1. Supporting Information Decomposition kinetics and recycle of binary hydrogen- tetrahydrofuran clathrate hydrate Hiroki Yoshioka 1, Masaki Ota 1,Yoshiyuki Sato 1, Masaru Watanabe 1, Hiroshi Inomata 1, Richard L. Smith, Jr.* 1, Cor J. Peters 2, 3 1 Tohoku University, Research Center of Supercritical Fluid Technology, Aoba-6-6-11, Aramaki Aza, Aoba-ku, Sendai 980-8579 Japan 2 Laboratory of Process Equipment, Department of Process and Energy, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands 3 Petroleum Institute, Chemical Engineering Program, Bu Hasa Building, Room 2203, P.O. Box 2533, Abu Dhabi, United Arab Emirates * Corresponding author: Tel: +81-22-795-5863, Fax: +81-22-795-5864, e-mail: smith@scf.che.tohoku.ac.jp

2. Figure S1. Raman spectra of liquid tetrahydrofuran (THF), THF-water solution, and THF clathrate hydrate product.

3. Figure S2. Reproducibility for experimental runs at conditions of 269 K, initial pressure of 5.0 MPa and for a particle size range of 500 - 600  m for two experimental runs (Table S1): (a) consumed hydrogen and (b) released hydrogen.

4. Figure S3. Typical pressure and temperature profiles for Run 1 (Table S1) for a particle size range of 500 - 600  m for: (a) H 2 clathrate hydrate formation and (b) H 2 clathrate hydrate decomposition.

5. Figure S4. Raman spectra of (a) liquid tetrahydrofuran (THF), THF-water solution, and THF clathrate hydrate product (outside the cell) and (b) THF clathrate hydrate, bulk hydrogen, binary H 2 -THF clathrate hydrate from formation, and product H 2 -THF clathrate hydrate during decomposition. a b

6. Figure S5. Hydrogen consumption by stoichiometric (19.06 wt%) THF clathrate hydrate particles as a function of time for several initial H 2 gas pressures for a particle size range of 500 - 600  m along with HHPD model parameters.

7. Figure S6. Hydrogen released through pressure reduction to 0.1 MPa for H 2 - saturated stoichiometric (19.06 wt%) THF clathrate hydrate particles as a function of time for several initial H 2 gas pressures for a particle size range of 500 - 600  m along with HHPD model parameters.

8. Figure S7. Hydrogen released and consumed during decomposition and formation of H 2 clathrate hydrates with stoichiometric (19.06 wt%) THF clathrate hydrate particles as a function of time for a particle size range of of 500 - 600  m.

9. Figure S8. Hydrogen consumption by stoichiometric (19.06 wt%) THF clathrate hydrate particles as a function of time for an initial H 2 gas pressure of 5.0 MPa and several particle size ranges along with HHPD model parameters.

10. Figure S9. Experimental results for conditions of 269 K, initial pressure of 5.0 MPa and for two particle size ranges: (a) formation and decomposition measurements and (b) decomposition results fitted with the HHPD model.

11. Figure S10. Hydrogen diffusion coefficients calculated from the later portions of the experimental data for formation of H 2 clathrate hydrates with stoichiometric (19.06 wt%) THF clathrate hydrate particles for a particle size range of 500 - 600  m and comparison with literature measurements. 17)