Speciation, structure and hydration of solutes under hydrothermal conditions

许多地质和工业过程是在远远超出常规室温测量范围的条件下进行的。这项提议的目的是发展所需的知识库和理论知识，以描述在发电站、先进核反应堆、地热矿体、深海热液喷口以及二氧化碳捕获和封存中遇到的极端温度和压力下水体系的行为。*灵敏流动量热仪和密度计由惰性材料制成，可承受腐蚀条件，将用于在温度高达400摄氏度、压力高达350大气压的液态水中测定简单电解液和有机分子的热力学性质，以研究接近水临界点的条件下离子电荷和有机官能团的影响。化学物种的形式及其平衡常数将通过在新型高温、高压流动池中使用紫外可见光谱、拉曼光谱、量热、密度测量和一种独一无二的高精度电导仪器进行现场测量来确定，所有这些都能够达到亚临界或超临界条件。这些测量将对溶质水化的基本性质以及溶质-溶质相互作用产生新的见解。该项目还将提供热力学数据、输运性质、半经验模型和理论方法，以预测水基地热系统和在极端温度和压力下运行的先进工业技术中无机和有机溶质的性质和相行为。*该计划将集中在三个领域：(I)基础研究，以了解物种形成和离子-离子相互作用对高于250oC的电解质溶液的汽液临界轨迹和较低临界溶液温度的作用；(2)与碳捕获和地质封存有关的二氧化碳和(二氧化碳胺)溶液在中温和高温下的热力学和相行为；(3)模拟热液生命起源假设机制所需的生物前分子的热力学和动力学稳定性。这项工作的新颖性在于正在研究的非常极端的条件，识别异常影响的可能性，以及开发专门的仪器技术以获得在这些非常激进的条件下复杂水体系的定量数据的必要性。

Many geological and industrial processes take place at conditions far beyond the range of conventional room temperature measurements. The objective of this proposal is to develop the knowledge base and theoretical understanding needed to describe the behaviour of aqueous systems at extremes of temperature and pressure encountered in electrical power stations, advanced nuclear reactors, geothermal ore bodies, deep-ocean hydrothermal vents, and the capture and sequestration of CO2. ******Sensitive flow calorimeters and densitometers, constructed of inert materials to withstand the corrosive conditions, will be used to determine the thermodynamic properties of simple electrolytes and organic molecules in liquid water at temperatures up to 400 oC and pressures as high as 350 atmospheres, to examine the effects of ionic charge and organic functional groups under conditions approaching the critical point of water. The form of the chemical species, and their equilibrium constants, will be determined by in situ measurements in novel high temperature, high pressure flow cells using UV-visible spectroscopy, Raman spectroscopy, calorimetry, densimetry and a one-of-a-kind, high-precision conductance apparatus, all capable of reaching sub-critical or supercritical conditions. These measurements will yield new insights into the fundamental nature of solute hydration, and solute-solute interactions. The project will also yield thermodynamic data, transport properties, semi-empirical models, and theoretical methods for predicting the properties and phase behaviour of aqueous inorganic and organic solutes in water-based geothermal systems and advanced industrial technologies that operate under extremes of temperature and pressure.******The program will focus on three areas: (i) basic research to understand the role of speciation and ion-ion interactions on the vapour-liquid critical locus and the lower critical solution temperature of electrolyte solutions above 250 oC; (ii) the thermodynamics and phase behaviour of CO2 and (CO2 + amine) solutions at intermediate and high temperatures relevant to carbon capture and geological sequestration; and (iii) the thermodynamic and kinetic stability of pre-biotic molecules required to model postulated mechanisms for the hydrothermal origin of life. The novelty in the work lies in the very extreme conditions being studied, the potential for identifying unusual effects, and the need to develop specialized instrumental techniques to obtain quantitative data for complex aqueous systems under these very aggressive conditions.