Search Results (31)

With the expansion of modern protected agriculture, the amount of post-harvest tomato biomass has increased sharply. Conventional unmanaged disposal practices disrupt carbon flows and cause substantial environmental emissions. Tomato plant residues (TPRs), which are rich in lignocellulose and selected high-value secondary metabolites, have considerable potential as feedstocks for green industrial materials. However, their complex biophysical properties, high physiological moisture content, and recalcitrant cell-wall barriers hinder large-scale processing. This review systematically examines the mechanisms and process architectures for converting TPRs into macromolecular products. First, it analyzes cross-scale anatomical heterogeneity and dynamic rheological properties of TPRs, defining their physicochemical boundaries as industrial precursors. Second, it summarizes the development of physical field-coupled equipment, ranging from anti-tangling harvest-shredding to die-roller densification. Furthermore, it examines the core mechanisms of multi-field-coupled pretreatment technologies, including steam explosion, deep eutectic solvents (DES), and mechanochemistry, in deconstructing vascular skeletons and reducing multiphase mass-transfer resistance. Finally, this review discusses reconstruction pathways for TPR-derived components in advanced polymer materials, including biodegradable nanocellulose films, bio-based composites, aerogels, and lignin-based polyurethane networks. Overall, it links microscopic reaction kinetics with macroscopic equipment engineering, proposes a closed-loop material conversion system from in-field volume reduction to cascaded biorefinery, and provides an engineering framework for future multi-machine intelligent collaboration and continuous production across the industrial chain. Full article

Yet-to-develop infrastructures like biorefineries are exposed to many uncertainties compared to established systems such as fossil-based ones. The exposure to fluctuations of biomass supply is a growing concern due to the increasingly magnified consequences of climate change. This paper presents a two-stage stochastic mixed integer linear programming framework to design circular production systems using biomass wastes subjected to yield uncertainty. The modelling framework embeds an expected profit objective function in a spatially explicit, multi-echelon, multi-period, multi-feedstock, and multi-product lignocellulose-based biorefining supply chain network. The modelling framework integrates a risk-constrained formulation based on downside risk to represent decision-makers’ propensity towards risk. A case study based on real data from south-west Hungary is presented. Results show that biobased biorefining systems remain a risky capital-intensive investment, but profitable configurations of the network can be achieved, despite the inclusion of large variabilities in the biomass yields. Although they exhibit expected profits either comparable or slightly lower than risk-neutral configurations, the solutions subjected to risk-based regularisation (risk-constrained), are more stable than their stochastic counterpart. Furthermore, biomass supply chains, that can develop either a centralised or a decentralised configuration, would correspond to different risk profiles. While the localisation of centralised plants generates higher expected profits compared to sparsely distributed facilities, the latter, with a more diffuse presence of plants in the territory, can lead to a more stable system and to a more homogenous integration with local communities. Full article

Consolidated bioprocessing (CBP) has been widely studied as an integrated route for converting biomass into biofuels and bioproducts, yet most quantitative modeling work has focused on ethanol as a single response. Because CBP systems can generate multiple products and co-products, this study develops a literature-derived benchmark for multi-product CBP modeling using a standardized dataset assembled from published endpoint experiments. Product prediction is formulated as both an observed-only product-wise problem and a joint multi-output problem, allowing direct comparison under study-aware grouped validation. The modeling space integrates biomass composition, pretreatment descriptors, microbial and consortium characteristics, reactor information, operating conditions, and engineered categorical descriptors of feedstock, pretreatment family, and process configuration. Predictive performance was strongly product-dependent and was shaped by target support and missing-label structure. The observed-only product-wise formulation consistently outperformed the joint missing-as-zero multi-output strategy, indicating that naive zero-filling of unreported products is not well suited to sparse literature-derived CBP data. Among the evaluated products, butanol showed the clearest predictive signal, ethanol was only moderately learnable, and the sparsest co-products remained too weakly supported for strong quantitative inference. Overall, this study provides a benchmark for multi-product CBP modeling and clarifies both the potential and the current limitations of literature-derived data for broader data-driven biorefinery analysis. Full article

