Kinetic study of the hydration of magnesium oxide for a chemical heat pump

A kinetic study of the hydration of magnesium oxide was performed to test the possibility of developing a magnesium oxide/water chemical heat pump. The hydration rate of magnesium oxide was measured by a gravimetric analysis with a sample of average particle size 10 mu m for the reaction temperature 373-423 K and the reaction vapor pressure 12.3-47.4 kPa. It was a reasonable hypothesis that the reactant magnesium oxide had four reaction regimes. An empirical rate equation based on this hypothesis was proposed with parameters determined from experimentally measured values. The performance of the heat pump was estimated numerically using the rate equation. The heat output rate was large enough in comparison with other common heat pumps. It was shown that the reaction system would be applicable to a chemical heat pump system. Copyright (C) 1996 Elsevier Science Ltd.