Publications by authors named "Greg A Mutch"

Metallic sealants are widely used with high-temperature membranes. Here we show that their use in supported molten-salt membranes results in order-of-magnitude differences in CO flux and introduces O co-permeation. The 'short-circuiting' effect they introduce has important implications for the design of future experiments, and the interpretation of past work.

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Article Synopsis
  • Separation processes become more challenging when the species to be separated is at low concentrations, requiring the overcoming of thermodynamic and kinetic constraints.
  • Researchers have developed a molten-carbonate membrane capable of increasing CO concentration from a low level (400 ppm) by using ambient energy from humidity differences.
  • This method not only allows CO to move 'uphill' against its concentration gradient but also significantly enhances CO transport rates through the creation of carriers within the molten salt, leading to a tenfold increase in CO flux even with a drastic reduction in input concentration.
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Vanadium redox flow batteries have applications for large-scale electricity storage. This paper reports the influence of carbon structural characteristics of sustainable walnut shell-derived carbons in carbon/polyvinylidene fluoride composite electrodes on vanadium redox reactions. Pyrolysis, gasification, and chemical treatment procedures were used to modify the structural characteristics of carbons.

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Membranes are a critical technology for energy-efficient separation processes. The routine method of evaluating membrane performance is a permeation measurement. However, such measurements can be limited in terms of their utility: membrane microstructure is often poorly characterized; membranes or sealants leak; and conditions in the gas phase are poorly controlled and frequently far-removed from the conditions employed in the majority of real processes.

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Solid metal oxides for carbon capture exhibit reduced adsorption capacity following high-temperature exposure, due to surface area reduction by sintering. Furthermore, only low-coordinate corner/edge sites on the thermodynamically stable (100) facet display favorable binding toward CO, providing inherently low capacity. The (111) facet, however, exhibits a high concentration of low-coordinate sites.

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