Search Results (758)

The expansion of the invasive Asian macroalgae Rugulopteryx okamurae along the coasts of the Azores represents a significant challenge for local marine biodiversity. A promising approach to managing the biomass produced by this alien alga is to valorize it in the context of the blue economy. This study characterizes and evaluates the potential of R. okamurae biomass for incorporation into cattle feed, with a focus on mitigating enteric methane production. The nutritional value of R. okamurae, its digestibility, and its potential as a mitigating agent for enteric methane production were analyzed in vitro. The results indicate that the inclusion of 5% R. okamurae in the diet significantly (p < 0.05) reduced accumulated methane production by 98% after 24 h of incubation. The addition of 1% algae over the same period resulted in a 38% reduction in methane production. However, a significant decrease (p < 0.05) in gas production of 57.02% and 73.5% was also observed in relation to control, with the inclusion of 1% and 5%, respectively, during 96 h. Nutritionally, R. okamurae was found to have a crude protein content of 18.68% and fiber (NDF) of 55.71% of DM. It is also worth highlighting the high content of ash (31.86%) that was identified in these brown macroalgae. In conclusion, the fresh biomass of R. okamurae could serve as a functional ingredient in cattle feed to mitigate enteric methane production, provided it is used in low percentages. However, it is important to emphasize that high concentrations in the first 12 h did not produce methane, which is also not recommended for enteric fermentation. However, before including it in animal feed, in vivo tests are needed to assess its toxicity. Full article

Aquaculture and waste valorization have the potential to show solid achievements toward food security and improvements in the circularity of resources, which are crucial aspects of achieving a sustainable lifestyle in agreeance with Agenda 2030 goals. This study aims to optimize and simplify the decision-making processes for the valorization of marine wastes (natural and from aquaculture) as secondary raw materials to produce high-value-added market goods. However, significant concentrations of pollutants may be present within wastes, compromising overall quality, and social dynamics can hinder their usage further. Goro’s lagoon was chosen as a case study, where the relations between the ecosystem services, a thriving bivalve economy, and social dynamics are deeply rooted and intertwined. Therefore, in the manuscript cost–benefit and foresight analyses are conducted to determine the best usage for algal biomass considering pollution, social acceptance, and profitability. These analyses are virtually conducted on bio-refineries that could be operating in the case study’s area: briefly, for a thirty-year running bio-plant, the CBA indicates the two best alternatives with an income of 5 billion euros (NPV, with a 5% discount rate) for a biofuel-only production facility, and a half for a multiproduct one, leading to the conclusion that the first is the best alternative. The foresight, instead, suggests a more cautious approach by considering external factors such as the environment and local inhabitants. Hence, the main innovation of this work consists of the decision-maker’s holistic enlightenment toward the complexities and the hidden threats bound to this kind of closed-loop efficiency-boosting process, which eventually leads to optimized decision-making processes. Full article

Power scarcity and pollution can be overcome with the use of green energy forms like ethanol, biogas, electricity, hydrogen, etc., especially energy produced from renewable and industrial feedstocks. In hilly areas, pine needles are the most abundant biomass that has a low possibility of valorization due to high lignin content. On the other hand, anaerobic digestion (AD) of lignin and animal waste has low biogas yield due to poor conductivity. This study focuses on the simultaneous production of biogas and electricity through the co-digestion of cow dung and pine needles. The digester was initially established and stabilized in the lab to ensure a continuous supply of inoculum throughout the experiment. The optimization process involved the determination of an ideal cow dung-to-water ratio and selecting the appropriate conductive material that can enhance the energy generation from the feedstock. Afterward, both batch and continuous anaerobic digestion experiments were conducted. The results revealed that the addition of powdered graphite (5 mM), activated charcoal (15 mM), and biochar (25 mM) exhibited maximum voltage of 0.71 ± 0.013 V, 0.56 ± 0.013 V, and 0.49 ± 0.011 V on the 30th, 25th and 20th day of AD, respectively. The batch experiment showed that 5 mM graphite powder enhanced electron transfer in the AD process and generated a voltage of 0.77 ± 0.014 V on the 30th day, indicating an increase of ~1.5-fold as compared to the control (0.56 ± 0.019 V). The results from the continuous AD process showed that the digester with cow dung, pine needle, and a conductive material in combination exhibited the maximum voltage of 0.76 ± 0.012 V on the 21st day of AD, while the digester with cow dung only exhibited a maximum voltage of 0.62 ± 0.015 V on the 22nd day of AD, representing a 1.3-fold increase over the control. Furthermore, the current work used discarded plastic items and electrodes from spent batteries to emphasize waste management and aid in attaining sustainable energy and development goals. Full article

