Winners

Philip Jessop

Chemistry

Queen's University

2008 NSERC John C. Polanyi Award

These aren't your grandfather's chemical reactions. The watchword for today's chemists is lean and green, and Queen's University's Philip Jessop has made some world-class contributions to "green chemistry."

Dr. Jessop looks for practical uses for carbon dioxide (CO₂), available in large quantities at little or no cost as more industries seek to capture and store this greenhouse gas. He has discovered a simple chemical process that not only puts CO₂ to work, but could vastly reduce the use of various solvents and other chemicals that are an essential part of many manufacturing and refining processes. His work has earned him the 2008 NSERC John C. Polanyi Award.

Industrial processes from oil refining to manufacturing pharmaceuticals involve multiple steps, each calling for a different type of chemical to make it work. Most of the time, those costly chemicals need to be removed before the next step can take place, consuming energy and time, while leaving behind a lot of waste, much of it toxic. Pharmaceuticals and fine chemicals are the worst offenders, generating anywhere from 50 kg to a staggering 16,000 kg of waste for each kilogram of final product.

New processes developed by Dr. Jessop and his research team could spell the end of some of these wasteful practices by moving to chemicals that are not only easier to separate but can be reused over and over again. The key lies in their ability to "switch" certain properties on and off at will, something he first achieved with solvents in 2005 and has since applied to other chemicals.

The process is deceptively simple. In manufacturing soybean oil, for example, a switchable solvent would extract oil from the beans. After filtering out the solids from the oil/solvent solution, the solvent would be switched off, loosening its hold on the oil, which could then be easily separated in preparation for the next step in refining.

As an added bonus, the trigger for Dr. Jessop's revolutionary process is provided by CO₂, a substance that's plentiful, non-toxic, and best of all, free. After the solvent and product are separated, the solvent is switched back on simply by exposing it to nitrogen, argon or even plain air, making it ready to be used again in the next batch.

Dr. Jessop says he had considered other ways to make solvents switch, but all involved adding large quantities of other chemicals. "All these things would probably work, but you'd be building up so much junk that you're defeating the purpose," he observes. "We figured the only way to get this to work and not kill the environment in the process would be to have the trigger be something incredibly cheap and benign."

In order to perform a chemical feat that his peers have called "brilliant" and "elegant," one of Dr. Jessop's biggest challenges involved overcoming a mental block: a conviction firmly entrenched in the scientific community that solvents simply do not change their properties. "I was taking an assumption that we all had and saying: ‘Wait a minute – I don't think I believe that any more.' We've all got those assumptions in our heads, and the fact that we believe them is our biggest liability. In order to get something new, you have to take one of those assumptions and reject it."

As a champion of green chemistry, Dr. Jessop is used to challenging assumptions. Since becoming a convert while working with Nobel Prize winner Ryoji Noyori in Japan during the mid-1990s, he has seen the focus of environmental protection move from cleaning up pollution to preventing it from being generated in the first place. "People were assuming that the pollution was a necessary part of economic activity," he says. "That's not good enough."

The next steps in his research include further exploration of areas where switchable chemicals could be beneficial, and scaling up his methods in order to apply them on an industrial scale. The more switchable compounds he can develop, the greater the likelihood that those who are designing chemical manufacturing processes will find one that meets their specific needs.

PARTEQ, Queen's University's commercialization organization, is helping bridge the gap from the lab to the marketplace. The initial focus will be on industries where Dr. Jessop expects the transition to be the easiest, including oil refining, plastics and agriculture. But the sky is the limit – virtually any process that calls for a chemical to be used in one step and discarded in the next could be a candidate for a switchable compound.

"This will keep me busy for a while," he comments.