Study of different models of prediction of the simple gas hydrates formation induction time and effect of different equations of state on them

摘要

Gas hydrates are crystals, similar to ice. In these crystals, no chemical bond is created between the water molecules (host) and the trapped gas molecules (guest). Gas hydrates are generally encountered in gas transportation pipelines and the industries related to natural gas. Gas hydrates block the path of transmission pipelines and process equipment, which in turn result in partial damage or destruction of the pipeline. For preventing these events, it is necessary and vital to predict the hydrate induction time. To tackle this important issue, this research aims at predicting different models of induction time for hydrate formation of simple gases. Moreover in the current study, these models are evaluated and compared based on the available experimental data in the literature. Additionally, the influence of different equations of state on the aforementioned models are investigated. The models of Natarajan et al., modified Natarajan, Kashchiev and Firoozabadi and Rasoulzadeh and Javanmardi were utilized to predict the induction time of hydrate formation of simple gases including methane and ethane. The results revealed that the models by Rasoulzadeh and Javanmardi, and modified Natarajan yielded the most accurate results. Furthermore, the results showed that various equations of states resulted in similar results, therefore, specified equation of state does not have a great influence on predicting the induction time of hydrate formation.