A volatile issue - the quest for safer, ‘greener’ energy sources
A project based in the Department of Chemistry is working towards safe, 'green' energy storage materials. The research is seeking to understand the molecular structure and reactivity of energetic compounds, with the ultimate goal of finding chemical systems which could efficiently store and release energy.
Several solutions exist for the age-old problem of storing and releasing energy, including pumped hydroelectric, electric capacitors, nuclear power stations and the rocket engine. These techniques have vastly different scales and characteristics of energy take-up, release and capacity.
For example, a rocket engine has to develop thrust rapidly and maintain it within certain limits over a period of time. This can require enormous amounts of energy and is achieved by converting chemical into kinetic energy. The chemical energy is contained in a combination of fuel and oxidiser that react to release hot gas which produces the necessary thrust.
Instead of the fuel/oxidiser approach the energy could also be provided by the thermal decomposition reaction of a single chemical compound. This approach has the potential to simplify the process and reduce environmental hazards. Funded by the Engineering and Physical Research Council (EPSRC), Chemist Dr Peter Portius and his group are exploring such compounds with a high nitrogen content.
When these compounds are heated up large volumes of hot nitrogen gas (the main component of air) are generated. This process requires no oxygen and releases neither carbon dioxide nor other greenhouse gases and less smoke. Under normal circumstances, the higher the nitrogen content the higher the energy density of a compound. However, many of these niotrogen rich compounds can decompose unpredictably and violently. Therefore an important part of Dr Portius's research focuses on the tricky problem of how to combine a high energy density with the ability to control energy release.
Dr Portius explains: "We need to understand how very large amounts of energy can be released within various time scales. Chemical sciences are integral to the goal of achieving safer, more environmentally friendly energy sources. This project is based on inorganic chemistry with collaborations across the sciences and with industry. Specifically, our research focuses on developing strategies for the syntheses of nitrogen-rich energetic materials, on the synthesis of new energetic molecules, and the search for the fundamental structural requirements of chemical compounds to bind a lot of nitrogen."
For further information, please contact Dr Peter Portius at:
email : p.portius@sheffield.ac.uk
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