Coupling amino acid L-Val with THF for superior hydrogen hydrate kinetics: Implication for hydrate-based hydrogen storage

How THF Tunes the Kinetics of H2–THF Hydrates? A Kinetic Study with Morphology and Calorimetric Analysis

“…In terms of final H 2 gas uptake, V H 2 is the highest at C THF = 3.5 mol %, reaching 2.37 v/v, which is 54.9% and 130.1% higher than the H 2 gas uptake for C THF = 5.56 mol % and C THF = 1.0 mol %, respectively. It should be noted that H 2 gas uptake was relatively low in this study compared with our previous study at C THF = 5.56 mol % ( V H 2 = 29.8 v/v). This can be attributed to the relatively large size of the hydrate reactor ( V = 0.6 L) employed in this study with the observation window and the inherent mass transfer limitations of H 2 at the gas–liquid interface associated with the reactor and stirring.…”

“…The spectral coverage of the Raman wavelength was from 100 to 4200 cm –1 with a resolution of 0.2 cm –1 . The grating scale was 1800 g/mm with an exposure time of 10 s. Details of the experimental setup and measurement methods can be found in our previous work . We prepared samples of the H 2 –THF hydrate at different THF concentrations under P = 15.0 MPa and T = 274.2 K. The H 2 –THF hydrate sample was extracted at T < 233.2 K and quickly transferred to a liquid nitrogen tank for storage.…”

“…The formation process was considered to be complete when the rate of pressure drop was less than 0.01 MPa/h. The calculation method of the amount of the H 2 –THF hydrate formed and the gas uptake of H 2 under different THF concentrations can be found in our previous study …”

“…The sample cell was pressurized with H 2 to P = 15.0 MPa, which is the same as that in the previous kinetic and morphological experiments, and was kept constant by the syringe pump. The isothermal procedure in the literature was adopted in all experiments . The temperature was decreased from 293.2 to 253.2 K at a rate of 0.1 K/min for H 2 –THF hydrate formation and kept stable at 253.2 K for 4.0 h to ensure the complete formation of the H 2 –THF hydrate.…”

“…Di Profio et al developed reverse micelles to form H 2 –THF (5.56 mol %) hydrate to reduce the mass transfer resistance during hydrate formation, but the H 2 storage capacity was only 0.12 wt %. Our recent study showed that by coupling 5.56 mol % THF with a kinetic promoter l -Val of 0.30 wt %, the H 2 storage capacity reached a maximum of 0.27 wt % at 12.0 MPa and 274.2 K …”