Biomass Conversion and Biorefinery最新文献

The orange juice manufacturing industry generates significant amounts of waste, consisting of peels, seeds, and pulp, which can pose environmental challenges if not properly managed. This study presents a novel two-phase bioprocess that combines enzymatic hydrolysis and bacterial fermentation. The process was developed to convert citrus waste (CW) into high-value products, achieving complete transformation into agronomic biostimulants and biofertilizers. The first phase involves enzymatic hydrolysis, which breaks down the biopolymeric components of CW—typically of low bioavailability—into simple sugars, peptides, and other metabolites with plant biostimulant properties. The second phase focusses on bacterial fermentation using strains naturally adapted to citrus waste, specifically Bacillus subtilis, which exhibits biofertilizer activities such as nitrogen fixation, phytohormone production, and siderophore secretion. The hydrolysed citrus waste served as the fermentation medium for B. subtilis. This bioprocess effectively manages CW by converting it entirely into biostimulant metabolites while generating biomass with biofertilizing functional activity. Beyond providing an environmentally sustainable solution for managing agricultural by-products, it demonstrates the potential of transforming waste into valuable agricultural resources. This approach creates a closed-loop system in line with the principles of the circular economy and offers new opportunities to advance sustainability and efficient resource management in the agricultural sector.

Lignocellulosic biomass, a rich source of carbohydrates, presents the hurdle of lignin and other compounds, such as calcium oxalate (CaOX), that hinder its utilization. Agave and other plants like prickly pear (Opuntia ficus-indica) have evolved traits, including crassulacean acid metabolism (CAM), that allow them to survive extreme heat and drought, including naturally high CaOX levels. This study demonstrated that the CaOx extraction from Agave tequilana Weber bagasse and Opuntia ficus-indica, followed by protic ionic liquid (PIL) pretreatment with ethanolamine acetate ([EOA][OAc]), significantly improved the chemical and structural properties and the enzymatic saccharification efficiency of the biomass. This enhancement was demonstrated as a notable increase in sugar concentrations, especially for Agave, which exhibited a 3.9-fold rise in monosaccharides. Improved glucan and xylan conversions were obtained in the CaOx-extracted samples. This effect was more evident in the pretreated samples at elevated temperatures (160 °C), attributable to the breakdown of biomass structure and higher accessibility of the enzymes to the secondary cell wall region. Furthermore, a strong correlation between lignin reduction and glucose release was identified, with the benefits being more pronounced in CaOx-extracted biomass. Thus, processing feedstocks with a naturally high CaOx content using this approach (CaOx extraction followed by PIL pretreatment) could effectively enhance the bioconversion potential, representing a breakthrough in biomass processing for biorefinery applications of CAM plants.

Despite the immense application potential and growing demand for keratin across the world, extraction of keratin from waste wool in an eco-friendly manner is one of the major hurdles for mass-scale valorization of undervalued and waste wool. This research presents, for the first time, the isolation of a keratin-degrading bacterial strain (AR 31), identified as Paenibacillus wulumuqiensis, sourced from poultry waste. An optimized protocol yielding 14.02 mg/ml soluble keratin by ~ 56% degradation of waste wool (5% concentration) with AR31 (5% inoculum) in a nitrogen-free minimal salt medium (pH-8) at 40 °C in 8 days was developed. The extracted keratin hydrolysate was analyzed for amino acid content, molecular size, functional groups, crystallinity, surface morphology and thermal stability. The study further explored the application of keratin hydrolysate in biofilm production by combining varying doses of keratin hydrolysate with polyvinyl alcohol (PVA), microcrystalline cellulose (MCC), and glycerin, optimizing the formulation using a Box–Behnken model. Twenty-seven biofilms with varied properties were developed, showing differences in areal density (121–551 g/m²), tensile load (4.2–17.4 N), tensile strength (0.32–1.16 KN/m), elongation (38.6–92 mm), breaking length (0.123–0.504 km), and crease recovery (61-154⁰). These biofilms showed differential behavior for the development of a zone potency index for Staphylococcus aureus and Escherichia coli. Principal component analysis indicated a positive effect of keratin on biofilm’s antimicrobial properties. These findings suggest that utilizing waste wool for keratin extraction not only provides an eco-friendly solution but also offers potential economic benefits to Indian sheep farmers and wool industries by turning an undervalued byproduct into a valuable resource.

