Catalytic carbon deposition-oxidation over Ni, Fe and Co catalysts: A new indirect route to store and transport gas hydrocarbon fuels

Development of new materials from waste electrical and electronic equipment: Characterization and catalytic application

Wastes of electrical and electronic equipment (WEEE) represent an important environmental problem, since its composition includes heavy metals and organic compounds used as flame-retardants. Thermal treatments have been considered efficient processes on removal of these compounds, producing carbonaceous structures, which, together with the ceramic components of the WEEE (i.e. silica and alumina), works as support material for the metals. This mixture, associated with the metals present in WEEE, represents promising systems with potential for catalytic application. In this work, WEEE was thermally modified to generate materials that were extensively characterized. Raman spectrum for WEEE after thermal treatment showed two carbon associated bands. SEM images showed a metal nanoparticles distribution over a polymeric and ceramic support. After characterization, WEEE materials were applied in ethanol steam reforming reaction. The system obtained at higher temperature (800°C) exhibited the best activity, since it leads to high conversions (85%), hydrogen yield (30%) and H₂/CO ratio (3,6) at 750°C.

Investigation of carbon deposition induced by pyrolytic decomposition of ethylene

We employed Raman spectroscopy to characterize the formed carbon deposits under different conditions inside a built-in U-shape quartz tube for unravelling mechanism of carbon deposition on stainless steel.

Iron ochre - a pre-catalyst for the cracking of methane

BACKGROUND

Iron ochres are gelatinous sludges that can cause problems in terms of water management. In this work, the application of iron ochre obtained from a river has been applied to catalytically crack methane - another potential waste product - into two useful products, hydrogen and a magnetic carbon-containing composite.

RESULTS

The powder X-ray diffraction (XRD) pattern of the iron ochre was found to be consistent with the expected 2-line ferrihydrite, and energy dispersive X-ray (EDX) analysis showed Fe to be a major component although some Si and Ca were present. The sample was observed to contain a fraction with a tubular morphology consistent with the presence of extra-cellular biogenic iron oxide formed by leptothrix. Upon exposure to methane at elevated temperatures, the material was found to transform into an active catalyst for hydrogen production yielding a magnetic carbon-containing composite material comprising filamentous carbon and encapsulating graphite.

CONCLUSION

The application of two waste products - iron ochre and methane - to generate two useful products - hydrogen and a magnetic carbon-containing composite - has been demonstrated. Furthermore, the ochre has been shown to comprise tubular morphology extra-cellular biogenic iron oxide which may be of interest in terms of other applications. © 2014 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.