Efficient conversion of agricultural and forest residues into bioethanol: BIOFLEXPOR as flexible technology towards sugar-based biorefineries [Poster]

ABSTRACT: Lignocellulosic ethanol is in the upfront of advanced biofuels to be commercialized worldwide. However, the commercial deployment of 2G ethanol is dependent of high biomass availability and cost-effective supply. In Europe, some agricultural residues are presently underused and constitute attractive renewable resources. In addition, residual forest biomass, non-seasonably available at low cost, might be complementarily used as raw material boosting the economy of biorefineries. In this context, the present work deals with the development of an innovative and sustainable technological strategy to produce advanced bioethanol using agricultural and forestry residual biomass. The bioprocess involves enzymatic hydrolysis of major lignocellulose polysaccharides (cellulose and xylan) with commercial enzymes and fermentation of the resulting sugars. A pre-treatment step should firstly be accomplished to make cellulose more amenable to hydrolytic enzymes, and the prototype is based on a proprietary non-catalysed steam explosion technology, i.e., without the addition of acids and using only high-pressure steam, called FLEXBIO™, which was initially developed in Brazil by the company STEX and since 2019 in partnership with LNEG. The proposed technology has been successfully demonstrated in a relevant environment (TRL 5) for the efficient conversion of corn stover, olive tree pruning and eucalyptus-based forest residual biomass, yielding close to 150 L of ethanol per metric tonne (dry basis) of biomass, corresponding to an overall yield close to 75% of maximal theoretical yield for glucan conversion. Both enzymatic hydrolysis and fermentation steps have achieved yields superior to 85% of the maximal theoretical conversion, and the optimization of process configuration, targeting the best integration with pre-treatment, is now under progress and higher yields will be expected. Given the higher xylan content of corn stover, both cellulose and xylan fractions are pursued. In addition, the upgrading potential of all wastewater streams will also be assessed, by studying the feasibility of its combined use to increase the ethanol yield as alternative to its use for biogas production through anaerobic digestion, with the goal to reach near-zero waste. In conclusion, the present study reveals the industrial potential of this flexible technology that might be applied to implement distinct small-scale sugar-based biorefineries by converting several lignocellulosic raw materials into distinct marketable biofuels/biomaterials, promoting the circular bioeconomy.

Keywords

Bioethanol Agricultural Residues Lignocellulosic biomass Biorefinery

URI

http://hdl.handle.net/10400.9/4215

Citation

Marques, S... et.al - Efficient conversion of agricultural and forest residues into bioethanol: BIOFLEXPOR as flexible technology towards sugar-based biorefineries. In: Abstract Book of 19th International Conference on Renewable Resources & Biorefineries (RRB’2023), 31 May – 2 June, Riga, Latvia, p. 99. (Poster 64)