Methane hydrates bearing synthetic sediments—Experimental and numerical approaches of the dissociation

• Published in: Chemical Engineering Science
• Main Authors: Tonnet, Nicolas, Herri, Jean-Michel
• Other Authors: Centre Sciences des Processus Industriels et Naturels (SPIN-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT), Département Géochimie, environnement, écoulement, réacteurs industriels et cristallisation (GENERIC-ENSMSE), Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT)-SPIN, Laboratoire des Procédés en Milieux Granulaires (LPMG-EMSE), Institut Mines-Télécom Paris (IMT)-Institut Mines-Télécom Paris (IMT)-Centre National de la Recherche Scientifique (CNRS), INTAS European project
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: Methane hydrate; Dissociation; Sediment core; Heat and mass transfer; [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering
• Online Access: https://hal.science/hal-00411385; https://hal.science/hal-00411385/document; https://hal.science/hal-00411385/file/CES-JMH-64-19.pdf; https://doi.org/10.1016/j.ces.2009.05.043

International audience The production of methane gas from methane hydrate bearing sediments may reach an industrial scale in the next decades owing to the huge energy reserve it represents. However the dissociation of methane hydrate in a porous medium is still poorly understood and controlled: the melting of methane hydrate involves fluids flows and heat transfer through a porous medium whose properties evolve as the hydrate phase disappears, and is replaced (or not) by an ice phase. Mass and heat transfers can be coupled in a complex way, firstly because of the permeability changes, and secondly due to material conduction changes. In our work, mass and heat transfers have been studied both experimentally and numerically. A 2D numerical model is proposed where heat and mass transfers govern the dissociation of methane hydrate. This model has been used to design an experimental device. Experiments have been obtained and finally the model has been validated. The experimental set-up consists of five cylindrical sand packs having the same diameter but different lengths. Each experiment starts by crystallizing a hydrate phase in a porous medium. Then the hydrate is dissociated by controlling the pressure at one boundary. The kinetic of dissociation is monitored by collecting gases in ballast. Simulations and experiments demonstrate that the dissociation limiting step switches from thermal transfer to mass transfer depending on the initial permeability and conductivity of the porous medium.