Measurements of isobaric heat capacities of gases from 323.15 to 573.15 K up to 30 MPa

A Setaram C-80 calorimeter has been modified in order to measure heat capacities at constant pressure of gases from ambient temperature to 573 K and at pressures up to 30 MPa. Special cells have been designed and an additional device has been incorporated into the calorimeter to better control the temperature. The calorimetric technique and the calibration method are described. Experimental heat capacities of CO2 in the temperature range 323.15–423.15 K at pressures up to 25 MPa are reported and compared with the best literature data.