Study Of Thermodynamics Calculation And Inhibitor Factors In Natural Gas Formation Process

Natural gas hydrate is a cage-like crystalline compound similar to the ice. At low temperature and high pressure, parts in natural gas will form ice-like substance with water. Hydrate will bring much disadvantages to the produce of natural gas once it forms,which can block gas pipeline and make transportation stop so as to bring economics loss to enterprise and country.Research to the natural gas hydrate has become world scientific research at present front porch and heatpoint , whose technique is fresh , difficulty greatly , moreover is significant sense and application value . The hydrate formation mechanism at respect of analog computation is not to obtain exact experimental data. It is very important to hydrate nucleation kinetics,for which is the significant measure of operation and means,by which directs and improves the test.Langmuir equation used in natural gas hydrate formation is studied in this paper. The limitations of the equation during the formation of the hydrates are analyzed; Energy variation of dynamics gas hydrate formation mechanism is divided into three parts, its improvement method of dynamic model simulate calculation is put forward; dynamic factor, critical radii effected by temperature and pressure in natural gas hydrate formation is calculated. And the relation between energy variation and critical radii and temperatures are also associated. Data calculated by this method is exact, which show that the method is suit to the calculation of energy variation and critical radii.And the quantum chemistry method MP2 is used to optimize the structure of hydrogen-bond in gas hydrate and kinetics inhibitor at the basis set level of 6-31G(d).And hydrogen-bond is calculated in bond length. total atomic charges and interation energy. The mechanism of kinetics inhibitor is discussed using quantum chemistry. The result shows that hydrogen-bond between kinetics inhibitor and H2O is stronger than that between H2O molecules, and the hydrogen-bond between kinetics inhibitor with H2O inhibitors hydrate to form more.Part of the original of test synthetised four kinds of hydrate kinetics inhibitors, and they are separately: PAM PVIMA PMAM and NVP/Vac. Builded a small scale natural gas hydrate formation unit in the test process, and the kinetics inhibitors (PAM PVIMA PMAM NVP/Vac and PVP)was added to hydrate formation unit. The curve of gas pressure adapted to time in the hydrate generative process was obtained below the specially designated concentration(1wt%).When the curve that obtained together with unmixed water and one kind of hydrate promoter acted as comparatively, analyses the kinetics inhibitors adjusting the natural gas hydrate generative process effect. The result has obviously showed that the kineticsinhibitors prolong the hydrate succeeds stone time and cut down hydrate format ion rate. Used gas pressure is lower than the uninhibitored system in the same time. Finally inhibitors decrease hydrate formation amount.