Rosu Cornelia, Pang Simon H, Sujan Achintya R, Sakwa-Novak Miles A, Ping Eric W, Jones Christopher W
School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
Global Thermostat LLC, 311 Ferst Drive, Atlanta, Georgia 30332, Unites States.
ACS Appl Mater Interfaces. 2020 Aug 26;12(34):38085-38097. doi: 10.1021/acsami.0c09554. Epub 2020 Aug 12.
Physical aging or degradation of amine-containing polymers and supported amine adsorbents is a critical issue that could limit the practical application of such materials for CO capture. However, to date, there is a scarcity of studies that evaluate the long-term stability of amine-based sorbents without the exclusive use of accelerated aging tests. Here, we demonstrate that extended aging (∼2 years) of linear poly(propylenimine) (LPPI) confined in mesoporous silica (SBA-15) supports does not drastically impact the CO adsorption performance under simulated flue gas (10% CO) and direct air capture (DAC, 400 ppm CO) conditions, although the behavior of the aged sorbents and polymers in the two CO concentration regimes differs. The sorbents made with aged LPPI have modestly decreased CO uptake performance (≲20% lower) compared to the fresh polymers, with overall good CO cycling performance. The data indicate that only slow degradation occurs under the deployed ambient storage conditions. Even after extended aging, the LPPI-based sorbents preserved their ability to display stable temperature-swing cycling performance. In parallel, the impact of blending LPPI polymers of different number-average molecular weights, , is evaluated, seeking to understand its impact on adsorbent performance. The results demonstrate that the blends of two aged LPPI give similar CO adsorption performance to adsorbents made from a single LPPI, suggesting that molecular weight will not negatively impact adsorbent performance in the studied range. After an accelerated oxidation experiment, the aged LPPI sorbents retained a larger portion of the samples' original performance when cycling under simulated flue gas conditions than under DAC conditions. However, in each case, the oxidized sorbents could be cycled repeatedly with consistent uptake performance. Overall, these first of their kind extended aging tests suggest that LPPI-based amine adsorbents offer promise for long-term, stable use in carbon capture applications.
含胺聚合物和负载型胺吸附剂的物理老化或降解是一个关键问题，可能会限制此类材料在二氧化碳捕集中的实际应用。然而，迄今为止，缺乏在不单独使用加速老化试验的情况下评估胺基吸附剂长期稳定性的研究。在此，我们证明，限制在介孔二氧化硅（SBA - 15）载体中的线性聚（丙烯亚胺）（LPPI）经过长时间老化（约2年）后，在模拟烟道气（10%二氧化碳）和直接空气捕集（DAC，400 ppm二氧化碳）条件下，其二氧化碳吸附性能不会受到显著影响，尽管老化吸附剂和聚合物在两种二氧化碳浓度条件下的行为有所不同。与新鲜聚合物相比，由老化LPPI制成的吸附剂的二氧化碳吸收性能略有下降（降低幅度≲20%），但总体二氧化碳循环性能良好。数据表明，在实际储存环境条件下仅发生缓慢降解。即使经过长时间老化，基于LPPI的吸附剂仍保持其展示稳定变温循环性能的能力。同时，评估了不同数均分子量的LPPI聚合物共混的影响，以了解其对吸附剂性能的影响。结果表明，两种老化LPPI的共混物与由单一LPPI制成的吸附剂具有相似的二氧化碳吸附性能，这表明在所研究的范围内分子量不会对吸附剂性能产生负面影响。经过加速氧化实验后，老化的LPPI吸附剂在模拟烟道气条件下循环时比在DAC条件下保留了更大比例的样品原始性能。然而，在每种情况下，氧化后的吸附剂都可以以一致的吸收性能反复循环。总体而言，这些首次进行的长时间老化试验表明，基于LPPI的胺吸附剂在碳捕集应用中具有长期稳定使用的潜力。
