Investigation of Methane Hydrate Formation in a Recirculating Flow Loop: Modeling of the Kinetics and Tests of Efficiency of Chemical Additives on Hydrate Inhibition

• Main Authors: Gaillard, C., Monfort, Jean-Pierre, Peytavy, J. L.
• Other Authors: Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Elf Aquitaine
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 1999
• Subjects: additives; methane hydrate; gas hydrate; kinetic inhibitor; transportation lines; hydrate de méthane; inhibiteur cinétique; additif; hydrate de gaz; conduite de transport; [CHIM.GENI]Chemical Sciences/Chemical engineering; Methane hydrate
• Online Access: https://hal.science/hal-02075813; https://hal.science/hal-02075813/document; https://hal.science/hal-02075813/file/gaillard_v54n3.pdf; https://doi.org/10.2516/ogst:1999033

International audience Gas hydrates can be formed when light gases, such as the components of natural gas, come into contact with water under particular conditions of temperature and pressure. These solid compounds give rise to problems in natural gas and oil industry because they can plug pipelines and process equipment. To prevent hydrate formation methanol and glycols are commonly and extensively used as inhibitors. Today, the thermodynamic equilibria of hydrate formation are well known, but the kinetics of gas hydrate formation and growth has to be studied in order to find means of controlling these processes and to explore the mechanisms for hydrate formation that follows non equilibrium laws. The present work deals with the kinetics of methane hydrate formation studied in a laboratory loop where the liquid blend saturated with methane is circulated up to a pressure of 75 bar. Pressure is maintained at a constant value during experimental runs by means of methane gas make-up. First the effects of pressure (35-75 bar), liquid velocity (0. 5-3 m/s), liquid cooling temperature ramp (2-15°C/h), and liquid hydrocarbon amount (0-96%), on hydrate formation kinetics are investigated. Then a new method is proposed to predict firstly the thermodynamic conditions (pressure and temperature) at the maximum values of the growth rate of methane hydrate and secondly the methane hydrate growth rate. A good agreement is found between calculated and experimental data. Finally the evaluation of the efficiency of some kinetic additives and some surfactants developed to avoid either nucleation or crystal growth and agglomeration of methane hydrates is tested based on the proposed experimental procedure. Les hydrates de gaz des composés légers du gaz naturel se forment lorsque ceux-ci entrent en contact avec l'eau dans certaines conditions de température et de pression. Ces composés solides sont nuisibles pour les industries gazière et pétrolière car des bouchons solides peuvent obstruer les lignes de transport et les ...