The first trial of hydrate continuous production: Paving way on hydrate-based carbon capture and storage

Hydrate-based solidified natural gas (SNG) technology presents wide promising prospect in the fields of carbon capture, utilization and storage (CCUS), but high-pressure production environment makes it difficult to separate and store the formed hydrate, causing difficulty in achieving continuous hydrate production. In this work, a spiral-agitated hydrate formation setup was proposed, which integrates the functions of hydrate formation, separation and storage, giving rise to hydrate continuous production for the first time. Amino acids were used to enhance hydrate growth kinetics, fast hydrate nucleation, growth and large conversion were obtained under the synergistic effect of amino acids and spiral agitation. CH4 uptake in hydrate in the storage tank is up to 166.71 (±3.44) V/V with a hydrate conversion of 96.92%, this gives rise to considerable CH4 apparent storage density in the storage tank, which is 109.22 (±3.76) V/V at a mild condition (5 MPa) and increases by 88.55% compared with compressed CH4. It totally requires 94.1 (±13.85) kW·h to stir and convey 1 m3 hydrate for continuous hydrate formation, which is significantly saved (40.61%) by pre-filled liquid. The presented technology can fulfill the continuous production of CH4, CO2 and H2 hydrate etc., promoting the application of hydrate-based SNG technology in CCUS.