含杂质CO_(2)混合体系的气液相平衡计算模型  

Calculation Models for Vapor-liquid Phase Equilibrium in Mixture Systems of CO_(2) Containing Impurities

作　　者：秦锋[1] 蔡子璇 明红芳 张帆 何梓睿 朱晨阳 李大树 QIN Feng;CAI Zixuan;MING Hongfang;ZHANG Fan;HE Zirui;ZHU Chenyang;LI Dashu(Technology Research and Development Center of CNOOC Gas&Power Group,Beijing 100028,China;Beijing Key Laboratory of Process Fluid Filtration and Separation/College of Mechanical and Transportation Engineering,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中海石油气电集团有限责任公司技术研发中心,北京100028 [2]中国石油大学(北京)机械与储运工程学院过程/流体过滤与分离技术北京市重点实验室,北京102249

出　　处：《油气与新能源》2024年第5期87-96,共10页Petroleum and new energy

基　　金：国家自然科学基金项目“低共熔溶剂+CO_(2)或H_(2)S混合体系溶解度与比热容的实验及理论研究”(52306217);中海石油气电集团有限公司科研项目“多相态二氧化碳运输持性研究”(QDKY-2023-YFZX-30)。

摘　　要：对含杂质CO_(2)体系相平衡的准确表征是CCUS(碳捕集、利用与封存)应用中的关键。为探讨针对此类体系相平衡计算的最佳热力学模型,基于CO_(2)/N_(2)、CO_(2)/O_(2)与CO_(2)/H_(2)O等3种二元混合工质的气液相平衡数据,分别使用状态方程(PR、SRK、BWRS、CPA、GERG-2008)和活度系数模型(NRTL、UNIQUAC)进行了气液闪蒸计算。结果表明,针对含杂质CO_(2)二元混合体系,CPA方程具有最高的计算精度,其结果与实验值的平均偏差仅为4.75%。随后,采用CPA方程对CO_(2)/N_(2)、CO_(2)/N_(2)/O_(2)和CO_(2)/N_(2)/O_(2)/H_(2)O等混合物的相包络线进行了预测,其对泡点、露点压力的计算与NIST(美国国家标准与技术研究院)方法计算结果的平均偏差小于3.5%,表明了CPA方程可作为一种简单且准确的含杂质CO_(2)混合体系相平衡计算方法。The accurate characterization of the phase equilibrium for CO_(2) systems containing impurities is a crucial step in CCUS applications.In order to discuss the optimal thermodynamic model for phase equilibrium descriptions of the systems,this paper conducts flash calculations based on the vapor-liquid equilibrium data of CO_(2)/N_(2),CO_(2)/O_(2),and CO_(2)/H_(2)O using equations of state(PR、SRK、BWRS、CPA、GERG-2008)and activity coefficient models(NRTL、UNIQUAC).The results indicate that the CPA equation has the highest accuracy for the calculation of vapor-liquid phase equilibrium of the binary CO_(2) mixtures containing impurities,with the average deviation from the experimental data of 4.75%.The phase envelope of CO_(2)/N_(2)、CO_(2)/N_(2)/O_(2),and CO_(2)/N_(2)/O_(2)/H_(2)O are then predicted using CPA,and the average deviations for its calculated bubble and dew point pressures from the NIST results are lower than 3.5%.These two calculations imply that the CPA equation can be a simple and accurate method to calculate vapor-liquid phase equilibrium in mixture systems of CO_(2) containing impurities.

关 键 词：含杂质CO_(2) 相平衡 活度系数模型 状态方程 

分 类 号：TE832[石油与天然气工程—油气储运工程]