Biomass pyrolysis has emerged as a flexible platform for converting low-value residues into higher-value energy carriers (bio-oil, biochar and gas) and carbon-rich materials, with realistic potential for negative emissions when biochar is deployed in long-lived sinks. Over the last decade, three developments have driven the field forward: first, a finer mechanistic understanding of devolatilization and secondary reactions; second, major improvements in analytical techniques for characterising feedstocks and products; and third, more rigorous techno-economic and life-cycle assessments that place pyrolysis in a broader energy-system context. Recent experimental work on forestry and agro-industrial residues has clarified how biomass composition, ash chemistry and operating conditions jointly govern product yields, energy content and stability. Parallel advances in GC×GC–MS, high-resolution mass spectrometry, NMR and thermogravimetric methods have shifted the discussion from bulk “bio-oil” and “char” to families of molecules and well-defined structural domains, which can be deliberately targeted by reactor and catalyst design. Data-driven models, ranging from support vector machines applied to TGA curves to ANFIS and random forests for yield prediction, are now accurate enough to support process screening and multi-objective optimisation. At the system level, commercial fast pyrolysis biorefineries report overall useful energy efficiencies on the order of 80–86%, while slow pyrolysis configurations centred on biochar can be economically viable when carbon storage and co-products are appropriately valued. Thermodynamic analyses confirm that indirect gasification via fast-pyrolysis oil sacrifices some energy and exergy efficiency relative to direct solid-biomass gasification but may offer logistical and integration advantages. This review synthesises recent work on (i) feedstock and process characterisation; (ii) state-of-the-art analytical methods for bio-oil, biochar and gas; (iii) modelling and machine-learning tools; and (iv) energy-system deployment of pyrolysis products. Throughout, the emphasis is on how characterisation and modelling inform concrete design choices and on the trade-offs that arise when pyrolysis is considered as part of a wider decarbonisation portfolio. By integrating laboratory-scale characterisation with system-level modelling, this review aligns biomass pyrolysis with several United Nations Sustainable Development Goals (SDGs). The optimisation of thermochemical conversion pathways for forestry and agro-industrial residues directly supports SDG 7 (Affordable and Clean Energy) by enhancing the efficiency of bio-oil and syngas production. Furthermore, the deployment of biochar as a stable carbon sink for negative emissions and soil amendment addresses SDG 13 (Climate Action) and SDG 15 (Life on Land). By converting low-value waste streams into high-value energy carriers and chemicals within a circular bioeconomy framework, the research further contributes to SDG 12 (Responsible Consumption and Production) and SDG 9 (Industry, Innovation and Infrastructure). Full article

Within a waste biorefinery framework, integrating agro-industrial by-products into the circular economy requires a detailed understanding of the thermochemical conversion behaviour of low-grade carbonaceous materials. This study evaluates the co-pyrolysis characteristics of Soma lignite (SL) and pectin-rich sugar beet pulp (SBP) as a sustainable route for upgrading these resources into clean energy carriers. Interactions between the two feedstocks were analysed by thermogravimetric measurements, triple-region kinetic modelling, and quantitative synergy indices at six mixing ratios, including the pure samples (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wt% SL:SBP). The Reactivity Index ($R_{\mathrm{m}}$) increased from 0.97 × 10⁻⁴ s⁻¹K⁻¹ for pure SL to 8.65 × 10⁻⁴ s⁻¹K⁻¹ for the 20:80 blend, showing that SBP acts as a highly reactive biomass component that accelerates devolatilisation in the main pyrolysis region. Synergy analysis indicated a shift from inhibitory behaviour in coal-rich blends to slightly positive synergy in SBP-rich mixtures, with the onset of positive $\Delta TC$ around 60 wt% SBP under the present single-heating-rate, non-replicated TGA conditions. This tentative threshold-like behaviour suggests that a critical level of literature-supported, hypothesised hydrogen-donating biomass radicals may be required to overcome the structural resistance of the coal matrix. Within these experimental limitations, the apparent macro-kinetic deviations and first-order Arrhenius parameters suggest that SL/SBP co-pyrolysis follows a complex, non-additive pathway that should be further validated by multi-heating-rate and product characterisation studies in future work. The primary contribution of this work lies in proposing this distinct threshold-like biomass fraction at the macro-kinetic level that governs the transition from heat-transfer-limited antagonism to radical-influenced synergy in low-rank coal and pectin-rich biomass blends. Overall, the combined $\Delta TC$, $\Delta E$ and $R_{\mathrm{m}}$ descriptors provide useful macro-kinetic benchmarks for guiding the optimisation of thermochemical processes for low-grade carbonaceous resources. Full article

