Investigation On Phase Equilibrium And Liquid Tension Of Gas Hydrate

The gas hydrates in the world are the huge organic carbon depots. In the next century, the gas hydrates will provide the important energy sources. The gas hydrates are the potential energy sources and have a wide development space.Being the basic research of the industrial application, the phase equlibria of the gas hydrates is the hot spot of the modern investigation. This work improves the VDW-P model from the molecule structures based on the quantum chemistry. The improved VDW-P model not only calculates the gas hydrate phase equilibria point, but also predicts the change tendency of the phase equilibria points, when molecule structures change lightly. The improved VDW-P model gives a new way to investigate the gas hydrate under microcosmic molecules. This work had set up a small-scale gas hydrate synthesis device and synthesized gas hydrate particles. The surfactant, SDS, will sffect thesynthesization speed of the gas hydrate. This work had an experiment on the synthesization speed in 100ppm, 200ppm, 300ppm SDS and analysized the phenomena theoretically.The first chapter discussed the background and significance of the task from the practical and theoretical viewpoints. The second chapter shows us the basic properties and research development of the gas hydrates. This work analyzed kinds of gas hydrate phase equilibria model and found the shortage of those models. Based on the quantum chemistry, this work analyzed the possibility of the gas hydrate growing, calculated the total potential energy and zero point energy under different structures of the gas hydrate. Based on this analysis, this work established a new phase equilibria model. Finally, this work set up a small-scale synthesis device and synthesized gas hydrates in 4 MPa, 5MPa. This work analysized the surface affection theoretically, according to the gas hydrate growing speed.