We used Aspen HYSYS V.10 simulations and techno-economic analysis to evaluate the potential of four hybrid membrane-cryogenic distillation flowsheets for the direct recovery helium from nitrogen and methane in pre-treated natural gas (i.e., CO₂, H₂S, and water removed from the gas). The study aims to increase energy efficiency and reduce the cost of helium recovery from natural gas by better integration of the helium recovery unit (HeRU) with the nitrogen rejection unit (NRU) and methane production. Our results demonstrate that a flowsheet (Design # d) with a distillation column that produces a 90 mol% He overhead stream that is further purified in a single-stage membrane unit can produce grade-A helium with better than 99 mol% He purity at a specific helium breakeven price (SHBP) of $67.72/MSCF of He product. This hybrid flowsheet leads to the lowest SHBP because (i) it reduces the separation load in the HeRU column, (ii) provides a high He concentration feed to the membrane unit, and (iii) does not require recompression of the HeRU overhead stream to feed the membrane unit because the pressure of the feed gas is not let down to close to atmospheric pressure as in a conventional NRU-HeRU flowsheet. This type of hybrid distillation-membrane process may also be of interest in other gas separations that currently only use cryogenic distillation such as oxygen and argon production from air, CO₂ capture, and olefin/paraffin separation.

我们使用Aspen HYSYS V.10模拟和技术经济分析来评估四种混合膜-低温蒸馏流程图在预处理天然气（即CO ₂，H _2）中直接从氮气和甲烷中回收氦气的潜力S，并从气体中除去水）。这项研究旨在通过更好地整合氦回收单元（HeRU）与脱氮单元（NRU）和甲烷生产来提高能源效率并降低从天然气中回收氦的成本。我们的结果表明，带有蒸馏塔的流程图（设计＃d）可产生90 mol％的He塔顶物流，并在单级膜单元中进一步纯化，可生产出纯度高于99 mol％的A级氦。 He产品的特定氦平衡价（SHBP）为$ 67.72 / MSCF。该混合流程可产生最低的SHBP，因为（i）降低了HeRU色谱柱中的分离负荷，（ii）为膜单元提供了高He浓度的进料，（iii）不需要再压缩HeRU塔顶物流以进料膜单元，因为进料气的压力没有像常规的NRU-HeRU流程图那样降低到接近大气压。这种类型的混合蒸馏-膜工艺也可能在当前仅使用低温蒸馏的其他气体分离中引起关注，例如从空气，CO中产生氧气和氩气₂捕集，并进行烯烃/石蜡分离。