A NEW SHORTCUT/GRAPHICAL METHOD TO DETERMINE THE REQUIRED MEG INJECTION RATE FOR NATURAL-GAS HYDRATE INHIBITION

摘要

Several thermodynamics models are available to calculate the required inhibitor concentration and injection rate to depress the hydrate formation to a desired temperature. However, their calculations may require rigorous computer solutions. Therefore, a shortcut method to minimize the calculation steps has been developed.Four diagrams are presented to predict the required Mono-Ethylene Glycol (MEG) weight percent in the rich solution and the flow rate for the desired depression of the hydrate formation temperature for natural gas streams. These diagrams are generated for a natural gas with relative density of 0.6 at pressures of 3, 5, 7, and 9 MPa and are applicable to wet gas temperature of 20, 30, 40, and 50°C. In order to extend the applications of these charts to wider ranges of natural gas mixtures with specific gravities of up to 0.8, two generalized correction factor charts are also provided. These charts and correction factors are based on rigorous computer simulation.The accuracy of this shortcut method is also compared with the rigorous computer simulation results obtained by commercial process simulators and excellent agreement has been obtained.