Dr Spence Taylor awarded 2010 Senior Moulton Medal
Tuesday 15 February 2011
The Senior Moulton Medal has been awarded annually since 1929 for the top paper "of a mature nature" published by the Institution of Chemical Engineers during the year. The award is named after Lord John Fletcher Moulton MP FRS (1844-1921) who, as Director-General of Munitions during the Great War, was associated with the development of chemical engineering in Britain during the early part of the 20th Century.
Dr Taylor’s paper describes a process for transferring precipitated asphaltenes from oil into water using temperature-dependent surfactant phase behaviour. This was the first reported demonstration of phase partitioning of this type of carbonaceous particle in a separation process. The award also highlights the Institution’s recognition of the practical importance of the study of disperse systems. Previous medal winners conducted research into microbubbles, aggregation, crystallisation, filtration and emulsion separation.
Dr Taylor’s work is potentially relevant to crude oil refining, and the need to maximise value from this natural resource. When the most valuable products have been distilled and cracked from crude oil, what remains is the “bottom of the barrel” residue. This contains the most dense, polar and aromatic fraction of the oil, termed the “asphaltenes”. Asphaltenes are strictly a solubility class of the crude oil, being soluble in aromatic solvents, but insoluble in paraffins.
Asphaltenes have long been a fascination, not least because their precise structures are still challenging chemists the world over. Generally, they are polycyclic aromatic compounds, possessing surface activity, and are considered to exist colloidally in the crude oil as “nano-aggregates” (formerly known as micelles - somewhat of a misnoma) and are particularly important in the stabilisation of crude oil emulsions, which is another of Dr Taylor’s interests.
Dr Taylor instigated the study some 25 years ago and only recently had the opportunity to complete it at Surrey. The early work involved working with colleagues at BP to scale up the initial bench-scale experiments to demonstrate the process using barrel quantities of asphaltene suspension. From the larger scale tests, it was demonstrated that, unlike separations such as filtration, the surfactant-based process strips away the oil from the asphaltene particles, generating an oil-free aqueous suspension, which has possible application as a boiler fuel.
However, Dr Taylor suggests that asphaltenes could have more technological applications in the future. As their structure is only a short step away from graphitic carbon, asphaltenes are a potential source of graphite, and possibly fullerenes and graphene that has received considerable recent publicity. Dr Taylor believes that further applications of this “waste material” will be developed in due course. Perhaps this is an opportunity to put asphaltenes on the map!