Hydrogen Storage Capacity of Tetrahydrofuran and Tetra-N-Butylammonium Bromide Hydrates Under Favorable Thermodynamic Conditions

An experimental study was conducted to evaluate the feasibility of employing binary hydrates as a medium for H2 storage. Two reagents, tetrahydrofuran (THF) and tetra-n-butylammonium bromide (TBAB), which had been reported previously to have potential to form binary hydrates with H2 under favorable conditions (i.e., low pressures and high temperatures), were investigated using differential scanning calorimetry and Raman spectroscopy. A scale-up facility was employed to quantify the hydrogen storage capacity of THF binary hydrate. Gas chromatography (GC) and pressure drop analyses indicated that the weight percentages of H2 in hydrate were less than 0.1%. The major conclusions of this investigation were: (1) H2 can be stored in binary hydrates at relatively modest pressures and temperatures which are probably feasible for transportation applications; and (2) the storage capacity of H2 in binary hydrate formed from aqueous solutions of THF over a concentration range extending from 2.78 to 8.34 mol % and at temperatures above 263 K and pressures below 11 MPa was <0.1 wt %.