Solid-supported amine-dense polymer (aminopolymer) sorbents are one of the most promising classes of technology for CO2 capture. While this technology has continued to receive increased attention for implementation at the industrial scale, a key remaining challenge is improving the working lifetime of the sorbents. More specifically, the aminopolymers that are responsible for the CO2 capture mechanism undergo degradation upon exposure to atmosphere (particularly oxygen), which can be accelerated by the elevated temperatures typically required for sorbent regeneration (i.e. desorption of captured CO2). Increasing the stability of these sorbents is therefore critical towards improving the economic viability of the technology.
This invention solves a limitation in the current practice of adding hydroxyl functional groups to the aminopolymer through the use of an alternative synthetic approach. The novelty of our approach is to produce new structurally modified relatives of common aminopolymers (PEI and PPI) as well as new functionalized materials in which the hydroxyl groups are tethered to a carbon in the backbone of the polymer structural repeat unit rather than the amine. In doing so, materials containing up to a one-to-one ratio of hydroxyls to amines can be synthesized while retaining the same distribution of amine functionalities (primary, secondary, and tertiary amines) as the unmodified polymeric structure.
- Improves aminopolymer carbon sorbent stability against oxidation degradation.
- Maximizes the protective effect of hydroxyl groups without sacrificing CO2 uptake capacity.
- Achieves high hydroxyl to amine ratios without eliminating CO2 uptake capacity.
- Applicable to Polyethylenimine (PEI) and Polypropylenimine (PPI) derivatives.
- Allows for more efficient CO2 desorption / material regeneration at lower temperatures and energy requirements.
Direct Air Carbon Capture, especially from coal or natural gas burning power plant operations
Current stage of technology development: TRL 3
LLNL has filed for patent protection on this invention.