Experimental Measurement of CO 2 Solubility in Aqueous Na 2 SO 4 Solution at Temperatures between 303.15 and 423.15 K and Pressures up to 20 MPa
Abstract
The geological storage of carbon dioxide CO2 in deep saline aquifers has
been gaining interest to reduce greenhouse gas emissions. Thus, the number of studies
focusing on the solubility of CO2 in brines at high temperature and high pressure has
been increasing in the last decades, but information remains scarce particularly at high
salt molality. In this work, an analytical method was developed for experimental
measurement of CO2 solubility in sodium sulfate (Na2SO4) solutions (1 and 2 mol/kg)
at high pressures (1.5−20 MPa) and temperatures (303.15, 323.15, 373.15, and 423.15
K). Forty-eight experimental points of CO2 solubility are reported here. Solubility has
been shown to increase with pressure evolution and decrease with temperature and
Na2SO4 concentrations evolution. A discussion is proposed about the salting-out effect
in Na2SO4 solutions, and a comparison is made with the same effect in aqueous systems
containing sodium chloride (NaCl) and calcium chloride (CaCl2).