Biofuels Bioproducts & Biorefining-Biofpr最新文献

The use of biomass for the production of hydrogen gas (H₂) offers a promising pathway toward sustainable energy systems. However, effective H₂ production is still hindered by technological challenges, particularly in selecting appropriate feedstocks and optimizing production processes. In this study, cashew apple bagasse (CAB) – a lignocellulosic byproduct generated in large quantities during cashew juice and nut processing – was evaluated as a feedstock for H₂ production using Enterobacter cloacae and dark fermentation. The influence of different nitrogen sources on process performance was investigated.

The highest hydrogen yield was obtained using an enzymatic hydrolysate of CAB (MCAB-EH) supplemented with peptone as the nitrogen source, resulting in a productivity of 59.7 mL L⁻¹ h⁻¹ and a cumulative volume of 1432.4 mL H₂ per liter of hydrolysate after 24 h of fermentation. In the absence of supplementation, hydrolysate-based fermentation yielded a productivity of 54.7 mL L⁻¹ h⁻¹. In addition to hydrogen, the process generated acetic, lactic, and formic acids, ethanol, and 2,3-butanediol as byproducts.

These findings demonstrate the potential of E. cloacae to produce H₂ from agroindustrial residues such as cashew apple bagasse through dark fermentation. Nitrogen supplementation – particularly with peptone – also enhanced H₂ production, emphasizing its importance for improving microbial hydrogen generation and advancing renewable energy technologies.

Biochar has attracted considerable attention in recent years for its wide-ranging applications, particularly its role in carbon sequestration as a strategy to mitigate greenhouse gas emissions. Its emerging uses within the circular bioeconomy also position it as a valuable tool for environmental management, and ongoing research continues to advance understanding of its mitigation potential. This article provides a comprehensive overview of biochar research development and applications. It includes a bibliometric analysis for the 2019–2023 period, complemented by a critical review of key technologies, characterization methods, and applications. This integrated approach clarifies the current state of biochar research and highlights emerging trends in its applications. The study reveals that 20 041 articles and reviews were published over the period from 2019 to 2023, highlighting China as the leading country in biochar research and development. Residual biomass is considered the feedstock of choice for biochar production, with pyrolysis emerging as the dominant technology, surpassing gasification and torrefaction. Adsorption has gained prominence for its potential in remediating contaminated soils. Emerging applications of biochar include its use in anaerobic digestion within the circular economy, warranting further investigation for full integration. Biochar is also increasingly recognized as a viable option for greenhouse gas (GHG) mitigation, with growing interest in its diverse applications. This article provides a comprehensive review of recent advancements in biochar research, emphasizing key trends and prospective applications across various sectors.

The Nigerian government’s interest in expanding the sugar sector has significantly increased sugarcane production, generating substantial bagasse by-products without adequate waste management strategies. This study examined the potential of sugarcane bagasse as a biogas feedstock by integrating a socioeconomic survey of 120 sugarcane farmers in Oyo State, Nigeria, and laboratory anaerobic digestion experiments. The survey revealed that 74.2% of farmers expressed willingness to adopt biogas technology, significantly influenced by educational level (odds ratio (OR) = 7.08), perception (OR = 12.72) and farming experience (OR = 1.12), whereas age had a negative effect (OR = 0.94). In laboratory experiments, anaerobic digestion of bagasse alone yielded a maximum methane content of 53.7%, while co-digestion with cow manure reached 53.8%, although statistical analysis indicated no significant difference (P = 0.841) in cumulative biogas production between these treatments. These findings highlight the necessity for targeted policy interventions, including farmer education and youth engagement, to enhance biogas technology adoption and efficient utilization of sugarcane bagasse, contributing toward sustainable energy generation and improved waste management in Nigeria.

