某海上项目天然气低温脱水工艺路线对比

Comparison of Low-Temperature Dehydration Process Routes for Natural Gas in a Certain Offshore Project

天然气开采中需对天然气进行净化后外输,主要包括:脱除固体杂质、脱水、脱烃、脱硫和脱二氧化碳,其中脱水脱烃是天然气开采过程中普遍存在的要求。分别对工业上广泛采用的脱水以及脱烃方法进行介绍,结合某海上天然气开采项目条件,针对该项目对天然气外输水露点和烃露点的要求,决定采用低温方法进行脱水脱烃,但考虑到不同工况的初始压力与外输压力之间的差值,采用Aspen HYSYS软件分别采用增压透平膨胀技术与膨胀+丙烷冷却技术对主要工况进行计算分析,最终得出采用增压透平膨胀技术路线能耗较低,且设备投资成本较低,且更适用于该海上天然气开采项目。

In natural gas exploitation,natural gas needs to be purified and exported,which mainly includes:Removal of solid impurities,dehydration,hydrocarbon removal,desulfurization and carbon dioxide removal,among which dehydration and hydrocarbon removal are common requirements in the process of natural gas exploitation.The dehydration and hydrocarbon removal methods widely used in industry are introduced respectively.Combined with the conditions of an offshore natural gas exploitation project,the requirements of the project on the dew point and hydrocarbon dew point of natural gas exported are discussed.However,considering the difference between the initial pressure and the external pressure under different working conditions,Aspen HYSYS software was used to calculate and analyze the main working conditions respectively by using the supercharged turbine expansion technology and the expansion+propane cooling technology.Finally,it was concluded that the supercharged turbine expansion technology route had lower energy consumption and lower equipment investment cost.And it is more suitable for this offshore natural gas exploitation project.