Biomass Conversion and Biorefinery最新文献

The present study reports the recovery of lignin from combined pomegranate and banana peels through the process of valorisation with a binary deep eutectic solvent (DES) system comprising of choline chloride (CC) and oxalic acid (OA). The valorisation process was further optimized by Response Surface Methodology-based Central Composite Design, yielding an enhanced lignin recovery of 52.75 ± 0.55%. The interactions between the valorisation process variables and their effect on lignin recovery was analysed by developing a predictive quadratic model. Temperature and time had a profound influence on the valorisation process. The purity of the lignin was measured as 85.70 ± 1.62%. UV-Visible and Fourier Transform Infrared Spectroscopy confirmed the presence of the major functional groups of lignin. Field Emission Scanning Electron Microscopy images revealed agglomerated and spherical lignin structure; whereas X-Ray diffraction analysis identified its amorphous nature. Energy Dispersive X-ray Spectroscopy showed its higher and lower amounts of carbon and sulphur content compared to the commercially available lignin. ¹H Nuclear Magnetic Resonance Spectroscopy (NMR) depicted characteristic signals for methoxy, aliphatic, and aromatic protons of the lignin. The major interunit linkages of lignin along with their relative contents were identified by 2D Heteronuclear Single Quantum Coherence NMR spectra. The thermal stability of the lignin was confirmed by Differential Scanning Calorimetry measuring glass transition temperature of 88.75 ℃. The recovered lignin demonstrated higher antioxidant and antibacterial activities compared to commercial lignin. Overall, the RSM method was efficient in optimizing mixed fruit waste valorisation with CC-OA DES, resulting an enhanced lignin yield and purity.

Pyrolysis technology, as a biomass resource utilization technique, demonstrates broad application prospects due to its ability to efficiently convert biomass into high-value-added products such as biochar. However, current research has predominantly focused on single types of biomass feedstocks. This study proposes the hypothesis that the biochar production process via pyrolysis is primarily influenced by five organic components present in the biomass: cellulose, hemicellulose, lignin, protein, and lipids. Based on these organic components, this study investigated the thermal decomposition reaction mechanism of biochar preparation and constructed a general empirical mathematical model under low-temperature and slow heating conditions (300 °C, heating rate of 5 °C per minute, residence time of 150 min). The results indicate a high degree of consistency between the model’s predicted values and experimental data, with all parameters exhibiting an R² value exceeding 99%. By applying a response surface optimization method under specific constraint conditions, the optimal component ratios were determined to be: cellulose 11.4%, hemicellulose 13.1%, lignin 28.7%, protein 13.2%, and lipids 33.6%. In actual mixed experiments, the synergistic effect between protein and lignocellulose promoted the structural formation of the biochar, demonstrating that this component-based empirical framework provides a reliable predictive tool for producing biochar under target low-temperature, slow-pyrolysis conditions.

Forestry industries generate significant volumes of bark as an inherent by-product of timber processing, yet its utilization remains largely confined to low-value combustion despite its distinct chemical potential. In Pinaceae species, bark presents a composition enriched in extractives, lignin, and suberin, together with limited accessibility of structural polysaccharides, which collectively constrain conventional carbohydrate-driven valorization routes and require alternative processing strategies. This review examines Pinaceae bark as a dedicated feedstock for forest biorefineries by explicitly linking compositional features with fractionation strategies and downstream conversion pathways within a systems-oriented framework. Fractionation approaches, including conventional hydroalcoholic extraction, emerging solvent systems, and process intensification techniques, are critically assessed in terms of selectivity, scalability, and mass transfer limitations associated with bark structure. Downstream conversion routes are comparatively evaluated across thermochemical, hydrothermal, biochemical, and material-oriented pathways, highlighting the dominant suitability of lignin-rich residues for thermochemical processing and the conditional feasibility of biochemical conversion under intensified pretreatment schemes. Order-of-magnitude mass and energy considerations are incorporated to elucidate process interdependencies, trade-offs, and the role of internal energy recovery, providing a quantitative basis for assessing integrated configurations. The analysis supports a staged processing strategy in which early extractive recovery is followed by the conversion of lignin- and suberin-rich fractions, establishing clear links between upstream fractionation and downstream performance. Overall, this work provides a structured and quantitatively informed perspective that advances beyond descriptive analyses by integrating compositional constraints, process design considerations, and system-level performance, thereby supporting the development of robust and value-oriented biorefinery concepts for Pinaceae bark.