Forest biomass energy, when utilized responsibly, presents a carbon-neutral and viable alternative to fossil fuels for energy storage. This research investigates the energy potential of various coniferous species, focusing on their complex chemical compositions and suitability for energy production. Key characteristics such as moisture content, volatile matter, ash content, and fixed carbon were analyzed, along with elemental composition (including nitrogen, carbon, oxygen, and hydrogen) and both gross and net heating values across different species. The proximate analysis revealed significant interspecies variations. For example, Pseudotsuga menziesii and Chamaecyparis lawsoniana exhibited the lowest moisture contents. Elemental analyses showed a broad range of values, with Larix decidua having the lowest nitrogen content and Sequoiadendron giganteum the highest carbon content. Gross and net heating values also varied considerably, with Podocarpus macrophyllus showing the lowest values and Pinus strobus the highest. Principal component analysis (PCA) was employed to identify underlying patterns, revealing correlations between the analyzed variables and the energy potential of the species. Additionally, PCA combined with cluster analysis allowed for the identification of coherent groups of species with similar characteristics. Overall, these findings highlight the diverse energy valorization potential inherent in coniferous species, underscoring the importance of considering specific chemical compositions for efficient energy production. The insights provided here are valuable for selecting coniferous species for energy valorization, emphasizing the need to consider both chemical composition and calorific potential. Full article

This study focuses on applying ash reduction treatments in order to explore the potential for industrial-scale thermochemical utilization of Spent Mushroom Compost (SMC). SMC is a waste byproduct generated by the mushroom industry. Typically, for every kilogram of produced mushrooms, five kilograms of SMC are discarded, with current disposal methods involving landfills or incineration, causing environmental problems. Utilizing SMC effectively presents challenges due to the inherent properties of this biomass type, characterized by high moisture and ash content, low fixed carbon content, and material heterogeneity. These attributes create difficulties when employing a thermochemical valorization route due to the low carbon content and mineral treatments involved. The results have unveiled the heterogeneous nature of the material and its individual components when physically separated. Among the three identified fractions (agglomerated, woody, and fines), the woody fraction showed the highest potential for thermochemical utilization. Notably, when subjected to washing with distilled water and citric acid treatments, it resulted in up to 66% ash reduction, a significant outcome. Other fractions of the material may find potential applications in agriculture. The effective utilization of such high-volume waste biomasses demands diverse and innovative approaches, underlining the urgency and complexity of the problem and the need to employ the principles of a circular economy. Full article

Lignin, the earth’s second-most abundant biopolymer after cellulose, has long been relegated to low-value byproducts in the pulp and paper industry. However, recent advancements in valorization are transforming lignin into a sustainable and versatile feedstock for producing high-value biofuels, bioplastics, and specialty chemicals. This review explores the conversion of lignin’s complex structure, composed of syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H) units, into value-added products. We critically assess various biochemical and analytical techniques employed for comprehensive lignin characterization. Additionally, we explore strategies for lignin upgrading and functionalization to enhance its suitability for advanced biomaterials. The review emphasizes key areas of lignin valorization, including catalytic depolymerization methods, along with the associated challenges and advancements. We discuss its potential as a feedstock for diverse products such as biofuels, bioplastics, carbon fibers, adhesives, and phenolic compounds. Furthermore, the review briefly explores lignin’s inherent properties as a UV protectant and antioxidant, alongside its potential for incorporation into polymer blends and composites. By presenting recent advancements and case studies from the literature, this review highlights the significant economic and environmental benefits of lignin valorization, including waste reduction, lower greenhouse gas emissions, and decreased reliance on non-renewable resources. Finally, we address future perspectives and challenges associated with achieving large-scale, techno-economically feasible, and environmentally sustainable lignin valorization. Full article

