Abstract Lignocellulosic biomass is the most abundant biobased raw material worldwide. This category involves agricultural residues, forestry waste, and municipal solid waste. The estimated annual availability of lignocellulosic biomass is between 181 500 and 200 000 million metric tons. From the total, 3.8–4.0% comes from dedicated forest, agricultural, and grass sources, while 2.5–2.6% corresponds to agricultural waste. The availability of this biomass makes biofuels production attractive, representing a promising alternative. Conversion technologies, including thermochemical and biochemical, have demonstrated promising results for biofuels, such as bioethanol, sustainable aviation fuel (SAF), renewable diesel (RD), renewable natural gas (RNG), and hydrogen (H 2 ). Conversion yields can reach 330 L of bioethanol, up to 250 L of RD, up to 150 kg of SAF and up to 130 kg of H 2 per dry metric ton of biomass, as well as approximately 60% of RNG for each ton of biogas. The projected annual growth rates for biofuels range from 4 to 6% for bioethanol, SAF, and RD and up to 30% for RNG, and are expected to increase exponentially for H 2 . Industrial‐scale implementation faces several challenges, including seasonal variability, biomass fractionation, and transportation, which in some cases account for up to 50% of the costs. Conversion, fractionation, and enzymes account for approximately 25–30% of operating costs. Current production costs for bioethanol, SAF, and RD range from $0.52 to $0.57 L −1 , and can decrease with integration strategies such as byproduct valorization. For hydrogen, it is expected to have a value of $2 kg −1 of H 2 by 2026. Additionally, strategies such as CO 2 capture in biofuel production and the addition of high‐value products led to significantly promising results, achieving a notable decrease in environmental impacts. Finally, challenges related to social acceptance and policy support are critical for the long‐term success of alternative biofuels.
Improving fertilizer use efficiency is essential for reducing environmental pollution, sustaining agricultural production, and maximizing the economic profitability of crop production systems. This study tested the hypothesis that the formulation strategy of biochar-based fertilizers, rather than nutrient addition alone, is associated with systematic differences in crop performance and nitrogen-use efficiency under field conditions. Using sunflower as a test crop, biochar-based fertilizers developed using different decision frameworks (soil test, crop nutrient harvest, agroecological zones (AEZs), and industry recommendation) were evaluated against conventional chemical fertilization. Biochar was added at two different rates: 20% or 10% of the total fertilizer quantity. The results showed a consistent pattern: soil test-based formulation approaches provided higher nutrient use efficiency than other formulations and standard fertilizer treatment. Soil test-based formulations achieved seed yields up to 1.75 t ha-1, representing a 23.87% increase in seed yield compared with conventional fertilization. Other formulations resulted in intermediate yield performance between soil test-based formulations and the standard recommendation. However, there was no statistical difference in seed yield and aboveground biomass production between the 20% and 10% biochar treatments. Correlation analysis, principal component, and redundancy analyses indicated that improvement in crop yield under selected biochar-based fertilizer formulations occurred as a result of enhanced bioavailability and plant uptake of key soil nutrients. This study identified fertilizer formulation strategy as a critical, yet often overlooked, aspect of biochar-based fertilizer formulation. From an applied perspective, the results offer opportunities to develop decision-guided biochar-based fertilizers that could improve input efficiency and may lower dependence on synthetic fertilizers, with relevance for farmers, fertilizer manufacturers, and policymakers. Future research should address multiseason validation, cost-benefit assessment, underlying mechanisms, economic robustness, and broader applicability across agroecological contexts.
