The work deals with the optimization of methane hydrate storage in fixed-bed reactor systems made up of modified silica beads. Under transient conditions, rapid hydrate growth is achieved at 4 °C. Glass beads are modified via silanization and treated with peroxymonosulfuric acid. It is proven that the fixed-bed surface properties significantly determine the gas hydrate growth and final gas uptake and therefore determine the successful technical design of the system. The capillary pressure is calculated in each bed configuration and is set in relation to the overall gas uptake. A negative capillary pressure leads to a holdback of water in the fixed-bed system. A high water-to-hydrate conversion is obtained for an untreated fixed bed with a positive capillary pressure. In the presence of SDS, the capillary effects are negated by the kinetic promotion effects. An inhibiting behavior is observed when using hydrophilic beads after treatment with peroxymonosulfuric acid.

This work deals with the influences of surface‐active coatings made by silanization with an increasing hydrophobicity on methane hydrate formation in view of induction times, gas uptake, and rate of gas consumption. Hydrate formation was performed in a stirred pressure autoclave under stationary and transient conditions in presence of different coatings made from diverse silanes. With increasing carbon chain length of the silanes, promoting effects were observed while using stationary formation conditions.

Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.

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This contribution describes the influence of turbulent flow conditions in the liquid and/or gas phase and directly in the phase interface, different flow patterns (axial/radial), volume‐specific power inputs, mass‐specific energy consumptions, as well as volume‐specific mass transfer coefficients on the gas hydrate formation, derived from an experimental investigation of five different reactor setups. The results correspond to all fields of gas hydrate research, especially actually discussed technical hydrate applications, like hydrate‐based desalination, gas storage, gas separation, biogas and green hydrogen handling, carbon dioxide deposition, new phase transfer materials, and even electrical power supply. Two main objectives, first, to determine favorable hydrate forming conditions in stirred systems to provide competitive hydrate formation processes, and second, the search for a concept to enable the transfer of experimental results, for example, from a stirred reactor to a pipeline system for inhibitor research, through the targeted adjustment of similar and comparable turbulent flow conditions in different reactor setups could be achieved. So far, the targeted formation of gas hydrates has been investigated essentially from the point of view of optimizing the formation conditions with regard to pressure and temperature as well as the addition of auxiliary materials and promoters. In addition, some studies consider different reactor types and setups, for example, spray reactors or bubble columns. In many publications, stirred and cooled pressure autoclaves are described, whereby the gas and the liquid phase are brought into contact with each other by mixing to a greater or lesser extent by an agitator, then forming a solid gas hydrate phase. Often missing in previous research work is a systematic approach for determining the influence of flow conditions on gas hydrate formation. Many different influencing factors in a stirred reactor system can strongly affect the kinetics and formation of gas hydrates, for example, stirrer type, rotational frequency, stirrer and reactor geometry, and filling level. This is the starting point of the present investigation that deals with the influence of the flow conditions on the formation of gas hydrates. Tests were performed in a stirred autoclave to measure the effects of different stirrer configurations. The results obtained contribute to the explanation of the hydrate formation mechanism and can be used to optimize the targeted production of gas hydrates in technical hydrate applications. A rapid, immediate, hydrate formation is advantageous and can be achieved by suitable flow conditions in stirred reactors, which is successfully proven within this study contribution.

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