ENVIRONMENTAL BENEFITS AND TRADE-OFFS OF PRODUCING BIO-ENERGY AND BIO-MATERIALS FROM AUSTRALIAN SUGARCANE

THIS PAPER reports the findings of a project that examined the environmental implications of producing bio-energy and bio-materials from Australian sugarcane. Life cycle assessment (LCA) was used to quantify some of the environmental impacts of a diversified sugar industry relative to a conventional sugar-producing model. The entire life cycle of the sugarcane agro-industrial systems was considered, from the extraction of resources, through to the end-of-life disposal of products, wastes and emissions. A number of scenarios considered the utilisation of mill by-products from existing sugarcane processing (ethanol from molasses, electricity from bagasse, and ethanol from bagasse). These were found to result in some significant environmental gains, reducing non-renewable energy use and greenhouse gas emissions (GHG). These benefits come with few trade-offs. Of the three by-product utilisation scenarios, electricity generation from bagasse provided the best gains if all impacts are considered. Other scenarios considered expanded cane growing for production of ethanol and PLA plastics from cane juice. These scenarios yielded very high gains in non-renewable energy use and GHG emissions, but came with trade-offs–the additional environmental impacts of expanded agricultural production (land use, water use and potential water quality impacts).