Overview
Research Interests
My research involves the conception, design, characterisation, modelling, and optimisation of electrochemical processes, consuming electrical energy to effect useful chemical change. Such processes are used for industrial production of Cl2 + NaOH, NaClO3, NaClO4, Al, Co, Cu, Mg, Mn, Na, Ni, Zn, adiponitrile, etc. Chlor-alkali electrolyses alone consume ca. 2 % of the total US electrical power output and one plant at Runcorn consumes ca. 1 % of UK electrical power. Hence, the energy efficiencies of such processes are economically and environmentally crucial, since energy costs dominate their overall running costs, and, though they are intrinsically clean in themselves, they cause pollution (CO2, SO2, NOx) at a distance if energised by power stations burning fossil fuels. Recently completed and present projects involve(d):
- Modelling of spatial distributions of electric potentials, current densities [4] / local reaction rates and concentrations [3] in electrochemical reactors, for industrially relevant conditions.
- Modelling of electrode kinetics, current efficiencies (i.e. the proportion of total current used in the required reaction) and specific electrical energy consumptions for electrochemical processes involving multiple electrode reactions. This enables improved understanding, possibly resulting in improved performance, of existing industrial processes, and in the longer term, could lead to improved reactor designs.
- Conception, design, characterisation, modelling, and optimisation of novel processes for treatment of effluents [1,5,a] and wastes (electronic scrap, catalysts etc.) containing a range of precious and base metals [c].
- Measurements of the spatial distributions of bubbles in electrochemical reactors and of the coalescence kinetics of individual bubbles with planar electrolyte / gas interfaces. Most of the most industrially important electrolytic processes generate bubbles of chlorine or oxygen, and hydrogen, which accumulate with height, decreasing electrolyte conductivities, increasing specific electrical energy consumptions and distorting current density distributions.
Selected Research Projects
- "Electrochemical Recovery of Precious Metals from Alumina-Supported Catalysts"
- "Modelling Potentials, Concentrations and Current Densities in Three-Dimensional Electrodes for Metal Recovery from Dilute Liquid Effluents"
- "Recovery of Metals from Waste Electrical and Electronic Equipment (WEEE) by Leaching and Electrowinning".