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Due to its abundant reserves of uranium, coal and natural gas,Australia is nominally self-sufficient in energy except fortransport fuels and heavy oils. Currently, bioethanol and biodieselare being imported as renewable replacements for petrol and diesel,respectively. Australian annual bioethanol production capacity is 440 ML, and biodiesel production is 500 ML, although not all production facilities are operating atfull capacity due to a shortage of feedstock. In times of global concern about food security, there is a seriousethical debate about using food crops and arable land for biofuelproduction. In the USA, almost one-third of the corn crop is grownfor bioethanol production. Brian Fleay of the AustralianAssociation for the Study of Peak Oil and Gas ( ASPO Australia ) calculated that if the entire sugarcane and wheat crop inAustralia is converted to ethanol, it would only supply 20 per centof Australian transport fuels. This means that by burning our foodfor fuel, we would have no bread or sugar and very little fuel. Due to food and energy security concerns, many countries including Australia are promoting biofuel crops that can begrown on land not suited for food production, so that the twosystems are complementary rather than competitive . The recent L.E.K. Consulting Advanced Biofuels study proposed several alternative biofuel feedstocks that do notcompete with food production. Microalgae are being developed as abiodiesel feedstock, but there are still challenges such as the high capital and production costs of scaling up fromlaboratory to commercial production. Pongamia ( Milletia pinnata ) and Indian mustard ( Brassica juncea ) are oilseeds and have been suggested as feedstocks for biodiesel . Pongamia is a tropical tree legume native to India and Australia;plantations have been established at Gatton and Caboolture insouthern Queensland, Roma in south-central Queensland and Kununurrain Western Australia. A breeding program for elite varieties fromexisting superior germplasm is now being undertaken by the ARC Centre of Excellence for Integrative Legume Research at the University of Queensland. Indian mustard is an annualoilseed crop closely related to canola and rapeseed. An Indianmustard breeding program for biodiesel production was establishedin 2006 at the University of Sydney Plant Breeding Institute at Narrabri by Professor Richard Trethowan. Indian mustard is now part of thefour-year rotation there and there are two biodiesel batchprocessing plants to provide biodiesel self-sufficiency atNarrabri. The breeding program has been successful and 600 newadvanced lines based on Pakistani/Australian crosses were tested in2011. Promising high yielding lines with high oil content are nowbeing tested in multi-locational pre-commercial regional trials. Another potential bioethanol feedstock is agave ( Agave spp.). Agave uses a type of photosynthesis called Crassulacean Acid Metabolism (CAM); agave plants open their stomata (microscopic pores) at night and take up carbon dioxide in thedark to form malic acid , which is then metabolised to release carbon dioxide for photosynthesis during the following day. By closing the stomata during the day,less water is lost and water use efficiency may be as much as sixtimes greater than a C3 photosynthesis species , such as wheat. Hence, agave is adapted to semi-arid land notsuitable for food production. I conducted a study in collaboration with the University of Oxford,showing that bioethanol derived from agave has a positive energy balance: the bioenergy created is five timesthe amount required to produce it. In June 2009, Don Chambers andJoseph Holtum of James Cook University planted the first trial of blue agave ( Agave tequilana ) at Kalamia Estate, near Ayr in north Queensland. The plants arenow two years old, and have survived two wet seasons as well asCyclone Yasi. Growth rates have been higher than agave planted atthe same time in Mexico. New and novel feedstock conversion technologies are being developedsuch as fast pyrolysis and supercritical water treatment that can now convert any biomassfeedstock such as wood residues (e.g., Eucalyptus spp.), agricultural residues (e.g., wheat and corn stalks), woodyplants (e.g., poplar and willow coppice) and herbaceous C4 grasses(e.g., switchgrass, Miscanthus and sweet sorghum) into a green biocrude that can be processedinto jet fuel, biodiesel, and bioethanol. Professor ThomasMaschmeyer at the University of Sydney is now developing a commercial supercritical water treatment for processing forestry waste and seaweed (macroalgae) intobiocrude for companies such as Ignite Energy and Licella . The transport sector uses 60 per cent of global oil production andhas relied on fossil-based liquid fuels for more than a century.Large-scale biofuel production has been criticised for replacingfood production and consuming arable land. Hence, we should promotesustainable biofuel feedstocks growing on non-arable land toproduce future renewable bioenergy in harmony with continued foodand fibre production. Daniel Tan is a senior lecturer in agriculture at the University of Sydney . I am an expert from cold-rollformingmachine.com, while we provides the quality product, such as China K Span Roll Forming Machine , China Sandwich Panel Machine, Roof Roll Forming Machine,and more.
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