Measurement of the intrinsic mass transfer coefficient for CO2 dissolution in brine

Abstract

A full-factorial designed experiment was completed to quantify the effect of temperature, wet CO2 density and brine Na–Ca–Cl salinity on the liquid-side mass transfer coefficient kL for the dissolution of CO2 into brine. The range of experimental conditions corresponds to those relevant to the surface dissolution approach to geologic storage of anthropogenic CO2.The measured range of kL was from 0.015 to 0.056cm/s. An empirical correlation was developed for kL as a function of temperature to wet CO2 density and NaCl salinity. Greater temperature and smaller NaCl salinity increase kL. There is an interaction effect between temperature and wet CO2 density, which increases or decreases kL depending on the value of each. CaCl2 salinity does not have a statistically significant effect on kL.Wet CO2 density was used as an independent variable, in the place of pressure, since it was found to play a critical role in the onset of gas entrainment. Geologic storage of CO2 via the surface dissolution method requires different operating conditions for different applications. Importantly, since the composition of brine varies between locations, the dependency of kL on NaCl salinity allows for location specific process design.