The rapid growth of the global population and the impending depletion of fossil fuels, currently meeting approximately 80% of the world’s power needs, have intensified interest in biofuels derived from renewable biomass. This editorial refers to the Special Issue, “Biofuel Production and Processing Technology, 3rd Edition,” which highlights the transition of fermentation-based technologies from isolated processes into integrated, multifunctional biorefinery platforms. The collection includes nine contributions (eight original articles and one review) covering diverse advancements, including: The valorization of industrial intermediates, strategies to improve anaerobic digestion through co-digestion and heat recovery integration, mechanistic insights into syngas fermentation and the development of multi-product microbial systems, emerging frontier technologies, such as biological hydrogen production in depleted oil and gas reservoirs. Collectively, these studies emphasize that the future of sustainable energy relies on system-level optimization, balancing feedstock flexibility, energy integration, and environmental performance within a circular bioeconomy. Full article

Agricultural leftovers from oilseed crops represent an underutilized lignocellulosic resource for integrated biorefinery. In this work, rapeseed straw (RS) and sunflower stalk (SS) were evaluated as raw materials for the simultaneous recovery of hemicelluloses, lignin, and cellulose-rich fibers. Direct soda pulping (20% NaOH, 160 °C, 45 min) or a combination of soda pulping with water pretreatment or alkaline extraction (water or 2% NaOH, 110 °C, 40 min) were the methods used in the process. Acid precipitation was used to remove lignin from the process fluids, whereas ethanol was used to separate hemicelluloses. FTIR spectroscopy, HPLC of acidic hydrolysates, and chemical composition analysis were used to analyze solid fractions and recovered biopolymers. The combination alkaline extraction–soda pulping produced the greatest material removal: 55% for RS and 70% for SS. Xylan was the main component of the isolated hemicellulose fraction: 44.86% for RS and 40.09% for SS. Paper sheets produced from the resulting pulps exhibited tensile strength indices of 35–55 N·m/g and burst indices of 1.1–2.4 kPa·m²/g, meeting requirements for hygiene and fluting packaging papers. These results prove that RS and SS are suitable feedstocks for integrated, multi-stream biorefinery, enabling the concurrent production of paper-making fibers and value-added biopolymers. Full article

Guangxi, one of China’s dominant sericulture regions, generates substantial silkworm excrement (SE) annually, yet most remains underutilized. This study optimized cellulase-assisted ethanol extraction of flavonoids and chlorophyll from silkworm frass. Systematic experimentation (n = 31) revealed that extraction temperature exerted dominant influence on both contents (r = 0.54 and 0.37 for chlorophyll and flavonoids, respectively), while the two contents exhibited near-zero correlation (r = 0.06). An XGBoost model achieved R² = 0.9146 for flavonoid prediction; SHAP analysis identified a critical temperature threshold (~40 °C). Monte Carlo simulation (n = 10,000) constructed a Pareto frontier for multi-objective optimization. The optimized condition (9% enzyme, 50 °C) achieved chlorophyll and flavonoid contents of 1.13 and 6.42 mg/g, respectively. These findings demonstrate that sericulture waste can serve as a biorefinery feedstock and that interpretable machine learning can navigate multi-objective extraction challenges under data constraints. Full article

Multi-product biorefineries, which transform biomass feedstocks into multiple valuable bio-based products, are pivotal for transitioning from a fossil-based economy to a sustainable circular bioeconomy. This work proposes a processing pipeline for fractionating the macrocomponents of Nannochloropsis oceanica, which can serve as a basis for multi-product microalgae biorefineries. It consists of high-pressure homogenization (1200 bar, 1 cycle) to permeabilize the cells, and sequential membrane processing (0.2 µm dia-microfiltration followed by 100 kDa ultrafiltration) and ethanolic extraction (60 mL ethanol/g dry weight, 1 h) to fractionate the disrupted biomass. This biorefinery resulted in four final fractions: (1) enriched in water-soluble proteins (39.0 ± 2.8% w/w proteins; 10.7 ± 0.8% w/w carbohydrates); (2) remaining soluble components (5.7 ± 0.4% w/w proteins; 4.3 ± 0.9% w/w carbohydrates); (3) lipid-rich extract (62.4 ± 5.8% w/w lipids); and (4) non-extracted components (11.8 ± 4.5% w/w lipids), with mass recovery yields of 23.2 ± 2.1%, 6.9 ± 1.0%, 10.6 ± 1.9%, and 60.4 ± 4.1%, respectively. The ultrafiltration protein selectivity was not optimal, despite yielding a 2.6 times more concentrated fraction. Lipid extraction yield (35–60%) and purity (56–68%) were highly affected by the water content of the microfiltration retentate. Overall, 10.0 ± 0.9% of the proteins, 9.7 ± 1.8% of the carbohydrates, and 42.4 ± 13.4% of the lipids of N. oceanica were recovered in fractions 1, 2, and 3, respectively. Full article