Abstract The biochemical conversion of gaseous components to produce chemical products is considered a promising alternative when compared to existing techniques. Value‐added products such as methanol and ethanol are building block of many chemicals and they are used in the chemical industry as an alternative fuel source, antifreeze, and as precursors of many other compounds. The conversion of the greenhouse gas carbon dioxide (CO 2 ) into value‐added fuels (methanol and ethanol) via biochemical approaches needs to receive more attention in C1 chemistry, as the higher alcoholic products are recognized as fuel additives, reaction solvents, and intermediates. However, this approach is very challenging due to the functional inertness of CO 2 . This review summarizes and analyses the recent advances in biocatalytic CO 2 conversion to methanol and ethanol that promise to outperform conventional techniques such as electrochemical or photo‐assisted methods. This review gives an overview of the potential sources of CO 2 and its utilization, followed by the current status of methanol and ethanol production and its use. Next, the review focuses on several aspects of the biochemical process that direct conversion of CO 2 to methanol/ethanol enjoys over existing methods. Bacteria‐based conversion, especially methanotrophic, acetogenic, and cyanobacteria‐based processes, are discussed at length. Algae and enzymes also play an important role in the biochemical conversion of CO 2 . Biomass from renewable sources is a promising intermediate product for CO 2 conversion and research efforts are needed to scale up these processes to industrial levels and integrate them into existing infrastructure for large‐scale biochemical CO 2 utilization to value‐added products.
Abstract Climate change is driven largely by CO 2 emissions from the combustion of fossil fuels in everyday human activities. It is essential to reduce CO 2 emissions to meet the targets of the Paris Agreement, but this presents challenges for the stability of energy supplies. This review examines emerging technologies that address this dilemma, focusing on carbon capture and storage (CCS) and carbon capture and utilization (CCU). Carbon capture and storage involves capturing CO 2 emissions – particularly from high‐emitting industries such as petrochemicals, cement, and steel – for long‐term geological storage. Carbon capture and utilization provides pathways for converting captured CO 2 into value‐added products, including fuels, chemicals, and polymers, supporting circular economy principles. This review critically evaluates the four main carbon capture approaches – post combustion, precombustion, oxy‐fuel combustion, and direct air capture. Integration of these technologies with renewable energy sources is identified as a promising route toward global decarbonization and sustainable economic growth. However, widespread adoption of CCS and CCU remains limited because of high costs, technical barriers, and substantial energy demands. Continued innovation, together with strong policy support, will be required to overcome these barriers and enable large‐scale implementation.
Abstract Biomass, as the sole carbon‐containing renewable resource in nature, holds significant potential to replace fossil fuels in the production of fuels, chemicals, and materials while achieving carbon neutrality or even negative emissions. Thermochemical conversion methods, including pyrolysis, gasification, and hydrothermal liquefaction, have emerged as promising approaches to address the limitations of traditional biomass processing, such as incomplete utilization and low conversion efficiency. This review explores recent advancements in thermochemical conversion technologies, focusing on innovations that enhance process efficiency, product quality, and environmental sustainability. Key aspects include the integration of catalytic processes, novel reactor designs, and the development of bio‐oil upgrading techniques. Challenges, optimization strategies, and future perspectives for large‐scale application are also discussed, paving the way for sustainable biomass utilization.
Abstract Bioactive phenolic compounds derived from medicinal materials have gained significant global attention owing to their diverse therapeutic properties and potential applications in various industries. This review explores phenolic bioactive extraction techniques and the pharmacological significance of these natural compounds, highlighting their roles in pharmaceuticals, cosmeceuticals, and nanotechnology. Conventional techniques for bioactive compounds extraction are time consuming and require large volumes of solvent; hence, advanced novel green techniques are required. Green techniques minimize the time and energy required as well as the solvent used for extraction. This review discusses innovative and sustainable green extraction techniques for bioactive compounds from plants. The novel techniques discussed include microwave‐assisted extraction, ultrasound‐assisted extraction, supercritical fluid extraction, pressurized liquid extraction and pressurized hot water extraction. Bioactive substances like alkaloids, flavonoids, and terpenoids have antibacterial, anti‐inflammatory, and anticancer properties, making them useful in drug development in pharmaceuticals. In the cosmeceutical sector, these substances promote skin health, anti‐aging, and UV protection, improving the efficacy of skin care products. Furthermore, the combination of bioactive chemicals with nanotechnology has resulted in advances in drug delivery systems, including improved bioavailability, targeted therapy, and controlled release. This review gives a comprehensive overview of the most recent research and technological breakthroughs, with a focus on the potential of bioactive substances derived from medicinal materials to deliver sustainable and innovative solutions in various industries.
