Biofuels Bioproducts & Biorefining-Biofpr最新文献

We have gained much and lost much through industrial agriculture with its emphasis on purchased farm inputs, greatly increased farm scale, decreased biodiversity and farming practices that leave soil bare and lifeless during much of the year. ‘Farming carbon’ through regenerative agroenergy systems enables better agricultural practices that improve the beauty and ecological health of rural areas while mitigating climate change and increasing the prosperity of farmers and farm communities.

Potassium ferrate (PF) exhibits strong oxidative potential for lignocellulosic biomass pretreatment; however, its high cost and instability under alkaline conditions restrict large-scale application. Likewise, ultrasonic pretreatment (UP), although effective in physically disrupting biomass, is energy intensive and unsuitable for substantial lignin degradation when applied alone. This study presents the first systematic investigation of the synergistic effects of PF and UP pretreatments, emphasizing the influence of application sequence on methane production and delignification efficiency. Three strategies were evaluated: UP followed by PF (UP → PF), PF followed by UP (PF → UP), and their simultaneous application (UP + PF), across varying PF dosages (0.333–0.999 mmol g⁻¹ total solids). Among these, the UP → PF sequence achieved the best performance, yielding 37.9% lignin removal and methane production of 234.9 mL g⁻¹ (volatile solids) – nearly a fivefold improvement compared with untreated controls. The enhanced outcomes are attributed to UP-induced structural disruption, which increases surface accessibility, facilitating more effective lignin oxidation by PF. Methane production kinetics were successfully modeled using both the modified Gompertz equation (R² = 0.9977–0.9995) and autoregressive integrated moving average (ARIMA) models (R² = 0.9980–0.9999), with ARIMA demonstrating slightly superior predictive accuracy. These findings highlight the potential of optimized sequential PF and UP pretreatments as a novel strategy to enhance biomethane recovery from lignocellulosic waste, advancing the development of efficient and sustainable bioenergy systems.

Biodiesel is an ecofriendly alternative to fossil fuels. Its production generates substantial amounts of crude glycerol, which can pose environmental hazards. Converting glycerol into value-added chemicals offers a practical strategy to mitigate these risks. Recent advances make it possible to transform crude glycerol directly into high-value products, including diols (1,3-propanediol, propylene glycol), polyols, solketal, epichlorohydrin, glycerol carbonate, and biofuels using catalytic (acetalization, dehydration, hydrogenation, oxidation, esterification, and etherification) and biological (fermentation) processes. Heterogeneous catalysts enhance recyclability and process efficiency, and both catalytic and biocatalytic methods have achieved high yields. The integration of microbial and chemical processes in hybrid technologies enables closed-loop biorefineries that convert waste glycerol into fuels, polymers, cosmetics, and pharmaceuticals. This review highlights recent developments in crude glycerol conversion, emphasizing reaction mechanisms, catalyst design, techno-economic challenges, and potential industrial applications. These approaches aim to enhance biodiesel sustainability and promote a robust bioeconomy by redefining crude glycerol as a versatile feedstock rather than a waste liability.

This study investigates the co-pyrolytic behavior of waste tires (WT) and Platanus orientalis leaves (SL) as hybrid feedstocks for thermochemical valorization. Pyrolysis experiments were conducted under nitrogen atmosphere using thermogravimetric analysis across a temperature range of ambient to 745 °C, with heating rates of 5, 10, 15, 20, and 25 K min⁻¹. Five blend ratios (100% WT, 75/25, 50/50, 25/75, 100% SL by mass) were assessed to evaluate thermal degradation profiles and kinetic characteristics. A Box–Behnken experimental design within the response surface methodology (RSM) framework was employed to optimize the effects of temperature, heating rate, and blend ratio on pyrolysis performance. The statistical model showed a high predictive capability with R² >0.995. Kinetic parameters were calculated using Coats–Redfern, Flynn–Wall–Ozawa, and Kissinger methods, with activation energies for the major decomposition stage (Stage 3C) ranging from 114.3 to 125.2 kJ mol⁻¹. A significant negative correlation was found between activation energy and SL content (r = −0.82), while WT content showed a positive correlation (r = 0.87), indicating that biomass reduces the energy barrier for thermal degradation. Fourier transform infrared analysis confirmed the breakdown of functional groups such as OH, CO, and aromatic CC after pyrolysis, indicating extensive structural transformation. Scanning electron microscopy imaging revealed morphological changes from fibrous structures in SL to carbonized, fractured surfaces in the char. Energy-dispersive X-ray spectroscopy analysis indicated a high carbon content (91.2%), supporting the suitability of the product for energy applications. Overall, the study demonstrates the synergistic potential of WT and SL in co-pyrolysis, improving thermal behavior, reducing activation energy, and yielding carbon-rich products. These findings support the development of integrated waste-to-energy strategies aligned with circular economy principles.