The growing global demand for clean energy and sustainability has increased interest in lignocellulosic biomass as a viable alternative to conventional fossil fuels. Among the various biomass resources, sugarcane bagasse, an abundant agro-industrial by-product, has emerged as a promising feedstock to produce renewable fuels and value-added chemicals. Its high carbohydrate content offers significant potential for bioconversion. However, its complex and recalcitrant lignocellulosic matrix presents significant challenges that necessitate advanced pretreatment techniques to improve enzymatic digestibility and fermentation efficiency. This review consolidates recent developments in the valorization of sugarcane bagasse focusing on innovative pretreatment and fermentation strategies for sustainable bioethanol production. It emphasizes the synergistic benefits of integrating various pretreatment and fermentation methods to improve bioethanol yields, reduce processing costs and enhance overall process sustainability. This review further explores recent technological advancements, the impact of fermentation inhibitor, and emerging strategies to overcome these challenges through microbial strains and innovative fermentation methods. Additionally, it highlights the multi-faceted advantages of bagasse valorization, including waste minimization, renewable energy production and the promotion of sustainable agricultural practices. By evaluating the current state of research and outlining future perspectives, this paper serves as a comprehensive guide to advancing the valorization of sugarcane bagasse in the transition towards a low-carbon economy. The novelty of this review lies in its holistic integration of technological, economic, and policy perspectives, uniquely addressing the scalability of integrated pretreatment and fermentation processes for sugarcane bagasse, and outlining practical pathways for their translation from laboratory to sustainable industrial biorefineries within the circular bioeconomy framework. Full article

Seaweed holds significant promise as a renewable feedstock for bioenergy due to its rapid growth, carbon sequestration capacity, and non-competition with terrestrial agriculture. This review examines recent progress in multi-method synergies for optimized energy conversion from seaweed biomass. Physical pre-treatments (e.g., drying, milling, ultrasound, microwave) enhance substrate accessibility but face energy intensity constraints. Chemical processes (acid/alkali, solvent extraction, catalysis) improve lipid/sugar recovery and bio-oil yields, especially via hydrodeoxygenation (HDO) and catalytic cracking over tailored catalysts (e.g., ZSM-5), though cost and byproduct management remain challenges. Biological methods (enzymatic hydrolysis, fermentation) enable eco-friendly valorization but suffer from scalability and enzymatic cost limitations. Critically, integrated approaches—such as microwave-solvent systems or hybrid thermochemical-biological cascades—demonstrate superior efficiency over singular techniques. Upgrading pathways for liquid bio-oil (e.g., HDO, catalytic pyrolysis) show considerable potential for drop-in fuel production, while solid-phase biochar and biogas offer carbon sequestration and circular economy benefits. Future priorities include developing low-cost catalysts, optimizing process economics, and scaling synergies like hydrothermal liquefaction coupled with catalytic upgrading to advance sustainable seaweed biorefineries. Full article

Lignocellulosic agricultural residues represent a rich source of potential feedstock for biorefinery applications, but their valorization remains challenging. The white-rot fungus Irpex lacteus J2 exhibited a promising degradation effect, but its molecular mechanisms of lignocellulose degradation remained largely uncharacterized. Here, we performed high-quality whole-genome sequencing and untargeted metabolomic profiling of I. lacteus J2 during the degradation of corn straw as the sole carbon source. The assembled I. lacteus J2 genome contained 14,647 protein-coding genes, revealing a rich genetic repertoire for biomass degradation and secondary metabolite synthesis. Comparative genomics showed high synteny (mean amino acid sequence identity 92.28%) with I. lacteus Irplac1. Untargeted metabolomic analysis unveiled a dynamic metabolic landscape during corn straw fermentation. Dominant metabolite classes included organic acids and derivatives (27.32%) and lipids and lipid-like molecules (25.40%), as well as heterocyclic compounds (20.41%). KEGG pathway-enrichment analysis highlighted significant activation of core metabolic pathways, with prominent enrichment in global metabolism (160 metabolites), amino acid metabolism (99 metabolites), carbohydrate metabolism (24 metabolites), and lipid metabolism (19 metabolites). Fermentation profiles at 3 and 15 days demonstrated substantial metabolic reprogramming, with up to 210 upregulated and 166 downregulated metabolites. Correlation analyses further revealed complex metabolic interdependencies and potential regulatory roles of key compounds. These integrated multi-omics insights significantly expand our understanding of the genetic basis and metabolic versatility, enabling I. lacteus J2 to efficiently utilize lignocellulose. Our findings position I. lacteus J2 as a robust model strain and provide a valuable foundation for developing advanced fungus-based strategies for sustainable bioprocessing and valorization of agricultural residues. Full article

