Engineering investigation of hydrogen storage in the form of a clathrate hydrate: Conceptual designs of underground hydrate-storage silos

This paper describes the conceptual designs of a facility for storing, in the form of a clathrate hydrate, hydrogen produced in an industrial complex area. We recently reported the first engineering investigation of hydrate-based hydrogen storage, focusing on the conceptual design of hydrate production plants applicable for the large-scale stationary storage in urban or industrial complex areas (Nakayama et al., Energy Fuels 2010;24:2576−2588). This paper complements the previous study by presenting conceptual designs of underground hydrate-storage silos each to be coupled to a hydrate production plant. Several different types of underground silos each having a 35,000 m3 capacity were planned and designed on a construction-engineering basis, which included (a) a tunnel-type silo consisting of several levels radially arranged around an access shaft, (b) a tunnel-type silo consisting of several levels that branch off from a single access level connected to an access shaft, and (c) a vertically-oriented cylindrical tank-type silo. For each type of silo, we have specified the hydrate loading and unloading equipment as well as the cooling system, and have estimated the construction cost.