针对硫回收装置对酸性气中H₂S摩尔分数有要求的问题，提出了一种能耗低并且能够显著提高系统出口酸性气中H₂S摩尔分数的工艺方案。采用模拟手段，对富甲醇热闪蒸及再生工艺流程进行了优化改进；对改进后的富甲醇热闪蒸汽提再生工艺原料气适应性进行了计算分析，探讨了改进后的提浓工艺机理，得到了汽提塔理论板数。研究结果表明，针对低硫进料气，通过热闪蒸及预提浓后酸性气中H₂S摩尔分数能达到40%及以上。改进的酸性气提浓工艺可调节的操作参数多，适应性强，对于更低硫含量的原料气，酸性气产品中的H₂S也能得到充分提浓。此外，新的提浓工艺具有投资低、操作费用节省的优点。

Aiming at the requirement of sulfur recovery unit for H₂S concentration in acidic gas,a process scheme with low energy consumption and significant improvement of H₂S concentration in acidic gas at the outlet of the system is proposed.By means of calculation and simulation,the methanol-rich thermal flash and regeneration process is optimized and improved.The adaptability of feedstock gas for the improved methanol-rich hot flash steam extraction regeneration process is calculated and analyzed.The mechanism of the improved process is discussed,and the theoretical plate number of gas stripper is obtained.Study results show that the concentration of H₂S in acidic gas can exceed 40% after the feed gas with a low sulfur content has been treated through hot flash and preconcentration.The improved acidic gas extraction and concentration process has many adjustable operating parameters and strong adaptability.For feedstock gas with lower sulfur content,H₂S in acidic gas can be fully concentrated.Moreover,the new concentration process possesses the advantages such as low investment,saving operation cost,etc.