TECHNICAL-ECONOMIC-ENVIRONMENTAL ASSESSMENT OF BIOETHANOL PRODUCTION FROM WASTE BIOMASSES

This study had as main objective to promote bioenergy integration in energy systems and to support the use of waste biomasses in biorefinery systems. The adopted approach consisted in a sequential technical-economic-environmental assessment (TEEA) of the sustainability of bioethanol production from waste biomasses. In details, the technical assessment considered the biological conversion into ethanol of the waste biomasses; the economic assessment was aimed at the definition of the cut-off size of the plant necessary to achieve profitability; the environmental assessment was based on Life Cycle Analysis (LCA) and energy balance. In EU-28, the most abundant waste biomasses in 2018 belong to three main categories: lignocellulosic (329.41 Mt), starch (160 Mt) and sugar-based (58.56 Mt) biomasses. For each category at least one waste biomass, which could be considered representative in terms of available amount and chemical-physical composition, was analysed: sugar cane for sugar-based, potatoes for starch-based and rice straw, cattle manure and food waste for lignocellulosic biomasses. The technical assessment lead respectively to the following bioethanol yields (kg/kg): 0.16, 0.17, 0.22, 0.19 and 0.14. The economic profitability was reached by all biomasses and NPV (M Euro) were: 0.85 for sugar cane, 0.11 for potatoes, 0.09 for rice straw, 0.11 for cattle manure and 0.39 for food waste. From the environmental perspective, cattle manure reached the highest reduction of climate change and acidification impacts compared to other four biomasses, while sugar cane achieved the lowest energy input consuption around 64%.