The synthesis of a Zirfon-type porous separator with reduced gas crossover for alkaline electrolyzer
The synthesis of a Zirfon-type porous separator with reduced gas crossover for alkaline electrolyzer
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DOI：
10.1002/er.5038
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发表时间：
2019-12-10
影响因子：
4.6
通讯作者：
Kim, Chang Hee
中科院分区：
文献类型：
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作者：
Lee, Hae In;Dao Thi Dung;Kim, Chang Hee
由于可再生能源的间歇性和不稳定性，其快速扩张对平衡电网提出了巨大挑战。剩余的能量不能被使用或出售，因此为了维持电网平衡而削减。多余的电力可以通过电力到天然气技术转化为气态能量载体氢气。碱性水电解可以大规模使用可再生能源以动态模式操作。然而，当电解槽在低部分负荷或高压下操作时，气体穿过多孔隔板的风险迅速增加，导致效率损失和安全问题。商业多孔隔板Zirfon PERL，由85wt%组成氧化锆纳米颗粒和15重量%聚砜表现出约2.5巴的令人满意的泡点压力性能和0.3 Ω cm（2）的离子电阻。然而，Zirfon PERL隔板由于其130 nm的大平均孔径而表现出20 × 10（-12）mol cm（-1）bar（-1）sec（-1）的高氢渗透率值，导致电解槽的有限动态范围。因此，有必要开发一种具有减少气体穿越的多孔分离器。在这项研究中，我们通过改变ZrO 2的量（75-85 wt.%）来合成多孔ZrO 2/聚砜复合隔膜。通过薄膜流延方法。75wt.% ZrO 2/25重量%与ZirfonPERL隔膜相比，含有少量ZrO 2的聚砜复合隔膜显示出3.8巴的高泡点压力、0.3 Ω cm（2）的低离子电阻，以及4.2 × 10（-12）mol cm（-1）巴（-1）秒（-1）的降低的氢渗透性。该隔膜的增强性能归因于约70 nm的减小的平均孔径和具有75度接触角的高表面润湿性。这一结果将有助于碱性电解槽系统作为更可控的负载运行。
The rapid expansion of renewable energy sources presents a great challenge to balance the electric grid due to their intermittent and volatile nature. The surplus energy generation cannot be used or sold so that it is curtailed in order to maintain the grid balance. The excess power can be converted into a gaseous energy carrier, hydrogen via power-to-gas technology. Alkaline water electrolysis can be operated in a dynamic mode using renewable energy sources on a large scale. However, the risk of gas crossover across a porous separator rapidly increases when the electrolyzer operates at a low partial load or at high pressure, leading to efficiency loss and a safety issue. The commercial porous separator Zirfon PERL, which is composed of 85 wt.% zirconia nanoparticles and 15 wt.% polysulfone, exhibits a satisfactory bubble point pressure performance of approximately 2.5 bar and ionic resistance of 0.3 omega cm(2). However, the Zirfon PERL separator exhibits a high hydrogen permeability value of 20 x 10(-12) mol cm(-1) bar(-1) sec(-1) due to its large average pore size of 130 nm, resulting in a limited dynamic range of the electrolyzer. Therefore, it is necessary to develop a porous separator with reduced gas crossover. In this study, we synthesize a porous ZrO2/polysulfone composite separator by varying the amount of ZrO2 (75-85 wt.%) via the film-casting method. The 75 wt.% ZrO2/25 wt.% polysulfone composite separator, which contains a low amount of ZrO2, shows a high bubble point pressure of 3.8 bar, a low ionic resistance of 0.3 omega cm(2), and are reduced hydrogen permeability of 4.2 x 10(-12) mol cm(-1) bar(-1) sec(-1) compared with that of Zirfon PERL separator. The enhanced performance of this separator is attributed to the reduced average pore size of around 70 nm and high surface wettability with a contact angle of 75 degrees. This result will help alkaline electrolyzer systems be operated as more controllable loads.