Recovery of H₂ and N₂ from the tail gases of the ammonia synthesis plant could significantly improve the ammonia output and economic benefits. In this work, we measured the formation conditions of tail gas hydrates, conducted separation of tail gases via hydrate formation in tetrahydrofuran (THF) and ammonia solution, and proposed a two-stage separation process. The separation effects of temperature, pressure, and gas–liquid ratio (GLR) were investigated as well. The results show that the two-stage separation can effectively remove CH₄ from the tail gases. The total concentration of H₂ and N₂ in gas products is more than 94 mol %, with a recovery of up to 95%.

中文翻译：

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氨合成尾气的两步分离，通过水合物形成回收H ₂和N ₂

从氨合成装置的尾气中回收H ₂和N ₂可以显着提高氨的产量和经济效益。在这项工作中，我们测量了尾气水合物的形成条件，通过在四氢呋喃（THF）和氨溶液中形成水合物进行尾气分离，并提出了一个两阶段的分离过程。还研究了温度，压力和气液比（GLR）的分离效果。结果表明，两步分离可有效去除尾气中的CH ₄。气体产品中H ₂和N ₂的总浓度超过94 mol％，回收率高达95％。