Abstract:

To achieve carbon peaking and neutrality targets, the development of efficient carbon capture technologies is essential. Membrane absorption, which integrates chemical absorption with emerging membrane technology, holds advantages of both methods. However, its absorption performance is restricted by membrane wetting. In this study, a superhydrophobic PVDF membrane was prepared via in-situ FeOOH growth and low surface energy substance grafting. The successful modification of superhydrophobic FeOOH/PVDF membrane was confirmed through scanning electron microscope, Fourier infrared spectrometer, X-ray photoelectron spectroscopy, contact angle analyzer, etc. The static water contact angle of the modified membrane was 152.6° and the rolling angle was 8.2°, proving it's superhydrophobic. CO₂ membrane absorption experiments revealed that the modified membrane held CO₂ removal rate that higher than 50% under various operating conditions, showing good absorption performance. In a 40-hours membrane absorption experiment, the modified membrane consistently maintained an average absorption flux of 4.4mmol/(m²∙s), while the pristine membrane got wet within 20hours and its flux decreased to 2.8mmol/(m²∙s), proving the significant role of superhydrophobic modification in enhancing the membrane's lifespan.

Key words: iron hydroxide oxide, superhydrophobic membrane, membrane contactor, membrane absorption, carbon dioxide

摘要：

为了实现“双碳”目标，开发高效的碳捕集技术至关重要。膜吸收技术耦合了化学吸收法与新兴的膜技术，兼具两者的优点，但其吸收效果受限于膜的润湿性。本文采用FeOOH原位生长协同低表面能物质的修饰对商业PVDF膜进行了超疏水改性。使用扫描电子显微镜、傅里叶变换红外光谱仪、X射线光电子能谱仪和接触角测量仪等分析仪器证实了超疏水F/FeOOH/PVDF膜的成功制备。改性膜的静态水接触角为152.6°、滚动水接触角为8.2°，具有超疏水性。通过膜吸收CO₂实验发现，在多种操作条件下改性膜的CO₂脱除率均高于50%，表现出良好的CO₂膜吸收性能。在40h的膜吸收实验中，改性膜维持了平均4.4mmol/(m²∙s)的稳定吸收通量，而原膜在20h内润湿，通量下降到了2.8mmol/(m²∙s)，表明超疏水改性对提升膜的抗润湿性发挥了显著作用。

关键词: 羟基氧化铁, 超疏水膜, 膜接触器, 膜吸收, 二氧化碳