摘要
回收天然气中的乙烷及以上组分时,当原料气中CO2含量超过一定值以后,膨胀机出口及脱甲烷塔顶部容易发生CO2冻堵。采用外输干气回流的乙烷回收工艺——部分干气循环工艺(RSV),可以在不降低乙烷回收率的前提下提高脱甲烷塔的操作压力,降低外输干气再压缩功率的同时有效避免CO2冻堵的发生。采用HYSYS软件模拟RSV工艺回收天然气中的乙烷及以上组分,实例研究表明:原料气CO2的物质的量分数为2.4%时,乙烷回收率为86%,乙烷回收装置不会发生CO2冻堵;分离器过冷气相的比例不宜过高,一般为10%～30%;外输干气回流的比例一般为10%～20%;根据不同的原料气组成及操作工况,分离器液相可以选择全部过冷也可以部分过冷。
When using turbo-expander refrigeration process to recover ethane from natural gas,if the content of CO2 in feed gas was higher than a limit value,the outside of the expander and the top of demethanizer might cause the formation of solid CO2.Using Recycle Split-Vapor（RSV） Process to recover ethane from natural gas could increase the pressure of the demethanizer without reducing ethane recovery rate,avoiding forming solid CO2 while reducing the compression power of residue gas.HYSYS software was used to simulate RSV process for recovering ethane from natural gas.The results showed that when CO2 mole fraction in feed gas was 2.4%,ethane recovery ratio was 86%,and there was no solid CO2 formation in the ethane recovery device;the rate of subcooled separator vapor should not be too high,commonly being between 10% and 30%;the rate of reflux residue gas was commonly between 10% and 20%;and depending on feed gas composition of the and operation conditions,all of the lean oil liquid from separator would be subcooled and then fed to demethanizer or a portion of lean oil liquid was withdrawn to be subcooled and then fed to demethanizer,while the rest of it was fed to demethanizer directly.
出处
《天然气化工—C1化学与化工》
CAS
CSCD
北大核心
2012年第2期65-68,78,共5页
Natural Gas Chemical Industry
关键词
天然气
凝液回收
膨胀机
二氧化碳
干气
natural gas； NGL recovery； expander； carbon dioxide； split-vapor
