Research on the enhanced method of CO2-seawater hydrate generation
The salt ion components in seawater hinder the hydrate nucleation process,making the hydrate method for marine carbon sequestration take a long time and have a low sequestration rate.Considering the non-homogeneous nucleation characteristics of hydrates,it is feasible to implement a storage method that achieves preferential hydrate nucleation in local areas,leading to the extended generation of hydrates across large sea areas.Therefore,fundamental research on the enhanced generation of seawater hydrate is essential for promoting the application of the hydrate method for ocean carbon sequestration.Based on this premise,laboratory-scale investigations were conducted to study the effects of high subcooling,additives(TBAB),and variable temperature rates on the seawater hydrate generation characteristics,aiming for efficient and high conversion rate hydrate generation.The results indicated that the natural generation of hydrates in seawater at a depth of 400 m is extremely difficult due to the inhibitory effects of salt ions.However,increasing the supercooling degree of the generation process can enhance the driving force for hydrate formation.Although the thermodynamic additive TBAB did not significantly improve the conditions for seawater hydrate generation in the present experiments,it did increase the rate of generation.Furthermore,the study found that the hydrate conversion rate at a cooling rate of 0.3 K/min was enhanced by 1.28 and 1.19 times compared to the effects of subcooling degree and additives,respectively.In conclusion,future studies should consider the coupling effects of various enhanced generation methods to develop technical means that can better mitigate the challenges of seawater hydrate generation.
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