Search Results (171)

Lignin used in this work was isolated from sapele (Entandrophragma cylindricum) wood through a hybrid pulping process using soda/ethanol as pulping liquor and denoted soda-oxyethylated lignin (SOL). SOL was mixed with a polyethylene glycol (PEG)–glycerol mixture (80/20 v/v) as liquefying solvent with 98% wt. sulfur acid as catalyst, and the mixture was taken to boil at 140 °C for 2, 2.5, and 3 h. Three bio-polyols LBP1, LBP2, and LBP3 were obtained, and each of them exhibited a high proportion of -OH groups. Lignin-based polyurethane foams (LBPUFs) were prepared using the bio-polyols obtained with a toluene diisocyanate (TDI) prepolymer by the one-shot method. Gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and carbon-13 nuclear magnetic resonance spectroscopy (¹³C NMR) were used characterize lignin in order to determine viscosity, yield, and composition and to characterize their structure. The PEG-400–glycerol mixture was found to react with the lignin bio-polyols’ phenolic -OHs. The bio-polyols’ viscosity was found to increase as the liquefaction temperature increased, while simultaneously their molecular weights decreased. All the NCO groups were eliminated from the samples, which had high thermal stability as the liquefaction temperature increased, leading to a decrease in cell size, density, and crystallinity and an improvement in mechanical performance. Based on these properties, especially the presence of some aromatic rings in the bio-polyols, the foams produced can be useful in automotive applications and for floor carpets. Full article

Here, we report the discovery of silica- and sulfur-enriched deposits forming on the seafloor off Zannone Island (western Mediterranean Sea), where hydrothermal activity is ongoing. Our multidisciplinary investigation reveals that these deposits form through the interplay between hydrothermal processes and microbial activity. The deposits result from a dynamic equilibrium involving microbial mediation, sedimentation, and episodic lithification, driven primarily by two mineralization pathways: silica and sulfur precipitation. This study provides new insights into the bio-sedimentary processes shaping authigenic crusts in shallow submarine hydrothermal settings, contributing to a broader understanding of mineralization in marine environments influenced by both geological and biological factors. Full article

The projected depletion of fossil resources has initiated research on new and sustainable fuels which can be utilized in combination with conventional fuels. Lignocellulosic biomass, and more specifically lignin, can be depolymerized towards phenolic and aromatic bio-oils which can be converted downstream into bunker fuel blending components. Within this study, solvolysis under critical ethanol conditions and mild catalytic hydrotreatment were applied to heavy fractions of lignin pyrolysis bio-oils with the aim of recovering bio-oils with improved properties, such as a lower viscosity, that would allow their use as bunker fuel blending components. The mild reaction conditions, i.e., low temperature (250 °C), short reaction time (1 h) and low hydrogen pressure (30–50 bar), led to up 65 wt.% recovery of upgraded bio-oil, which exhibited a high carbon content (63–73 wt.%), similar to that of the parent bio-oil (68.9 wt.%), but a lower oxygen content and viscosity, which decreased from ~298,000 cP in the parent lignin pyrolysis oil to 526 cP in the hydrotreated oil, with a 10%Ni/Beta catalyst in methanol, and which was also sulfur-free. These properties permit the potential utilization of the oils as blending components in conventional bunker fuels. Full article

Spice by-products, often discarded as waste, represent an untapped resource for sustainable packaging solutions due to their unique, multifunctional, and bioactive profiles. Unlike typical plant residues, these materials retain diverse phytochemicals—including phenolics, polysaccharides, and other compounds, such as essential oils and vitamins—that exhibit controlled release antimicrobial and antioxidant effects with environmental responsiveness to pH, humidity, and temperature changes. Their distinctive advantage is in preserving volatile bioactives, demonstrating enzyme-inhibiting properties, and maintaining thermal stability during processing. This review encompasses a comprehensive characterization of phytochemicals, an assessment of the re-utilization pathway from waste to active materials, and an investigation of processing methods for transforming by-products into films, coatings, and nanoemulsions through green extraction and packaging film development technologies. It also involves the evaluation of their mechanical strength, barrier performance, controlled release mechanism behavior, and effectiveness of food preservation. Key findings demonstrate that ginger and onion residues significantly enhance antioxidant and antimicrobial properties due to high phenolic acid and sulfur-containing compound concentrations, while cinnamon and garlic waste effectively improve mechanical strength and barrier attributes owing to their dense fiber matrix and bioactive aldehyde content. However, re-using these residues faces challenges, including the long-term storage stability of certain bioactive compounds, mechanical durability during scale-up, natural variability that affects standardization, and cost competitiveness with conventional packaging. Innovative solutions, including encapsulation, nano-reinforcement strategies, intelligent polymeric systems, and agro-biorefinery approaches, show promise for overcoming these barriers. By utilizing these spice by-products, the packaging industry can advance toward a circular bio-economy, depending less on traditional plastics and promoting environmental sustainability in light of growing global population and urbanization trends. Full article

