Christopher L. Bray

Bio: Christopher L. Bray is an academic researcher from University of Liverpool. The author has contributed to research in topics: Clathrate hydrate & Methane. The author has an hindex of 8, co-authored 10 publications receiving 525 citations. Previous affiliations of Christopher L. Bray include South China University of Technology.

Methane storage in dry water gas hydrates.

Abstract: Dry water stores 175 v(STP)/v methane at 2.7 MPa and 273.2 K in a hydrate form which is close to the Department of Energy volumetric target for methane storage. Dry water is a silica-stabilized free-flowing powder (95% wt water), and fast methane uptakes were observed (90% saturation uptake in 160 min with no mixing) as a result of the relatively large surface-to-volume ratio of this material.

Rapid and reversible hydrogen storage in clathrate hydrates using emulsion-templated polymers.

Abstract: A method for greatly accelerating the storage of gases such as hydrogen in clathrates by supporting the clathrate phase on a highly macroporous emulsion-templated polymer is presented. The gravimetric penalty is low due to the low bulk density of the support, no mechanical mixing is required, and the system is fully recyclable over multiple charge/ discharge cycles.

Reversible Hydrogen Storage in Hydrogel Clathrate Hydrates

Abstract: The use of inexpensive hydrogels as supports to significantly improve H2 enclathration kinetics and capacities in THF–H2O clathrate hydrate with respect to bulk solutions is demonstrated. Polymer hydrogels give rise to significant rate and capacity enhancements for hydrogen clathrate formation with respect to unmixed bulk systems, suggesting potential for accelerated gas-storage kinetics in clathrate-based technologies.

Reversible Methane Storage in a Polymer-Supported Semi-Clathrate Hydrate at Ambient Temperature and Pressure

Abstract: A key issue regarding the use of clathrates and semi-clathrate hydrates for practical gas storage is the pressure−temperature stability of the material. For many practical applications, the avoidance of cooling, gas overpressure, and mechanical mixing would be very desirable. Here, we show that porous emulsion-templated polymer supports greatly enhance methane uptake kinetics in tetra-iso-amylammonium bromide semi-clathrate hydrates without introducing complex mixing technologies. These systems show unprecedented thermal stability and can be decomposed upon demand to release the gas. Single crystal X-ray structure analysis of the semi-clathrates loaded with methane or krypton were obtained, confirming that the gases are stored in the dodecahedral A′ and A′′ cages.

Fractionation of Poly(vinyl acetate) and the Phase Behavior of End-Group Modified Oligo(vinyl acetate)s in CO2

Abstract: Poly(vinyl acetate) (PVAc) is an inexpensive, high-tonnage bulk commodity polymer which, unlike most vinyl polymers, is moderately biodegradable. PVAc has been shown to exhibit anomalously high solubility in CO2 with respect to other vinyl hydrocarbon polymers. Understanding the phase behavior of PVAc in CO2 and its variation with structure is very important for its potential application as suitable surfactant, ligand, or phase transfer agent in a CO2 solvent process. In this article, PVAc has been fractionated using a supercritical fluid extraction method (SCFE) to provide low molecular weight fractions with narrow polydispersity. The phase behavior of hydroxyl terminated poly(vinyl acetate)s (PVAc-OH) were determined by a high throughput gravimetric extraction (HTGE) screening method and a cloud-point pressure method using a variable volume view cell (VVVC). The solubility of PVAc in CO2 strongly depends on the molecular weight. Oligomer PVAc-OH (Mw < 3000 g·mol−1) is soluble in CO2 at low pressures but...

Clathrate Hydrates: From Laboratory Science to Engineering Practice

Abstract: Clathrate hydrates have steadily emerged as an important field in the areas of flow assurance, energy storage and resource, and environment. To better understand the role of hydrates in all of these areas, knowledge developed in laboratory experiments must be effectively transferred to address the challenges related to hydrate formation, dissociation, agglomeration, and stability. This paper highlights the recent hydrate literature focusing on the thermodynamics, kinetics, structural properties, particle properties, rheological properties, and molecular mechanisms of formation. The foundation for continued understanding and development of hydrates in engineering practice will rely on laboratory measurements utilizing traditional and innovative tools capable of probing time-dependent and time-independent properties.

Functional Porous Polymers by Emulsion Templating: Recent Advances

Abstract: Porous materials are currently of great scientific as well as technological interest. A strategy that is increasingly employed to prepare highly porous and well defined macroporous polymers is emulsion templating, whereby the droplets of a high internal phase emulsion are used to create pores in a solid material by curing or polymerization of the emulsion continuous phase. This Feature Article covers recent work in this area, focusing on: the preparation of such materials from new precursors and via novel approaches; the chemical modification of existing materials; and the application of the resulting porous structures in diverse areas of science and technology.

Gas hydrates in sustainable chemistry

Abstract: Gas hydrates have received considerable attention due to their important role in flow assurance for the oil and gas industry, their extensive natural occurrence on Earth and extraterrestrial planets, and their significant applications in sustainable technologies including but not limited to gas and energy storage, gas separation, and water desalination Given not only their inherent structural flexibility depending on the type of guest gas molecules and formation conditions, but also the synthetic effects of a wide range of chemical additives on their properties, these variabilities could be exploited to optimise the role of gas hydrates This includes increasing their industrial applications, understanding and utilising their role in Nature, identifying potential methods for safely extracting natural gases stored in naturally occurring hydrates within the Earth, and for developing green technologies This review summarizes the different properties of gas hydrates as well as their formation and dissociation kinetics and then reviews the fast-growing literature reporting their role and applications in the aforementioned fields, mainly concentrating on advances during the last decade Challenges, limitations, and future perspectives of each field are briefly discussed The overall objective of this review is to provide readers with an extensive overview of gas hydrates that we hope will stimulate further work on this riveting field