Biomass is a key renewable resource for advancing sustainable and circular energy systems. In contrast to prior reviews that predominantly emphasized well-established biomass types and conventional conversion technologies, this work offers a comparative synthesis that underscores underutilized feedstocks and emerging valorization pathways, providing a strategic perspective for sustainable process development. This review critically examines the current state of high-value-added bioproducts derived from biomass, focusing on their relevance to climate mitigation and resource efficiency. It explores sustainable process design strategies that enhance the environmental and economic performance of biomass conversion. Particular attention is given to recent advances in process intensification, including novel reactor configurations and heat integration techniques. The integration of sustainability assessment tools and multi-objective optimization approaches is analyzed to support data-driven decision-making. Multi-product biorefineries are discussed as central platforms for valorizing diverse feedstocks, supported by emerging models for supply chain integration. Present limitations such as feedstock heterogeneity, infrastructure constraints, and energy coupling challenges are reviewed, along with new opportunities in digitalization, modularization, and policy support. The novelty of this work lies in its cross-sectional synthesis of technologies, methodologies, and system-level strategies, offering a unified framework to unlock the full potential of biomass as a strategic vector for sustainable process development. Full article

The effective use of biowaste resources becomes crucial for the development of bioprocessing alternatives to current oil- and chemical-based value chains. Targeting the development of multi-product biorefinery approaches benefits the viability and profitability of these process schemes. Certain oleaginous microorganisms, such as oleaginous red yeast, can co-produce industrially relevant bio-based products. This work aims to explore the use of industrial and urban waste as cost-effective feedstock for producing microbial oil and carotenoids using Rhodosporidium toruloides. The soluble fraction, resulting from homogenization, crushing, and centrifugation of discarded vegetable waste, was used as substrate under a pulse-feeding strategy with a concentrated enzymatic hydrolysate from municipal forestry residue obtained after steam explosion pretreatment (190 °C, 10 min, and 40 mg H₂SO₄/g residue). Additionally, the initial nutrient content was investigated to enhance process productivity values. The promising results of these cultivation strategies yield a final cell concentration of 36.4–55.5 g/L dry cell weight (DCW), with an intracellular lipid content of up to 42–45% (w/w) and 665–736 µg/g DCW of carotenoids. These results demonstrate the potential for optimizing the use of waste resources to provide effective alternative uses to current biowaste management practices, also contributing to the market of industrially relevant products with lower environmental impacts. Full article

Establishing the utilization of lignocellulosic biomass in integrated biorefineries can reduce environmental impacts and dependency on imported raw materials by substituting fossil-based products. Whereas energetic biomass utilization is common, chemical utilization is still poorly established, primarily due to the lack of feedstock availability. Hence, literature-based estimation and geographical mapping of biomass potentials are key to implementing successful production networks for biobased chemicals. Using the example of Germany, a geographical information system (GIS) analysis was conducted to allocate residual biomass potentials spatially. Based on the obtained GIS data model, a facility location optimization model was developed. The results of a location-allocation analysis for innovative biorefineries, which are integrated with biogas plants, showed an optimal location network for maximizing the amount of residue biomass covered. In a promising model scenario, each biorefinery has a maximum catchment radius of 23 km and a minimum input of 94,500 tonnes of dry matter per year (t DM/a) (31.5 kt DM/a × 3), allowing only existing biogas locations as locations for biorefineries. The results show that a mix of lignocellulosic residual biomass in certain areas can sustainably satisfy the demand for running 69 decentralized, integrated and multi-feed small-to-mid-scale biorefineries in Germany. Full article