降低液化石油气脱硫醇装置抽提后汽油钠含量探索及实践  

Exploration and practice of reducing sodium content inextracted gasoline of LPG de-mercaptan unit

作　　者：兰敏[1] 曹章 孙智华[1] Lan Min;Cao Zhang;Sun Zhihua(SINOPEC Guangzhou Company,Guangzhou,Guangdong 510725)

机构地区：[1]中国石油化工股份有限公司广州分公司,广东省广州市510725

出　　处：《炼油技术与工程》2024年第12期18-21,共4页Petroleum Refinery Engineering

基　　金：中国石油化工股份有限公司广州分公司项目(2023-Ⅱ-10)。

摘　　要：液化石油气脱硫醇装置多采用传统的Merox法,在生产过程中,再生碱性溶剂中含有的二硫化物均采用汽油抽提法脱除,致使抽提后汽油含有微量碱性物质,导致抽提后汽油钠含量及pH值升高,影响下游生产。研发了一条能有效降低抽提后汽油钠含量的工艺技术路线:增设物理沉降、水洗及吸附过滤工艺流程。结果表明:增设2个50 m3的沉降罐后,可延长22.2 h的油、碱分离时间,汽油钠质量分数由400 ng/g左右降至200 ng/g左右;于沉降罐入口增加注水流程,投用初期汽油中钠质量分数最低降至73 ng/g,但长期运行会出现钠含量回升及废碱排放量大等问题;采用分子筛过滤器过滤并充分沉降,可使汽油钠质量分数降至20 ng/g左右,总脱钠率高达95%。The traditional Merox process is commonly used in the de-mercaptan unit of LPG.During the production process,the disulfides contained in the regenerated alkaline solvent are removed by gasoline extraction,resulting in trace amounts of alkaline substances in the extracted gasoline,which increases the sodium content and pH value of the extracted gasoline and affects downstream production.The paper introduces a process technology route that can effectively reduce the sodium content in extracted gasoline:adding physical settling,water washing,and adsorption filtration processes.The results show that adding two 50 m 3 settling tanks can extend the separation time of oil and alkali by 22 hours,and the mass fraction of sodium in gasoline can be reduced from 400 ng/g to about 200 ng/g.Add a water injection process at the inlet of the settling tank reduces the sodium mass fraction in gasoline to a minmum of 73 ng/g during the initial use.However,during long-term operation of the device,problems such as a rise in sodium content and a large amount of waste alkali emissions may occur.By using a molecular sieve filter for filtration and sufficient settling,the sodium mass fraction in gasoline can be reduced to about 20 ng/g,with a total sodium removal rate of up to 95%.

关 键 词：液化石油气脱硫醇装置 抽提后汽油 钠含量 分离时间 物理沉降 沉降罐 吸附过滤 注水 

分 类 号：TE624.55[石油与天然气工程—油气加工工程]