By using an infrared absorption method together with a synthetic method, experimental results on the phase behavior of CO2-limonene and CO2-citral binaries have been obtained. Experiments were performed in the temperature range 310-323 K and in the pressure range 7-10 MPa for the CO2-limonene mixture and from 310 to 330 K in the pressure range 7.9-12 MPa for the CO2-citral mixture.