Beckwée Emile Jules, Watson Geert, Houlleberghs Maarten, Arenas Esteban Daniel, Bals Sara, Van Der Voort Pascal, Breynaert Eric, Martens Johan, Baron Gino V, Denayer Joeri F M
Department of Chemical Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussel, Belgium.
Center for Ordered Materials, Organometallics and Catalysis, Department of Chemistry, Ghent University, Krijgslaan 281, B-9000, Ghent, Belgium.
Heliyon. 2023 Jun 28;9(7):e17662. doi: 10.1016/j.heliyon.2023.e17662. eCollection 2023 Jul.
Biomethane is a renewable natural gas substitute produced from biogas. Storage of this sustainable energy vector in confined clathrate hydrates, encapsulated in the pores of a host material, is a highly promising avenue to improve storage capacity and energy efficiency. Herein, a new type of periodic mesoporous organosilica (PMO) nanotubes, referred to as hollow ring PMO (HR-PMO), capable of promoting methane clathrate hydrate formation under mild working conditions (273 K, 3.5 MPa) and at high water loading (5.1 g water/g HR-PMO) is reported. Gravimetric uptake measurements reveal a steep single-stepped isotherm and a noticeably high methane storage capacity (0.55 g methane/g HR-PMO; 0.11 g methane/g water at 3.5 MPa). The large working capacity throughout consecutive pressure-induced clathrate hydrate formation-dissociation cycles demonstrates the material's excellent recyclability (97% preservation of capacity). Supported by ex situ cryo-electron tomography and x-ray diffraction, HR-PMO nanotubes are hypothesized to promote clathrate hydrate nucleation and growth by distribution and confinement of water in the mesopores of their outer wall, along the central channels of the nanotubes and on the external nanotube surface. These findings showcase the potential for application of organosilica materials with hierarchical and interconnected pore systems for pressure-based storage of biomethane in confined clathrate hydrates.
生物甲烷是一种由沼气产生的可再生天然气替代品。将这种可持续能源载体储存在封闭的笼形水合物中，该水合物包裹在主体材料的孔隙中，是提高储存容量和能源效率的一个非常有前景的途径。在此，报道了一种新型的周期性介孔有机硅（PMO）纳米管，称为中空环PMO（HR-PMO），它能够在温和的工作条件（273K，3.5MPa）和高水负载量（5.1g水/g HR-PMO）下促进甲烷笼形水合物的形成。重量吸收测量显示出陡峭的单步等温线和明显较高的甲烷储存容量（0.55g甲烷/g HR-PMO；在3.5MPa下为0.11g甲烷/g水）。在连续的压力诱导笼形水合物形成-分解循环中较大的工作容量证明了该材料具有出色的可回收性（容量保留率为97%）。在非原位低温电子断层扫描和X射线衍射的支持下，推测HR-PMO纳米管通过将水分布和限制在其外壁的介孔中、沿着纳米管的中心通道以及在纳米管外表面上来促进笼形水合物的成核和生长。这些发现展示了具有分级和相互连接的孔系统的有机硅材料在基于压力的生物甲烷储存在封闭笼形水合物中的应用潜力。