Abstract Achieving a secure, abundant, and affordable energy future requires a robust and adaptable energy strategy, with bioenergy playing a pivotal role. Biomass‐based energy presents a promising pathway to use domestic resources while fostering economic opportunities in rural areas. Despite the potential to source more than 1 billion dry short tons of biomass annually in the US, significant infrastructure and economic barriers hinder full utilization for energy production. This study used the Biofuel Infrastructure, Logistics, and Transportation (BILT) model to assess biorefinery siting and scale and determine the number and size of facilities required to maximize use of the US biomass potential. A spatially agnostic approach first assessed the effects of facility capacity and transportation constraints on biomass use. Then, a spatially explicit analysis integrated county‐level biomass availability from the US Department of Energy's 2023 Billion‐Ton Report and technoeconomic assessments to evaluate different biorefinery deployment scenarios. The results indicate that an optimized mix of facility sizes is essential to leverage biomass resources fully across varying regional production densities to maximize use of the US biomass potential. Larger biorefineries or co‐located smaller facilities significantly enhance biomass use while reducing costs through economies of scale. These findings underscore the importance of strategically balancing facility capacity and spatial distribution to optimize the bioenergy supply chain. This study provides critical insights for advancing the US bioenergy economy by aligning biorefinery deployment with biomass resource availability and economic viability.
Abstract Hydrogen is widely recognized as an essential element in achieving a net‐zero economy; however, the majority of global hydrogen production relies heavily on fossil fuels and employs highly polluting production techniques. Consequently, to meet the global targets of reducing fossil fuel consumption and lower greenhouse gas emissions, hydrogen production from renewable and clean resources, including biomass and water, has attracted considerable attention. In this context, this review discusses the recent technological advancements in thermochemical conversion (gasification and supercritical water gasification) and biological conversion (dark fermentation and photo‐fermentation) of biomass, as well as chemical conversion (photocatalytic water splitting). This review also highlights the technical challenges and barriers faced by each hydrogen production technique and offers new insights into the selection of highly effective and suitable hydrogen production methods from biomass and its derived waste and from water.
Abstract The transition to sustainable CO 2 capture demands novel solvents balancing performance and environmental impact. This study develops a workflow screening of bio‐based solvents based on environmental and technical criteria, then assesses ternary MEA–water–bio‐based solvent mixtures (50–30–20 wt%) for post‐combustion capture. COSMO‐RS predicts reduced vaporization enthalpies and enhanced CO 2 physical solubility without compromising diffusivity or volatility. Cyrene‐ and levulinic acid‐based mixtures offer optimal trade‐offs, enabling water‐lean formulations for biorefinery‐integrated CCS. These findings prioritize candidates for validation, advancing biomass‐derived solvents in circular carbon capture and utilization systems.
The growing demand for renewable energy sources and sustainable technologies positions microalgae as a promising alternative, given their ability to produce biomass rich in lipids, which can be converted into biofuels. In the same scenario, the leachate produced by the decomposition of organic waste along with the infiltration of rainwater represents one of the main current problems associated with landfills. In this context, the leachate can be transformed into a valuable opportunity by being used as a culture medium for microalgae, providing the essential nutrients for the growth of these microorganisms and contributing to the production of sustainable bioproducts such as carbohydrates, lipids, proteins, and pigments. This approach plays a crucial role in bioremediation by removing toxic compounds and reducing the environmental impact of leachate. Thus, by integrating microalgae cultivation with the reuse of leachate, not only is a clean energy source obtained, but also the promotion of a circular economy is achieved, turning waste into resources. This review critically synthesizes the current literature on microalgae cultivation in landfill leachate, highlighting technological advances, biomass valorization, and their environmental implications, thereby providing a comprehensive framework to guide future research and industrial applications.
