Present situation and development direction of chemical thermodynamics

In terms of basic data, a large number of thermochemical data, P-V-T relationship data, phase equilibrium and chemical equilibrium data have been accumulated, and many accurate generalized calculation charts (such as generalized compressibility factor diagram) have been compiled, and hundreds of state equations have been developed. A few state equations can also be used for gas-liquid two phases. On the basis of activity coefficient equation and state equation, the phase equilibrium correlation has made remarkable progress. For many common systems, the experimental data of binary systems can be used to predict the vapor-liquid equilibrium and gas-liquid equilibrium of multicomponent systems. There are several methods of group contribution, and group parameters can be used to estimate the vapor-liquid equilibria and liquid-liquid equilibrium of many systems. This method has played a great role in the development of new technology. Significant progress has also been made in the calculation of chemical equilibrium of complex systems. The thermodynamic analysis method of chemical process has been initially formed. In recent research work, in addition to the determination of basic data, it is a very active field to establish the equation of state with reliable theoretical basis, which requires that the equation be applicable to polar substances, substances containing hydrogen bonds and polymer compounds, and can be used in gas phase, liquid phase and critical region at the same time. The vapor-liquid equilibrium, liquid-liquid equilibrium and liquid-solid equilibrium of abnormal substances, as well as the vapor-liquid equilibrium and gas-solid equilibrium related to the new technology of supercritical fluid extraction, and the study of electrolyte solutions related to gas absorption, hydrometallurgy and marine energy development have attracted many people's interest. The application of chemical thermodynamics in biochemical engineering is also remarkable. It must also be pointed out that due to the development of non-equilibrium thermodynamics theory, the limitation of classical thermodynamics that does not involve process rate has been broken. Because of the importance of energy conservation, the study of thermodynamic analysis of chemical processes is also in the ascendant.