Why is this research needed?

Despite commitments made by the UK government in 2019 in declaring a climate emergency and a target of net-zero greenhouse gas (GHG) emissions by the year 2050, the current trajectory is one of increased emissions, further warming and a potential breach of the 1.5C average warming threshold as early as 2030. Mitigation scenarios that achieve these ambitions targets rely on GHG emission reductions combined with net carbon dioxide removal from the atmosphere. Most assessment models are unable to find a solution to meet these targets without the use of CCS with BioEnergy with Carbon Capture and Storage (BECCS) featuring in most of these scenarios. The Energy Technologies Institute have estimated that by 2050, around 55 Mt of CO₂ per annum could be removed by BECCS, half that of the UK’s emission targets in 2050. Adsorption for CCS is an attractive technology as its advantages include the ability for retrofitting to existing large point sources. The driving force for research in the field of adsorption-based CCS is the reduction of CO₂ capture cost by minimising energy requirements and improving the efficiency, hence developing innovative and cost-effective adsorbents and their associated processes. With an anticipated increase in biomass combustion, the co-generation of biomass combustion products (BCP) presents a significant social, economic and environmental burden. Owing to their unique properties, BCP have demonstrated potential for niche applications in adsorption-based CO₂ capture.

This research project will seek to build from the research team’s successful project (EP/P026214/1 – UKCCSRC’s 2020 Flexible Funding Call). The 2020/2021 project has revealed the feasibility of two uniquely different BCPs in in-situ CCS through both thermogravimetric and fixed-bed experimental campaigns. The two routes explored encompass inorganic and organic adsorbent materials through the zeolitisation of biomass combustion fly ash alongside the extraction and subsequent activation of carbon from biomass combustion bottom ash. Using the experimental data obtained in the previous project, the viability of BCP-derived adsorbents in a post-combustion carbon capture process can be revealed. Conceptualisation of an innovative adsorption-based CCS plant will be developed via process simulation. The team’s existing experimental data will be substantiated through exploitation of the existing fixed-bed reactor that will simultaneously inform and validate the process model that will be generated in this work.

What is this research investigating?

This research will be investigating the viability of BCP valorisation in in-situ decarbonisation of biomass combustion facilities such as those at Drax Power Plant where the BCP has been sourced.

This research aims to enhance the CO₂ uptake capacity of our existing adsorbents, synthesised from Drax biomass combustion ash, and to study the viability of the associated process in CO₂ capture processes. In this context, the research objectives comprise:

1. To enhance CO₂ adsorption performance of BCP-derived adsorbent materials produced in the previous project via further adsorbent activation and modification (Work Package 1).
2. To develop a process model using experimental data obtained in the previous project (EP/P026214/1), with which to investigate the techno-economics of BCPs in in-situ CCS (Work Package 2);

What does the research hope to achieve?

This research bridges the gap across two core areas of chemical engineering: synthesis of enhanced waste-derived adsorbents (Work Package 1) and process design and development (Work Package 2). On this ground, the findings in this work will be able generate new knowledge within these two core areas:

1. The findings in WP1 will be useful to both chemists, chemical engineers along with material scientists as this will reveal unique information on the chemical and physical properties of modified UK-based biomass combustion ash and the activation/modification methods. This will generate new research ideas for further improvement of such adsorbents for CO₂ capture; and
2. The findings in WP2 will be useful for chemical engineering scientists working on adsorption processes, looking to improve process efficiency and advanced optimisation based on experimentally-generated datasets.

The findings in this research will be made available to the academic and scientific communities in the UK and abroad via the four routes below:

• The results of this research will be submitted as one journal paper to the Chemical Engineering Research & Design Journal.
• The research findings will be submitted to and presented at the 2022 AIChE Annual Meeting to be held in Arizona, USA and/or IEEE Nano 2022.
• The research findings will be presented at UK Carbon Capture and Storage Research Centre (UKCCSRC) biannual meeting 2021/2; either in the form of an oral presentation or a poster presentation.