Building up resistance to oil deposits

A consortium of UK universities is to research ways to minimise the build-up of deposits from crude oil and so increase the efficiency of the UK‘s oil refineries.

ImperialCollegeLondon and the universities of Bath and Cambridge are collaborating on a three-year project, starting in the autumn, which aims to increase the industry’s understanding of asphaltenes — compounds in crude oil which foul equipment and reduce the efficiency of the heat exchange system.

The process by which these compounds solidify and form hard deposits inside the refinery is not very well understood, but according to project leader, Prof Geoff Hewitt from ImperialCollege, it is a problem which is costing the industry a fortune.

‘It costs more than £1bn a year in lost production time, cleaning and most importantly energy wastage,’ said Hewitt. ‘The asphaltene deposit acts like a layer of insulation on the heat exchange and limits the energy that can be produced.’

As part of the project the researchers will build a modified oil rig at ImperialCollege which they can study to understand the process of asphaltene deposition. This must be able to operate at extremely high temperatures, but also be accessible to researchers to study how the deposits are formed. To do this, researchers at Bath have developed a robust sensor which can be placed inside the rig and will use fluidics to measure the presence of the encroaching deposits, and the rate at which they build up.

The way in which heat exchangers are cleaned will also be investigated to see if there are other technologies to make the process more efficient, and their overall design will be looked at in detail to discover if a new design would minimise the asphaltene build-up. Sophisticated thermodynamics and molecular modelling techniques will also be employed to understand how the asphaltene molecules are shaped, and how they disperse through the crude oil.

The work is being undertaken in collaboration with the Engineering Sciences Data Unit, which works with industry to help in areas such as the modelling of heat transfer dynamics. The project is being funded by a £2.2m research grant from the EPSRC.