Fuelling the future

October 07, 2015

Curtin University showcases complex engineering strengths to address climate change and sustainability.

The complex engineering that drives renewable energy innovation, global satellite navigation, and the emerging science of industrial ecology is among Curtin University’s acknowledged strengths. Advanced engineering is crucial to meeting the challenges of climate change and sustainability. Curtin is addressing these issues in several key research centres.

Bioenergy, fuel cells and large energy storage systems are a focus for the university’s Fuels and Energy Technology Institute (FETI), launched in February 2012. The institute brings together a network of more than 50 researchers across Australia, China, Japan, Korea, Denmark and the USA, and has an array of advanced engineering facilities and analytic instruments. It also hosts the Australia-China Joint Research Centre for Energy, established in 2013 to address energy security and emissions reduction targets for both countries. 

Curtin’s Sustainable Engineering Group (SEG) has been a global pioneer in industrial ecology, an emerging science which tracks the flow of resources and energy in industrial areas, measures their impact on the environment and works out ways to create a “circular economy” to reduce carbon emissions and toxic waste.

And in renewable energy research, Curtin is developing new materials for high temperature fuel cell membranes, and is working with an award-winning bioenergy technology that will use agricultural crop waste to produce biofuels and generate electricity.

Solar’s big shot

Curtin’s hydrogen storage scientists are involved in one of the world’s biggest research programs to drive down the cost of solar power and make it competitive with other forms of electricity generation such as coal and gas. They are contributing to the United States SunShot Initiative – a US$2 billion R&D effort jointly funded by the US Department of Energy and private industry partners to fast track technologies that will cut the cost of solar power, including manufacturing for solar infrastructure and components.

SunShot was launched in 2011 as a key component of President Obama’s Climate Action Plan, which aims to double the amount of renewable energy available through the grid and reduce the cost of large-scale solar electricity by 75%.

Professor Craig Buckley, Dean of Research and Professor of Physics at Curtin’s Faculty of Science and Engineering, is the lead investigator on an Australian Research Council Linkage Project on energy storage for Concentrating Solar Power (CSP), and a chief investigator with the SunShot CSP program. His team at Curtin’s Hydrogen Storage Research Group is using metal hydrides to develop a low cost hydrogen storage technology for CSP thermal energy plants such as solar power towers.

CSP systems store energy in a material called molten salts – a mixture of sodium nitrate and potassium nitrate, which are common ingredients in plant fertilisers. These salts are heated to 565°C, pumped into an insulated storage tank and used to produce steam to power a turbine to generate electricity. But it’s an expensive process. The 195 m tall Crescent Dunes solar power tower in Nevada – one of the world’s largest and most advanced solar thermal plants – uses 32,000 tonnes of molten salt to extend operating hours by storing thermal energy for 10 hours after sunset.

Metal hydrides – compounds formed by bonding hydrogen with a material such as calcium, magnesium or sodium – could replace molten salts and greatly reduce the costs of building and operating solar thermal power plants. Certain hydrides operate at higher temperatures and require smaller storage tanks than molten salts. They can also be reused for up to 25 years.

At the Nevada plant, molten salt storage costs an estimated $150 million, – around 10–15% of operation costs, says Buckley. “With metal hydrides replacing molten salts, we think we can reduce that to around $50–$60 million, resulting in significantly lower operation costs for solar thermal plants,” he says. “We already have a patent on one process, so we’re in the final stages of testing the properties of the process for future scale-up. We are confident that metal hydrides will replace molten salts as the next generation thermal storage system for CSP.”

From biomass to fuel

John Curtin Distinguished Professor Chun-Zhu Li is lead researcher on a FETI project that was awarded a grant of $5.2 million by the Australian Renewable Energy Agency in 2015 to build a pilot plant to test and commercialise a new biofuel technology. The plant will produce energy from agricultural waste such as wheat straw and mallee eucalypts from wheatbelt farm forestry plantations in Western Australia.

“These bioenergy technologies will have great social, economic and environmental benefits,” says Li. “It will contribute to the electricity supply mix and also realise the commercial value of mallee plantations for wheatbelt farmers. It will make those plantations an economically viable way of combating the huge environmental problem of dryland salinity in WA.”

