QUB takes top prize for developing ways to take the pollution out of industrial processes, writes Danielle Barron
Organic may not always be good for you, at least when it comes to chemistry. So say a team of chemists and engineers at Queen's University Belfast, who are developing alternatives to the polluting organic solvents used by a wide range of industries.
They are studying new inorganic solvents known as ionic liquids, which they describe as the basis of a new "green" chemistry that aims to make chemical processes environmentally friendly.
Queen's University Ionic Liquid Laboratories (Quill) was founded in 1999 as a consortium between QUB and 16 different chemical industries. Earlier this year QUILL was awarded a Queen's Anniversary Prize for Higher and Further Education for their pioneering work in the field of ionic liquids.
These liquids had been in existence for years, explains Prof Ken Seddon, who is a co-director of the centre with Prof Jim Swindall. Until now these ionic liquids were only used in very specialised applications. The concept behind QUILL was to expand their use so that they could be used as general solvents, Seddon explains.
Solvents are used in chemical processes to dissolve raw materials and catalysts and to purify products. Conventional solvents are carbon-containing or "organic" compounds. The vapours that these solvents emit are a major source of carbon-based pollution in the atmosphere.
Ionic liquids, however, are solvents composed entirely of ions, charged particles, a fact which gives these liquids their name. They do not emit vapours, making them an environmentally friendly alternative to organic solvents, and they can readily be used in fine chemicals, fragrance and petroleum processes.
The inherent differences between these solvents and conventional organic solvents means that basic chemistry does not apply here. Indeed, when it comes to working with ionic solvents, you can chuck the chemistry rulebook out the window, says Seddon.
"The energies will be different, the thermodynamics and kinetics will change," he says. "You are not just changing the solvent, the rules of chemistry are completely different."
The potential of ionic solvents is immense, says Seddon. There are at least a million of these in existence, and up to a trillion different liquids can be prepared by pairing different positive and negative ions. This means that the physical properties of a solvent can be tuned to suit specific applications.
Part of Quill's job is deciding exactly which solvents will be useful to their various industry partners. "We are trying to gain an understanding of which are the best ones," says Seddon.
Andrew Brennan, a postgraduate student working in Quill, is involved in creating these "designer solvents". The idea behind their work is to design a complete industrial process having designed a suitable ionic solvent, says Brennan. This is in contrast to the traditional approach, where several solvents may be tested before finding the one that is most appropriate. "Before the solvent was chosen on a trial and error basis. We design the solvent to meet the needs of the process at an early stage in development," he explains.
This is a brand new approach, explains Seddon. "The tradition is that industry makes a mess, and someone comes along and cleans it up," he says. Green chemistry prevents hazardous waste being formed in the first place, so no clean up is required.
Previously languishing in the backwaters of chemical research, ionic liquids have now come to the fore as a new method of tackling pollution. And the field is experiencing phenomenal growth, says Seddon.
"A decade ago 20 papers were published on ionic liquids. This year we estimate the figure will be in the region of 20,000," he says.
Brennan says that the close links Quill maintains with its industry partners is crucial to its work. "We are getting input from the people who are eventually going to use the technology. Our work is therefore focused towards solving real industrial problems."