Adsorption combined with aqueous phase electrochemical regeneration has been shown by researchers at The University of Manchester (UoM) to offer an alternative approach to the removal of organics from waters and wastewater's. The process, based on a regenerable graphite intercalation compound (GIC) adsorbent, produces no secondary waste, is energy efficient and chemical free. A company, Arvia Technology Ltd., was set up in 2007 to commercialise the technology. As part of a growth and development strategy Arvia investigated other possible applications of the technology and found that odour removal from gas streams might be a good fit with technology features. This Engineering Doctorate (EngD) was a direct investigation into both this technology fit and into the market opportunity for technologies treating odours and volatile organic compounds (VOCs) in gas streams.The research conducted demonstrated that the technology in its different applied forms had certain process drawbacks. Where mass transfer, adsorption and regeneration were combined in a single unit, enhanced transfer as a result of higher pollutant Henry's coefficient was offset by lower adsorbate affinity which varied with hydrophobicity. This relation between affinity and hydrophobicity was different for oxygen functionalised aromatic molecules than for the aliphatic molecules studied. Where adsorption occurred in the gaseous phase and regeneration in the aqueous phase, disadvantages such as short adsorbent packed bed lifetimes and lower current efficiencies of oxidation as a result of adsorbate desorption were shown to be an issue. When the above process challenges were set against the challenging market environment and relatively small market opportunity (approx. £52 million in Europe, 2012) it was difficult to recommend further broad research into the technology. However it was concluded that the concept might still be usefully applied to odour and VOC abatement and that further work should focus on a two phase system with a gas phase adsorbent regeneration technique.The relation observed between adsorbate affinity, hydrophobicity and structure allowed the demonstration of the preferential removal of phenol from solutions containing significantly higher concentrations of aliphatic molecules. This finding is considered the most important project output as it highlights an opportunity to develop Arvia's water treatment technology into a targeted water treatment system for the removal of specific, industrially important, organic contaminants.
|Date of Award||31 Dec 2012|
- The University of Manchester
|Supervisor||Edward Roberts (Supervisor)|
- Electrochemical regeneration
- Volatile organic compound