Thermophysical properties of aqueous NaOH−H2O solutions at high concentrations

The working Iluids, used in the majority of all mechanical heat pumps, are expected to bc phased out within some few years due to their contribt, tion to the stratospheric ozone depletion and global warming. Absorption heat pt, mps and transformers are receiving a new renaissance in the field of heating, refrigeration, air-conditioning, and heat recovery. Sodium hydroxide solutions are more propitious to the pulp and paper industry compared to other working pairs. Novel correlations have been developed to compute the vapor pressure. density, enthalpy, and viscosity of sodium hydroxide solutions. These correlations cover the most extensive range of validity ever proposed: 273-473 K for temperatures and 0.2-I kg water per kg solution for concentrations.