Thermophysical Properties of Long-Chained Hydrocarbons, Alcohols, and their Mixtures with Dissolved Gases

目前，在化学和能源工程中可以发现对含有溶解气体的液体的工艺的技术兴趣日益增加。一些例子是通过合适的吸收剂分离烟道气，从合成气生产高价值燃料或石油产品，或通过液体载体储存和运输氢。为了设计和优化相应的过程，有关所涉及的流体系统的热物理性质的准确信息是必要的。然而，到目前为止，在很宽的热力学状态范围内的液体与溶解气体的输运和平衡性质是稀缺的。这是由于实验方法的局限性以及缺乏理论模型和预测方法造成的。在建议的中德研究项目中，提出了在高达约600 K的宽温度范围内对烃、醇及其与溶解气体的混合物的不同热物理性质的系统研究。对于这些特定的系统，调查应有助于从根本上了解液体和溶解气体的分子结构的变化如何影响密度，溶解度，粘度和表面张力等热物理性质。埃尔朗根-纽伦堡大学的德国研究小组专注于通过分子动力学（MD）模拟和表面光散射（SLS）表征系统。除了密度和粘度，MD模拟还应该访问溶解度和表面张力。虽然对于后者的性质，MD方法必须在项目中进行改进，但德国研究团队最近开发了SLS技术，用于在高温下可靠地测定粘度和表面张力。对于这些性质，Xi交通大学的中国研究小组应用了基于硬球和对应态理论的理论模型，以及以水滴和振弦技术形式的实验方法。由两个团队同时测定的相同选定系统的粘度和表面张力将作为相互参考数据。德国研究小组通过振动U形管法测定密度，中国研究小组通过重量分析法测定溶解度，这两项单独的活动是互补的，具有共同的利益。因此，两个研究团队之间现有的合作将在项目中进一步扩展。对于选定的溶解气体的液体，预期的可靠和全面的数据库应作为基础，从根本上了解它们的结构-性质关系。这支持的发展的理论和经验模型的描述的任意系统组成的烃或醇与溶解气体的热物理性质。

At present, increasing technical interest in processes with liquids containing dissolved gases can be found in chemical and energy engineering. Some examples are the separation of flue gases by suitable absorbents, the production of high-value fuels or petroleum products from synthesis gas, or the storage and transport of hydrogen via liquid carriers. For the design and optimization of corresponding processes, accurate information about the thermophysical properties of the involved fluid systems is necessary. Until now, however, transport and equilibrium properties for liquids with dissolved gases over a wide range of thermodynamic states are scarce. This is caused by limitations of experimental methods as well as the lack of theoretical models and prediction methods. In the suggested Sino-German research project, a systematic study of different thermophysical properties of hydrocarbons, alcohols, and their mixtures with dissolved gases over a wide range of temperatures up to about 600 K is proposed. For these specific systems, the investigations should contribute to a fundamental understanding how the variation of the molecular structure of the liquids and of the dissolved gases influences the thermophysical properties density, solubility, viscosity, and surface tension. The German research team at the University of Erlangen-Nuremberg focuses on the characterization of the systems by molecular dynamics (MD) simulations and surface light scattering (SLS). Besides density and viscosity, the MD simulations should also access solubility and surface tension. While for the latter properties the MD methodology has to be refined within the project, the SLS-technique was recently developed by the German research team for a reliable determination of viscosity and surface tension at high temperatures. For these properties, the Chinese research team at Xi'an Jiaotong University applies theoretical models based on hard sphere and corresponding states theory as well as experimental methods in form of the pedant drop and vibrating wire techniques. Viscosities and surface tensions determined in parallel by the two teams for the same selected systems will serve as mutual reference data. The individual activities in form of the determination of density via the vibrating U-tube method by the German team and of the solubility via a gravimetric technique by the Chinese team are complementary and of joint interest. Thus, the already existing co-operation between both research teams will be further extended within the project. For the selected liquids with dissolved gases, the expectable reliable and comprehensive database should serve as basis for a fundamental understanding of their structure-property relationships. This supports the development of theoretical and empirical models for the description of thermophysical properties of arbitrary systems consisting of hydrocarbons or alcohols with dissolved gases.