Thermodynamic modeling of hydrate formation conditions using different activity coefficient models in the presence of tetrahydrofuran (THF)

The clathrate hydrate is a major problem in gas transportation lines and on the other hand, can be used as a tool for natural gas storage. Moreover, it could be used for gas separation such as monoxide and dioxide carbon from combustion chambers. In this work, a thermodynamic model is developed to calculate gas hydrate formation conditions of single and binary gases in the absence and presence of the thermodynamic promoter such as tetrahydrofuran (THF). A three-phase solid-liquid-gas equilibrium calculation is carried out so that the van der Waals-Platteeuw model is applied for the hydrate phase, SRK EoS for the gas phase and the different activity coefficient models such as local composition and group contribution models for the aqueous solution. The binary interaction parameters for the present activity coefficient models are adjusted through the optimization of the hydrate formation data for the single gases in the presence and absence of THF. Using the local composition and group contribution models, allows one to compare the calculated results with experiment through the percent of Absolute Average Deviation (AAD %)-in pressures and temperatures of the gas hydrate formation conditions so that it is observed the present results are in a good agreement with the experiment. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.