Replacement or debottlenecking of the extremely energy-intensive cryogenic distillation technology for the separation of ethylene from ethane has been a long-standing challenge. Membrane technology could be a desirable alternative with potentially lower energy consumption. However, the current key obstacle for industrial implementation of membrane technology is the low mixed-gas selectivity of polymeric, inorganic or hybrid membrane materials, arising from the similar sizes of ethylene (3.75 Å) and ethane (3.85 Å). Here we report precise molecular sieving and plasticization-resistant carbon membranes made by pyrolysing a shape-persistent three-dimensional triptycene-based ladder polymer of intrinsic microporosity with unparalleled mixed-gas performance for ethylene/ethane separation, with a selectivity of ~100 at 10 bar feed pressure, and with long-term continuous stability for 30 days demonstrated. These submicroporous carbon membranes offer opportunities for membrane technology in a wide range of notoriously difficult separation applications in the petrochemical and natural gas industry.

更换或消除用于分离乙烯和乙烷的极其耗能的低温蒸馏技术的瓶颈一直是一个长期的挑战。膜技术可能是一种理想的替代方案，具有较低的能耗。然而，目前膜技术工业化应用的主要障碍是由于乙烯（3.75 Å）和乙烷（3.85 Å）尺寸相似，聚合物、无机或杂化膜材料的混合气体选择性较低。在这里，我们报告了通过热解具有固有微孔性的形状持久的三维三蝶烯基梯形聚合物而制成的精确分子筛分和抗塑化碳膜，具有无与伦比的混合气体性能，用于乙烯/乙烷分离，在10时选择性约为100 bar 进料压力，并经过 30 天的长期连续稳定性证明。这些亚微孔碳膜为膜技术在石化和天然气工业中各种众所周知的困难分离应用中提供了机会。