This study investigates the structural effects of dilute acid and alkali treatments on cotton fibers, aiming to understand the influence of chemical pretreatment on cellulose morphology. Cotton samples were exposed to 1% sulfuric acid and 1% sodium hydroxide at 90 °C, and the resulting changes were evaluated using scanning electron microscopy and nonlinear optical imaging techniques. The results indicate that sulfuric acid causes significant fiber degradation, leading to fragmentation and reduced fiber thickness. In contrast, sodium hydroxide treatment results in a roughened, flaky surface while preserving the overall structural integrity, with fibers appearing fluffier and more accessible to enzymatic processes. Untreated cotton fibers maintained a smooth and uniform surface, confirming the chemical specificity of the observed changes. These findings are crucial for optimizing biomass pretreatment methods, demonstrating that dilute chemical treatments primarily affect macrostructural features without significantly disrupting the cellulose microfibrils. The study provides valuable insights for the development of efficient biorefining processes and sustainable bio-based materials, highlighting the importance of selecting appropriate chemical conditions to enhance enzymatic hydrolysis and biomass conversion while maintaining the core structure of cellulose. This research contributes to advancing the understanding of cellulose’s structural resilience under mild chemical pretreatment conditions. Full article

The world’s energy demand increases daily, fostering the search for renewable fuels to reconcile production needs with environmental sustainability. To prevent the severe atmospheric impact of fossil fuels, reducing greenhouse gas emissions is both essential and urgent, reinforcing the necessity of developing and adopting renewable fuel alternatives. Therefore, this work aimed to produce bio-oil through sugarcane bagasse fast pyrolysis. The methodology is based on fast pyrolysis operation in a fluidized bed reactor (pilot plant) as a thermochemical method for bio-oil production. This research required the conditioning of the raw material for system feeding, along with optimizing key variables, operating temperature, airflow, and sugarcane bagasse feed rate, to achieve improved yields compared to previous studies conducted in this pilot plant. The sugarcane bagasse was conditioned through drying and milling, followed by characterization using various analytical methods, including calorific value, thermogravimetric analysis (TGA), particle size analysis by laser diffraction (Mastersizer—MS), and ultimate analysis (determining carbon, hydrogen, nitrogen, sulfur, and oxygen by difference). The bio-oil produced showed promising yield results, with a maximum estimated value of 61.64%. Fourier Transform Infrared Spectroscopy (FT-IR) analysis confirmed the presence of aromatic compounds, as well as ester, ether, carboxylic acid, ketone, and alcohol functional groups. Full article

This research work seeks to introduce eco-friendly, low-carbon, and high-octane biofuel gasoline production using a synergistic approach. Four types of high-octane gasoline, including SynergyFuel-92, SynergyFuel-95, SynergyFuel-98, and SynergyFuel-100, were generated, emphasizing the deliberate combination of petroleum-derived gasoline fractions using reformate, isomerate, and delayed coking (DC) naphtha with octane-boosting compounds—bio-methanol and bio-ethanol. A set of tests have been performed to examine the effects of antiknock properties, density, oxidation stability, distillation range characteristics, hydrocarbon composition, vapor pressure, and the volatility index on gasoline blends. The experimental results indicated that the gasoline blends made from biofuel (SynergyFuel-92, -95, -98, and 100) showed adherence to important fuel quality criteria in the USA, Europe, and China. These blends had good characteristics, such as low quantities of benzene and sulfur, regulated levels of olefins and aromatics, and good distillation qualities. By fulfilling these strict regulations, Synergy Fuel is positioned as a competitive and eco-friendly substitute for traditional gasoline. The results reported that SynergyFuel-100 demonstrated the strongest hot-fuel-handling qualities and resistance to vapor lock among all the mentioned Synergy Fuels. Finally, the emergence of eco-friendly, low-carbon, and high-octane biofuel gasoline production with synergistic benefits is a big step in the direction of sustainable transportation. Full article

