天然气脱硫醇工艺评述

A review on demercaptan process of natural gas

关键词:  物理化学混合溶剂法  砜胺法  混合胺  分子筛法  脱水  脱硫醇  LE-703溶剂  HySWEET工艺 

Key words:  physico-chemical mixed solvent method  sulfinol process  mixed amines  molecular sieve method  dehydration  demercaptan  LE-703 solvent  HySWEET process

摘要:

介绍了物理化学混合溶剂法、(新型)混合胺法及分子筛法等3种从天然气中脱除硫醇工艺的技术要点,同时指出:①物理化学混合溶剂法的硫醇脱除率通常可达到90%以上,但不宜应用于重烃含量较高的油田伴生气；②添加活化剂后的新型混合胺溶剂的甲硫醇脱除率可提高至约90%,再生酸气中烃摩尔分数则降至≤1.25%；③对于硫醇含量高的原料气,要求净化后硫醇质量浓度≤16 mg/m³时,宜采用“粗脱+精脱”的“1+1”工艺；④分子筛法脱水脱硫醇的工艺比较复杂,特别是在处理油田伴生气时,涉及水、硫醇与重烃三者之间的相互影响与干扰,且不同的原料气组成及产品气净化度要求均与分子筛品种选择及相应操作参数的确定密切相关。 

Abstract:

The technical features of three demercaptan methods from natural gas were introduced which include physico-chemical mixed solvent, mixed amine process and molecular sieves process. It could also be concluded that:①the demercaptan efficiency of physico-chemical mixed solvent might reach over 90%, but it was inapplicable for the associated gas containing higher content of heavy hydrocarbons; ②methyl mercaptan removal efficiency of new mixed amine solvent with active agents might reach about 90% and mole fraction of hydrocarbon in acid gas would decrease to ≤1.25%; ③for the raw gas containing high content of mercaptan, when mercaptan mass concentration ≤16 mg/m³ was required in purified gas, using “rough removal + refine removal”(“1+1” technology) might be suitable; ④the process of simultaneous removal of water and mercaptan by molecular sieves was complex and especially for treating associated gas there were a lot of mutual influence and interfere among water, mercaptan and heavier hydrocarbon. In addition the raw gas composition and purified gas requirements were closely related to the selection of molecular sieves and their operating parameters.