Showing papers by "Thomas E. Rufford published in 2014"

A review of conventional and emerging process technologies for the recovery of helium from natural gas

Abstract: Helium is a unique gas with a wide range of important medical, scientific and industrial applications based on helium's extremely low boiling temperature, inert and non-flammable nature and small molecular size. The only practical sources of helium are from certain natural gas (NG) fields. As world demand for helium rapidly increases, the value of NG fields that contain it even in very small amounts is likely to rise significantly if the helium can be recovered efficiently. However, recovering the helium from the NG using conventional cryogenic distillation processes is expensive and energy intensive. We review the scope for improving the efficiency of the conventional helium recovery and upgrade processes, and evaluate the potential of emerging technologies based on adsorption or membrane separations for helium upgrade and purification. Helium recovery and purification processes are comparable in many ways with systems designed for hydrogen purification and thus, many of recent technological advances for...

Green Carbon Materials : Advances and Applications

Abstract: Agricultural and food industry waste materials have been an important feedstock for activated carbon production for many years. In the development of cleaner energy production and utilization processes, new advanced carbon materials with enhanced properties have been studied. Techniques to tailor pore structure and surface chemistry can produce better carbon materials for energy storage, electrode materials, and selective adsorption of pollutants. This book surveys available waste materials and processes for carbon production and then reviews the recent developments in the use of carbon materials for energy storage, as catalyst supports, and for environmental applications.

Effects of structural properties of silicon carbide-derived carbons on their electrochemical double-layer capacitance in aqueous and organic electrolytes

Abstract: High surface area silicon carbide-derived carbons (Si-CDCs) synthesized by chlorination of beta silicon carbide (βSiC) with two different particle sizes (6 μm and 50 nm) show different porosities with graphitic structure Transmission electron microscopy, Raman spectroscopy and argon (Ar) and carbon dioxide (CO2) sorption analyses are used to examine the textural properties of the Si-CDCs The results show that the particle size of the precursor affects the surface area and porosity of carbons Furthermore, an additional heat treatment of the Si-CDC with 50-nm particle size for 24 h at 1,000 °C results in a collapse of the pore structure and reduces the surface area The capacitive behaviours are investigated in H2SO4 and in tetraethyl ammonium tetrafluoroborate (TEABF4)/acetonitrile (AN) The electrochemical performance of the Si-CDCs is influenced by the particle size, surface area, pore volume and pore size distribution The Si-CDCs exhibit capacitances in 1 M H2SO4 of up to 179 F g−1 and very stable charge–discharge performance over 5,000 cycles This study shows the crucial importance of ultramicropores less than 1 nm combined with nanosized particles for achieving high capacitance in aqueous electrolyte Moreover, the graphitic degree at the surface of the Si-CDCs enhances considerably the rate capability and stability in both electrolytes

Adsorbed Natural Gas and Hydrogen Storage

Abstract: New nanostructured carbons based on cellulose derived aerogel (Carbon AeroCellulose, CAC) have been developed as a 'greener', biomass-based replacement for carbon black (CB) in materials used for energy storage and conversion. The correlation between the formulation, synthesis conditions, material morphology and electro-chemical properties is presented and discussed. Two examples in which CAC can be used, Proton Exchange Membrane Fuel Cell (PEMFC) and primary battery (Li/SOCl2), are given. We show that by tailoring the texture of these new 'green' carbons we can increase the electrochemical performance in comparison with carbon black (CB).

Biomass-derived carbon electrodes for electrochemical double-layer capacitors

Abstract: Waste biomass from agricultural and food production processes can be used to prepare activated carbons with high surface area for energy storage in electrochemical double-layer capacitors The activation process and biomass carbon source can be selected to influence the pore structure and heteroatom content (for example, nitrogen and oxygen) of the activated carbon product In this chapter, we review the effect of carbon pore structure and the effects of heteroatoms on the capacitance of carbon electrodes and compare the electrochemical performance of activated carbons prepared from three biomass wastes: coffee waste, sawdust and sugarcane bagasse, popcorn and sucrose (as a refined carbon source)