Activated carbons are commonly used for adsorption/depollution applications, but only a few studies are related to their lubricating properties. In order to investigate a new family of friction reducers, the tribological properties of biochars and derived activated carbons obtained from sugar cane bagasse are investigated. Activated carbons are obtained from either a physical (steam water) or chemical (with phosphoric acid) activation process. The tribological tests show that the activated carbons present very low friction coefficients, close to 0.08. The correlation of textural and tribological investigations shows that the specific surface area of the compounds as well as the microporous and mesoporous domain extensions are key parameters to optimize the friction reduction properties of activated carbons. The friction properties of the compounds are improved if the mesoporous domain extension is above 40% of the total porous volume. This study shows that local biomass waste valorization is possible and that sugar cane bagasse-derived activated carbons appear as interesting new friction reduction additives for lubricants. Full article

Bio-oil combined steam/dry reforming (CSDR) with H₂O and CO₂ as reactants is an attractive route for the joint valorization of CO₂ and biomass towards the sustainable production of syngas (H₂ + CO). The technological development of the process requires the use of an active and stable catalyst, but also special attention should be paid to its regeneration capacity due to the unavoidable and quite rapid catalyst deactivation in the reforming of bio-oil. In this work, a commercial Rh/ZDC (zirconium-doped ceria) catalyst was tested for reaction–regeneration cycles in the bio-oil CSDR in a fluidized bed reactor, which is beneficial for attaining an isothermal operation and, moreover, minimizes catalyst deactivation by coke deposition compared to a fixed-bed reactor. The fresh, spent, and regenerated catalysts were characterized using either N₂ physisorption, H₂-TPR, TPO, SEM, TEM, or XRD. The Rh/ZDC catalyst is initially highly active for the syngas production (yield of 77% and H₂/CO ratio of 1.2) and for valorizing CO₂ (conversion of 22%) at 700 °C, with space time of 0.125 g_catalyst h (g_oxygenates)⁻¹ and CO₂/H₂O/C ratio of 0.6/0.5/1. The catalyst activity evolves in different periods that evidence a selective deactivation of the catalyst for the reforming reactions of the different compounds, with the CH₄ reforming reactions (with both steam and CO₂) being more rapidly affected by catalyst deactivation than the reforming of hydrocarbons or oxygenates. After regeneration, the catalyst’s textural properties are not completely restored and there is a change in the Rh–support interaction that irreversibly deactivates the catalyst for the CH₄ reforming reactions (both SR and DR). As a result, the coke formed over the regenerated catalyst is different from that over the fresh catalyst, being an amorphous mass (of probably turbostractic nature) that encapsulates the catalyst and causes rapid deactivation. Full article

