STAR丙烷脱氢工艺中深冷单元操作条件为3.20 MPa、-78℃，一方面反应产物中大量氢气随之压缩，另一方面需深度脱水，能耗高。可通过在产物预冷之后采用膜分离协同分离氢气、脱除水分并进行梯级压缩来改进该工艺。以35万t/a STAR工艺为例，引入3 000 m²的prism-Ⅱ膜单元进行改进后，渗余气含水质量分数降至0.9×10^-6，可省去干燥塔及解吸气压缩功190 kW；同时，梯级压缩功为6540 kW，较改进前节约310 kW；氢气摩尔分数由82.8%提高到95.9%，年产氢量约1.24亿m³，新增经济效益9 070万元/a。

In STAR propane dehydrogenation (PDH) process,the operating conditions for cryogenic unit include 3.20 MPa and -78℃.On the one hand,a considerable amount of hydrogen is compressed with reaction effluent;on the other hand,the process needs deep dehydration,which leads to excessive energy consumption.In this work,hydrogen separation membrane is utilized behind the products pre-cooling unit to perform synergic hydrogen separation,dehydration and cascade compression.Taking a typical 350 000 t/a STAR PDH plant for instance,if a 3 000 m² Prism-II membrane unit is added,the water content in residual gas can be reduced to 0.9×10^-6,which can omit the drying tower and save 190 kW of energy consumption in desorption gas compression.Meanwhile,the power for cascade compression is 6 540 kW,310 kW lower than that in the traditional process.The mole fraction of hydrogen can be improved from 82.8% to 95.9% and the hydrogen production is around 124 million Nm³/a.Annual gross profit can be increased by RMB 90.7 million.

肖红岩(1993-),男,硕士生