Well-defined meso/macroporous materials as a host structure for methane hydrate formation: Organic versus carbon xerogels

• Published in: Chemical Engineering Journal
• Main Authors: Cuadrado-Collados, C., Farrando-Pérez, Judit, Martínez-Escandell, M., Ramírez Montoya, Luis Adrián, Menéndez Díaz, José Ángel, Arenillas de la Puente, Ana, Montes Morán, Miguel Ángel, Silvestre-Albero, J.
• Other Authors: Ministerio de Economía y Competitividad (España), Principado de Asturias
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2020
• Subjects: Xerogels; Gas hydrates; Confinement effects; Porous structure; Surface chemistry; Methane hydrate
• Online Access: http://hdl.handle.net/10261/217241; https://doi.org/10.1016/j.cej.2020.126276; https://doi.org/10.13039/501100003329; https://doi.org/10.13039/100011941

A series of xerogels with a properly designed porous structure and surface chemistry have been synthesized and evaluated as a host structure to promote the nucleation and growth of methane hydrates. Organic xerogels (OGs) have been synthesized from resorcinol-formaldehyde mixtures using a sol-gel approach and microwave heating. These xerogels are hydrophilic in nature and possess designed meso/macrocavities in the pore size range 5–55 nm. Carbon xerogels (CGs) have been synthesized from their organic counterparts after a carbonization treatment at high temperature. Interestingly, the carbonization process does not alter/modify substantially the porous network of the parent xerogels, while developing new micropores. Under water-supplying conditions, the two types of xerogels exhibit a large improvement in the methane adsorption capacity compared to the pure physisorption process taking place in dry conditions (up to 200% improvement), and associated with a significant hysteresis loop. These excellent values must be associated with the promoting effect of these xerogels in the water-to-hydrate conversion process. The comparison of OGs and CGs as a host structure anticipates that surface chemistry, total pore volume and pore size are critical parameters defining the extent and yield of the methane hydrate formation process. Authors would like to acknowledge financial support from the MINECO (projects MAT2016-80285-p and CTQ2017-87820-R). Principado de Asturias-FICYT-FEDER (Project PCTI-Asturias IDI/2018/000118) is also acknowledged. L.A. Ramírez-Montoya thanks CONACyT, México, for a post-doctoral grant (CVU No 330625, 2017). Peer reviewed