The transition from mineral to OMFs in agriculture is driven by the need to address climate change, resource limitations, and stable crop production. This study focuses on developing and testing organo-mineral micronutrient fertilizers for maize (Zea mays L.), using biomass as a carrier for micronutrients. Fertilizers containing zinc (1 kg/ha), manganese (0.4 kg/ha) and copper (0.2 kg/ha) were tested at 100, 150 and 200% doses for two years. Crop yield, quality, and multi-elemental composition (ICP-OES) were assessed and compared to traditional inorganic fertilizers to assess micronutrient bioavailability. Maize treated with OMFs showed a 10% increase in micronutrient content compared to commercial fertilizers. The best results were observed at 100% and 150% doses, with higher doses reducing micronutrient transfer. Biofortified maize grains, enriched with zinc, manganese, and copper, offer a potential solution to address micronutrient deficiencies in food and feed. The fertilizers are cost-effective and environmentally sustainable, providing an effective way to recycle biomass and improve crop nutrition. They contribute to addressing global micronutrient deficiencies and support more sustainable agricultural practices.

This study explores the feasibility of using biochar derived from discarded oak mushroom logs (OMB) for the remove of cadmium (Cd) from industrial wastewater. OMB was produced through pyrolysis of the oak mushroom logs at temperatures of 500, 600, and 700 °C, and its physicochemical properties were analyzed. Subsequently, batch adsorption experiments were conducted to evaluate the effects of pyrolysis temperature, reaction time, and Cd concentration on Cd adsorption efficiency. Pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models were used to investigate the adsorption kinetics, with Langmuir, Freundlich, and Dubinin–Radushkevich isotherm models were applied to fit the equilibrium adsorption data. Among the tested biochars, OMB–500 demonstrated the highest Cd adsorption capacity of 41.07 mg/g. Kinetic analysis indicated that the adsorption was predominantly governed by chemisorption. Response surface methodology (RSM) was employed to optimize the adsorption conditions, considering pH, biochar dose, reaction time, and ionic strength as the key environmental variables. Spectroscopic and experimental investigations revealed that Cd adsorption occurred via surface complexation and ion exchange interactions with oxygen-containing functional groups. These findings suggest that OMB is a cost-effective and sustainable alternative to commercial adsorbents for Cd removal from wastewater.

Lignocellulosic biomass is a globally abundant renewable resource with diverse applications in energy and chemical production. It can be directly combusted or processed into solid fuels, bio-oil, biochar, and various value-added chemicals. However, plant growth inherently accumulates inorganic matter containing alkali/alkaline earth metals (AAEMs), transition metals, P, S, Cl, and other elements. These inorganic constituents frequently pose challenges to downstream processing, affecting product quality, yield, and equipment reliability. This review systematically evaluates the critical role of lignocellulosic biomass de-ashing technology in enabling sustainable bioresource utilization. It begins by establishing the necessity of biomass energy development and the technical requirements for ash removal in producing high-value products. Subsequent sections provide a comprehensive analysis of biomass structure-property relationships, state-of-the-art de-ashing methodologies (including water, inorganic acid, and organic acid treatments), and advanced analytical techniques for ash characterization. Particular emphasis is placed on mechanistic insights into ash-mineral interactions and process optimization strategies. The concluding section synthesizes recent advancements in de-ashing technologies, highlighting their potential to enhance biomass conversion efficiency and reduce operational constraints. Future research directions are proposed to address remaining challenges, including improving process scalability, minimizing environmental impact, and developing cost-effective integrated systems. By consolidating current knowledge and identifying innovation opportunities, this review aims to facilitate the industrial adoption of de-ashing processes, thereby promoting lignocellulosic biomass as a viable feedstock for sustainable bioeconomy development.

A biorefinery can operate with various plant materials as feed stock, (in contrast to fossil-based oil refineries). It has been defined by the International Energy Agency, Task 42, as “the sustainable processing of biomass into a spectrum of marketable bio-based products (chemicals, materials) and bioenergy (biofuels, power, heat)”. One of the challenges in operating large-scale facilities is that the biomass supply-chain is dependent on reliable availability of appropriate raw materials, continuous at all seasons while maintaining a high quality. Currently, various types of biorefineries are frequently discussed e.g. sugar-based bio refineries or thermochemical bio refineries; however, both strategies are dependent on solid and well-known characteristics of the biomass regarding their chemical and biological processes. A woody biomass supply-chain, from forest residues are influenced by factors such as: tree species, growth conditions and occasionally forest fertilization but how these factors influence the composition of the biomass are poorly understood. In this study, we used field experiments in Sweden where poplar, hybrid aspen, birch, Scots pine and Norway spruce were grown at various sites across a latitude gradient and treated with fertilizers within each site – making direct comparisons between tree species and fertilization treatment possible. The presented results demonstrate that there are minor differences in biomass composition i.e. cellulose, lignin, hemicelluloses (mannan, xylan, galactan, arabinan) and oil content, between forest site and fertilization treatment. Moreover, our results demonstrate that geographic location (northern or southern latitudes) has limited effect on the chemical composition In addition, our results demonstrate that deciduous tree species (poplar, birch and hybrid aspen) have similar biomass composition but that the compositions are different to coniferous species. For an industrial context, our results suggest that if biomasses are a blend of coniferous and deciduous tree species, the process design must be adjusted to reach optimal usage of the lignocellulosic feedstock in full-scale industrial processes.

