Adiabatic compression heating coefficients for high-pressure processing of water, propylene-glycol and mixtures – A combined experimental and numerical approach

The compression heating of water and water/propylene-glycol mixtures during high-pressure processing was studied using a purpose-designed experimental setup allowing for near-adiabatic conditions. The fluids were pressurised in a Stansted ISO-LAB FPG11501 HPP 3 L unit up to 750 MPa. Pressure/temperature profiles at varying initial temperatures (5–90 °C) were recorded and numerically evaluated to obtain pressure and temperature dependent compression heating properties of water/glycol mixtures at 0%, 25%, 50%, 75% and 100% glycol concentration. A further step was implemented in the numerical routine to derive the compression heating properties as function of pressure, temperature and glycol concentration.Similarly, the proposed method also can be used to determine compression heating properties of any other liquid or semi-solid material, allowing for accurate prediction of adiabatic temperature increases upon pressurisation in high-pressure processing.