Research progress of incremental synthesis and enhancement mechanism of natural gas hydrates: A review

As a new type of energy storage technology, the gas storage technology of hydrate-based method has being paid more attention Achieving the rapid formation and efficient gas storage is the major objective of the gas storage technique. However, the technique of hydrate-based transportation and natural gas storage suffers from issues related to lengthy induction time (IT), sluggish formation rate, and low storage density. The rapid formation and incremental synthesis of hydrates have become the key issues and important challenges in this field, considering as an important direction in the future. In this work, a comprehensive review was conducted on the formation properties of CH4 hydrate in various systems and the associated kinetic principles. The quantitative effects of various factors about the formation and storage process of CH4 hydrate and the kinetic mechanism are analyzed deeply. On this basis, the influence mechanism of additives, porous media, reaction system, driving force and other factors on the CH4 hydrate formation are described comprehensively. The quantitative influences of different factors on the gas uptake, IT, gas storage capacity (SC) of hydrate and gas consumption are revealed, so as to systematically analyze the enhancement mechanism of the natural gas hydrates formation process. Finally, the shortcomings and future development direction of natural gas storage and transportation technology by the hydrate method are pointed out. It is necessary to do further in-depth research on the promotion mechanism and kinetic of CH4 hydrate by various additives and additional research of the compound additive is warranted. •Analyzed CH4 hydrate formationeffects.•Described CH4 hydrate formationmechanism.•Revealedenhancement mechanism of hydrate.