Biomass Conversion and Biorefinery最新文献

Natural or man-made catastrophes, such as asteroid strikes, super-volcano eruptions, or nuclear war, could create environments with low sunlight and temperatures, severely disrupting agriculture and requiring alternative food and energy sources. Lignocellulosic biomass, rich in cellulose, offers potential as an energy source for human survival. Biological agents can effectively break down this biomass and increase the efficiency of enzymatic conversion of cellulose to glucose, a biofuel precursor. In this study, we asked whether single or sequential inoculation with two white-rot fungi, oyster (Pleurotus ostreatus) and shiitake (Lentinula edodes) mushrooms, could be used to pretreat willow (Salix spp.) biomass to increase saccharification efficiency without any supplements at 15 °C, mimicking a post-catastrophic environment. To answer this question, mushroom-pretreated biomass was incubated with the Cellic CTec2 enzyme to produce glucose. Overall, the cellulose [44–60% w/w; dry basis (db)] and lignin content (21 to 25%; db) of the pretreated willow did not change compared to untreated willow. However, sequential inoculation of oyster and shiitake, regardless of the inoculation order, enhanced saccharification efficiency yielding more glucose (28–31%) compared to untreated willow (14%) after enzymatic treatment. Based on our data, one kilogram of willow, after undergoing sequential fungal inoculations and enzymatic treatment, would yield 311 g of glucose suitable for biofuel or food production. Additionally, the mushroom fruiting bodies derived from willow provide 12%, 13%, and 2% of the daily carbohydrate, protein, and fat requirements, respectively, for a moderately active person. To achieve a balanced macronutrient supply, additional sources such as single-cell microorganisms, edible insects, and small-scale ruminants can be incorporated.

CO₂-assisted co-gasification has emerged as a promising thermochemical technology for sustainable energy production and waste management. This review explores the synergistic effects of combining various feedstocks, including biomass, coal, plastics, and mixed wastes, in CO2-assisted co-gasification processes. By utilizing CO₂ as a gasifying agent, this approach offers dual benefits: reducing greenhouse gas emissions and enhancing syngas yields with improved energy efficiency. The literature reviewed indicates that synergistic interactions between feedstocks can lead to notable improvements in key performance metrics such as syngas yields, carbon conversion rates, process reactivity, and hydrogen-to-carbon ratios, compared to the gasification of individual feedstocks. The addition of CO₂ optimizes gasification kinetics, allowing for a reduction in the formation of harmful tars and char. Advanced reactor designs, catalysts, and process optimization techniques have further improved performance, with some studies reporting calorific value enhancements of up to 10 MJ/kg in selected cases, while minimizing environmental impacts. Despite these advantages, challenges remain in terms of feedstock variability, scalability, catalyst deactivation, and process energy requirements, which may limit near-term industrial adoption. This review provides comprehensive insights into the technological advancements and prospects of CO₂-assisted co-gasification, emphasizing its potential for biofuel production, chemical synthesis, and carbon-neutral energy systems. Future research focused on advanced catalysts and process integration will be crucial for bridging the gap from laboratory-scale success to industrial-scale application.

Industrial composition is one of the fundamental properties of biochar. In conventional near-infrared (NIR) spectroscopy technology for rapid, noninvasive analysis, the NIR spectral signal may vary with the variation of the spectrometer. Effective calibration transfer is essential for improving the applicability of NIR models in proximate analysis of biochar. In this study, 85 copyrolysis biochar samples (animal manures and crop residues, 300–700 °C) were prepared. Optimized NIR PLS models with high accuracy (high correlation coefficient of prediction (R²_P), low root mean square error of prediction (RMSEP), and high ratio of prediction to deviation (RPD)) based on three different NIR spectrometers were developed to quantify the contents of ash (>0.86, <2.31, and >2.6), volatile matter (VM) (>0.97, <2.24, and >5.0), and fixed carbon (FC) (>0.87, <2.55, and >2.7) in biochar. Four calibration model transfer approaches with the spectrometers were tested using the chemometric algorithms of spectral subtraction correction (SSC), direct standardization (DS), piecewise direct standardization (PDS), and slope/bias correction (SBC). In terms of accuracy, the 3 spectrometers exhibited equivalent performance. The results were comparable to those obtained by the original NIR spectral models when the models were transferred across the three NIR spectrometers using a suitable method (for RMSEP value increases (%), ash: <47.5%, VM: <85.0%, and FC: <-26.7%). Generally, the orders of accuracy of the optimized NIR PLS models and the transfer models were the same, i.e., VM > FC and ash. The transfer performance of the models varied with different industrial compositions, transfer methods and NIR instruments.

