Prediction of gas hydrates equilibria using molecular dynamics simulation

In this thesis, Molecular Dynamic (MD) Simulation will be used for the prediction of methane and ethane gas hydrate equilibrium. The MD Simulation is done using "Moldy" which is a highly portable C program for performing molecular-dynamic simulations of solids and liquids. The van der Waals and Platteeuw model is the first thermodynamic model to predict the equilibrium condition of gas hydrates. However, the van der Waals model considers the rigid lattice assumption for the calculation of the equilibrium conditions. In this work, the concept of lattice expansion or stretching is incorporated for the prediction of the gas hydrate equilbria. The equilibrium pressures of hydrates are obtained by using constant temperature and volume ensemble in MD simulation. These pressures are compared to experimental data to obtain equilibrium volume and energy. From the data obtained from MD simulation a simple model is created for methane and ethane gas hydrate. This model can be used to predict the equilibrium conditions of methane and ethane hydrates at a given temperature or pressure.