Several biomasses were processed: Barley Straw (BS), Sweet Corn Cob (SCC), Blue Agave Bagass (BAB), Wheat Straw (WS), Sugarcane Crop Residues (SCR), Eucalyptus Forest Residues (EFR) and Corn Stover (CS). The sugar and ethanol productions are mainly dependent on the pretreatment efficiency, the solid loading in the bioreactor, and the contents of polysaccharides in the biomass. BS, BAB and SCC present the best results. The set objectives for hydrolysis and fermentation yields and ethanol concentration are reached. For WS and CS, fermentation yields reach the objective but the hydrolysis yields need to be improved with further experiments. SCR and EFR are more recalcitrant biomasses to the pretreatment due to high contents in lignin and minerals respectively.
The scaling up of the pretreatment and bioconversation processes to TRL5 is successful at both laboratory and pilot scales. The Simultaneous Saccharification and Co-fermentation strategy is successful with prompt consumption of sugars and production of ethanol. The Co-fermentation of hexose and pentose sugars is reached with commercial yeast and the new engineered yeast strain developed during the project.
An industrial plant and a numerical model for simulations at industrial scale were designed for the techno-economic and environmental evaluations and the life cycle assessments were performed in the perimeter field to tank. All the by-products obtained in the production chain are valorised: liquors produce biomethane through anaerobic digestion, lignin produced heat for the processes as fuel for the boiler, remaining organic and mineral matters in the digestate are conditioned as exportable pellet fertilisers and biogenic carbon dioxide from fermentation and biogas purification recovered and valorised for exportation. Several production scenarios were investigated with exportation of biomethane or electricity/heat in the case of cogeneration. This choice of products and scenarios allows adapting the plant model to the national economic and market conditions of the business cases.
Best lignocellulosic biomass feedstock have been identified for all business cases: CS in France, WS in Germany, SCR in Argentina, EFR in Uruguay and BAB in Mexico, and best localisation for industrial plants have been defined, generally in the centre of the biomass catchment areas (50km radius). Under such production conditions and the current economic hypothesis for the purchasing of goods and selling of the products, small-scale plants processing 30,000 tons biomass per year can be economically profitable. The environmental performances are within the set targets for the energy efficiency (twice more energy produced than consumed) and for the carbon foot print (33 gequivalent CO2/MJ produced), except for Argentina where the GHG impact of electricity from fossil origin is high and for Uruguay where harsher conditions for the pretreatment of the biomass are required.
The main results of the project have been presented in the countries of the business case in dedicated workshops with public audiences composed of national experts and stakeholders in the areas of biofuel/bioenergy. Three business cases are most favourable for the implementation of pilot plants after the project.
