ENERGY YIELD AND COST IN A SUGARCANE BIOMASS SYSTEM

THE sharp rise in the price of crude oil and the increased awareness of the environmental impact of the extensive use of fossil fuels have sparked a renewed interest in the use renewable feedstock for energy production. There is today a growing realisation of the importance of biomass and this will generate many new opportunities and create expansion opportunities for the use of existing agricultural crops including sugarcane. For renewable energy production, realisation of sufficient land productivity (e.g. MJ/ha/year) to deliver energy at a price competitive with or better than that from fossil fuels, and returns that are competitive with those from alternative land uses, will be very important. Sucrose in the stalk only represents approximately 30% of the total energy of the aboveground biomass of sugarcane. Between 2005 and 2008 the farmgate cost of sugarcane biomass in Australia varied between 41 and 52 US$/tonne. Using the lower heating value of cellulosic biomass, the energy production cost in Australia was calculated. The production cost varied between 2.4 and 3.0 US$/GJ and this translates to a price per barrel oil equivalent between 11 and 15 US$. The gain in total energy is highest in a system where insoluble components such as fibre are increased at the expense of water solubles such as sugars.