net zero agenda.
Applied smouldering has recently emerged as a scalable, energy-efficient, and sustainable thermal technology. It has been applied to treat hazardous materials and recover energy and resources from challenging wastes, e.g., faeces within off-grid systems in low-income regions and hazardous waste liquids in remote locations worldwide. Smouldering is therefore highly compatible with a circular economy. However, as waste is combusted to CO2, carbon emissions remain a key sustainability limitation.
Carbon mineralisation in ultramafic rocks has the potential to sequester 1-10 GT CO2 annually. However, this mineralisation is often limited to 3-10% of total CO2 mineralisation potential due to inhibiting compounds. Thermal activation prior to carbon mineralisation can release these compounds and address this limitation.
Carbon-negative smouldering systems can harness energy from wastes to thermally activate ultramafic rocks. Through combining expertise in smouldering, geosciences, and carbon solutions, this project will use experimental and modelling tools to advance carbon-negative smouldering beyond proof-of-concept towards large-scale operation. This project will:
Evaluate thermal activation experimentally across smouldering and ultramafic rock conditions, which is needed to quantify the potential for carbon-negative waste treatment.
Integrate thermal activation geochemistry processes into an existing smouldering numerical model, which is needed to forecast dynamics in large-scale systems.
Identify economic and sustainability factors that govern carbon-negative smouldering scale-up success through a techno-economic analysis and life cycle assessment.
Altogether, this project is poised to unlock follow-on opportunities on an accelerated path to carbon-negative smouldering application, including scale-up experiments and field demonstrations. Alongside an international team of partners, our project will open a new field that aims to improve waste sustainability worldwide.
This project will provide the scientific basis needed to scale-up carbon-negative smouldering, a new carbon-negative waste treatment technology that integrates smouldering combustion with carbon sequestration via thermal activation of ultramafic rock. This integration will directly harness energy from waste to drive carbon sequestration.
Current waste management systems release 0.1 to 2 kg CO2-equivalent per kg waste. In contrast, our proof-of-concept research suggests that carbon-negative smouldering may sequester up to 7 kg CO2 per kg waste. Given the novel state of this technology, key knowledge gaps related to geochemistry, heat and mass transfer dynamics, and economic and sustainability success factors must be addressed to advance from proof-of-concept to large-scale operation. Tarek Rashwan, Phil Renforth, Christine Switzer, José Torero, and Katherine Dobson will address these knowledge gaps alongside an international team of industry partners.
Carbon-intensive waste management is a major societal challenge. Globally, over 2 billion tonnes of municipal solid waste are generated annually, and traditional waste management systems currently output ~5% of global CO2 emissions. These emissions are tough to abate. By 2050, global waste generation is projected to increase to 3.4 billion tonnes per year and will require management systems that output 2.6 GT CO2-equivalent annually. In the UK, major national commitments recognise waste management challenges and aim to maximise resource circularity and minimise environmental pollution, while also pursuing low-carbon solutions needed to reach net zero targets by 2050.
Carbon-negative smouldering can improve waste treatment systems, addressing global waste management challenges and contributing positively to the UK’s environmental goals and net zero agenda.
Applied smouldering has recently emerged as a scalable, energy-efficient, and sustainable thermal technology. It has been applied to treat hazardous materials and recover energy and resources from challenging wastes, e.g., faeces within off-grid systems in low-income regions and hazardous waste liquids in remote locations worldwide. Smouldering is therefore highly compatible with a circular economy. However, as waste is combusted to CO2, carbon emissions remain a key sustainability limitation.
Carbon mineralisation in ultramafic rocks has the potential to sequester 1-10 GT CO2 annually. However, this mineralisation is often limited to 3-10% of total CO2 mineralisation potential due to inhibiting compounds. Thermal activation prior to carbon mineralisation can release these compounds and address this limitation.
Carbon-negative smouldering systems can harness energy from wastes to thermally activate ultramafic rocks. Through combining expertise in smouldering, geosciences, and carbon solutions, this project will use experimental and modelling tools to advance carbon-negative smouldering beyond proof-of-concept towards large-scale operation. This project will:
Evaluate thermal activation experimentally across smouldering and ultramafic rock conditions, which is needed to quantify the potential for carbon-negative waste treatment.
Integrate thermal activation geochemistry processes into an existing smouldering numerical model, which is needed to forecast dynamics in large-scale systems.
Identify economic and sustainability factors that govern carbon-negative smouldering scale-up success through a techno-economic analysis and life cycle assessment.
Altogether, this project is poised to unlock follow-on opportunities on an accelerated path to carbon-negative smouldering application, including scale-up experiments and field demonstrations. Alongside an international team of partners, our project will open a new field that aims to improve waste sustainability worldwide.