Sewage sludge represents a primary organic waste stream in wastewater treatment plants, where anaerobic digestion enables biomethane recovery; however, the initial digestion phase is frequently rate-limited by complex organic hydrolysis. This study evaluated the potential of enzymes produced by an autochthonous cellulolytic bacterial consortium isolated from digested sludge to enhance biomethane production, comparing free and activated carbon-immobilized forms against commercial cellulolytic enzymes (Cellic CTec2). Non-immobilized autochthonous enzymes increased biomethane yield by up to 21.7% relative to untreated sludge, achieving performance comparable to commercial preparations (p > 0.05). Mechanistically, free enzymes accelerated early-stage hydrolysis during the initial 3–5 days, whereas carrier-immobilized enzymes exhibited a controlled-release kinetic profile extending hydrolytic activity up to day 7 while offering protection against endogenous proteolytic degradation. Additionally, activated carbon carrier supplementation facilitated the adsorption of inhibitory extracellular polymeric substances (EPS) specifically protein (PN) and polysaccharide (PS) fractions, reducing mass transfer resistance and stabilizing digestion kinetics. Although net cellulose degradation remained unvaried across treatments due to rapid baseline microbial turnover, enzymatic addition shortened effective digestion lag times. Overall, autochthonous enzyme harvesting provides an effective, low-input strategy to enhance anaerobic digestion efficiency without relying on costly external enzyme inputs.

Industrial processing of Prunus species, including apricot, peach, plum, cherry, almonds, and nectarine, generates substantial quantities of peels, pomace, stones, shells, and kernels that remain underexploited despite their richness in bioactive and functional constituents, including oils, proteins, polyphenols, anthocyanins, carotenoids, tocopherols, dietary fibers, and lignocellulosic polymers. These residues represent promising renewable feedstocks for recovering value-added compounds and developing functional ingredients, nutraceuticals, cosmetic formulations, biomaterials, adsorbents, and bioenergy. However, effective valorization requires matrix-specific strategies that optimize extraction efficiency and selectivity, preserve target compound functionality, and address technological and economic constraints associated with industrial scale-up. This review critically examines the composition and valorization potential of major Prunus processing by-products and evaluates conventional and emerging extraction technologies for the recovery of high-value bioactive and functional compounds. Particular emphasis is placed on extraction mechanisms, selectivity, matrix-specific behavior, target compound stability, solvent sustainability, process intensification, and scale-up feasibility. The review further explores integrated biorefinery strategies for the sequential recovery of valuable fractions, including lipids, proteins, polyphenols, fibers and other functional components, from a single biomass stream. Key challenges, including raw material variability, detoxification of cyanogenic glycosides, solvent recovery, compound stability, process standardization, regulatory compliance, and techno-economic feasibility, are critically assessed. Addressing these barriers requires hybrid extraction platforms, life cycle assessment, techno-economic analysis, pilot-scale validation, AI-assisted process optimization, and continuous biorefinery systems. Overall, this review highlights pathways to transform Prunus processing residues into value-added bioproducts and to facilitate their industrial integration within a circular bioeconomy.

Sugarcane bagasse is an abundant lignocellulosic residue with a high hemicellulose content, making it suitable for furfural production. This study investigates furfural formation from delignified bagasse via bench-scale pyrolysis and evaluates thermal decomposition kinetics using TGA at multiple heating rates (5, 10, and 15 K min^− 1). Furfural was extracted from the pyrolysis condensates and characterized using FTIR and GC-MS. Isoconversional methods (KAS, OFW, Starink, Friedman) revealed average activation energies of 144–151 kJ mol^− 1, varying across conversion (α) ranges, reflecting multi-step devolatilization and char formation. The crude bio-oil contained significant amounts of organic acids that promoted furfural instability. Therefore, stabilization studies were performed by alcohol-assisted reactive distillation using a solid-acid catalyst to produce esterified acids. The stabilized bio-oil had a reduced moisture content of 2.5 wt%, improved pH of 6.6, and HHV of 25.7 MJ kg^− 1. The combined kinetic and upgrading data demonstrate a viable pathway for producing and stabilizing furfural from bagasse, and recommendations for scale-up and analytical validation are provided.

The cocoa bean hull is one of the main residues generated by the cocoa industry, accounting for approximately 10–20% of the total bean weight and resulting in large amounts of discarded biomass, which is rich in valuable components, including phenolic compounds (PC) and cellulose. This study aimed to valorize cocoa bean hull through the extraction of PC and cellulose using an eco-friendly approach and to propose the utilization of this residue by integrated processes resulting in value-added biobased products. For PC extraction, raw cocoa bean hulls (RCBH) and autoclave pretreated cocoa hulls (PTH) were subjected to a heat-assisted extraction (HAE) with water and to an ultrasound-assisted extraction (UAE) with water or 50% ethanol, while cellulose-rich materials were obtained by peracetic acid treatment. HAE applied to RCBH provided the highest PC content (16.67 mg GAE/g db) and antioxidant capacity, reaching 48 mg TE/g db by DPPH and 156 mg TE/g db by ABTS. Peracetic acid treatment promoted substantial delignification, increasing cellulose contents from 25.06 to 40.48% in the starting materials to 46.87–69.20% in the corresponding cellulose-rich fractions. The extracted materials exhibited increased crystallinity, reaching 74.4%. Overall, the results support further investigation of cocoa bean hull as a feedstock for integrated recovery of PC and cellulose, although process scalability, environmental impacts, economic feasibility, and valorization of the remaining fractions require further evaluation.