Li estimates that WA’s farms produce several million tonnes of wheat straw per year, which is discarded as agricultural waste. Biomass gasification is a thermochemical process converting biomass feedstock into synthesis gas (syngas) to generate electricity using gas engines or other devices.

One of the innovations of the biomass gasification technology developed at FETI is the destruction of tar by char or char-supported catalysts produced from the biomass itself. Other biomass gasification systems need water-scrubbing to remove tar, which also generates a liquid waste stream requiring expensive treatment, but the technology developed by Li’s team removes the tar without the generation of any wastes requiring disposal. This reduces construction and operation costs and makes it an ideal system for small-scale power generation plants in rural and remote areas.

Li’s team is also developing a novel technology to convert the same type of biomass into liquid fuels and biochar. The combined benefits of these bioenergy/biofuel technologies could double the current economic GDP of WA’s agricultural regions, Li adds. future scale-up. We are confident that metal hydrides will replace molten salts as the next generation thermal storage system for CSP.”

Keeping renewables on grid

Professor Syed Islam is a John Curtin Distinguished Professor with Curtin’s School of Electrical Engineering and Computing. It’s the highest honour awarded by the university to its academic staff and recognises outstanding contributions to research and the wider community. Islam has published widely on grid integration of renewable energy sources and grid connection challenges. In 2011, he was awarded the John Madsen Medal by Engineers Australia for his research to improve the prospect of wind energy generation developing grid code enabled power conditioning techniques.

Islam explains that all power generators connected to an electricity network must comply with strict grid codes for the network to operate safely and efficiently. “The Australian Grid Code specifically states that wind turbines must be capable of uninterrupted operation, and if electrical faults are not immediately overridden, the turbines will be disconnected from the grid,” he says.

“Wind energy is a very cost effective renewable technology. But disturbances and interruptions to power generation mean that often wind farms fall below grid code requirements, even when the best wind energy conversion technology is being used.”

Islam has led research to develop a system that allows a faster response by wind farm voltage control technologies to electrical faults and voltage surges. It has helped wind turbine manufacturers meet grid regulations, and will also help Australia meet its target to source 20% of electricity from renewable energy by 2020.

Islam says micro-grid technology will also provide next-generation manufacturing opportunities for businesses in Australia. “There will be new jobs in battery technology, in building and operating micro-grids and in engineering generally,” he says.

“By replacing the need for platinum catalysts, we can make fuel cells much cheaper and more efficient, and reduce dependence on environmentally damaging fossil fuels.”

Cutting fuel cell costs

Professor San Ping Jiang from FETI and his co-researcher Professor Roland De Marco at University of the Sunshine Coast in Queensland recently received an Australian Research Council grant of $375,000 to develop a new proton exchange membrane that can operate in high-temperature fuel cells. It’s a materials engineering breakthrough that will cut the production costs of fuel cells, and allow more sustainable and less polluting fuels such as ethanol to be used in fuel cells.

Jiang, who is based at Curtin’s School of Chemical and Petroleum Engineering, has developed a silica membrane that can potentially operate at temperatures of up to 500°C. Fuel cells directly convert chemical energy of fuels suchas hydrogen, methanol and ethanol into electricity and provide a lightweight alternative to batteries, but they are currently limited in their application because conventional polymer-based proton exchange membranes perform most efficiently at temperatures below 80°C. Jiang has developed a membrane that can operate at 500°C using heteropoly acid functionalised mesoporous silica – a composite that combines high proton conductivity and high structural stability to conduct protons in fuel cells. His innovation also minimises the use of precious metal catalysts such as platinum in fuel cells, reducing the cost.

“The cost of platinum is a major barrier to the wider application of fuel cell technologies,” Jiang says. “We think we can reduce the cost significantly, possibly by up to 90%, by replacing the need for platinum catalysts. It will make fuel cells much cheaper and more efficient, and reduce dependence on environmentally damaging fossil fuels.”

He says the high temperature proton exchange membrane fuel cells can be used in devices such as smartphones and computers, and in cars, mining equipment and communications in remote areas.

