Abstract

The purpose of this paper is to investigate the thermodynamics of the adsorption/desorption processes of hydrogen on silica aerogel. Hydrogen is a promising alternative fuel for gas turbines as it is carbon free and an excellent energy storage medium. However, the storage of hydrogen itself presents some challenges when stored in liquid or gaseous states. Thus, storing hydrogen in its adsorbed state provides a potential pathway to large scale economic hydrogen storage. The adsorption process is based on weak Van Der Waals forces that make the adsorbate (hydrogen) stick to the adsorbent surface (Silica Aerogel). A 2D CFD model was elaborated to examine the temperature and pressure changes along the adsorption/desorption processes. A grid independence analysis was conducted on meshes ranging from 5000 to 100000 nodes resulted in a similarity of thermodynamic properties after 80000 nodes. The Dubinin-Astakhov (D-A) model was adopted to determine the change in the quantity adsorbed with changing Temperature and pressures. The D-A model declared promising results when implemented in various adsorption studies. The simulation revealed an exothermic and endothermic processes during the adsorption and desorption respectively. A change in temperature during the storage/ discharge of (ΔT = 95K) provides an estimate of the amount of heat to be removed or added during the adsorption and desorption processes. The choice of silica aerogel resides on its feature of being among the lightest materials existing on earth which makes our system suitable for hydrogen storage in transportation. Furthermore, it is largely available and affordable. The outcome of this research can be extrapolated to several gas/silica aerogel combinations’ comparisons. This will be the focus of the upcoming research studies. Additionally, small storage units could provide healthcare applications with breathing air or oxygen packs, diving, space, and aircraft life support would also benefit from this storage technology which endows the system with a portability trait.

This content is only available via PDF.
You do not currently have access to this content.