Life cycle assessment of wheat straw lignocellulosic bio-ethanol fuel in a local biorefinery prospective

A ″cradle-to-wheel” life cycle analysis was carried out to investigate the environmental profile of bioethanol (EtOH) production from lignocellulosic wheat straw (WS) and its use as transport fuel in E10 (10% of EtOH and 90% of gasoline) and E85 (85% of EtOH and 15% of gasoline) vehicles. The aims of this study were: (i) to evaluate the environmental performance of the whole WS-EtOH supply chain and (ii) to identify the best performing feedstock for a prospective bio-refinery network in Campania Region (Southern Italy). A comparison of WS-EtOH system against the fossil counterpart (gasoline passenger car) and similar bio-based production-use chains was conducted to fulfil one of the main goals of EnerBiochem and BioPoliS projects: investigating the environmental profitability of a bio-refinery system in Campania Region. Starting from the use of residual feedstock (wheat straw) or the revaluation of marginal lands (cultivation of dedicated perennial giant reed or annul fiber sorghum), through the investigation of an advanced lignocellulosic conversion processes, this work assesses the environmental feasibility of bio-energy production in Campania Region. The WS-E10 environmental profile was driven by the gasoline input in the blend, whilst the WS-E85 results showed the relevance of the crop phase. The comparison of the different blends and the gasoline-fuelled car highlighted for E10-blends similar profiles for almost all the impact categories, nearly overlapping with the conventional vehicle. Differently, for E85 vehicles, the differences between the bio-based systems appeared amplified according to the specific impacts of the feedstock supply and the conversion steps. On the whole, Fiber Sorghum-E85 system showed the worst environmental profile whilst WS-E85 entailed the best performance.