To address greenhouse gas (GHG) emissions from the maritime sector, the European Union (EU) has introduced the FuelEU Maritime regulation to incentivize ships to adopt diversified compliance pathways and energy solutions. This study aims to determine the optimal alternative fuel configurations for dual-fuel ships of different types under environmental, economic, and regulatory constraints. An integrated environmental and cost assessment model from a well-to-wake (WtW) perspective to systematically evaluate the environmental benefits and economic feasibility of fossil-based, bio-based, and renewable electricity-based alternative fuels applied in dual-fuel ships. By incorporating the PROMETHEE II method within a multi-criteria decision analysis (MCDA) framework, together with the CRITIC objective weighting method, the study enables a robust ranking of alternative fuel configurations across three key dimensions: environmental performance, cost feasibility, and regulatory compliance. The results indicate that, regardless of ship type, the very low sulfur fuel oil (VLSFO) + marine gas oil (MGO) and VLSFO + methanol (MEOH) combinations fail to meet the GHG intensity targets for 2025–2050. Only the VLSFO + electrolytic liquid hydrogen (E-LH₂) and VLSFO + electrolytic ammonia (E-NH₃) configurations are compliant. Although e-fuels incur the highest annual costs, the EU compliance penalty associated with fossil fuels increases exponentially. In contrast, e-fuels retain long-term cost advantages, ultimately driving a sector-wide transition toward e-fuel-dominated energy structures by 2050. Their superior environmental performance and regulatory compatibility emerge as the core drivers of the maritime energy transition. Full article

Hydrogen (H₂) production by photosynthetic microorganisms is a viable option for renewable energy due to its sustainability and potential for widespread application. Green algae, cyanobacteria, and purple non-sulfur bacteria have shown great promise in bio-H₂ production. However, problems such as low H₂ production rates and high H₂ production costs continue to hinder the commercial scalability of these systems. To overcome these obstacles, genetic engineering selection of robust strains capable of coping with variable environmental conditions, optimization of growth conditions, use of wastewater, and biotechnological approaches such as immobilization are carefully considered. The aim of this review is to provide a thorough overview of the methods and developments that can improve H₂ production and to highlight current difficulties and future directions for further studies. Full article

Bio-oil energy use in agricultural systems provides sustainable solutions for powering machinery operations and heating and cooling environments in facilities. However, its potential in South Africa is constrained by the limited availability of energy substrate that does not compromise food production, land use, and water resources. This study investigated the physical and chemical properties of six invasive alien plant species (IAPs), three woody species (Acacia mearnsii, Eucalyptus grandis, and Pinus patula), and three nonwoody species (Lantana camara, Chromolaena odorata, and Solanum mauritianum) to assess their suitability for bio-oil production. Key analyses included structural, elemental, proximate, atomic ratio, higher heating value (HHV), and thermogravimetric analysis (TGA) analyses. The results showed that woody IAPs had a significantly higher structural composition (p < 0.05), improving bio-oil yield. The bio-oil can be blended with diesel for agricultural use, while lignin-derived biochar serves as a soil amendment. Higher carbon and hydrogen contents enhanced HHV and combustion, while lower nitrogen and sulfur levels reduced emissions. Despite oxygen hindering pyrolysis, its bioactive properties support crop protection. Compared to South African coal, IAP-derived bio-oil shares similarities with peat coal and could be used for greenhouse heating. This study promotes energy efficiency in agriculture, reduces fossil fuel dependence, and supports environmental sustainability by repurposing IAPs. Additional studies should focus on lignin pretreatment and bio-oil upgrading to reduce oxygenated compounds. Full article

A two-year field study was conducted using canola to check the efficacy of different soil amendment treatments (SAT), i.e., with elemental sulfur (ES), bio-sulfur (BS), and compost (Cp) mixtures against insecticide-treated (Carbosulfan) and untreated controls regarding aphid populations. The results of the experiment revealed that ES treatments significantly reduced aphid abundance, followed by Cp and ES+Cp. However, BS improved aphid herbivory. The number of siliques, seeds, thousand-seed weight, and yield were improved with a trend of ES+Cp > Cp > BS+Cp. Similarly, physiological mechanisms revealed the regulation of nutrient and phenolic contents in canola with ES improving sulfur, BS nitrogen, Cp, and ES+Cp calcium, and BS+Cp enhancing phosphorus, potassium, iron, and zinc. Furthermore, RP-HPCL indicated that ferulic acid was highest in insecticide-treated plot. Similarly, Cp improved quercetin and gallic acid; ES+Cp caffeic, chlorogenic, m-coumaric, and sinapic acid; and BS+Cp enhances syringic, vanillic, ferulic, p-coumaric, and cinnamic acid. The analysis regarding health risk assessment revealed among different SAT, ES+Cp significantly reduced the Hazardous Quotient (HQ) of Cu and Zn. However, further research is still needed to explore SAT’s potential to remediate other heavy metal stresses with possible implications for pest management in different field crops. Full article

