天然气中甲烷及非烃组分混合物的汽液相平衡研究

发布时间：2018-03-19 13:03

本文选题：天然气　切入点：汽液相平衡　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：天然气主要成分是甲烷,除此之外还含有其他烃类组分(乙烷、丙烷、丁烷等)以及各种非烃组分(氮气、氦气、二氧化碳、硫化氢和水等)。非烃组分是天然气中非常重要的组成部分。实现天然气中非烃组分与甲烷的分离,不仅可以提高天然气的利用效率,还可以产生附加的经济价值,对天然气的开发和利用具有重要的意义。而对天然气中的非烃组分进行分离的过程设计和优化涉及到相平衡的相关知识,因此,开展对天然气中甲烷和非烃组分的相平衡研究对天然气工业的发展具有重要意义。基于以上考虑,本文对甲烷和天然气中常见的非烃组分N2、C02以及具有珍贵价值的Ar的混合物的汽液相平衡开展研究工作,主要研究内容有以下几部分:(1)基于对现有文献的大量调研,将初期研究到近年来发表的可查阅的所有关于甲烷与非烃组分(N2、C02、Ar)汽液相平衡研究的实验数据进行了汇总,并对前人的研究范围、实验方法以及理论计算方法等进行了总结,为后续的研究提供有力的指导。(2)基于相平衡理论自行编写程序,采用四种状态方程(SRK,PR,PRSV,NM)和五种混合法则(vdW,HV,MHV1,MHV2,LCVM)建立模型,系统性地对所获取的大量的实验数据进行关联,对比分析了不同计算模型的预测能力。经比较发现:MHV1混合法则和PR状态方程对于天然气中不同类型的混合物在不同温度下的汽液相平衡均具有较高的关联精度,而其他混合法则(vdW,HV,MHV2,LCVIM)和状态方程(SRK,PRSV,NM)则具有一定的局限性。与此同时,在相平衡计算的基础上,利用获取的模型参数对甲烷和非烃组分的热力学性质进行深入的分析与讨论。另外还对天然气中混合物的临界点进行了研究,给出了能够精确预测甲烷和非烃组分混合物临界点的经验法,并对不同的混合体系给出了优化的模型参数。(3)本文对原有实验装置存在的问题进行了深入的剖析,在此基础上提出了改进措施:采用自制的循环泵代替原来的液相泵、改进保温方法以及减小排空管路段的死体积,从而提高了实验装置的可靠性和实验效率。用改进后的实验装置获取了甲烷和氩气在95K～135K温度范围内的相平衡实验数据(此温区的相平衡数据对于甲烷和氩气的低温分离操作的设计和优化具有非常重要的作用),并用相平衡物理模型对其二元混合物的热力性能进行了详细的分析与讨论,为后续的研究提供可靠的基础。
[Abstract]:The main component of natural gas is methane, in addition to containing other hydrocarbons (ethane, propane, butane, etc.) as well as a variety of non hydrocarbon components (nitrogen, helium, carbon dioxide, hydrogen sulfide and water etc.). Non hydrocarbon is a very important part of natural gas. The non hydrocarbon separation and the methane in natural gas, not only can improve the utilization efficiency of natural gas, also can produce additional economic value, has an important significance to the development and utilization of natural gas. The related knowledge, while the non hydrocarbon components in natural gas for process design and optimization of separation involves phase equilibrium so on the methane in natural gas and non hydrocarbon phase equilibrium study on the development of natural gas industry has important significance. Based on the above considerations, the common non hydrocarbon of methane in natural gas and N2 gas liquid mixture C02 and has precious value of Ar phase The balanced development of research work, the main research contents are as follows: (1) a lot of research on the existing literature on the basis of the initial research to be published in recent years can be found in all about methane and non hydrocarbon components (N2, C02, Ar) vapor-liquid equilibrium experimental data of the study are summarized, and the previous studies, experimental methods and theoretical calculation methods were summarized, to provide effective guidance for the subsequent research. (2) based on the phase equilibrium theory of self programming, using four kinds of equation of state (SRK, PR, PRSV, NM) and five (vdW, HV, the mixing rule of MHV1, MHV2. LCVM) model, are systematically related to a large number of experimental data obtained by the comparative analysis of the prediction ability of different models. It is found that: MHV1 mixing rule and PR equation of state for liquid vapor complexes at different temperatures with different types of natural gas in phase equilibrium were Associated with high precision, and other mixing rule (vdW, HV, MHV2, LCVIM) and the equation of state (SRK, PRSV, NM) has some limitations. At the same time, based on the calculation of phase equilibrium, in-depth analysis and Discussion on methane and non hydrocarbon components using thermodynamic properties model to obtain the parameters. In addition to the mixture of natural gas in the critical point of research, gives accurate predictions of the experience method of methane and non hydrocarbon mixture critical point, and to give the mixed system of different model parameters were optimized. (3) this paper analyses the existing problems of the original experimental device on this basis, the improvement measures are put forward: using self-made circulating pump instead of liquid pump, improve insulation method and reduce the dead volume of exhaust pipe sections, thereby improving the reliability of the experimental apparatus and experiment with the improved efficiency. The experimental device for obtaining methane and argon in 95K ~ 135K in the temperature range of the phase equilibrium experimental data (plays a very important role in the design and optimization of phase equilibrium data in this temperature region for low temperature separation of methane and argon, and the) by phase equilibrium thermodynamic performance of the physical model of the Qi Eryuan mixture are analyzed and discussed in detail, providing a reliable basis for the follow-up study.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE642

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