催化裂解装置液化石油气分离系统脱丙烷方案优化  

Optimization of depropanization scheme forliquefied petroleum gas separation system in catalytic cracking unit

作　　者：李春晓 Li Chunxiao(SINOPEC Guangzhou Engineering Co.,Ltd.,Guangzhou,Guangdong 510620)

机构地区：[1]中石化广州工程有限公司,广东省广州市510620

出　　处：《炼油技术与工程》2024年第7期1-4,共4页Petroleum Refinery Engineering

摘　　要：随着催化裂解装置裂解深度的增加,液化石油气中二烯烃含量增加。液化石油气分离常规流程中脱丙烷塔底温度约108℃,较高的温度增加了二烯烃聚合的可能性,影响装置运行周期和经济效益,国内几家催化裂解液化石油气分离装置的脱丙烷塔普遍存在塔釜和重沸器结焦堵塞的情况。在实际生产中为了缓解脱丙烷塔底结焦引起的停工等问题,通常在进料和塔底物料中加入阻聚剂,以降低物料聚合速率。文中分析了压力对脱丙烷体系相对挥发度和塔底温度的影响,得出较低的塔压有利于降低塔釜温度、提高轻重关键组分的相对挥发度,使分离更容易。塔压在0.9~1.1 MPa范围内较为合适,可将塔釜温度控制在80℃以下,在满足脱丙烷塔分离要求的前提下,减少因塔釜结焦造成的装置非计划停工。另外,文中从能耗和设备投资两方面对优化方案和常规方案进行了对比,优化方案能耗比常规方案降低约37%,主要设备投资也比常规方案低。As the cracking depth of the catalytic cracking unit increases,the content of alkadienes in the catalytic liquefied gas increases.The bottom temperature of the depropanizer in the conventional process of catalytic liquefied gas separation is about 108℃.The higher temperature increases the possibility of alkadiene polymerization,affecting the operating cycle and economic benefits of the unit.Several domestic catalytic cracking liquefied gas separation units commonly experience coking and blockage in the tower kettle and reboiler of the depropanizing tower.In actual production,in order to alleviate the shutdown caused by coking at the bottom of the depropanizer,polymerization inhibitors are usually added to the feed and bottom materials to reduce the polymerization rate of the materials.The article analyzes the influence of pressure on the relative volatility and bottom temperature of the depropanized system.Lower tower pressure is beneficial for reducing the tower kettle temperature,increasing the relative volatility of light and heavy key components,and making separation easier.The tower pressure is suitable within the range of 0.9-1.1 MPa,and the tower kettle temperature can be controlled below 80℃to reduce unplanned shutdown caused by coking of the tower kettle while meeting the separation requirements of the depropanizing tower.In addition,the article compares the optimized plan with the conventional plan in terms of energy consumption and equipment investment.The optimized plan reduces energy consumption by about 37%compared to the conventional plan,and the main equipment investment is also lower than the conventional plan.

关 键 词：催化裂解装置 液化石油气分离 脱丙烷塔 压力 温度 关键组分 相对挥发度 理论板数 

分 类 号：TE624.41[石油与天然气工程—油气加工工程]