MTBE装置转产叠合油工艺及优化措施  

Process and Optimization Measures for Oligomer Production by Revamping MTBE Unit

作　　者：刘成军 Liu Chengjun(CNPC East-China Design Institute Co.,Ltd.,Qingdao Shandong 266071)

机构地区：[1]中石油华东设计院有限公司,山东青岛266071

出　　处：《中外能源》2021年第10期79-86,共8页Sino-Global Energy

基　　金：中国石油集团工程股份有限公司科研课题“MTBE转产异辛烷的工艺研究与开发”(编号:2018ZYGC-04-11)。

摘　　要：某异丁烯选择性叠合装置由闲置的MTBE装置改造而成,采用"预反应+催化蒸馏+萃取塔+回收塔"工艺流程生产以二异丁烯为主要组分的叠合油,操作条件缓和,产品辛烷值、终馏点等满足设计要求,但由于在生产过程中会产生叔丁醇-水共沸物,水与其他组分会发生反应生成仲丁醇等副产物并不断累积,造成异丁烯转化率及产品纯度下降,有必要对该流程进行优化。优化措施主要包括共沸精馏、萃取精馏、反应精馏、催化蒸馏塔侧线抽出、变压精馏。前三种是在现有流程基础上将叔丁醇从其与水的共沸物中分离出去,分别需要从外部引入共沸剂、萃取剂、反应剂,增加了叠合工艺的复杂性;后两种取消了现有流程中的萃取塔和回收塔,不需要添加外部介质,并可实现含醇污水零排放,对环境更加友好。上述5种方法各有特点,由于催化蒸馏塔侧线抽出流程简单,设备和操作费用低,在不过度追求产品纯度的前提下建议优先选用。An isobutene selective polymerization unit,which was revamped from an idle MTBE unit,adopts the process flow of pre-reaction,catalytic distillation,extraction tower and recovery tower to produce oligomer oil with diisobutylene as the main component.The operation conditions are mild,and the octane number and final boiling point of the product meet the design requirements.However,tert-butyl alcohol/water azeotrope will be generated during the production,and the water in the azeotrope reacts with other components to form secbutyl alcohol and other by-products,which will continuously accumulate,resulting in the decrease of isobutene conversion and product purity.Therefore,it is necessary to optimize the existing process flow.The optimization measures include azeotropic distillation,extractive distillation,reactive distillation,side draw of catalytic distillation column and pressure swing distillation.The first three methods separate the tert-butyl alcohol from its azeotrope with water on the basis of the existing process by introducing azeotrope,extractant and reactant respectively from the outside,increasing the complexity of the process.The last two methods eliminate the extraction tower and recovery tower in the existing process flow,need no external media,and can realize zero discharge of alcohol-containing wastewater,so they are more friendly to the environment.Each of the above five methods has its own characteristics.Without excessive pursuit of product purity,it is recommended to give priority to the side draw of catalytic distillation column due to its simple process flow and low equipment and operation cost.

关 键 词：异丁烯 选择性叠合 优化措施 共沸精馏 萃取精馏 反应精馏 催化蒸馏塔侧线抽出 变压精馏 

分 类 号：TE626.21[石油与天然气工程—油气加工工程]