轻烃回收系统双塔流程改造的可行性分析

针对中国石油天然气股份有限公司独山子石化分公司10 Mt/a常减压装置所配套设置的脱乙烷塔的双塔流程,分析了轻烃回收系统干气组成、液态烃球罐存储条件、常一线热量处理、防腐和对装置及下游装置的影响等问题。探讨了双塔流程改造为单塔流程的可行性,确认液态烃可满足球罐储存压力要求;不会对常一线热处理造成影响;停用后的系统应采取有效的隔离和防腐措施。单塔流程还避免了干气憋压和切液对下游装置的影响;改造为单塔流程后,干气中的轻烃组分用作制乙烯原料,轻烃收率增加0.08百分点,总经济收益可达304万元/a。改造项目成本仅21.8万元。

Analysis of feasibility of technical revamping of double-tower process for light-end recovery system

Based upon the double-tower process de-ethanizer for the 10 MM TPY atmospheric-vacuum distillation unit,the analysis of compositions of dry gas of light-ends recovery system and the analysis of storage conditions of spherical tanks for liquid hydrocarbons,handling of heat from 1 st atmospheric sidedraw,corrosion protection and impact on the downstream unit,the feasibility of revamping the double-tower process into single-tower process is studied.The liquid hydrocarbons can meet the requirement of storage pressure of spherical tanks and will have no impact on the heat removal of from 1 st atmospheric sidedraw.Effective corrosion protection and separation measures have been adopted for the shutdown facilities.The single-tower process has avoided the impacts of pressure build-up of dry gas and liquid run down.After the revamping into the singletower process,the light hydrocarbons in the dry gas are used as the feedstock for ethylene production.The recovery rate of light hydrocarbons is increased by 0.08％.The total economic benefit is as high as 3.04 million Yuan (RMB) a year.The cost for revamping is only 218,000 Yuan (RMB).