硫化氢吸收塔的碱液复配和运行参数优化

Optimization of H_(2)S Absorption Performance in Simulated Alkali Washing Tower

为解决目前NaOH碱液吸收塔在去除硫化氢气体(H_(2)S)过程中存在的高p H值碱液导致设备易腐蚀,以及成本过高的问题,采用自搭建的碱液吸收塔,通过加入成本更低的Na_(2)CO_(3)进行复配来缓冲碱液p H值。运用单一变量原则,以硫化氢去除率为指标,先对纯Na OH溶液和纯Na_(2)CO_(3)溶液作为碱洗液时吸收塔的运行参数(气液比、p H值和冲淋液温度)进行优化;再测定纯Na OH溶液、纯Na_(2)CO_(3)溶液,以及两者体积比分别为4∶1和3∶2的复配碱液对H_(2)S的去除率,以确定两种碱液最佳的复配体积比。实验结果表明,碱液吸收塔最佳运行参数为:气液比为60∶1,p H值为11,冲淋液温度为35℃,两种碱液的最佳复配体积比为4∶1。在该参数下,碱液吸收塔对浓度为20 mg·m^(-3)的H_(2)S气体去除率达93.05%,分别比纯Na OH溶液、纯Na_(2)CO_(3)溶液高3.82%、11.16%左右。

To reduce the high corrosion rate and high cost caused by the high pH value of the NaOH alkaline solution in removing hydrogen sulfide gas(H_(2)S)in the NaOH washing tower,this experiment reduces the pH value of the alkaline solution by adding a lower-cost Na_(2)CO_(3) to the NaOH solution,using a self-built alkaline washing tower.The single-variable principle is adopted with the removal rate of H_(2)S as the indicator,and the operational parameters(gas-liquid ratio,pH value,and scrubbing liquid temperature)of pure NaOH solution and pure Na_(2)CO_(3) solution as scrubbing solutions are optimized.Then,the H_(2)S removal rate of pure NaOH solution,pure Na_(2)CO_(3) solution,and mixtures of the two with a volume ratio of 4∶1 and 3∶2 respectively are determined,and the optimal volume ratio of the two alkaline solutions is thus acquired.The experimental results show that the optimal operational parameters of the alkaline absorption tower are:gas-liquid ratio at 60∶1,pH value at 11,scrubbing liquid temperature at 35℃,and the optimal volume ratio of pure NaOH solution and pure Na_(2)CO_(3) solution at 4∶1.Under these parameters,the removal rate of H_(2)S gas with a concentration of 20 mg·m-3 in the alkaline absorption tower reaches 93.05%,about 3.82%higher than that of pure NaOH solution and 11.16%higher than that of pure Na_(2)CO_(3) solution.