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The olive oil production process generates significant quantities of waste, including value-added substances such as residual oil, carbohydrates, and phenolic compounds. This study presents a scalable laboratory process for optimizing the extraction of phenolic compounds from olive mill waste derived from a two-phase olive mill. The proposed process combines acidic hydrolysis with ultrafiltration. The acidic hydrolysis was optimized using a full factorial design followed by a central composite design to identify key operational parameters and determine the conditions for maximum extraction efficiency. The optimal conditions involved the addition of 304 mL of water to 50 g of waste (solid-liquid ratio: 0.164), 3.5 mL of H₂SO₄, and continuous stirring at 70 °C for 60 min. The phenolic-rich aqueous solution was then processed through a series of ultrafiltration stages using membranes with nominal molecular weight cut-offs of 30 kDa, 10 kDa, and 5 kDa. Phenolic compound retention rates were 15.1% for the 30 kDa membrane, 33.4% for the 10 kDa membrane, and 73.7% for the 5 kDa membrane. In terms of sugar reduction, the 5 kDa membrane achieved a 90.3% decrease in sugar concentration in the filtrate corresponding to a 99.1% reduction relative to the original waste. The 10 kDa permeate offers the optimal balance, featuring a high TPC/TOC ratio and a low SUG/TOC ratio, indicating a phenolic-rich solution with reduced sugar content. This study demonstrates a practical and efficient approach for recovering phenolic compounds from OMW, highlighting its potential for sustainable waste valorization and production of high-value bioactive compounds.

Biomass-based fuels are regarded as greener, renewable, and sustainable alternatives to fossil fuels, contributing to a reduced carbon footprint. However, the direct use of biomass for fuel may disrupt food and oxygen supplies. Agricultural residues, such as rice straw (RS), a by-product of cereal cultivation, are an underutilised resource for bio-oil production. Rice straw conversion into bio-oil faces challenges, including high water content and oxygenated compounds, which reduce fuel quality. The co-pyrolysis of rice straw (RS) with waste plastics, such as polypropylene (PP), offers a viable solution for improving the yield and quality of biochar. This study investigated the catalytic co-pyrolysis of RS and PP using an economical cement catalyst in a fixed-bed reactor. Under optimal process conditions, a 1:1 blend ratio (3 g: 3 g) yielded 55.7 wt% liquid fuels, 23.5 wt% gases, and 20.8 wt% biochar. Co-feeding PP enhanced the liquid fuel yield by 15.6% and reduced the biochar yield by 7.3%, whereas an RS: PP ratio of 1:3 further increased the liquid yield to 72.2 wt% and enriched the gas phase with hydrocarbons (CH₄, C₂H₄, C₂H₆). The cement during co-pyrolysis significantly improved the gas yield to 28.4 wt% and reduced water content in bio-oil from 27% to nearly zero. The pyrolysis of rice straw alone generated 88.91 mL/g of carbon dioxide, whereas co-pyrolysis with a 3:1 polypropylene-rice straw mixture reduced emissions to 21.20 mL/g. This significant reduction highlights co-pyrolysis as an effective strategy for minimizing greenhouse gas emissions and reduction in carbon footprints, promoting sustainable waste management and eco-friendly bio-oil production.These findings demonstrate the potential of catalytic co-pyrolysis for converting agricultural residues and plastic waste into high-quality, sustainable fuels, providing a pathway for waste valorization and energy production.

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This study compares the yield and characteristics of cellulose-rich fibre extracted from waste banana pseudostem through three distinct methods: mechanical extraction, anaerobic digestion (retting), and bio-augmentation with a xylanolytic and pectinolytic Bacillus strains. Mechanical extraction produced the highest fibre yield of 37.6% (on wet w/w basis), with ~ 44.2% cellulose content, but generated substantial residual biomass and was power intensive (6–8 kWh/100 kg). Anaerobic retting produced lower fibre yield (26.1%) with moderate cellulose content (49.4%), but required longer processing time (17 to 20 days) and with high water consumption (40–45 L/kg). Meanwhile, bio-augmentation was more attractive, yielding 30.5% fibre with highest cellulose content (58.8%), within a short recovery (8–10 days), at a lower power (4 kWh/100 kg) and water consumption (20–25 L/kg). SEM and contact-angle analyses confirmed improved surface properties and hydrophilicity of the bio-augmented fibres. Aligned with biorefinery principles, this work demonstrates that bio-augmentation enhances the selective biochemical conversion of lignocellulosic biomass while minimising resource inputs and environmental burden. The high-purity cellulose fibres obtained through this process represent a valuable intermediate for downstream biorefinery pathways, including nanocellulose, bio-composites, and other high-value materials, thereby supporting sustainable biomass valorisation within circular bioeconomy frameworks.

