23 December 2014

Natural gas is a cleaner and cheaper fuel than oil, and Australia has an expanding industry in utilising its significant gas reserves. This burgeoning industry promises to be the first to benefit from a research breakthrough in the design of ultraporous crystals that will lead to much more energy efficient gas storage and processing.  

Natural gas ‘sweetening’ is one of the cleaning processes that removes unwanted gasses like hydrogen sulphide or carbon dioxide from the raw product—but this process consumes a large part of the energy used in processing the gas.

Currently, naturally porous minerals called zeolites are used to sweeten gas, however ARC Future Fellow, Dr Matthew Hill, is leading a CSIRO based research team that has developed a synthetic crystal that is more porous, more efficient in the sweetening process and durable. As well as holding the promise of revolutionising the efficiency of natural gas processing, these crystals have many other potential uses.

“If you look at them they look like salt or sugar crystals but inside are lots of holes and those holes are a nanometre (one millionth of a millimetre) in size,” said Dr Hill.

“We use them to sieve gas molecules, but you can also use them as a sponge to soak up gaseous fuels. These crystals can capture as much as three times the carbon dioxide of any commercial method of recovery.”

Gas once captured in these ultraporous crystals is easily stored and transported. As well as finding an application in processing natural gas, the technology is being intensively developed for use in carbon capture systems, and for storing liquid fuels. These crystals can store more gas than any other known porous material and, have other novel properties as a consequence of their nano-engineered design.

“With any material that you use to mop up gas, you have to expend energy to clean the stored gas out of it. But one of the crystals we have now designed to wring itself out like a sponge when it is exposed to sunlight—UV light releases the captured gas.”

Dr Hill’s research breakthroughs were recognised this year at the Prime Minister’s Prizes for Science with the award of the 2014 Malcolm McIntosh Prize for Physical Scientist, and he has previously won the Australian Leadership Award and Eureka Prize for Emerging Leadership in Science (2012).

The potential impacts of Dr Hill’s research breakthroughs on industry are still unfolding.

“Our most important recent achievement is the ability to manufacture our materials at a meaningful scale,” said Dr Hill. 

“Originally we could make our ultraporous crystals only in quantities of 1g which took many hours—now we can make 20kg per day.”

“These improvements of process have come about through the use of continuous-flow chemistry. Instead of doing reaction in a flask we now do it in a pipe that is set up with a controlled mix of ingredients, and at the other end of the pipe they come out as a continual flow.”

“It is a very easy process to control and in fact, I believe it is the future of all chemical manufacturing in this country. There are some molecules you can’t make any other way.”

Dr Hill’s research also demonstrates the importance of the ARC’s Future Fellowships scheme.

“The Future Fellowship gave me a profile as a researcher which helps me to interact with Australian industry, the main thing it does is allow me to focus and concentrate on what the industry challenges are.”

“At the same time as making fundamental breakthroughs I can work with industry to develop a publishing and a patent portfolio.”

“A fellowship is also one of the things that helps make links with Industry, as you have lots of approaches from people with some new magic ‘solution’. Having my research validated by the award of a Future Fellowship gave me the edge.”

Dr Hill’s research laboratory is located close to the Australian Synchrotron—partly funded by the ARC through the $25 million Special Research Initiative in Synchrotron Science. This facility has quickly become a fundamental part of Dr Hill’s research toolkit, with the Synchrotron’s small angle x-ray scattering beam line regularly employed to establish the properties of newly created materials.

“When we have new material that shows some promise we explore its performance in-situ using the Synchrotron—it’s a huge game changer. I used to have to go overseas to do this, which involved months of planning; now I can just walk over the road.”

Dr Hill describes his research team as a ’one stop shop’.

“We have mathematicians, physicists and engineers as well as chemists in our team.”

Dr Hill’s team is also a training ground for the next generation of material engineers.

“My job as much as anything is to be a coach of young researchers. We bring students to shadow us when we are in meetings with our industry partners, and we encourage them to contribute on the scientific detail. The feedback from our students is that they get a lot from this experience.”

Having accrued invaluable experience at the helm of one of Australia’s most creative laboratories, many of these graduates are now looking to continue their careers in the chemical industry in Australia.

These graduates are likely to be even more valuable to Australian industry than the ultraporous crystal sponges that are emerging from Dr Hill’s laboratory.

For more information please contact Dr Matthew Hill.

Image: Dr Matthew Hill. 
Photo Courtesy: WildBear/Prime Minister’s Prizes for Science.