Carbon nanotubes-based porous media constructed via 3D printing for methane hydrate formation

Abstract

Utilizing porous materials (e.g., activated carbon) as a fixed bed has been established as an effective method for promoting methane hydrate formation. However, hydrate growth typically leads to significant volume expansion within the fixed bed, resulting in reduced apparent hydrate density. In this study, 3D printing with carbon nanotubes (CNTs) as substrates was employed to create porous media specifically designed for methane hydrate formation. This approach enabled precise control over the size and structure of the media, as well as the ability to achieve pores of varying scales and porosities. As fixed beds, these porous media provided ample pore space (particularly millimeter-sized pores) for methane hydrate growth, leading to compact agglomeration of hydrates and a substantial increase in the apparent methane storage capacity, which is increased from approximately 60 v/v in a pure SDS solution system to 90–100 v/v in the porous medium. Furthermore, unlike traditional activated carbon, which typically undergoes volume expansion during hydrate growth, the porous media developed in this study avoided any volume expansion due to their unique one-piece design and pre-engineered pore structures. This research presents a novel approach to constructing gas hydrate fixed beds, offering significant potential for application in hydrate-based energy storage technologies.