In Colombia alone, 12.6 million bags of green coffee are produced, but at the same time, 784,000 tons of waste biomass are dumped in open fields, of which only 5% is recovered or used, and 10 million tonnes of coffee emit 28.6 million tonnes of CO₂ eq annually. This presents a worrying dilemma, and the need to develop a technology to transform the waste into usable products is increasing. As a response to this, the valorization of coffee waste was explored through the production of biochar and platform chemicals by implementing a set of hydrothermal experiments with different biomass/water ratios (1:5, 1:10, 1:20, 1:40), particle sizes (0.5, 1, 2, 5 mm), stirring rates (5000 and 8000 rpm), and catalysts (H₂SO₄, NaHCO₃ and CH₃COOH) at 180, 220, and 260 °C in a batch reactor with autogenous pressure. Notably, the smaller B:W ratios of 1:20 and 1:40, as well as smaller particle sizes of 0.5 and 1 mm, yielded higher amounts of platform chemicals, while stirring showed minimal influence. CH₃COOH significantly enhanced the process compared to other catalysts. The biochar was characterized as anthracite, and this obtaining of coal-like materials from biomass itself represents a remarkable feat. Said anthracite presented little to no variation in physical parameters, while catalysts induced functionalization. By optimizing factors like B:W ratio, particle size, and catalyst application, valuable insights have been gained into enhancing the yield of platform chemicals and quality of biochar from coffee waste. The findings not only contribute to sustainable waste management practices but also highlight the importance of exploring innovative solutions for utilizing agricultural by-products effectively. Full article

This study delves into the valorization of pea pod waste using hydrothermal processes, focusing on optimizing key parameters such as temperature, biomass-to-water ratio, particle size, and catalyst influence. Noteworthy findings include the significant impact of temperature variations on product yields, with 180 °C favoring sugars, HMF, and furfural, while 220 °C and 260 °C lead to distinct platform chemical productions. The utilization of a 1:20 biomass-to-water ratio consistently enhances yields by 10%, underscoring its importance in promoting efficient hydrolysis without excessive product degradation. Furthermore, the investigation into particle size reveals that smaller dimensions, particularly 1 mm particles, improved heat and mass transfer, reduced diffusion barriers, and enhanced digestibility, ultimately boosting overall efficiency in platform chemical production. Moreover, the study sheds light on the role of catalysts in the hydrothermal processes, showcasing the differential impact of acid and basic catalysts on product yields. Acid catalysts demonstrate a notable increase of up to 135.5% in the production of platform chemicals, emphasizing their crucial role in enhancing reaction efficiency. The complex relationship between agitation, temperature, and product formation is elucidated, with experiments revealing varying outcomes based on the presence or absence of agitation at different temperatures. These findings provide valuable insights into optimizing pea pod waste valorization, offering a pathway towards sustainable and efficient conversion of agricultural residues into valuable platform chemicals. Full article

Arthrospira platensis holds promise for biotechnological applications due to its rapid growth and ability to produce valuable bioactive compounds like phycocyanin (PC). This study explores the impact of salinity and brewery wastewater (BWW) on the mixotrophic cultivation of A. platensis. Utilizing BWW as an organic carbon source and seawater (SW) for salt stress, we aim to optimize PC production and biomass composition. Under mixotrophic conditions with 2% BWW and SW, A. platensis showed enhanced biomass productivity, reaching a maximum of 3.70 g L⁻¹ and significant increases in PC concentration. This study also observed changes in biochemical composition, with elevated protein and carbohydrate levels under salt stress that mimics the use of seawater. Mixotrophic cultivation with BWW and SW also influenced the FAME profile, enhancing the content of C16:0 and C18:1 FAMES. The purity (EP of 1.15) and yield (100 mg g⁻¹) of PC were notably higher in mixotrophic cultures, indicating the potential for commercial applications in food, cosmetics, and pharmaceuticals. This research underscores the benefits of integrating the use of saline water with waste valorization in microalgae cultivation, promoting sustainability and economic efficiency in biotechnological processes. Full article

Nearly zero energy buildings (NZEBs) might play a significant role in addressing current global environmental problems, i.e., greenhouse gas (GHG) emissions. Buildings are one of the main electricity consumers. With current electricity production coming mainly from fossil fuel power plants, buildings contribute indirectly to GHG emissions. This report shows potential energy-saving alternatives (thus reducing the carbon footprints) for an 18-story office building in South Jakarta’s central business district. Four alternatives are considered, namely cooling tower and CWP pump replacement, BAS installation, LED dim light replacement, and solar panel installation. The project that implements all four alternatives indeed produces the biggest emissions savings. However, its net present value (NPV) is negative, which means the project is not economically feasible. Furthermore, any combination of projects involving solar panel installation will produce negative NPVs. The combination of cooling tower and CWP pump replacement, BAS installation, and LED dim light replacement will be the best option, with an NPV of IDR 437,853,822, an energy consumption index (IKE) value of 11.76 (meaning the “efficient” building category) and a carbon emissions reduction of 1172.65 tons of CO₂. Full article

