New experimental density data and derived thermophysical properties of carbon dioxide – Sulphur dioxide binary mixture (CO 2 -SO 2 ) in gas, liquid and supercritical phases from 273 K to 353 K and at pressures up to 42 MPa

Abstract : Due in part to the toxicity of the CO 2-SO 2 binary system, there are no density data available in the literature. Densities for this system were measured using a vibrating tube densitometer (VTD), Anton Paar DMA 512, and the forced path mechanical calibration (FPMC) method in the gas, liquid and supercritical phases at pressures up to 41.7 MPa. The mole fraction of the mixture was 0.9478 CO 2 + 0.0522 SO 2 at 298 K and 0.9503 CO 2 + 0.0497 SO 2 at 273, 283, 323 and 353 K. The compressibility factor, isobaric heat capacity and bubble points were also derived from the measured densities. The classical cubic equations of state, i.e., Soave-Redlich-Kwong (SRK), Peng-Robinson (PR) and Valderrama version of Patel-Teja (VPT) with the CO 2 volume correction term and Peneloux shift parameter in addition to a multi parameter EoS based on Helmholtz energy were evaluated using the measured density data. The most accurate EoSs for the investigated system were the multi parameter EoS and the PR-CO 2 with overall AAD of 0.6% and 1.0%, respectively.