Hydrogen storage as clathrate hydrates in the presence of 1,3-dioxolane as a dual-function promoter

Abstract

As mankind turns towards renewables and a safe transition into a low carbon future, hydrogen (H2) is rapidly gaining prominence as a key player in the clean energy portfolio. H2 storage as solid hydrates, especially when influenced by thermodynamic promoters such as Tetrahydrofuran (THF), is viewed as a safe technology with high energy density potential. However, issues of low gas storage capacity and sluggish hydrate formation continue to hinder its applicability. Here, we introduce 1,3-dioxolane (DIOX) as a dual-function (thermodynamic and kinetic) promoter for H2-contained (sII) hydrate formation, used at the stoichiometric concentration (5.56 mol%). Depending on the available gas phase volume, the average gas uptake in 2 h of mixed H2/DIOX hydrate growth ranged from 24.74 (±1.58) to 26.51 (±1.79) volume of gas/volume of hydrate (v/v), which to the best of our knowledge, presents a 21.5–30.2% increase over the maximum value reported using the conventional promoter THF. Visual observation mapping and in-situ Raman spectroscopy measurements performed concurrently with hydrate growth provided insight into the macro- and micro-scale properties of the system, respectively. We expect our results to be the foundation towards developing a feasible hydrate based H2 storage technology.