Doing more with less

The SEG at Curtin University has been involved in energy efficiency and industrial analysis for just over 15 years. It’s been a global leader in an emerging area of sustainability assessment known as industrial ecology, which looks at industrial areas as ‘ecosystems’ that can develop productive exchanges of resources.

Associate Professor Michele Rosano is SEG’s Director and a resource economist who has written extensively on sustainability metrics, charting the life cycles of industrial components, carbon emission reduction and industrial waste management. They’re part of a process known as industrial symbiosis – the development of a system for neighbouring industries to share resources, energies and by-products. “It’s all about designing better industrial systems, and doing more with less,” Rosano says.

Curtin and SEG have been involved in research supported by the Australian’s Government’s Cooperative Research Centres Program to develop sustainable technologies and systems for the mineral processing industry at the Kwinana Industrial Area, an 8 km coastal industrial strip about 40 km south of Perth. The biggest concentration of heavy industries in Western Australia, Kwinana includes oil, alumina and nickel refineries, cement manufacturing, chemical and fertiliser plants, water treatment utilities and a power station that uses coal, oil and natural gas.

Rosano says two decades of research undertaken by Curtin at Kwinana is now recognised as one of the world’s largest and most successful industrial ecology projects. It has created 49 industrial symbiosis projects, ranging from shared use of energy and water to recovery and reuse of previously discarded by-products.

“These are huge and complex projects which have produced substantial environmental and economic benefits,” she says. “Kwinana is now seen as a global benchmark for the way in which industries can work together to reduce their footprint.”

An example of industrial synergies is waste hydrochloric acid from minerals processing being reprocessed by a neighbouring chemical plant for reuse in rutile quartz processing. The industrial ecology researchers looked at ways to reuse a stockpile of more than 1.3 million tonnes of gypsum, which is a waste product from the manufacture of phosphate fertiliser and livestock feeds. The gypsum waste is used by Alcoa’s alumina refinery at Kwinana to improve soil stability and plant growth in its residue areas.

The BP oil refinery at Kwinana also provides hydrogen to fuel Perth’s hydrogen fuel-cell buses. The hydrogen is produced by BP as a by-product from its oil refinery and is piped to an industrial gas facility that separates, cleans and pressurises it. The hydrogen is then trucked to the bus depot’s refuelling station in Perth.

Rosano says 21st century industries “are serious about sustainability” because of looming future shortages of many raw materials, and also because research has demonstrated there are social, economic and environmental benefits to reducing greenhouse emissions.

“There is a critical need for industrial ecology, and that’s why we choose to focus on it,” she says. “It’s critical research that will be needed to save and protect many areas of the global economy in future decades.”

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Planning for the future

Research by Professor Peter Teunissen and Dr Dennis Odijk at Curtin’s Department of Spatial Sciences was the first study in Australia to integrate next generation satellite navigation systems with the commonly used and well-established Global Positioning System (GPS) launched by the United States in the 1990s.

Odijk says a number of new systems are being developed in China, Russia, Europe, Japan, and India, and it’s essential they can interact successfully. These new Global Navigation Satellite Systems (GNSS) will improve the accuracy and availability of location data, which will in turn improve land surveying for locating mining operations and renewable energy plants.

“The new systems have an extended operational range, higher power and better modulation. They are more robust and better able to deal with challenging situations like providing real-time data to respond to bushfires and other emergencies,” says Odijk.

“When these GNSS systems begin operating over the next couple of years, they will use a more diverse system of satellites than the traditional GPS system. The challenge will be to ensure all these systems can link together.”

Integrating these systems will increase the availability of data, “particularly when the signals from one system might be blocked in places like open-pit mines or urban canyons – narrow city streets with high buildings on both sides.”

Teunissen and Odijk’s research on integrating the GNSS involves dealing with the complex challenges of comparing estimated positions from various satellites, as well as inter-system biases, and developing algorithms. The project is funded by the Cooperative Research Centre for Spatial Information, and includes China’s BeiDou Navigation Satellite System, which is now operating across the Asia-Pacific region.

Rosslyn Beeby

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