海底沉积物层CO2封存中水合物研究进展

海底沉积物层内CO2封存被认为是缓解全球气候变暖的有效途径，本文介绍了CO2封存时水合物自封机理、水合物形成条件和水合物稳定带范围，描述了水合物生成动力学研究现状，包括成核动力学、生长动力学以及水合物结晶过程驱动力，水合物的成核模型有成簇成核模型、成簇成核扩展模型、界面成核模型、Chen-Guo模型，水合物生长动力学模型有Englezos、Kvamme生长模型、指数增长模型、流体流动模型以及LB模型，水合驱动力有化学势差、温差、吉布斯自由能差、浓度差、压差或逸度差。总结了多孔介质渗透率和孔隙度随水合物成核和生长的演化关系，有KC模型、NR模型、平行毛细管束模型、渗透率下降模型和Morisdis相对渗透率模型，最后介绍了CO2水合实验情况，展望了CO2海底沉积物层内封存与水合物相关的科学问题。

Research advancement in hydrate formation during CO2 sub-sea sediments sequestration

CO2 sub-sea sediments sequestration is considered as an effective method to mitigate global warming.The paper introduced hydrate self-sealing mechanism,formation conditions and stability zone,described the advance of kinetics for hydrate formation,including kinetics of hydrate nucleation, growth,and the driving force of hydration.The hydrate nucleation models are clustering nucleation model,extension model,interface nucleation model,and Chen-Guo model.The hydrate growth models are Englezos model,Kvamme model,exponential growth model,fluid flow model,and LB model.The driving forces of hydration are chemical potential difference,temperature difference,Gibbs free energy difference,concentration difference,pressure or fugacity difference.The KC model,NR model,parallel capillary bundle model,permeability decreasing model,and Morisdis’ relative permeability model were summarized to describe the evolution of the porosity and the permeability of sediments during hydrate nucleation and growth.Finally,some hydration experiments were introduced and related scientific problems on CO2 sequestration and hydrate formation in marine sediments were prospected.