This study examined the extent to which lignin upgrading is possible when maximizing ethylene glycol (EG) production during the hydrogenolysis of lignocellulosic biomass over bifunctional tungsten–nickel catalysts. Reductive catalytic fractionation (RCF) was selected as a benchmark lignin valorization process because its reaction conditions resemble those of biomass hydrogenolysis. Evaluation of the effects of hydrogen pressure, temperature, catalyst loading (Raney Ni and sodium polytungstate), and pH on EG and lignin depolymerization showed that complete lignin solubilization was not obtained under the tested conditions. Under the optimal conditions for maximizing EG yield (34.3 wt%) – 260 °C, 60 bar H₂ (room temperature), pH ~ 3.3, with 10 wt% biomass loading – approximately 45% of the initial lignin was solubilized, and only approximately 5% (gel permeation chromatography area integration) of lignin-derived monomers and dimers formed. Identified monomers included guaiacol, 4-methyl guaiacol (4-MethG), 4-ethyl guaiacol (4-EthG), 4-propylguaiacol (4-PropG), and homovanillic acid (HVac). Hydrogen pressure emerged as a critical parameter affecting EG production, solubilization, and lignin depolymerization. Higher hydrogen pressure hindered the solubilization of lignin, although the average molecular weight of solubilized lignin was higher. Despite the various experimental conditions and types of biomass tested – both softwood and hardwood – the lignin depolymerization remained limited with monomer plus dimer yields below 20 wt% based on solubilized lignin. These findings highlight the limitations in lignin valorization under one-pot hydrogenolysis conditions relative to more specialized approaches for lignin valorization such as RCF.

Surface mining has significantly altered landscapes in Appalachia, impacting forested ecosystems, natural habitats, and water quality. Building on recent regional modeling efforts in Pennsylvania, this study used high-resolution datasets (2011, 2016, 2020) to assess land cover change and identify operationally feasible post-mining lands for bioenergy crop development in West Virginia. It identified 9435 ha of postmining land that met suitability criteria, including slope (<15%), low vegetation cover, and at least 2 ha in size. Over the study period, forest cover increased by 8583 ha from 2011 to 2016 and 8448 ha from 2016 to 2020. Of the lands found suitable for bioenergy crop development, the results show that businesses controlled 6880 ha, private individuals 1913 ha, and government entities 518 ha of the identified land. Our analysis provides finer scale insights into where, and under what conditions, bioenergy crop establishment may be feasible. These mine lands are transitioning rapidly from herbaceous cover to shrubland and forest through natural succession, increasing the cost and complexity of bioenergy crop development. As such, the window for lower input biomass establishment is narrowing, making proactive planning and policy support essential.

