Weak Electrolyte Vapor-Liquid Equilibria

研究概述：一个成功地建立了状态方程模型， 关联了弱电解质的汽液平衡行为 含氨、硫化氢和二氧化碳的系统 是由主要研究者最近开发的。 早期的工作主要集中在气相上，因此， 对于给定的总液相组成的气相行为 成功地进行了表征。 在这个项目中，工作将集中在 液相。 具体而言，对 将对现有模式进行审查， 液相中的单个物质将成功地 表征了 此外，还讨论了更换 扰动的硬链方程，目前在模型中， 用立方状态方程，将被检查。 最后通过一个 将进行实验程序， 温度，以及两相的密度和电导率将 在现场测量。 这些结果，沿着与理论 模型，然后将用于计算相组成。 的 程序将消除两个功能， 传统的方法太麻烦了--过于复杂的理论 从平衡池中取出并分析样品。 创新：拟议的工作将导致两个科学 创新。 首先，它将继续开发应用程序 弱电解质体系的状态方程。 方程 国家发展将导致一个更简单的模式， 比目前用来代表弱电解质的模型 行为 所提出的方法将具有许多优点 使得物态方程成为一种流行的 非电解质汽液平衡 第二个创新 是一种实验性的技术将被开发出来， 消除了从样品中取出和分析样品的需要， 平衡电池 以目前的技术，这是最 困难的一步，所以它的消除将确实是一个重大的 发展用于研究这些系统的方法。 意义：拟议的研究将具有相当大的意义 在酸性水处理领域的实际影响， 净化、天然气加工和重油精炼。 这项工作适用于如此多领域的原因是， 用于CO2-NH3-H2O和H2S-NH3-H2O系统的技术可以 很容易扩展到氨被取代的系统， 胺、二醇或醇。 因此，许多工业利益 由于天然气中H2S脱除的重要性， 通过胺处理。 在这一点上，与 弱电解质汽液平衡问题尚未得到满意的解决。 的 所提出的技术结合了实验中的新方法， 程序与新的方法来模拟行为在一个 可以解决问题的方式。

Research Summary: An equation of state model which successfully correlates vapor liquid equilibria behavior of weak electrolyte systems containing ammonia, hydrogen sulfide, and carbon dioxide has recently been developed by the principal investigators. This earlier work was focused primarily on the vapor phase, so that the vapor phase behavior for a given overall liquid phase composition was successfully characterized. In this project, work will focus on the liquid phase. Specifically, several proposed modifications to the existing model will be examined so that concentrations of individual species in the liquid phase will be successfully characterized. In addition, the feasibility of replacing the perturbed hard chain equation, which is presently in the model, with a cubic equation of state, will be examined. Finally, an experimental program will be undertaken whereby total pressure, temperature, and the density and conductivity of both phases will be measured in situ. These results, along with the theoretical model, will then be used to calculate phase compositions. The program will eliminate the two features which have given traditional methods so much trouble--overly complex theoretical models and removing and analyzing samples from equilibrium cells. Innovation: The proposed work will lead to two scientific innovations. First, it will continue to develop the application of equations of state to weak electrolyte systems. The equation of state development will lead to a model which will be simpler than those models currently used to represent weak electrolyte behavior. The proposed methods will possess the many advantages which have made equations of state so popular for representing non-electrolyte vapor liquid equilibria. The second innovation is that an experimental technique will be developed which will eliminate the need to remove and analyze samples from the equilibrium cell. With current techniques, this is the most difficult step, so its elimination will indeed be a major development in the methods used to study these systems. Significance: The proposed research will have considerable practical impact in the area of sour water processing, water purification, natural gas processing, and heavy oil refining. The reason this work is applicable in so many areas is that techniques for the CO2-NH3-H2O and H2S-NH3-H2O systems can be easily extended to systems in which the ammonia is replaced by amines, glycols, or alcohols. Thus, much industrial interest results because of the importance of H2S removal from natural gas by amine treating. At this point, the problems associated with weak electrolyte VLE have not been solved satisfactorily. The proposed techniques couple new approaches in the experimental procedure with new approaches to modelling the behavior in a manner that may solve the problem.