Designing a 'Best Practice' Model of Integrated Biosystems of Waste Re-Use in a Typical Rural Town: Final Report - July 2004

There is increasing pressure worldwide for firms to become more efficient in their use of resources and to reduce waste emissions to landfill, air and water. Consequently, individual firms and groups of firms are seeking to develop innovative and commercially attractive alternatives to waste disposal. Wastes are increasingly being regarded as 'by-products' rather than wastes and one firm's waste is increasingly being regarded as another's input. There is potential now to develop 'industrial ecosystems' where waste is re-used and the waste loop is closed. Closing the loop does, however, require a significant amount of multidisciplinary research in order to understand the nature of the waste streams available and the various options for transforming these, economically, into re-usable inputs. This report summarises the results of one such study. Because many rural towns tend to have similar waste streams, this study lays the groundwork for the development of industrial ecosystems in regional Australia. Regional centres such as Tamworth (NSW), where this study was undertaken, have agro-industrial estates that produce significant levels of organic by-product. The Glen Artney Industrial Estate (GAIE) in Tamworth is home to two abattoirs, a meat products manufacturer, livestock saleyard, hydroponic vegetable producer, industrial laundry and a range of other smaller service industries. There is also potential to double the number of firms operating within its boundary. A survey and analysis of the GAIE reveals that the major wastes presently produced include heat, carbon dioxide, various wastewaters, plant and animal waste products (including paunch). As part of the endeavor to understand how loops might be closed, this report provides a technical discussion of the major processes for transforming organic waste to energy. Included in this discussion are: direct combustion, gasification; pyrolysis; anaerobic digestion and alcoholic fermentation. The advantages and disadvantages of each process for the disposal of organic waste are also discussed. The nature, amount and type of waste produced suggest that the process of anaerobic digestion might have the most potential. This conclusion is supported by the imminent development of a commercial anaerobic digester at a similar agro-industrial estate in Wagga Wagga (NSW). There are, however, other issues that need to be addressed before general recommendations and development of this process can be recommended. These include OH&S issues, institutional (including legal and bureaucratic) constraints, possible problems in obtaining a constant, reliable quality and quantity of required organic inputs on which new systems will depend, and the development of efficient transport systems. More research is required in these areas.