Microbial corrosion poses a significant threat to architectural heritage worldwide. This study used metagenomics to investigate microbial diversity and taxonomic groups present in the door walls of the Ji family’s residential houses, as well as their biological functions and chemical cycles. Taxonomic annotation revealed the predominant microbial taxa associated with wall corrosion, shedding light on their potential impact on structural integrity. Moreover, analyzing the metabolites and pathways present in these microbial communities allows for a thorough understanding of their functional capabilities. Our results revealed that areas with significant damage (dwelling bad door (DBD) and dwelling bad wall (DBW)) exhibited a higher microbial diversity compared to undamaged areas (dwelling good door (DGD) and dwelling good wall (DGW)), with variations in the occurrence of archaeal and bacterial species. The presence of bacteria was found to be connected with impaired function in DBW, whereas changes in the community patterns of Sphingobium and Sphingomonas, as well as a decrease in Cercospora proportion and an increase in Fusarium proportion, were correlated with damage in DBD. Both the Entner–Doudoroff (ED) route and sulfide oxidation processes were observed in both damaged locations (DBD and DBW). However, significant nitrogen-cycling mechanisms, including dissimilatory nitrate reduction to ammonium, were only found in DBW. Furthermore, DBD specifically detected the shift from methyl mercaptan (MMPA) to methyl mercaptan (MeSH). This research highlights the intricate interplay between microbial communities and the physical deterioration of residential structures, emphasizing the importance of understanding microbial ecology in mitigating such issues. Full article

In this study, Acidthiobacillus ferrooxidans LX5 was used as an experimental microbial strain, and differences in biological oxidation between high-sulfur coal and pure pyrite were thoroughly investigated over 18 days in acidic environments with initial pH values of 1.70, 2.00, 2.30, and 2.60. The results showed that the pyrite bio-oxidation efficiency in the coal biological desulfurization system exceeded that in the pure pyrite bio-oxidation system at the same initial pH. The net increase in SO₄²⁻ concentration in the coal biological desulfurization system increased with increasing initial pH values, consistent with the net increasing trend in SO₄²⁻ in the pure pyrite biological oxidation system. The net increase in SO₄²⁻ concentration in the high-sulfur coal biological oxidation system with an initial pH of 2.60 reached 4589.06 mg/L after 18 days. The density of A. ferrooxidans LX5 in both systems increased with increasing initial pH values. With increasing initial pH levels, the inorganic sulfur (pyritic sulfur and sulfate sulfur) removal efficiencies increased in both the coal biological desulfurization and pyrite biological oxidation systems, reaching 88.28% and 9.25%, respectively, at an initial pH of 2.60. The results are of great significance for better understanding the biological desulfurization process of coal. Full article

Agriculture significantly impacts the environment in terms of greenhouse gas emissions, soil nutrient depletion, water consumption, and pollution and waste produced by intensive farming. Wool has great potential and can be a valuable resource for agriculture due to its high nitrogen, carbon, and sulfur content and good water absorption and retention properties, benefiting soil carbon storage and fertility, as well as decreasing the risk of water contamination due to the slow decomposition and nitrogen release. This review aims to provide an overview of bio-based solutions that can benefit agroecosystems as a circular bioeconomy practice. Raw wool and wool hydrolysate are the most common applications, but also wool pellets, wool compost, and wool mats are interesting treatments for plant growing. Waste wool showed positive effects on soil fertility by primarily increasing nitrogen and sulfur content. Improved water retention capacity and microbial activity were also recorded in several studies. The use of wool as mulching is effective for weed control. Attention to the plant species tested aimed at identifying the most promising cultivations in terms of treatment efficiency, possibly lowering environmental impact on the agroecosystem. To eco-design and scale-up processes that strengthen the circular use of wool into widespread practices, further research should be encouraged in conjunction with environmental impact assessments and economic evaluations. Full article

Zinc oxide (ZnO) particles were successfully synthesized through the green method using aloe vera extract and zinc nitrate (1:1). The structure, morphology and properties of the biosynthesized ZnO (bioZnO) particles were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), time of flight secondary ion mass spectrometry (TOF-SIMS) and thermogravimetry (TG). The morphology and the size of ZnO particles were elucidated by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). Then, the ability of bioZnO to activate sulfur curing of natural rubber (NR) was tested and compared to commercial ZnO traditionally used as vulcanization activator. The bioZnO showed similar activity in the vulcanization process to commercial ZnO. NR composites containing bioZnO were pro-ecological in nature and exhibited better mechanical characteristics and durability against thermo-oxidative aging than NR with commonly used micrometric ZnO. Moreover, NR vulcanizates containing bioZnO showed good mechanical properties in dynamic conditions and satisfactory thermal stability. The present research is new and in addition to the analysis of biosynthesized ZnO particles, the effect of the activator in the vulcanization process of the NR elastomer and its influence on the properties of the final products were additionally discussed. Full article