Liquid-liquid-vapor equilibria and critical points in the ternary system carbon dioxide-water-propionic acid were measured with an analytical view cell. At 298, 313, and 333 K, the whole pressure range in which liquid-liquid-vapor equilibria exist was covered (pressures between 5 and 11 MPa). Temperature and pressure at the tricritical point of the system are reported. Where possible, the results are compared to literature data. Furthermore, pressures and temperatures for four-phase equilibria and critical points in the system carbon dioxide-water-isopropanol were measured. Temperature and pressure at one (of two) tricritical points for this system are determined.