Liquid viscosity, interfacial tension, thermal diffusivity and mutual diffusivity of n-Tetradecane with dissolved carbon dioxide

Abstract

Systems in connection with hydrocarbons with dissolved carbon dioxide (CO2) are widespread in various chemical and engineering applications such as Fischer–Tropsch (FT) synthesizes, carbon capture and storage (CCS) and enhanced oil recovery (EOR). The thermophysical properties are necessary for understanding and designing those relevant processes. In this work, the liquid viscosity, interfacial tension, thermal diffusivity and mutual diffusivity of n-tetradecane with dissolved CO2 were investigated under macroscopic equilibrium from 323 to 473 K and over a pressure range up to 5.6 MPa. With a careful evaluation of the uncertainty, the average expanded uncertainty of liquid viscosity, surface tension, thermal diffusivity and mutual diffusivity was 2.9%, 2.4%, 11.4% and 4.4%, respectively. The liquid viscosity and interfacial tension decline when the pressure of the system or the mole fraction of CO2 in the liquid phase increases. Empirical correlations were used to represent the liquid viscosity and interfacial tension with an absolute average deviation (AAD) of 2.8% and 0.2 mN·m − 1. A comparison of available liquid viscosity and interfacial tension from the literature were performed. In the overlapped temperature and pressure region, good agreement can be found. In terms of the thermal diffusivity, there is no obvious dependency on pressure. The mutual diffusivity decreases with pressure at 323 K, while the decline behavior cannot be observed above 323 K when taking the combined uncertainty into consideration. This work was expected to provide reliable and accurate fundamental thermophysical properties of liquid with dissolved gas systems in engineering and chemical processes.