Achieving a clean atmosphere requires the implementation of environmentally sustainable strategies to mitigate the detrimental effects of fossil fuels, which are associated with high sulfur content, substantial greenhouse gas emissions, and limited reserves. Biodiesel, with its low sulfur content, represents a promising and sustainable alternative. Ionic liquids are green catalysts that align with the principles of sustainability and green chemistry, and are used increasingly in biodiesel production. The conversion of CO₂ – a major contributor to global warming – into value-added products offers a viable strategy to mitigate climate change. However, comprehensive reviews addressing the use of ionic liquids as catalysts in biodiesel production and their application in the conversion of CO₂ and sulfur compounds into valuable chemicals are lacking.

This review provides an in-depth analysis of recent advances in biodiesel production using ionic liquid-based catalysts, including magnetic, enzymatic, and photocatalytic systems, with a focus on modifications to their acidic and basic properties. Notably, polyoxometalate-based ionic liquids have demonstrated complete sulfur removal from diesel. The review also explores the utility of CO₂-derived products in sustainable biodiesel production and evaluates the roles of ionic liquids and deep eutectic solvents as green solvents and catalysts. Greener synthesis pathways for these catalysts and their potential for commercialization are evaluated through techno-economic assessments.

Biogas purification technologies facilitate the production of value-added products such as biomethane and industrial chemicals. This review was based on the assumption that biogas purification is underrepresented in the literature despite its significant potential for clean energy and greenhouse gas mitigation, warranting a comprehensive bibliometric and scientometric analysis. Using data from Clarivate Analytics’ ISI Web of Science, the study examines research on biogas purification and CO₂ capture. The results show relatively few in-depth publications, but there is growing interest in biogas as a sustainable alternative to natural gas and conventional fuels, driven by emission reduction goals. Key challenges include high costs, limited technological advances (e.g., membranes, chemical absorption), and insufficient regulatory support. The leading areas of publication are energy fuels, environmental engineering, and environmental sciences. China, UK, and the USA are major contributors; however, the EU leads in commercial deployment, reflecting more advanced integration into sustainable energy systems. In addition to biogas, the fermentation process produces organic residues with significant potential for valorization through nutrient recovery, composting, and extraction of high-value products, enhancing resource efficiency and sustainability. Biogas represents a promising solution for energy transition, sustainable development, and circular economy integration.

The world’s population is expected to grow rapidly, with the vast majority of people living in urban areas. Closing nutrient loops is therefore increasingly important for food security and environmental stability. In Germany however, the current treatment of organic and green waste and sewage sludge (derived from wastewater) includes composting and co-incineration, resulting in significant nutrient losses. This paper analyses the technical potential of novel urban biorefinery concepts for the recycling of plant nutrition minerals from waste streams and waste water in metropolitan regions. Using the Stuttgart region as a case study, four modular biorefinery concepts were assessed, including phosphorus precipitation, membrane gas absorption, and insect-based bioconversion. These technologies produce valuable recycling fertilizers – such as ammonium sulfate, struvite, and organic NPK fertilizers – which meet legal requirements but differ in nutrient concentrations and availability to plants. The implementation of the evaluated biorefinery technologies has the potential to replace almost all conventional fertilizers used in the Stuttgart region with regionally produced recycling fertilizers, while mitigating environmental impacts and creating economic opportunities within a circular bioeconomy. In order to realize this potential, it is necessary to treat not only organic and green waste, but all urban wastewater streams in urban biorefineries. Finally, an urban biorefinery concept is proposed that optimally matches waste streams and specific biorefinery technologies, enabling nutrient recovery from organic waste and wastewater and supporting the development of regionally adapted circular strategies.

A sustainable hydrogen source is essential for improving the environmental performance of industries that are heavily reliant on hydrogen. Transitioning from commercial hydrogen to cleaner sources is vital for reducing fossil fuel dependence. This study investigated the technical feasibility of a more environmentally friendly hydrogenation method for acid oils using in situ hydrogen generation. This approach uses sustainable ethanol under supercritical conditions combined with cost-effective zinc oxidation in an aqueous medium. The technology enhances environmental sustainability while improving safety, storage, and transportation, offering significant economic advantages. The process also produces zinc oxide, a value-added material, widely used industrially and typically priced at about 10% higher than metallic zinc. Various strategies optimized hydrogen production by enhancing both hydrogen generation and fatty acid hydrogenation. Using zinc, fatty acid saturation reached 55% at 220 °C, while near-complete saturation (95%) was achieved at 280 °C with supercritical ethanol and a cost-effective nickel catalyst. These findings highlight promising pathways for sustainable hydrogen production and hydrogenation using low-cost catalysts, milder reaction conditions, and recyclable materials, supporting a circular economy.

