Articles
Publication Date: 2025
Energy (0360-5442)335
Sustainable and non-food-competing bioresources are essential for meeting global energy demands while ensuring food security. Acorn waste represents a promising feedstock for biofuel production within a biorefinery framework. This study investigates three scenarios for biofuel production from acorn wastes, involving acid-catalyzed organosolv pretreatment, solvent extraction (using ethanol, hexane, and water), enzymatic hydrolysis, fermentation with Mucor indicus, anaerobic digestion, and transesterification. In Scenario I, the fermentation of acorn produced 354.9 L of ethanol per ton of waste, equivalent to 235.1 L of gasoline, with 95 % of the energy derived from the kernel. Scenario II focused on anaerobic digestion, yielding 456 m3 of biomethane per ton of acorn waste (dry mass), equal to 514.5 L of gasoline equivalent, with 40.8 % of energy from the extracted kernel. Scenario III integrated ethanol and biogas production with lignin recovery, resulting in 354.6 L of ethanol, 209.2 m3 of biomethane, and 642 kg of lignin per ton, totaling 557.6 L of gasoline equivalent. Additionally, acorn kernel oil offered a biodiesel feedstock equivalent to 47.4 L of gasoline per ton. Overall, the integrated biorefinery approach significantly enhanced energy and material recovery from acorn waste, presenting a highly efficient and sustainable route for advanced biofuel production. © 2025 Elsevier Ltd
Publication Date: 2025
Science of the Total Environment (0048-9697)976
This study aimed to contribute to the sustainable development of the Blue Bioeconomy via cascade biorefineries of macroalgae by investigating the environmental sustainability of two algae-biorefinery systems that utilize endemic brown macroalgae Nizimuddinia zanardini. The first scenario involved the production of fuel ethanol, and electricity, while the second scenario included the co-production of fuel ethanol, electricity, and high-value bio-based chemicals, i.e., protein, mannitol, and alginate. Combining process simulation tools with consequential life cycle assessment, the study provides a comprehensive evaluation of the environmental impacts associated with the valorization of 1 metric ton of dry algae considering three areas of environmental protection namely human health, ecosystem quality, and resource depletion. The results demonstrated that the biorefinery approach led to net savings of −2.61 × 10−3 DALYs, −1.18 × 10−5 species.yr, and − 76.8 USD2013 per ton of macroalgae on human health, ecosystem quality, and resource depletion, respectively. Conversely, the only-fuel approach resulted in a net savings of −74.6 USD2013 per ton of macroalgae on resource depletion, and the net impact of 2.14 × 10−4 DALYs, 5.33 × 10−7 species.yr per ton of macroalgae on human health, and ecosystem quality, respectively. In general, the biorefinery approach compared to the only-fuel approach led to significant savings in all damage categories owing to the generation of high-value products. These findings highlight the significant potential of biorefineries for the sustainable valorization of macroalgae. © 2025 Elsevier B.V.
Publication Date: 2024
Process Safety and Environmental Protection (17443598)187pp. 398-407
Bio-hydrogen (bio-H2) production from dark co-fermentation of pruning wastes, from pine, cypress, and berry trees, and food-rich municipal solid waste (FMSW) was evaluated as a promising way to combine waste management and renewable energy production. The inoculum was initially optimized by heat-shock pretreatment at 65, 75, 85, and 95 ℃ for 15, 30, and 45 min to maximize bio-H2 yields. The optimum pretreatment conditions (75 °C for 45 min) were applied for dark co-fermentation analyses. The highest bio-H2 production yield of 84 ± 6 mL/g VS was obtained by dark co-fermentation of 20 g/L pruning wastes and FMSW under initially neutral conditions. The fermentation of individual substrates led to 40.9, 0.2, 0.1, and 0.2 mL/g VS from FMSW, pine, berry, and cypress, respectively, 85% lower than that obtained through dark co-fermentation. Therefore, co-processing of a “stiff substrate”, lignocellulose, with a “loose part”, starchy FMSW, leads to a higher bio-H2 yield. Dark co-fermentation led to the bio-conversion of more than 76% of starch, 31% of glucan, and 41% of hemicellulose, besides 41% lignin removal. The modified Gompertz model (MGM) and Logistic model (MLM) were well-fitted on kinetic data (with R2 values ≥0.98), and the kinetic parameters were calculated. © 2024
