Abstract:

Temperature-swing adsorption is an effective technique for CO₂ capture, but the temperature swing procedure is energy-intensive, especially the heating and cooling processes. The low-energy-consumption temperature-swing system is realized by using polypyrrole-based nitrogen-doped porous carbon PPy-650 which combines passive radiative cooling and solar heating. During the adsorption process, the adsorbent layer is coated with a layer of hierarchically porous poly (vinylidene fluoride-co-hexafluoropropene) [P(VdF-HFP)_HP], which can cool the adsorbents to a sub-ambient temperature under sunlight through radiative cooling. For desorption, PPy-650 with excellent photothermal conversion ability is exposed to light irradiation for heating. The heating and cooling process is driven entirely by solar energy without any energy input. The regeneration of PPy-650 was investigated by means of adsorption-desorption cycles carried out at 700 W/m². The results demonstrate that PPy-650 has a good CO₂ working capacity (35.69 cm³/g) in this temperature-swing adsorption system, the adsorption capacity of PPy-650 did not decrease.

Key words: CO₂ capture, adsorption, solar energy, radiative cooling, N-doped porous carbon

摘要：

变温吸附是一种有效的二氧化碳(CO₂)捕集技术，但变温过程需要消耗大量能量，尤其是加热和降温过程。将被动辐射制冷和太阳能加热相结合并应用于聚吡咯基氮掺杂多孔碳PPy-650对CO₂的捕集过程，从而实现变温系统的低能耗。在吸附过程中，聚(偏氟乙烯-六氟丙烯)膜[P(VdF-HFP)_HP]覆盖于吸附剂层，在太阳光照射下通过辐射冷却效应将吸附剂冷却至室温以下。对于脱附过程，将具有优异光热转换能力的PPy-650暴露在太阳光下，利用光能进行加热。整个加热和冷却过程完全由太阳能驱动，不需要额外消耗能量。700 W/m²模拟光下的吸附-脱附循环测试结果表明，PPy-650在这一变温吸附系统中具有良好的CO₂工作容量(35.69 cm³/g)。经过真实太阳光下的吸附/脱附循环后，PPy-650的吸附能力未见下降。

关键词: CO₂捕集, 吸附, 太阳能, 辐射制冷, 氮掺杂多孔碳