Isobaric heat capacity of 1,2-propanediol at high temperatures and high pressures

Abstract

Abstract Present paper reports new high-temperature and high-pressure isobaric heat capacities (CPPT relationship) of 1,2-propanediol. Measurements were made over the temperature range from (298 to 473) K and at pressures up to 147 MPa using two different methods, differential scanning and isothermal heat-conduction calorimeters. The expanded uncertainty of the heat capacity, pressure, and temperature measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 2.4%, 0.05%, and 15 mK, respectively. The measured CPPT data were used to calculate the second temperature derivatives of specific volume or curvature of the V-T isobars as (∂2V/∂T2)P = − T−1(∂CP/∂P)T. The measured data were also used to check accuracy and reliability existing Tait-type ρ(P, T) equations of state for liquid 1,2-propanediol at high temperatures and high pressures.