Agroindustrial activity generates substantial waste during harvesting and processing. This study investigated the potential use of sugarcane bagasse, corn cob husk, and wheat bran as substrates for enzyme production by Aspergillus niger and Ceriporiopsis subvermispora. Aspergillus niger and C. subvermispora exhibited comparable filter paperase (FPase) activity (21.99 and 20.37 U g⁻¹, respectively) when cultivated on corn cob husk supplemented with wheat bran and when cultivated on unsupplemented corn cob husk. However, C. subvermispora showed the highest carboxymethylcellulase (CMCase) activity (6858 U g⁻¹) in unsupplemented corn cob husk medium. Laccase activity (1.688 U g⁻¹) was detected exclusively in C. subvermispora cultures. Crude laccase from C. subvermispora was used to treat the azo dye Congo red and the indigoid dye indigo carmine, achieving decolorization efficiencies of 25% and 27%, respectively, after 30 h incubation. Phytotoxicity assays with Lactuca sativa seeds showed that decolorized solutions did not significantly affect germination but caused a 2.5-fold reduction in root elongation when exposed to decolorized Congo red (50 and 100  mg L⁻¹) and indigo carmine (100 mg L⁻¹). These findings indicate that laccase treatment can partially decolorize these dyes, although further optimization is needed to reduce the phytotoxic effects of the degradation products.

Chestnut (Castanea sativa Mill.) shell, a byproduct of chestnut processing, is a valuable source of phenolic compounds that have a range of industrial applications. This study investigated the optimization of gallic acid extraction from the outer shell of the chestnut using ultrasound-assisted extraction (UAE) and deep eutectic solvents (DES). A Box–Behnken design (BBD) was employed to determine optimal extraction conditions, considering variables such as extraction time, temperature, water content, liquid-to-solid ratio, material treatment, and DES type. Results indicate that baked chestnut shell samples and choline chloride:ethylene glycol (1:2) DES yielded the highest gallic acid content, with optimal conditions of 70 °C, 35 min, 20% water content, and a 10:1 liquid-to-solid ratio. This study highlights the environmental and economic advantages of DES-based UAE, supporting its use as a sustainable method for extracting bioactive compounds for application in the food, pharmaceutical, and cosmetic industries.

The southeast region of the USA has the potential to be a significant producer of biobased products; however, research is needed to demonstrate the most cost-effective feedstock delivery system. This study considers a distributed network of five pellet depots to supply feedstock (i.e., switchgrass pellets) for the operation of a hypothetical biorefinery located near South Boston, VA, USA. The study was divided into four main categories: (1) feedstock delivery from satellite storage locations (SSLs) to the pellet depots; (2) pellet production at the depots; (3) pellet storage at the depots, and (4) pellet delivery to the biorefinery to supply a continuous operation 24 h per day, 7 days per week, and 48 weeks per year. The cost analysis begins with round bales in SSLs and ends when a load of pellets arrives at the biorefinery. This study does not include a farmgate payment to grow, harvest, and store round bales in SSLs, and it also does not include receiving facility operations at the biorefinery. The weighted average cost for annual delivery to the biorefinery from the five depots was USD 129.32 per Mg pellets. The division of this cost was 51% feedstock delivery, 38% pelleting, 2% pellet storage, and 9% pellet delivery. The cost for the smallest depot was USD 145.37 per Mg pellets, in comparison with USD 115.22 per Mg pellets for the largest depot. These results indicate an economy-of-scale influence; there was a 21% reduction in cost as the depot size increased from 66 450 to 140 430 Mg pellets per year.