Abstract--The dehydration reaction of kerolite was investigated using high-pressure differential thermal analysis at pressures as high as 600 bars. The peak associated with the dehydration is broad, suggesting the presence of a series of overlapping reactions ranging from the release of adsorbed water to interlayer water. The peak temperature is 136"C at 1.8 bars and increases to 5160C at 586 bars. The primary reaction represents loss of adsorbed water having a bond energy of 1.5 + 1 kJ/mole. A small amount of water may be present as interlayer water and has a bond energy of 7.5 +_ 3 kJ/mole.