Lignocellulose is a major biopolymer in plant biomass with a complex structure and composition. It consists of a significant amount of high molecular aromatic compounds, particularly vanillin, syringeal, ferulic acid, and muconic acid, that could be converted into intracellular metabolites such as polyhydroxyalkanoates (PHA) and hydroxybutyrate (PHB), a key component of bioplastic production. Several pre-treatment methods were utilized to release monosaccharides, which are the precursors of the relevant pathway. The consolidated bioprocessing of lignocellulose-capable microbes for biomass depolymerization was discussed in this study. Carbon can be stored in a variety of forms, including PHAs, PHBs, wax esters, and triacylglycerides. From a biotechnology standpoint, these compounds are quite adaptable due to their precursors’ utilization of hydrogen energy. This study lays the groundwork for the idea of lignocellulose valorization into value-added products through several significant dominant pathways. Full article

Recently, there has been a burgeoning interest in harnessing the potential of biomass and industry byproducts for the development of novel products and materials. In particular, this study explored the efficient valorization of sunflower meal (SFM), an underutilized byproduct of the oil extraction industry, usually discarded or used as low-value animal feed through enzyme-aided fractionation, specifically targeting the extraction and conversion of its abundant carbohydrate component, xylan, into emerging prebiotic compounds—xylo-oligosaccharides (XOSs)—which are recognized as promotors of a healthy gut microbiome and overall human wellbeing. An enzymatic treatment using Alcalase^® 2.4 L was implemented for facilitating the recovery of a highly pure hemicellulosic fraction (92.2% carbohydrates) rich in β-(1→4)-linked xylose residues with arabinose and glucuronic acid substitutions (DP-xylan). A further enzymatic treatment of this substrate, using ROHALASE^® SEP-VISCO under optimized conditions (70 °C, pH 6, 0.005% v/v enzyme concentration), produced 52.3% of XOSs with a polymerization degree (DP) less than 20 after two hours. Further analyses demonstrated that the majority of the obtained product had a DP less than 6, predominantly consisting of di- and trisaccharides (XOS2 and XOS3) without the significant generation of xylose. These findings highlight the significant potential of SFM for the generation of valuable prebiotic compounds in a sustainable manner. Full article

The environmental impacts of the postindustrial era, which rely on fossil fuels, have compelled a reconsideration of the future of energy and chemical industries. Fungi are a valuable resource for improving a circular economy through the enhanced valorization of biomass and plant waste. They harbor a great diversity of oxidative enzymes, especially in their secretome. Enzymatic breakdown of the plant cell wall complex and lignocellulosic biomass yields sugars for fermentation and biofuel production, as well as aromatic compounds from lignin that can serve as raw materials for the chemical industry. To harness the biocatalytic potential, it is essential to identify and explore wild-type fungi and their secretomes. This study successfully combined genome mining and activity screening to uncover the oxidative potential of a collection of underexploited ascomycetes and basidiomycetes. The heme peroxidase and laccase activities of four promising candidates, Bipolaris victoriae, Colletotrichum sublineola, Neofusicoccum parvum and Moesziomyces antarcticus, were investigated to gain a deeper insight into their enzyme secretion. Furthermore, a plant-based medium screening with the phytopathogen C. sublineola revealed that soybean meal is a beneficial component to trigger the production and secretion of enzymes that catalyze H₂O₂-dependent oxidations. These results demonstrate that understanding fungal secretomes and their enzymatic potential opens exciting avenues for sustainable biotechnological applications across various industries. Full article