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A deeper shade of green

It’s no secret: in humanity’s give-and-take planetary contract, we’re not keeping our end of the bargain. With big changes required throughout society, the University of Adelaide is looking well below the surface.

Introducing renewable energy into high-heat industry

When it comes to climate change, heavy industry is a key player. Burning copious amounts of fossil fuels to satisfy its need for near-constant high-temperature heat, it generates an estimated 16 per cent of global carbon emissions. In the past, incorporating renewable energy into such processes has proven difficult. But innovative University of Adelaide–led research appears to be finding a way.

The University is working closely with global aluminium heavyweight Alcoa, together with a number of other industry and research collaborators, to investigate incorporating low-cost concentrated solar thermal (CST) energy into the ‘Bayer process’, the principal means of refining bauxite to alumina. If successful, it will be the first time a commercially viable path has been identified for integrating renewable heat in a high-temperature industrial process.

The research is part of an overarching four-year Australian Renewable Energy Agency solar energy project. According to Alcoa’s Australia-based Senior Engineering Specialist Ray Chatfield, the University’s CST technology—and Bayer-process incorporation method—passed its first economic “stage gate” in mid-2018, providing a strong indicator of commercial viability.

“There’s still work to do, but getting over this hurdle’s very exciting,” says Chatfield. “Reducing our carbon footprint is a long-term strategic imperative, and this technology could potentially be retrofitted into our plants all over the world. We’re looking forward to developing it further.”

Lead researcher Professor Gus Nathan, who directs the University of Adelaide’s Centre for Energy Technology, is similarly delighted with his team’s progress. “This technology could play a significant role in the fight against global warming,” he enthuses.

“In Australia, the energy-intensive nature of aluminium production means that the Bayer process accounts for around 40 per cent of our national industrial emissions. Incorporating CST could halve that.”

Nathan believes the low-cost CST technology and methodology has similar potential for other high-temperature industrial processes in locations that, like Australia, have coincident mineral and solar resources. “In many regions, CST has real potential to displace at least half the energy currently supplied by fossil fuels for high-temperature process heat,” he explains. “If we can show our method for doing this is cost-effective, it could be used for other big emission-generating processes like iron and steel making.”

Turning agricultural waste into high-value products

Additional University of Adelaide contributions to global sustainability are coming through innovative uses of agricultural waste; of which the world produces around 1 billion tonnes annually. The University has just been appointed to lead an 18-partner collaborative research consortium investigating the field, working closely with organisations such as Sweden’s KTH Royal Institute of Technology, US-based ingredients manufacturer Ingredion, and Danish brewer Carlsberg.

The research team is using a sequential extraction process to obtain as many valuable “biomolecules” for application in high-value products as possible. “We can derive numerous compounds from agricultural and horticultural waste biomass that have highly desirable health and structural benefits,” says lead investigator Professor Vincent Bulone.

“For example, discarded or cosmetically inferior apples and cherries contain anthocyanins, which have antioxidant properties; and mushrooms contain chitosan, which has antimicrobial properties and can be used as a bonding agent. In addition, marine organisms contain mycosporines and mycosporine-like amino acids (MAAs) that are outstanding UVA and UVB radiation absorbers.

“We’ve already been able to combine all three of these into a trial skincare product that could provide excellent protection for damaged or sensitive skin.”

Waste from broccoli can supply sulforaphane, he adds, which has shown potential benefits for diabetic patients; while cellulose extracted from crop waste can be used as nanofibres to strengthen composite materials and create compostable bioplastics.

“Recently we even successfully combined cellulose materials with a catalyst to create an eco-friendly antimicrobial foam. It’s perfect for use in air purification systems, such as in piggeries and food storage rooms.”

The impacts, he continues, will be many and significant: increased profitability and sustainability for the agricultural and horticultural industries; health and economic benefits for societies generally; and the ability to replace environmentally damaging petroleum-derived products with green alternatives.

“Agriculture is already a key contributor to the global economy. But its huge potential to generate additional high-value products and create new post-farm-gate industries hasn’t yet been realised. We’re incredibly excited to help make that happen, and particularly with fully recyclable or biodegradable products.

“This is a valuable step towards stemming the flow of rubbish that’s choking our environment.”

Supporting native pollinators

Another critical aspect of agricultural sustainability is pollination. We rely on insects like bees, flies and butterflies to pollinate many of our crops, including canola, lucerne, almonds, berries, melons, apples and pears; and worldwide, those insects are struggling to survive in farming areas.

Widespread native vegetation clearance has left them with nutritional deficiencies and a lack of nesting opportunities, while pesticides are increasing their vulnerability to disease. There’s also the small matter of the Varroa mite, which has decimated US and European wild honey bee populations. Pollination deficits are now commonplace, and farmers are becoming dangerously reliant on human-controlled honey bee hives, in which Varroa’s impact is more easily managed.

This presents humanity with a big problem. Economically, the total value of pollination to Australia alone, including spin-offs, is estimated at AUD$6 billion per annum. There are also serious implications for employment in the sector, and of course global food supply.

Here too, the University of Adelaide is making an important contribution. A University research team is leading a major Australian collaborative project identifying strategies for best-practice native revegetation in areas surrounding crops, with the intention of providing a wide variety of native pollinators much-needed shelter and ideal—and ideally timed—diets.

While their work is initially focusing on the Australian context, lead researcher Dr Katja Hogendoorn says the process will provide a valuable model for similar efforts internationally. “Although plantings for crop pollinators next to pollination-dependent crops have been done in Europe and the US, they’ve tended to only support generalist species—typically bumble bees.

“Our research produces advice to growers for native vegetation plantings that support crop-pollinating insects. This advice is tailored to the region, the crop and the specific pollinators.”

Working closely with government environmental bodies, the University of Adelaide group is also: providing planting cost-benefit analyses; producing detailed planting guides; and developing a landscape design tool that will enable farmers to tailor the strategies for their local environment.

“This is a really important step for crop-farming sustainability,” enthuses Hogendoorn. “We’re making a vital contribution to the establishment of international protocols for native revegetation.”

Related links:
Food Innovation website
Faculty of Sciences website

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