SMART - Solvent Management At Reduced Throughput – A Prototype Demonstration Plant

Joel, Lucas; Pokora, Marcin; Ibrahim, Aisha; Lucquiaud, Mathieu; Michailos, Stavros; Gibbins, Jon

Abstract

It is important to verify in advance by pilot testing that amine solvents used for a post-combustion capture application can be maintained in good condition indefinitely and that emissions can be kept at acceptable levels as the solvent ages. UK permitting guidance now recommends that this is done on a slipstream of the actual flue gas for extended periods (e.g. 8000 hrs or longer) with realistic process conditions, including full reclaiming and other solvent management techniques. This would ideally be done in a large pilot unit (e.g. 0.4 m diameter columns, ~ 10tCO2/day) to give realistic column packing performance, but equipment costs are of the order £10M or more. Also, with many potential UK sites with different, specific flue gas characteristics, and a number of potential solvents, the UK CCS sector would require multiple parallel tests to take place, and sharing of a small number of large facilities would not be feasible. And, of course, if different approaches are to be tested and each test takes many months that it is virtually essential to be able to run multiple tests in parallel.
To this direction, this paper describes fundamental laboratory research on the interaction between reclaiming and full PCC cycle operation. The equipment being developed at the University of Sheffield is representative, but small scale, of testing of amine post-combustion capture applications, and includes on-site use by UK industry. Features in the design include: integrated thermal reclaimer, externally heated reboiler with low skin temperatures to avoid thermal degradation hot spots, acid wash for emission control, absorber with low-liquid loading packing to give a ‘short, fat’ absorber (for easier transport and location on site) that can still achieve representative solvent loadings.
The immediate objective is to build a laboratory version of the SMART equipment that will determine the design details for future units to be used on commercial sites. Building a prototype unit for use in laboratory setting very importantly allows modifications to be undertaken quickly in service – this is a novel system, and it will no doubt be necessary to adjust aspects of the equipment to achieve the desired performance. The prototype will also not be designed for unattended or fully automatic operation, which very significantly reduces costs and complexity (crucially, given the limited funds available) – but adding this capability in ‘production’ units is a routine matter once the fluid flow and heat and mass transfer aspects of the design and operation have been researched and defined. It will, however, be possible to run the prototype unit with minimal or no manual intervention for long periods, allowing extended trials as ‘background activity’ in the laboratory.
Reclaimer trials and full SMART operation is able to start with a charge of aged MEA from the TERC 1 tCO2 day-1 unit to give accelerated results. Operation in the laboratory environment will also allow novel analytical techniques, such as online solvent concentration and loading measurements to be refined under realistic circulating-solvent conditions.
Anticipated CO2 capture rates are 20-100 kg CO2/day, depending on flue gas. Novel features include:
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Integrated reclaiming – based on previous UKCCSRC/industry-funded PCC-CARER research.
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Realistic desorber/reboiler pressures and hence temperatures –essential to match thermal degradation effects – the pressurised desorber also allows direct feed to a ‘short, fat’ absorber without pumping.
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Realistic solvent loadings – the absorber will use low-liquid-loading gauze packing to give a relatively ‘short, fat’ column, making the unit much easier to locate and move.
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Realistic solvent cycling rate – the number of solvent cycles per day and residence times at different stages in the cycle will also be reproduced, based on detailed commercial plant data available.
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Realistic flue gas conditioning and absorber exit emission countermeasures –water and acid washes will be included as separate columns, giving flexibility in reproducing different equipment options.
The reclaimer is initially being tested in a standalone mode before integration with the rest of the SMART rig.

Citation

Joel, L., Pokora, M., Ibrahim, A., Lucquiaud, M., Michailos, S., & Gibbins, J. (2024, October). SMART - Solvent Management At Reduced Throughput – A Prototype Demonstration Plant. Presented at 17th Greenhouse Gas Control Technologies Conference (GHGT-17), Calgary, Canada

• Presentation Conference Type: Conference Paper (published)
• Conference Name: 17th Greenhouse Gas Control Technologies Conference (GHGT-17)
• Start Date: Oct 20, 2024
• End Date: Oct 24, 2024
• Acceptance Date: Dec 19, 2024
• Online Publication Date: Dec 20, 2024
• Deposit Date: Mar 18, 2025
• Publicly Available Date: Mar 31, 2025
• Journal: SSRN
• Print ISSN: 1556-5068
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.2139/ssrn.5064129
• Keywords: Amine post-combustion capture; Solvent management; Reclaiming
• Public URL: https://hull-repository.worktribe.com/output/5085207