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Chemical treatment with alkalis is one method of improving the physical, chemical, thermal and mechanical properties of plant fibers by increasing their tensile strength and modulus of elasticity while improving their adhesion to the matrix and reducing their water absorption in composite reinforcement. This study seeks to improve the physical, mechanical, and chemical properties of RC (Rhecktophyllum camerunense) raw fibers using 5% sodium hydroxide (NaOH) concentration for potential composite reinforcement. The fibers were characterized physically, mechanically, thermally and chemically in accordance with standard norms and protocols. The results show that the water absorption and density of RC raw fibers decreased by 45.57% and increased by 36.96%, respectively, with the 5% NaOH treatment. Morphological SEM analysis showed that RC5 fibers had a smooth, clear surface compared with RC raw fibers. The crystallinity index of the RC fibers, initially 47.8%, increased to 61.3% after alkaline treatment. Similarly, the thermal stability temperature rose from 220 °C to 250 °C, demonstrating the effectiveness of the alkaline treatment. The RC5 fibers had the best mechanical properties in fiber traction (strength at break (121.3 MPa), elastic modulus (2.1 GPa), and strain (34.1%). The Weibull model two-parameter analysis allowed us to quantify the degree of dispersion in diameters and the mechanical properties of each fiber category. The fibers showed low dispersion in diameters and mechanical properties, and RC5 was found to be better. Compared to some fibers in the literature, RC5 fibers are recommended for reinforcing polymer matrices, particularly ceramic matrices such as plaster.

Seaweeds have emerged as one of the most commercially important marine resource that harbours industrially relevant bioactive compounds such as polysaccharides, proteins, dietary fibres, minerals, pigments, polyphenolic compounds etc. This in turn has fostered an extensive research on extraction of seaweed based high value compounds. Conventional methods which were popularly used for extraction of seaweed bioactive compounds are being replaced by advanced “greener” techniques such as supercritical fluid, eutectic solvents, microwave, enzymatic, ultrasound assisted extraction etc. Among all sustainable techniques, ultrasound assisted extraction (UAE) is the most economical method for seaweed biovalorization. Employing ultrasonic waves aids in effective disruption of seaweed cell walls facilitating higher extraction rate in short period of time. Judicious integration of UAE with other efficient extraction systems are reported to yield several high value added products such as phenolic compounds, hydrocolloids, biochar, hydrochar, fertilizers, seaweed based biostimulants, biofuels, feeds etc. and hence can pave way towards establishment of successful seaweed biorefineries. The core aim of the present review is to give a comprehensive understanding of the principles and application of UAE in seaweed biovalorization by enhancing the recovery of different biomolecules when used as a major process or as a pre or post treatment step. Furthermore, the advantages, challenges and drawbacks of UAE in comparison with other extraction processes is also discussed in detail.

This study reports for the first time the use of Fraxinus americana seeds (FAS) as biosorbent for the removal of aniline blue (AB) dye from natural water and textile effluents, demonstrating its potential as a cost-effective and sustainable alternative for water treatment. An experimental design was used to identify the optimal variables for AB removal. These variables were a biosorbent dose of 2.5 g L^− 1, and solution pH = 3. These conditions resulted in an experimental biosorption capacity of 18.4 mg g^− 1 and a removal efficiency of 91.8%. To understand the biosorption mechanism of AB on FAS, different characterization techniques were used, including scanning electron microscopy, Fourier transform spectroscopy using the attenuated total reflectance technique, Boehm titration, and the determination of pH at point of zero charge. Biosorption kinetics showed that FAS saturation was reached at 30 min using initial AB concentration of 50 mg L^− 1, while 60 min were necessary for initial AB concentrations of 100 and 200 mg L^− 1. Pseudo first order, pseudo second order, Elovich, and intraparticle diffusion models were used to fit the biosorption kinetic data, while the Langmuir, Freundlich, and Sips models were applied to correlate the biosorption isotherms. The experimental values were best fitted to the pseudo-second order model. The results obtained from the biosorption isotherms fit better to the Langmuir isotherm model, indicating a maximum theoretical biosorption capacity of 40.3 mg L^− 1. This value represents the model-predicted capacity under monolayer adsorption conditions. Dye biosorption was thermodynamically spontaneous and an exothermic monolayer process where hydrogen bonding and electrostatic interactions played a relevant role. The application of the biosorbent to real samples showed a removal efficiency of up to 93.6%. These results are promising because the biosorbent was obtained from waste that is widely available in nature and does not require physical or chemical treatment for effective AB removal. This study contributes to the valorization of FAS residues for water and wastewater treatment within the framework of a circular economic model.