烷氧基丙胺类新型溶剂分子设计及其脱除高酸性天然气中硫醇  

Designing novel alkoxypropylamine solvents for removing mercaptans from high-acidity natural gas

作　　者：刘传磊 陈宇翔 郭冠初 赵起越 姜豪 孙辉 沈本贤[1] LIU Chuanlei;CHEN Yuxiang;GUO Guanchu;ZHAO Qiyue;JIANG Hao;SUN Hui;SHEN Benxian(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;International Joint Research Center of Green Energy Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;Key Laboratory of Oil&Gas Fine Chemicals,Ministry of Education&Xinjiang Uyghur Autonomous Region,Xinjiang University,Urumqi 830046,Xinjiang,China)

机构地区：[1]华东理工大学化工学院,上海200237 [2]华东理工大学绿色能源化工国际联合研究中心,上海200237 [3]新疆大学石油天然气精细化工教育部重点实验室,新疆乌鲁木齐830046

出　　处：《化工进展》2025年第1期184-191,共8页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21878097,22178109);上海市自然科学基金(21ZR1417700)。

摘　　要：硫醇类化合物是酸性天然气中普遍存在的有害组分,相较于硫化氢和二氧化碳,硫醇类化合物的酸性和反应活性较低,难以通过传统的胺洗脱硫工艺实现深度脱除。本研究采用基于COSMO-RS理论的溶解度预测方法筛选了对甲硫醇具有理想溶解性能的溶剂,然后在小试吸收实验装置上评价了其对甲硫醇的脱除效率,进一步借助量化计算揭示了其高效吸收溶解甲硫醇的机制。结果表明,烷氧基丙胺化合物对甲硫醇具有较好的溶解性能;在气液比不高于250的吸收条件下,使用质量分数不低于20%的烷氧基丙胺溶液可将原料气中5%的硫化氢和933mg S/m^(3)(标准状况)的有机硫分别脱除至0和20mg S/m^(3)(标准状况)以下,净化气硫含量满足《天然气》(GB17820—2018)一类气指标要求;溶剂-溶质间弱相互作用分析表明,烷氧基丙胺通过较强的氢键作用和大面积范德华作用可高效捕获甲硫醇分子。Mercaptans are hazardous components commonly found in natural gas.Compared to hydrogen sulfide(H2S)and carbon dioxide(CO_(2)),mercaptans exhibit lower removal efficiency in the conventional amine-based absorption processes because of their lower acidity and reactivity.Herein,the solubility prediction methods based on COSMO-RS theory were employed to identify a kind of alternative solvents with promising dissolving performance.The removal efficiency of these solvents for methyl mercaptan was evaluated on a custom-made absorption apparatus using simulated high-acid natural gas as the feedstock.Furthermore,we employed quantum chemistry calculation to elucidate the mechanisms for dissolution of methyl mercaptan into these solvents.Present study demonstrates that the alkoxypropylamine solvents have effective solubility for methyl mercaptan,and the contents of hydrogen sulfide and organic sulfide can be reduced from 5%and 933mg S/m^(3)(standard condition)in the raw gas to 0 and less than 20mg S/m^(3)(standard condition)in the purified gas,respectively,by using alkoxypropylamine solutions with a concentration of no less than 20%(mass fraction)under the gas-to-liquid ratio of less than 250.The sulfur content of purified gas can meet the specification for Chinese first-grade commercial《Natural Gas》(GB17820-2018).Analyses on intermolecular interactions between the solvent and solute indicate that methyl mercaptan molecules can be captured in alkoxypropylamines via strong hydrogen bonding and big area van der Waals interaction.

关 键 词：天然气净化 甲硫醇 脱硫溶剂设计 烷氧基丙胺 相互作用 

分 类 号：TQ028.25[化学工程]