利用LNG冷能的轻烃分离高压流程  

Light hydrocarbons separation at high pressure from liquefied natural gas with its cryogenic energy utilized

作　　者：高婷[1] 林文胜[1] 顾安忠[1] 

机构地区：[1]上海交通大学制冷与低温工程研究所,上海200240

出　　处：《化工学报》2009年第S1期73-76,共4页CIESC Journal

摘　　要：利用LNG冷能能以较低的能耗分离回收其中高附加值的C2+轻烃资源,同时实现LNG气化,是LNG冷能利用的有效方式。本文提出一种新型的利用LNG冷能的轻烃分离流程,脱甲烷塔在较高的压力下运行,从而分离出的富甲烷天然气能以较低能耗压缩到管输压力;脱乙烷塔在常压下运行,可以直接得到常压液态乙烷及LPG产品,方便产品的储运。脱甲烷塔中再沸器的热耗由燃气提供,经计算只需消耗1%左右的天然气;脱乙烷塔中冷凝器所需的冷量由LNG提供。该流程轻烃回收率可达90%以上,其中乙烷回收率可达85%左右。以某气源组分为基础,考察了乙烷含量和乙烷价格变化对装置经济性的影响,结果表明,使用该流程进行轻烃回收效益可观。C+2 light hydrocarbons,which are resources with high additional values,can be separated from LNG with low power consumption by efficiently utilizing its cryogenic energy,and LNG is gasified meanwhile.A novel light hydrocarbons separation process is proposed in this paper:the demethanizer works at higher pressure,thus the methane-rich natural gas can be compressed to pipeline pressure with low power consumption;the deethanizer works at atmosphere pressure,consequently liquefied ethane and LPG(liquefied petroleum gas,i.e.C+3)at atmosphere pressure can be produced directly,which are easy to be stored and transported.The heat consumption of the reboiler in the demethanizer is provided by the combustion of the separated natural gas,which account for about 1% of the total amount;the cold energy of the condenser in the deethanizer is provided by the cryogenic energy of LNG.The recovery rate is more than 90% for light hydrocarbons,and about 85% for ethane.On the basis of one typical feed gas composition,the effects of the ethane content and the ethane price to the economics of the process are studied.The results show that recovering light hydrocarbons from LNG by this process can gain great profits.

关 键 词：液化天然气(LNG) 冷能利用 轻烃分离 高压流程 经济性分析 

分 类 号：TE89[石油与天然气工程—油气储运工程]