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Abstract: The south-west of Australia is being affected by a warming, drying trend in its climate. In response to these changing climatic conditions, as well as changes in farm commodity price relativities, farmers have adjusted their mix of enterprises to favour cereal production. As a result, an increasing potential source of cereal straw for bioenergy production has emerged. This paper examines how temporal and spatial costs of cereal straw accumulation may affect the establishment of a bioenergy plant in the region, with climate change impacts being highlighted. Logistics models based on mathematical programming are constructed for a range of plant sizes. Modelling results identify the cost structures of cereal straw accumulation for these plant sizes. Plant sizes are characterised by different cost structures and levels of volatility in their costs of grain accumulation. The profitability of bioenergy production based on cereal straw in this region of Australia is particularly exposed to climate variability, especially for larger plant sizes. The projected change in climate supports a relatively small reduction in the costs of cereal straw accumulation. These findings will affect decision-making over investment in a long-lived specific asset such as a bioenergy processing plant. [Copyright &y& Elsevier]

Abstract: This paper assesses the environmental impacts of producing bio-energy, bio-fuels and bio-materials from Australian sugarcane (Saccharum officinarum), and nominates the bio-production pathways offering the best environmental gains. A system-based, consequential approach was taken, which is different to past approaches that have commonly judged bio-production by comparing individual bio-products with their fossil-fuel counterparts. Possible diversified scenarios were developed, and the changes in environmental impacts from the system as a whole (per 100 t sugarcane processed) were assessed using life cycle assessment (LCA). Scenarios based on utilisation of co-products from existing sugarcane production (ethanol from molasses, and electricity and ethanol from surplus bagasse) were found to give modest reductions in non-renewable energy (NRE) use and global warming potential (GWP), and involve no or few trade-offs. Of these, ethanol and electricity from bagasse offer the best benefits. Scenarios necessitating expanded cane growing for dedicated production of ethanol and polylactide (PLA) plastics from cane juice were found to result in more substantial NRE and GWP savings, but involve the trade-offs associated with expanded agricultural production (land use, water use and potential water quality impacts). Of these, PLA production offers the better outcomes, amongst the scenarios. However, eco-efficient cane growing was found to be an equally important improvement strategy and should be implemented to enhance the benefits and mitigate some of the trade-off from bio-production. [Copyright &y& Elsevier]