Vapor–liquid equilibrium pressure of ethanolamine hydrochloride, and vapor–solid equilibrium pressure of methylamine, pyridine, and trimethylamine hydrochlorides by thermogravimetric method

Abstract

In this work, vapor–liquid and vapor–solid equilibrium pressure and enthalpies of amine hydrochlorides were determined using a thermogravimetric method. Ferrocene was used as the reference compound to determine the calibration constant k. Then, ammonium bromide, ammonium chloride and benzoic acid were used for testing the k-ferrocene. Experimental vapor–solid equilibrium pressure of methylamine hydrochloride obtained in this study showed good agreement with recent literature data. For the other substances investigated, ethanolamine hydrochloride, pyridine hydrochloride, and trimethylamine hydrochloride, no reliable equilibrium data is available in the open literature. Among these substances, ethanolamine hydrochloride was found to be the less volatile, followed by methylamine, trimethylamine, and pyridine hydrochloride. Regarding the equilibrium enthalpies found in this work, all salts have shown a similar value. This can be explained by the similar reaction (dissociation) that takes place for these substances.