The use of maize stover and sugar beet pulp as feedstocks in industrial fermentation plants - An economic and environmental perspective

The transition from a fossil to bio-based economy has promoted the valuation of renewable raw materials in biorefineries. Waste and by-products from industrial processing and agricultural activities are potential renewable feedstocks. This study investigates the environmental and economic profile of maize stover and sugar beet pulp as potential cellulosic raw materials to be valued in a biorefinery. Four scenarios were considered: beet pulp in France (BP -FR) and the United Kingdom (BP - UK); and maize stover in Italy (MS - IT) and Belgium (MS - BE). The functional unit is 1 GJ and the impact categories are: climate change (CC), terrestrial acidification (TA); freshwater eutrophication (FE); marine eutrophication (ME); human toxicity (HT); photochemical oxidant formation (POF); particulate matter formation (PM); and fossil depletion (FD). The economic analysis assessed the internal and external cost indicators. The results show that maize stover would reduce the total environmental burdens and production costs. The outcomes show total costs ranging from 22 (sic) (MS -IT) to 174 (BP -UK) (sic) per FU. The environmental results show that BP - UK scenario also represents the worst case. For CC, for instance, in the MS-IT scenario, the impact dropped by more than 80%, compared to BP - UK.