Sustainable Materials

Preventing Freezer Burn and Saving Human Tissue

It sounds simple, but Shah Razul’s work involves trying to understand what water molecules do when they get to below zero degrees Celsius because the possibilities that understanding offers could be life-changing.

When water crystallizes, its volume increases and it forms a regular structure that destroys, for example, cells, or, in the case of an organism, its delicate membranes and systems. As most of us will know, when food is frozen and we leave it too long, the ice separates out, leaving the food “freezer burned.” A wasted chicken breast is one thing, but this problem also exists, for example, in cryopreservation of cells, tissues and organs.

“When water’s in a close-to-frozen state, it has some interesting behaviour,” says Razul, an associate professor of chemistry at St. Francis Xavier University. “We’re trying to understand what the water molecules are doing.”

Razul’s overarching goal is to find a way to keep water from forming crystals and then applying that learning to real-world problems in areas such as food and health care.

“If we can, we can solve many problems related to freezing,” he says, including, for example, potentially creating environmentally safer antifreeze products to replace or minimize the use of road salt.

He looks to creatures such as the wood frog, which uses glucose to stop the freezing process from destroying its tissues in winter. Razul, therefore, is running simulations to look at the process of freezing and analyze what water molecules are doing in the fractions of a second just before they form crystals and freeze.

“A lot of my work now is involved with understanding how small biomolecules, such as different kinds of sugars and salts, stop water from freezing or slow down the process,” he says, adding that he wants to figure out a biomolecular combination that would achieve this goal.

Over the past five years, he’s been using computational principles to develop a cryoprotectant to preserve lobster meat.

“We’ve tried it and it works,” he says, adding that some companies from overseas are testing his system currently. “We had a taste test in Atlantic Canada, and we’ve published a couple of studies where the public indicated that it tastes as if it was cooked yesterday, preferring it to frozen lobster meat that is sold currently.”

His next frontier is looking at the ways in which his process can preserve muscle cells and brain cells to see what kind of applications it might have in the healthcare field.

“No one has a definitive answer to how these cryoprotectants work at the molecular level,” he says. “It’s basically all trial and error. We try a little bit of this and a little bit of that and see whether it works.”

To do his work, he’s watching the behaviour of water in minute detail — fractions of seconds — and then he replicates the test multiple times.

“Because of that, I generate a lot of data,” he says, and that’s why he couldn’t do his work without ACENET’s high performance computing.

“It’s almost impossible to do this work without ACENET,” he says. “I would need a year and a half to do it sequentially as opposed to one month with ACENET.”

Recasting Residue Into Power

Kelly Hawboldt imagines a world where Atlantic Canadians can have their own energy sources or their own water filtration systems built entirely on the region’s own biomass residue. Hawboldt is a chemical engineer who works in Memorial University’s faculty of engineering. She focuses on converting biomass residue from the forestry and fishery sectors — sawmill and pulp and paper waste, sawdust, saw chips and shellfish residue, for example — into items of value. “There’s a lot of added value in those residues, so we try to recover that usefulness,” she says. “We’ve developed processes that are green and sustainable to extract value and then we try to develop by-products that have lifecycle — they either degrade to what they started with or can be used to make something else.” Pyrolysizing (burning without oxygen at high temperatures) such residue can result in three products: a gas that can be used for energy, a liquid that will also produce energy, or a solid in the form of carbon, which can be used as an absorbent for contaminants. She works with Stephanie MacQuarrie, an associate professor of chemistry at Cape Breton University. “She’s a chemist and I’m a chemical engineer, so it’s a nice mix,” Hawboldt says. “We mix the mussel shells and the forestry residue and it changes the quality of the by-products. They might, for example, have better absorption capacity for certain types of contaminants.” She focuses on Atlantic Canada because it’s a small place, with a small population and plenty of biomass. “Because of transport, it’s hard to get the biomass residues to a market,” she explains. “So we focus on developing products and processes that will build that community rather than trying to export everything. Forestry companies could be supplying their own energy or their own water-filtration source. That’s where we’d like to go.” Hawboldt has been working in this area for the past 15 years and uses high-powered computing through ACENET and Compute Canada to do her work. Once she establishes processes for her residue-revamping, she models them so she can modify the designs. “Experimentally, this kind of work would take a long time, but we can vary things within the model and once we’ve validated it, it’s much quicker and easier to change things,” she says. Along with with Dr. MacQuarrie, she creates biochar — the solid product of pyrolysis and a highly porous material with various functions that must be analyzed to get the best benefits. “With ACENET, we’ve modelled the surface of the char and then we see if there’s a tendency for various contaminants to absorb,” she says. “So, I might take hydrogen sulphide or a metal and the molecular model would do a series of calculations to see if, based on the surface of that char, there’s a tendency for our contaminant of interest to absorb. If it does, we can then do the more detailed experiment. It’s a very useful screening tool.” ACENET, she says, is essential for her work. “Some of these models can take days to run. Without ACENET, I don’t think we could run them. You’d be talking about months instead of days.”

Oil Sands Upgrading Methodogies

The Alberta oil sands are the world’s third largest proven source of oil in the world and comprise 140,200 square kilometres. The majority of oil extracted there involves pumping high bitumin concentrated underground deposits to the surface, where the bitumin is then extracted from other components. Once this is done, it is upgraded to Synthetic Crude Oil, which is then refined for products we use daily. However, the extraction process is dirty, containing harmful chemicals such as sulphur and nitrogen. Upgrading and refining the oil for fuel and heat consumption means removing those dirty components. At the moment, the process of upgrading oil from Alberta’s oil sands is neither as efficient, nor as environmentally friendly as it should be. This has led to domestic and international criticism. For the past year and a half, Dr. Kai Ylijoki at Saint Mary’s University has been working with a team at the Institute for Oil Sands Innovation (IOSI) at the University of Alberta. IOSI’s vision is to have “Oil sands operations with a reduced environmental footprint by minimizing water use, consuming less energy, lowering greenhouse gas and other emissions, yielding high quality products at lower cost.” (http://www.iosi.ualberta.ca) Key to achieving this vision is understanding the complexes in the oil – what they are, their molecular structure, and the mechanism by which they work in upgrading. Dr. Ylijoki is, among other things, a computational chemist and his work involves studying these complexes with a view to identifying better catalysts. He does this by studying their properties to better understand their behaviour. The large size of the molecules renders them impossible to study on standard desktop computers, so he uses ACENET and Compute Canada’s advanced computing resources. Once he understands the complexes, then it’s a matter of finding very active catalysts for bond activation that don’t require large quantities, do the job more efficiently and are more environmentally friendly. IOSI has had success in this area – breaking certain complexes selectively – and finding ways to quicken the catalyst. Through the computational work of Dr. Ylijoki and his two students, the IOSI team is excited to be seeing some other unique aspects to the complexes that could be applied to other industries. Finding more efficient, environmentally better ways of cleaning oil from Alberta’s oil sands will help Canada economically, environmentally, and internationally. Dr. Ylijoki has received additional computing resources for 2015 through Compute Canada’s national Resource Allocation Competition.