Technoeconomic feasibility of integrated organics processing facilities with anaerobic digestion and composting: An...

To facilitate development of sustainable municipal organic processing in Australia, this research assessed feasibility and benefits of integrated composting and anaerobic digestion processing facilities. The paper reports on development of a decision support analytical framework for techno-economic feasibility of four different scenarios based on seven organic processing facility options with reference to a case study scenario in Southeast Queensland, Australia. Under the conditions of the case study entered into the techno-economic decision support framework, the following ideal outcome was recommended: Firstly, development of a new organics processing facility should consider integrated processing and co-location with a high energy consumer industry to maximise product value and economic benefits. Results show 28% improvement in financial returns over the single technology composting facility. Secondly, both new and existing composting facilities would benefit from receiving co-mingled food and garden organics for processing through a biogas facility. Although food made up just 37% of the feedstock, it was the largest source of methane, contributing 74% of the total gas yield. Lastly, facilities would benefit from implementation of biogas upgrading to sell biomethane and carbon dioxide alongside compost. Results revealed biomethane export has potential for a 77% financial gain over a compost facility but biomethane must be valued at retail values and will be more difficult to achieve. The current waste levy imposed by the local authority in the regional case study is key to providing incentive to divert organic waste from landfill, but suitable product pricing would drive further expansion to produce energy products.