Modeling of structure H hydrates using a Langmuir adsorption model

A Langmuir adsorption model is used to represent the conditions at which st ructure H hydrates may form. The two smaller cavities of structure H hydrat es are of similar size and are modeled using the same Langmuir constants. P arameters in a simple two-parameter Langmuir expression have been estimated for methane and nitrogen as guest molecules of the smaller cavities and fo r 12 possible guest molecules of the large cavity. The latter ones are all hydrocarbons with from 5 to 8 carbon atoms. Experimental hydrate formation temperatures are correlated with an average absolute temperature deviation of 0.15 K. Hydrate formation data for two ternary mixtures not used in the parameter estimation are modeled with approximately the same accuracy.