Cereal Chem 40:676 - 683.  |  VIEW ARTICLE

Heat of Vaporization for Shelled Corn.

J. H. Rodriguez-Arias, C. W. Hall, and F. W. Bakker- Arkema. Copyright 1963 by the American Association of Cereal Chemists, Inc. 

Heats of vaporization of shelled corn at various moisture contents were obtained from different analyses of the moisture equilibrium isotherms of the product. The Clausius-Clapeyron, the Othmer, and the Brunauer- Emmett-Teller (B.E.T.) equations were used for calculations of the values of the heats of vaporization. Over the temperature range of 86 to 122F. the heats of vaporization as calculated by the Clausius-Clapeyron equation were found to decrease from 700 cal./g. at a moisture content of 8% dry basis to a value of 602 cal./g. at 22% moisture content dry basis. The Othmer equation showed a similar trend, although the values were somewhat higher than obtained by the Clausius-Clapeyron equation. The B.E.T. equation only holds for moisture contents below 9%, which made comparison with the other two equations impossible over the 8 to 22% moisture content range. This investigation has shown that the heats of vaporization of agricultural products at moisture contents below 9% dry basis can be obtained successfully by using one of three equations: the Clausius-Clapeyron, the Othmer, or the B.E.T. equation. Above a moisture content of 9% dry basis, the first two are applicable.