Global mushroom production exceeds 12 million tonnes annually which generates an estimated 60–70 million tonnes of spent mushroom substrate (SMS) as a lignocellulosic byproduct. SMS retains 30–50% of cellulose, 10–25% of hemicellulose, 15–30% of lignin, and residual enzyme activity (cellulase 0.1–2.5 U/g; laccase 10–200 U/g) which makes it valuable for agriculture, bioenergy, enzyme recovery and biomaterials. Current valorization yields include biogas of 150–400 mL/g VS, bioethanol of 50–200 g/kg dry SMS, and crop yield increases of 10–40%. Yet most advanced pathways remain at TRL 3–6 due to their feedstock variability, absence of standardized characterization, and lack of techno-economic and life-cycle validations. Thus, this review critically synthesizes agricultural, bioenergy, enzymatic, and material valorization routes for SMS identification for commercialization challenges particularly missing techno-economic analysis (TEA), limited life-cycle assessment (LCA) data, and regulatory ambiguity as the primary constraints to scale-up. We propose an integrated biorefinery framework which combines omics-guided process design its decentralized processing and maintaining the standardized quality control to accelerate SMS transition from waste to platform biomass in the circular bioeconomy.

Hemicellulose valorisation in integrated biorefineries can enable circular-economy conversion of agricultural wastes into biodegradable plastics. This study optimised xylose release from rice husk under green-chemistry-oriented conditions and evaluated the resulting hydrolysate for poly(3-hydroxybutyrate) (PHB) production by Priestia megaterium. A preliminary screening evaluated multiple organic acids (formic acid (FA), oxalic acid, citric acid, and acetic acid) each paired with two mineral acids (HCl or H₂SO₄) to identify the most effective organic–inorganic combination; this selected acid pair (FA-HCl) was then optimised using a 3³ response surface design at 121 °C (solid-to-liquid ratio 1:10) to maximise xylose recovery while minimising degradation products (furfural and 5-hydroxymethylfurfural (5-HMF)). The desirability optimum (36.26% ODW (oven dry weight) FA, 4.49% ODW HCl, 128.97 min) was experimentally validated, achieving 77.78% xylose recovery with < 1% sugar degradation. After neutralisation and clarification, the 50% (v/v) hydrolysate provided the best balance between carbon availability and inhibitory pressure, yielding a maximum PHB content of 10% (w/w, DCW (dry cell weight)) at 24 h, followed by partial polymer turnover at 48 h. The production of PHB was confirmed by both FTIR and GC–MS analyses. These results demonstrate a dual-acid pretreatment that validates high xylose recovery with minimal furan formation and subsequent PHB synthesis from a local lignocellulosic waste stream by limited conditioning. However, further work is required to improve PHB yield, although these findings represent a promising starting point for the valorisation of non-conventional sugar sources.

The main objective of this study was to synthesize activated carbon derived from Scenedesmus sp. microalgal biomass cultivated in agro-industrial wastewater. The microalgae were initially cultivated in BG11 medium and progressively scaled up from 250 mL to 10 L, and subsequently cultivated in a 40 L photobioreactor. During this stage, the remediation capacity was evaluated, achieving removal efficiencies of 95.1% for ammoniacal nitrogen, 80.2% for orthophosphate phosphorus, and 81.9% for chemical oxygen demand (COD). The optimal synthesis of the activated carbon was achieved through chemical activation using 60% H₃PO₄ at a 1:3 precursor-to-activating agent ratio, followed by physical activation via carbonization under an inert nitrogen atmosphere at 300 °C, based on thermogravimetric analysis (TGA) results. The resulting carbon exhibited a porous structure, with an iodine value of 651 mg g⁻¹. SEM analysis revealed a mesoporous structure, while BET analysis indicated a specific surface area of 3.135 m² g⁻¹ and a pore size distribution within the mesoporous range (2–50 nm). FTIR analysis confirmed the presence of oxygenated functional groups (C–O), such as ethers, phenols, and carboxylic acids, which may contribute to adsorption-related interactions for potential environmental applications.