A method of cyclic icing and melting for stable and rapid formation of hydrate: Novel strategy of hydrate-based energy storage

Rapid and efficient hydrate formation is the critical step for hydrate-based energy storage technology. However, the high formation randomness and low formation rate are still the urgent issues. Therefore, in this study, we proposed the cyclic icing and melting method (CIMM) to improve the hydrate formation probability and formation rate. Meanwhile, the CIMM was applied in different scale reactors to verify its effects. The results indicate that CIMM has the advantages on shorting hydrate formation time, improving hydrate formation stability and water conversion rate. Surprisingly, compared with conventional method, the total hydrate formation time shortened by 4.3 h, the formation probability increased by 67 %, and the water conversion rate increased by 62.2 % within 12 h. What's more, the CIMM applying in large volume reactor (352 ml) also shows the better efficient: the hydrate formation pressure decreased to the minimal of 1.5 MPa, and the water conversion was over 65 %. Meanwhile, we analyzed the cost of the CIMM with the hydrate formation amount of 0.228 mol was only 0.52 rmb, which is only 1/4 than that of conventional method. This study can provide a reliable method for hydrate-based energy storage.