液化天然气中轻烃分离工艺的优化设计  

Optimized Design of Recovery Process of Light Hydrocarbons from LNG

作　　者：熊永强[1] 李亚军[1] 华贲[1] 

机构地区：[1]华南理工大学强化传热与过程节能教育部重点实验室,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2007年第7期62-66,共5页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家重点基础研究开发规划项目(G2000026307)

摘　　要：根据液化天然气(LNG)冷量的特性,按照冷量梯级利用的原则,设计了一种新的LNG轻烃分离流程,其特征在于轻烃分离过程不需要使用压缩机,能耗较低,而且可利用LNG的冷量将一部分分离完轻烃的甲烷再液化过冷并低压液相储存,使轻烃分离流程具有供气调峰功能,同时使分离获得的轻烃产品保持低压液相,方便产品的储运和销售.文中还以深圳项目进口的3.7×106t/a澳大利亚LNG为例,利用此流程进行轻烃分离的模拟计算.结果表明:相对现有工艺,新流程功耗降低47.3%,脱甲烷塔的热负荷降低27.3%,且能够将20%左右的甲烷低压储存用于供气调峰,经济效益明显;如将获得的C2+轻烃替代石脑油用于裂解制乙烯,可以降低乙烯装置的投资、生产能耗及成本.According to the characteristics of the cold energy of liquefied natural gas （LNG）, a new recovery process of light hydrocarbons from liquefied natural gas was presented based on the gradient utilization of cold energy. The proposed recovery process was performed without using any gas compressor, and the cold energy of LNG was used to re-liquefy the methane-rich residual gas and to re-condense and store the methane in tanks in low-pressure liquid phase, the process was of the function of peak shaving, and the recovered light hydrocarbons in low-pressure liquid phase were easy to store and sell. Then, a case study of applying the process was carried out for the imported 3.7×10^6 t/a LNG from Australia by Shenzhen. The results indicate that, as compared with the conventional technologies, the proposed process can reduce the power consumption by 47.3% and decrease the heat load by 27.3%, that approximately 20% of the methane-rich residual gas is re-condensed and stored in tanks in low-pressure liquid phase for the peak shaving of natural gas downstream system by vaporizing it, that the C2^＋ hydrocarbons recovered from LNG can be used as a substitution for naphtha and the feed of ethylene unit, with the advantages in decreasing the investment and saving the energy consumption and the cost.

关 键 词：液化天然气 冷量 C2^+轻烃分离 流程优化 流程设计 

分 类 号：TQ028[化学工程] TE64[石油与天然气工程—油气加工工程]