Aisha Ibrahim (University of Sheffield) and Briggs Ogunedo (Cranfield University) provide an insight into Parallel session 1a “CO2 Sourcing” at the UKCCSRC Spring 2023 Conference on “CCS from geographically dispersed industries”.
It is impossible to deliberate the theme of this year’s UKCCSRC Spring Conference without highlighting the efforts being made towards more sustainable CO2 sourcing. The first of two sessions on the topic was chaired by Jon Gibbins and incorporated presentations from three researchers with different specialties. The aim was to expose the knowledge-based society to new innovative technologies and process optimization mechanisms that could make CO2 capture more efficient.
The first speaker, Kunlei Liu (University of Kentucky), emphasized the balance required for process intensification especially with capture solvents since no perfect solvent exists. In the presentation, he demonstrated how his research team carried out process intensification of a CO2 capture facility. The resulting technology allows for the use of any amine-based solvent for CO2 capture, thereby making the facility independent of a specific solvent. When commercialized, it is expected to possess a 5% performance margin between different amine-based solvents. The technology has a 10% derate and would capture 1,700,00 tonnes of CO2/year at an estimated cost of $48.6/tonne with a plant thermal efficiency of 48%.
The second speaker, Kyra Sedransk Campbell (University of Sheffield & UKCCSRC), made a presentation on the challenge associated with corrosion for post-combustion CO2 capture using aqueous amine solutions. Carbon steel was used to demonstrate the corrosion challenge. During the corrosion process, initial oxidation, and dissolution of Fe ions from the ferrite phase was observed. This dissolution increases with time causing a precipitated solution of Fe-oxides. To understand the Fe-complexation in the solution, the solution was heated to 40C and 80C, and changes were observed in the increase to 80C consistent with octahedral and diiron Fe2+ complexes. This increase was linked to an increase in the coordination number and coexistence of some Cu2+. On probing the effect of Cu-complexation using electrochemical impedance spectroscopy, it was observed that addition of CuCO3 causes increase in charge transfer resistance thereby suppressing the anodic process.
In the final presentation, Enrico Andreoli (University of Swansea) and his team successfully scaled up F4_MIL-140 (ce), a Metal Organic Frame (MOF) for next generation carbon capture. The MOF was synthesized from Cerium Ammonium Nitrate and Tetrafluoroterephthalic acid linkers and was scaled up from 200mg to 100g. This corresponds to a 500-fold scale-up. The MOFs were reported to exhibit high CO2 selectivity and the result of a performance study on the MOFs showed a non-hysteretic step-shape CO2 adsorption isotherm. The advantages of these advanced materials include operational speed and environmental safety. However, a major benefit to the application of these MOFs is the use of pressure swing as a desorption technique which is less energy intensive compared to amine-based systems. Currently, progress is being made in shaping the F4_MIL-140 and the proposed estimated large-scale production cost is £16/kg (200 tonnes/year). Going forward, more comprehensive studies will be performed on the F4_MIL-140 to confirm its cycle capacity, mechanical stability and degradation.
The vital role that carbon capture plays in ensuring global warming is limited by 1.5ºC less than pre-industrial era over the next century can’t be over emphasized. Therefore, it is no surprise that this session stirred up several conversations regarding new possibilities at achieving optimal and efficient CO2 capture. Furthermore, an observed trend during the session is the collaboration and exchange of ideas between industry and researchers. This synergy is a crucial step that will define the success of CCS in the coming decade.