Opportunities for the Australian sugar industry in greenhouse gas abatement and carbon trading : final report QUT027

Abstract

New policies and market drivers are currently being implemented to stimulate additional investment in technologies and energy sources which result in reduced greenhouse gas emissions. In addition there is a rising demand from stakeholders and customers for information about the life cycle greenhouse gas emissions of products (carbon footprint).

A spreadsheet based template for the accurate and consistent Life Cycle Assessment (LCA) of sugarcane growing, milling, refining and distilling operations has been developed. The template performs material and energy balance calculations to produce data that can be used to conduct a full carbon footprint using commercially available LCA software. The tool enables a rapid and relatively low cost LCA evaluation of multiple scenarios relating to farming, harvest and transport practice, factory configuration, co-process integration strategies and the impact of extraneous fuels on the embodied emissions of cane products.

By way of demonstration, the model has been applied to two regional case studies. Carbon footprints were generated for products from two mills in the Burdekin and Mackay regions selected to represent significantly contrasting scenarios. In terms of farming and harvesting operations the majority of cane (91% for the mill considered) in Mackay is harvested green; in the Burdekin the majority of cane (100% for the mill considered) is burnt prior to harvest. On the processing side the Mackay case study considers a high degree of product diversification and process integration; the Burdekin case is focussed on maximising renewable power export. These case studies reinforced the importance of regional differences in farming operations as being the primary influencing factor in all food and energy related products. The case studies also provided quantitative evidence for the Greenhouse Warming Potential (GWP) benefits of replacing coal with surplus bagasse from surrounding mills for the provision of supplementary fuel.

The customised LCA software provides the processing sector with a powerful tool for and reduces the cost associated with quantifying the GWP associated with raw and refined sugar, molasses, electricity and ethanol.