As a highly toxic gas, H₂S is conventionally removed via a chemical absorption process. However, the high regeneration energy is still a challenge. 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN)/polyethylene glycol dimethyl ether (NHD) solution was developed as an efficient nonaqueous phase change absorbent for the removal of H₂S with low energy consumption. A homogeneous DBN/NHD solution turns into two immiscible liquid phases upon the absorption of H₂S, which results from the higher polarity of the product compared to that of the original solution. The loading capacity of H₂S can reach 0.16 g·g^–1 solvent even under a H₂S partial pressure of 10 kPa at 30 °C. After absorption, more than 94% of the absorbed H₂S is concentrated in the lower phase, which can be regenerated at 90 °C with an energy consumption estimated to be 1.69 GJ·t^–1 H₂S. The regeneration energy is 58% lower than that of 30 wt % aqueous solution of N-methyldiethanolamine. 81% of the initial H₂S loading was maintained after 4 absorption–desorption cycles. In addition, the selectivity of DBN/NHD solution to absorb H₂S from N₂ containing H₂S and CO₂ or from N₂ containing H₂S and CH₄ was investigated. It shows that the selectivity increases with the increase in the volume ratio of H₂S to CO₂, which can be as high as 27.8 when the ratio is 1:1. CH₄ cannot be absorbed in the DBN/NHD solution in the presence of H₂S and N₂.

中文翻译：

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用于吸收 H2S 且能耗低的高效非水相变吸收剂

_{H 2} S作为一种剧毒气体，通常通过化学吸收工艺去除。然而，高再生能量仍然是一个挑战。 1,5-二氮杂双环[4.3.0]壬5-烯(DBN)/聚乙二醇二甲醚(NHD)溶液被开发为一种高效的非水相变吸收剂，用于以低能耗去除H ₂ S。均匀的DBN/NHD溶液在吸收H ₂ S后变成两个不混溶的液相，这是由于产物的极性比原始溶液的极性更高。即使在30 ℃、10 kPa 的H _{2 S 分压下，H 2} S的负载量也可以达到0.16 g·g ^–1溶剂。吸收后，94%以上的H ₂ S集中在下相，可在90℃下再生，能耗估计为1.69 GJ·t ^–1 H ₂ S。再生能量为58比30wt％ N-甲基二乙醇胺水溶液低50％。 4次吸收-解吸循环后，初始H ₂ S负载量保持在81%。另外，研究了DBN/NHD溶液从含有H ₂ S和CO ₂的N ₂或从含有H ₂ S和CH _{4的N 2中吸收H 2 S的选择性。结果表明，随着H 2} S与CO ₂体积比的增加，选择性增加，当体积比为1:1时，选择性可高达27.8。在H ₂ S和N ₂存在下，CH ₄不能在DBN/NHD溶液中被吸收。