Evaluation of the effect of flue gas impurities on performance of monolithic MOFs (m-MOFs) for carbon capture from the industry sector
Why is this research needed?
Gas separation is one of the key building blocks of energy decarbonisation and transition towards the UK net-zero target.
The carbon dioxide (CO2) adsorption separation using nanoporous sorbents has been considered a promising strategy to limit the deleterious effect of anthropogenic CO2, and has already been developed for several applications, including carbon capture from point sources and carbon dioxide removal ambient air, biogas upgrading, and production of hydrogen and ammonia and cleaner fuels.
Porous solid adsorbents, including metal organic frameworks (MOFs), when optimised, offer a substantial cost reduction for CO2 capture due to lower energy requirements for regeneration, compared to conventional amine scrubbing approach. Despite their versatility and tunable properties, MOFs face several challenges that hinder their widespread implementation in carbon capture from industrial flue gases. These challenges include issues related to their stability in the presence of water, steam and flue gas, difficulties in scaling up production, and low volumetric adsorption capacity. Furthermore, although there have been advancements in the performance and stability of MOFs, their powder form is impractical for direct use in separation columns. As a result, MOFs need to be pelletized, which can lead to reduced adsorption performance.
To address these challenges, Immaterial has developed monolithic MOFs (m-MOFs) that can reach sizes of up to several centimetres. These m-MOFs offer advantages in terms of production scalability and a form factor that addresses the limitations of conventional MOFs. By achieving better material packing efficiency without unnecessary weight, the volumetric and gravimetric adsorption performance of m-MOFs has demonstrated an increase of over 100%. Although preliminary analyses have shown improved thermochemical stability, the adsorption performance of m-MOFs for CO2 capture from wet flue gases in the presence of impurities still requires evaluation.
Accordingly, the primary objective of the proposed study is to explore how water, steam and impurities present in flue gas (specifically SOx and NOx) affect the adsorption properties and long-term hydrochemical stability of novel MOFs. These findings are crucial for the advancement of m-MOFs as a promising technology for CO2 capture, as they can potentially contribute to the decarbonisation of carbon-intensive industries.
What is this research investigating?
The main objectives of the projects are:
- Formulation, synthesis, and characterisation of a series of m-MOFs. The material will be in the form of monoliths of 1mm and above, suitable for direct use in the adsorption column.
- Adsorption characterisation of synthesised m-MOFs through breakthrough measurement of typical industry wet flue gases in the presence and absence of impurities (NOx, SOx).
- Evaluation of long-term hydrochemical stability of m-MOFs in the presence of steam (for regeneration), and wet acid gases.
- Determine the effect of flue gas impurities on mass transfer coefficients.
What does the research hope to achieve?
This project will benefit a broad range of interested academics from many disciplines, including chemical, process and material engineers, chemists, and environmental scientists.
Academics and researchers undertaking process simulation of capturing carbon dioxide from point-source and other emitting industries, as well as cyclic adsorption processes, will benefit from the measured isotherms and breakthroughs as well as the derived mass transfer coefficients.
Chemical engineers, chemists, and material scientists will be able to utilise the new scientific inputs regarding the sorbents and their evaluated adsorption performance used for industrial carbon capture.
Furthermore, the findings of the project will be used at Cranfield University to enrich the contents of our taught Advanced Chemical Engineering MSc course. The teaching materials will also be offered to other universities and research institutes via guest lectures and seminars.
This research is ongoing. Outputs will be shared below as they become available.