Recent advances in high-efficiency formation of gas hydrates within fixed beds: Classification, mechanism, applications and challenges

Abstract

Gas hydrates represent an important technology with potential applications in the fields of gas storage and transportation, energy supply, and gas separation. However, their scalable application is restricted by slow hydration kinetics and the limited storage capacity. Mechanical stimulus and chemical promotors can effectively promote the gas–water hydration efficiency, yet these approaches raise concerns regarding high energy consumption and serious environmental pollution. Through providing a novel contact mode between gas and water molecules, fixed beds present an innovative solution that aligns with low-energy, eco-friendly, and efficient hydration reaction. Their intricate porous structures and tunable frameworks facilitate the mass and heat transfer processes, thereby boosting the hydration efficiency. This paper provides a comprehensive review of recent advances in the efficient gas–water hydration within various fixed beds. In this review, it first outlines the fundamental characteristics, kinetics, and thermodynamics of gas hydrates. According to the component and configuration, four types of fixed beds are classified (foam, gel, particle-packed, and 3D-printed), and their enhancement mechanisms for the efficient hydrate formation are discussed. Their representative and potential applications of gas hydrates and relevant underlying principles are overviewed. Finally, it summarizes the efficacy of fixed beds in hydration reaction and proposes the upcoming research focuses and directions. This paper aims to guide the development of efficient fixed-bed systems and provide valuable references for the application of fixed beds in hydrate-based technologies.