LNG轻烃分离工艺流程设计与分析  

Design and Analysis of LNG Light Hydrocarbon Separation Process

作　　者：李莉[1] Li Li(School of Petroleum Engineering,Xi'an Shiyou University,Xi'an Shaanxi 710000)

机构地区：[1]西安石油大学石油工程学院,陕西西安710000

出　　处：《中外能源》2023年第1期70-75,共6页Sino-Global Energy

摘　　要：为充分利用LNG冷能,以某LNG接收站为例,基于Peng-Robinson状态方程,选用模拟软件HYSYS,提出了一种新型LNG轻烃分离工艺流程,该流程主要分为原料预热、闪蒸塔预分离、脱甲烷塔、脱乙烷塔和管输气和液相调峰五部分,通过对流程中的脱甲烷塔和脱乙烷塔的塔顶压力和塔板数进行敏感性分析,分析其对甲烷物质的量含量和乙烷回收率的影响,从而确定最优的塔顶压力分别为2900k Pa和1950kPa、塔板数分别为12个和8个。该轻烃分离装置的富LNG处理量为348.8t/h,分离得到的管输气质量流量为171.2t/h,其物质的量分数为99.61%;乙烷质量流量为37.4t/h,纯度为97.99%;LPG质量流量为48.00t/h;轻烃分离后的天然气热值为33.94MJ/m3,满足商品天然气的热值要求。该流程总功耗为1889.49kW,单位轻烃能耗约为79.66kJ/kg,能耗较低。脱乙烷塔冷凝器和再沸器的负荷分别由加热器和工业余热提供,脱甲烷塔再沸器热负荷由海水提供。In order to make full use of LNG cold energy,a LNG receiving terminal is taken as an example to propose a new LNG light hydrocarbon separation process based on the Peng-Robinson equation of state and the simulation software HYSYS.The process is mainly divided into raw material preheating,flash tower pre-separation,demethanizer,deethanizer,and pipeline gas and liquid phase peak shaving.Through the sensitivity analysis of the overhead pressure and plate number in the demethanizer and deethanizer,their influences on methane content and ethane recovery are analyzed,and it is determined that the optimal overhead pressure is 2900kPa and 1950kPa and the number of plate is 12 and 8,respectively.The rich LNG processing capacity of the light hydrocarbon separation unit is 348.8t/h,the mass flow rate of the pipeline gas separated is171.2t/h,and its mole fraction is 99.61%.The mass flow rate of ethane is 37.4t/h and the purity is 97.99%.The mass flow rate of LPG is 48.00t/h.The calorific value of natural gas after light hydrocarbon separation is33.94MJ/m3,which meets the calorific value requirement of commercial natural gas.The total power consumption of the process is 1889.49kW,and the energy consumption per unit of light hydrocarbon is about79.66kJ/kg,so the energy consumption is low.The heat load of the condenser and reboiler in deethanizer is provided by heater and industrial waste heat respectively,while the heat load of demethanizer reboiler is provided by seawater.

关 键 词：LNG 轻烃分离 HYSYS软件 敏感性分析 

分 类 号：TE644[石油与天然气工程—油气加工工程]