江油轻烃回收装置C_3收率的影响因素分析及其改进措施探讨

Influencing factors analysis and improvement measures of the C_3 yield of Jiangyou light hydrocarbon recovery unit

江油天然气凝液回收装置采取低温分离法回收天然气中C_3及以上组分,设计处理量为45×10~4 m^3/d,现天然气处理量40×10~4 m^3/d。目前,中坝须二气藏呈高压气量逐步降低、低压气量逐步增加的趋势。原料气压力波动也较大,高压气压力由3.65 MPa降至约2.8MPa,轻烃厂主要生产参数与设计值存在较大偏差。此外,GB 11174-2011《液化石油气》于2012年7月1日正式实施后,新增对液化气中(C_3+C4)烃类组分体积分数不小于95%的规定,对装置的生产操作参数、液化气产量及C_3收率将产生一定的影响。目前,液化气气质在满足新国标要求的前提下,C_3收率仅61.12%。为此,在不改变现有装置的条件下,借助计算机模拟软件分析相关参数的敏感性,针对装置现状及主要敏感因素,提出提高原料气压力、降低原料气温度、稳定脱乙烷塔再沸器温度、参数优化及进行工艺改造等措施,以提高装置C3收率。

Low temperature separation process was used for Jiangyou natural gas condensate recovery unit to recovery the components of C＋3from the natural gas.The design treatment capacity is450×103 m^3/d,and now the practical natural gas processing capacity is 400×10~3 m^3/d.At present,the Zhongba Xuer Gas Reservoir indicates a flow decrease trend for high pressure gas and flow increase trend for low pressure gas.The feed gas pressure fluctuates significantly,and the high pressure gas pressure has reduced from 3.65 MPa to about 2.8MPa.The main production parameters of light hydrocarbon recovery unit deviate from design value obviously.In addition,after the implementation of GB 11174-2011 Liquefied Petroleum Gas on July 1st,2012,it is required that the volume fraction of C_3 and C_4 hydrocarbon components should not be less than 95%,which would influence the operation parameters,the liquefied gas production and the C_3 yield to a certain extent.At present,by the premise of the liquefied gas quality meeting the new national standard,the C_3 yield is only 61.12%.Under the condition of existing equipment,the sensitivity of the relevant parameters was analyzed by means of computer simulation software.According to the current situation and the main sensitive factors,some measures were proposed to improve the C3 yield,which included improving the feed gas pressure,reducing the feed gas temperature,making the deethanizer reboiler temperature stable,optimizing the parameters and reforming the process.