Title:
Catalytic and Biocatalytic Cascade Valorization of Lignocellulosic Biomass into High-value Biofuels and Bioproducts
Author(s):
Caporusso, A., Di Fidio, N., Albergo, R., Liuzzi, F., Giuliano, A., Panara, F., Viola, E., De Bari, I.
Document(s):
Paper
Slide presentation
Abstract:
Single-cell oils (SCOs) have recently attracted considerable attention as promising alternatives to vegetable oils for various industrial applications, supporting the shift from a fossil-based to a green economy. However, the commercial production of microbial oils remains economically challenging, underscoring the need for low-cost substrates and innovative biorefinery strategies to enhance both feasibility and sustainability. In this study, SCOs were produced from lignocellulosic residues using oleaginous yeast L. tetrasporus. The yeast was cultivated on hydrolysates derived from wheat straw and cardoon residues. Biomass pretreatment involved steam explosion, followed by polysaccharide hydrolysis using two different approaches: enzymatic hydrolysis and chemical hydrolysis with FeCl3. The enzymatic hydrolysis yielded the highest sugar conversion, with an efficiency of approximately 90%. In contrast, chemical hydrolysis using FeCl3 resulted in a 30% yield. The resulting cellulose and hemicellulose hydrolysates from both feedstocks were employed as a growth medium for L. tetrasporus. The yeast demonstrated the ability to grow on all tested media, producing around 10.g/L of microbial biomass with a lipid content of 30% (w/w). Under optimal conditions, specifically, the cellulose hydrolysate of wheat straw, it accumulated up to 50% intracellular lipids. The microbial lipids obtained were converted into biodiesel, achieving a conversion yield of 85%. Furthermore, the resulting microbial biodiesel exhibited physicochemical properties comparable to conventional vegetable oil-derived biodiesel, meeting both American and European quality standards. In alignment with circular economy principles and aiming to eliminate waste streams, platform molecules were also produced by fully valorising the residual polysaccharide fractions. In this context, approximately 63% of the residual glucans and 99.9% of the residual xylan were converted into levulinic (11.4.g) and formic acids (5.8.g). A techno-economic assessment estimated the minimum selling price of microbial lipids at €2.90 per kg for the enzymatic hydrolysis process and €1.30 per kg for the chemical hydrolysis process.
Keywords:
biorefinery, techno-economic analysis, levulinic acid, oleaginous yeasts, biomass pretreatment, microbial lipids
Topic:
Biomass, Bio-based Products and Bioenergy Integration
Subtopic:
Biomass use in biorefineries
Event:
33rd European Biomass Conference and Exhibition
Session:
3CO.3.1
Pages:
447 - 452
ISBN:
978-88-89407-25-7
Paper DOI:
10.5071/33rdEUBCE2025-3CO.3.1
Price:
FREE