The potential of a novel biobased sorbent, Lagenaria breviflora seed husk, for the removal of Ni²⁺ ions from aqueous solutions was investigated. The research examined the effectiveness of the bio-sorbent in both its unmodified form (UMLB) and after thermal modification (TMLB). The thermal modification involved carbonizing the seed husk at 550 °C, followed by washing with H₃PO₄ and deionized water. The adsorbents were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Brunauer, Emmett, and Teller (BET) surface area analysis. FT-IR results indicated that broad bands around 3000–3600 cm⁻¹, present in UMLB, diminished in TMLB due to the heat applied during thermal modification. Peak shifts from 2113 to 2102 cm⁻¹ and 1581 to 1564 cm⁻¹ suggested effective Ni(II) ion binding to both adsorbents. SEM analysis revealed that the thermal modification led to a more defined porous structure in TMLB, although some pore blockage was observed, potentially explaining the lower adsorption capacity of TMLB (0.685 mg/g) compared to UMLB (1.419 mg/g). The adsorption process was found to be pH-dependent, with an optimal pH of 8.0 for maximum Ni(II) ion removal. BET analysis revealed that thermal modification significantly increased the surface area of TMLB (407.286 m²/g) compared to UMLB (349.585 m²/g), though surface chemistry played a more critical role in adsorption performance. The adsorption isotherm studies showed that the Langmuir model best fit the experimental data, with R² – values of 0.9719 and 0.9736 for UMLB and TMLB respectively, indicating monolayer adsorption on a homogeneous surface. Kinetic studies favored the pseudo-second-order model, suggesting that the adsorption process was controlled by chemisorption. These findings suggest that Lagenaria breviflora seed husk, particularly in its unmodified form, is a promising bio-sorbent for the removal of Ni(II) ions from contaminated water.

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Microbial fuel cells (MFCs) have emerged as a sustainable technology for simultaneous wastewater treatment, electricity generation, and water desalination. In this study, a ceramic membrane incorporating bamboo leaf ash (BLA) was developed and integrated into an MFC. The primary objective was to optimize the amount of BLA for synthesis of membranes for achieving effective treatment of reverse osmosis (RO) reject water in MFC. The BLA-based ceramic membrane (20%) exhibiting a surface area of 20.364 m²/g, a pore volume of 0.03 cc/g, and a pore radius of 12.259 Å. Compared to MFC 2, whose pure ceramic membrane showed a 46% reduction in conductivity and a power output of 0.85 W/m², MFC 1 equipped with a 20% BLA membrane demonstrated a markedly higher 89% reduction in conductivity and an enhanced power density of 1.25 W/m². These enhancements are attributed to the increased porosity and surface area of BLA-based ceramic membrane, which facilitated improved ion transport and microbial activity. Overall, the results demonstrate that the addition of a proportion of 20% BLA to ceramic membranes offers a cost-effective and environmentally friendly solution for advancing MFC performance. This study provides a novel approach to membrane fabrication using biomass waste, contributing to sustainable water treatment and clean energy generation.

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The co-pyrolysis characteristics of low-rank coal and biomass were systematically investigated via thermo-gravimetric analysis and Fourier transform infrared spectroscopy, complemented by polycyclic aromatic hydrocarbons emission quantification using gas chromatography-mass spectrometry. For the first time, the study revealed a novel synergetic compensation mechanism between activation energy and pre-exponential factor during co-pyrolysis. Thermogravimetry (TG) analysis identified three distinct pyrolysis stages, where the activation energy (Ea) and pre-exponential factor (A) showed synchronous trends (r²>0.95), indicating kinetic compensation. Specifically, herb residue addition reduced the overall activation energy of coal pyrolysis by 12.5 kJ⋅mol^− 1, enhancing reaction activity. Real-time FTIR monitoring confirmed that CO₂, CO, and CH₄ were the dominant gaseous products, with H₂O and HCl emissions closely correlated with differential thermogravimetry (DTG) peaks. The addition of dregs to increase the escape of combustible gases, which is conducive to the overflow of pyrolysis gas to the combustion chamber at the end of the combustion of premixed combustion, diffusion and mixing conditions are greatly improved. Notably, the co-pyrolysis process achieved a 21.01% reduction in total PAHs emission (from 126.58 to 99.98 µg/g) compared to pure coal pyrolysis, primarily attributed to the suppression of PAHs via hydrogen donation from biomass. This work provides a green strategy for upgrading low-rank coal while minimizing environmental risks.