低温甲醇洗在合成气净化工艺中的应用研究

Application of Methanol Cleaning at Subzero Temperature in Methanol Synthesis gas Purification Process

本文重点分析了低温甲醇洗技术的吸收机理和气提、精馏的工艺原理。利用甲醇在低温、高压的条件下对粗甲醇合成气中SO_(2)、H_(2)S、COS等酸性气体较高的溶解度,而对H_(2)、CO、N_(2)等有效成分较低的溶解度的定向选择性,通过气提改变气体分压和多次气液传质的操作实现对粗甲醇合成气中SO_(2)、H_(2)S、COS等杂质气体的脱除。酸性气体脱除后,吸收了CO_(2)、H_(2)S及COS的富甲醇还可通过减压、闪蒸及气提等工艺进行再生,该过程实现冷量回收,节约能源。

The absorb mechanism of methanol cleaning at subzero temperature and the process principle of gas stripping and distillation are analyzed emphatically in this paper.Using the directional selectivity of methanol to rich solubility of acidic gas such as SO_(2),H_(2)S and COS and poor solubility of active components such as H_(2),CO and N_(2) in impurity methanol synthesis gas under low temperature and high pressure conditions.The gas con impurezas such as SO_(2),H_(2)S,and COS in impurity methanol synthesis gas were removed by gas stripping to change partial pressure of gas and multiple gas-liquid mass transfer.After the acid gases were removed,the rich methanol which has absorbed CO_(2),H_(2)S and COS can also be regenerated through decompressing,flash evaporation and gas stripping.The cooling capacity was recoveried and the energy was saved in this process.