Vinasse is a major organic industrial effluent with significant polluting effects. Its management and valorization are essential to improve the efficiency and sustainability of ethanol production. This study used Aspen HYSYS v11 to simulate and conduct a technoeconomic evaluation of two vinasse-to-energy treatment alternatives: A1 – incineration and electricity generation using concentrated vinasse (60 °Bx), and A2 – anaerobic digestion of diluted vinasse (7 °Bx) with electricity generation. Property prediction and evaluation employed the Lee–Kesler–Plöcker (LKP) and NBS Steam packages for A1, and the Peng–Robinson–Stryjek–Vera (PRSV) and NBS Steam packages for A2. Model validation produced results consistent with the literature. In A1, 198.6 kg h⁻¹ of fertilizer ash was produced, and surplus energy was generated, whereas A2 generated 472.5 kWh of electricity from biogas, with 77.52% removal of chemical oxygen demand (COD). Both alternatives reduced vinasse pollution significantly while valorizing the waste into energy and value-added products. Economic analysis confirmed the feasibility of both with positive net present values (NPVs) and internal rates of return (IRRs) exceeding the 12% discount rate. Alternative A1 was superior, yielding an NPV of USD 1.29 million, an IRR of 25.5%, and a payback period (PBP) of 1.8 years.

Despite early momentum, large-scale production of cellulosic ethanol has yet to achieve its expected breakthrough. The sector has faced setbacks, including project cancellations, unmet capacity targets, and the closure of key plants. Drawing on 15 years of monitoring the industry, we examine the underlying causes and evaluate the status of demonstration plants recorded in the International Energy Agency (IEA) Bioenergy Task 39 database. Following an initial period of progress up to 2015, when 50 facilities were operational, many projects were either canceled or idled. The expected capacities were not reached, and the anticipated breakthroughs have not materialized. The slow advancement of cellulosic ethanol development has occurred due to technological complexity, limited feedstock availability, high production costs, and modest commercial outcomes. Investor confidence has been further undermined by inconsistent policy support, competition from lower-cost biofuels, and the collapse of several large-scale ventures. In recent years, however, cellulosic ethanol production has shown promising progress and capacity to expand, particularly in rapidly developing economies such as Brazil and China. Success in these regions depends on a combination of measures: a regulatory framework that provides market incentives and offsets higher production costs, sustained support for technological research and development, and public funding for large-scale, first-of-a-kind facilities. Brazil currently leads the field, largely because cellulosic ethanol production from sugarcane bagasse is integrated effectively into existing sugar and ethanol industries.

The fuel industry remains closely tied to oil-based fuels. This relationship is responsible for increasing greenhouse gas emissions. Biofuels are an alternative to petroleum-based fuels that could make industrial production lines more sustainable. Neem oil (Azadirachta indica) was tested as a raw material for the enzymatic synthesis of biolubricants. Eversa Transform 2.0 lipase was tested as a biocatalyst during this process. The Taguchi method was used to determine the optimal point for maximizing production. The best result was achieved with a molar ratio of 1:5 (mol mol⁻¹) between free fatty acids and 2-ethylhexan-1-ol, using 10% biocatalyst at 40 °C for 96 h. Theoretical conversion was 89.9%, whereas the experimental value was 89.2% ± 0.04%. A theoretical study showed that eicosanoic acid interacts with His 268 (NAC), a component in the enzyme’s active site, displaying favorable free energy and forming specific hydrogen bonds along with alkyl and π–alkyl interactions. Finally, the characterization analyses – gas chromatography–mass spectrometry (GC–MS) and Fourier transform infrared (FTIR) spectroscopy – confirm the efficient production of biolubricants from neem oil. This vegetable oil is thus a promising source of biofuels.

The transition to a low-carbon economy has intensified the search for sustainable hydrogen (H₂) production routes. Sugarcane and its byproducts, such as bagasse, molasses and vinasse, have emerged as promising feedstocks due to their ready availability and renewable nature. However, comprehensive evaluations of the efficiency, limitations, and optimization strategies of different H₂ production methods remain limited. This review systematically evaluates thermochemical (pyrolysis, gasification, and reforming), biological (dark fermentation and photofermentation), and hybrid approaches for hydrogen production from sugarcane biomass. The advantages and challenges of each technique are discussed, with a particular focus on process efficiency, catalyst development, and sustainability aspects. This review also highlights critical gaps in the literature, including the need for enhanced pretreatment strategies, more efficient microbial strains, and optimized biorefinery integration. By providing a comparative analysis of current methodologies and proposing future research directions, this study aims to guide technological advancements toward a more viable and scalable hydrogen production framework from sugarcane.