The urgent need to mitigate climate change demands the development of low‐carbon fuels, especially for the aviation and maritime sectors where internal combustion engines remain essential and alternatives like batteries and hydrogen face limitations. This review examines biomass‐derived carbon‐based heterogeneous catalysts as a sustainable route for biodiesel production from waste cooking oils and non‐edible fats. Transesterification of triglycerides and esterification of free fatty acids benefit from such catalysts owing to their reusability, ease of recovery, and lower downstream processing requirements. Evidence from books, patents, and peer‐reviewed studies shows that tailoring the surface area, porosity, and acidity of biochar and hydrochar – particularly through sulfonation (–SO 3 H functionalization) – enhances catalytic performance. Interdisciplinary insights highlight opportunities for improving efficiency and durability, while challenges such as sulfonic group leaching and catalyst deactivation are critically assessed alongside regeneration strategies. Economic analyses confirm the viability of biodiesel production, with char‐based catalysts improving sustainability by valorizing biomass waste and reducing chemical dependence. Future directions include scalable catalyst fabrication, integration into circular bioeconomy frameworks, and deeper mechanistic studies. Overall, this work underscores the global relevance of char‐based catalysts for advancing biodiesel as a cost‐effective and environmentally responsible alternative to fossil fuels.
Nanocellulose, a renewable and abundant bionanomaterial with exceptional physical, chemical, and biological properties, is a very promising functional material. Its potential applications, including composites, biomedical products, membranes, electrodes, supercapacitors, and flexible electronics, have been limited by high production costs. This study evaluates the industrial adoption of nanocellulose following the peak of the technology hype cycle, focusing on efforts to commercialize lower‐cost production routes. The study also highlights the primary advanced applications, beyond biomedical products, in which nanocellulose is increasingly adopted by industry. The results are relevant not only to researchers in chemistry, materials science, biotechnology, and engineering, but also to professionals in the bioeconomy sector.
Optimal biomass use in a circular bioeconomy requires a system perspective to guide decision‐making. The Optimizing Biomass Use (OptiBiU) model was developed for this purpose. The model distinguishes among primary biomass production, intermediate products, and biobased products, and incorporates recycling. Soil organic matter formation is explicitly included to reflect its importance for soil fertility, biodiversity, and carbon storage. This study focused on the application of OptiBiU to the utilization of lignocellulosic biomass in the Netherlands. The results indicate potential to reduce land use and increase carbon storage while meeting current demand for biobased products. OptiBiU also generated insights into more fundamental system characteristics. It showed, on a general level, what is needed to increase carbon storage, notably long service lifetimes and effective reuse and recycling options.
Xanthan gum, a high molecular weight exopolysaccharide synthesized by Xanthomonas campestris , is employed extensively in the food, pharmaceutical, cosmetic, and petroleum industries due to its exceptional rheological properties, thermal and pH stability, and biodegradability. Despite its versatility, large‐scale industrial production remains constrained by the high costs associated with conventional carbon sources such as glucose and sucrose. This review provides a comprehensive analysis of cost‐effective and sustainable alternatives, emphasizing the valorization of agroindustrial and food‐processing residues, including molasses, whey, melon waste, jackfruit seed powder, rice bran, and olive mill effluents as viable substrates for xanthan gum fermentation. Numerous studies have demonstrated that these unconventional feedstocks, when subjected to suitable pretreatment protocols and nutrient optimization, can yield xanthan gum at levels comparable to or exceeding those obtained from traditional sources. Incorporating circular economy principles into the production chain not only enables significant cost reductions but also mitigates the environmental burden associated with organic waste disposal. Advances in artificial intelligence (AI), particularly through machine learning (ML) techniques such as artificial neural networks, support vector machines, and evolutionary algorithms, have further expanded the potential for xanthan gum production by accurately modeling and optimizing the complex parameters of bioprocesses. These data‐driven methodologies outperform traditional statistical tools in predicting sugar release, enhancing fermentation efficiency, and reducing process variability. By facilitating the efficient utilization of low‐cost substrates and improving process control in both hydrolysis and fermentation stages, AI‐based optimization contributes to the development of scalable, resilient, and environmentally sustainable bioprocesses. Ultimately, the synergistic integration of waste‐derived feedstocks, bioprocess engineering, and intelligent modeling aligns xanthan gum manufacturing with the broader objectives of sustainable development and the global bioeconomy.
The vision of using microalgae to obtain organic chemicals in a carbon‐neutral manner is intriguing. It promises to produce various substances including biofuels by photosynthesis, without competing with agricultural land. Processes have been established whereby microalgae undergo a growth phase followed by a stress phase, which induces lipid synthesis (two‐phase‐cultivation). The neutral lipid triacylglycerol is finally extracted to produce biodiesel. However, improvements to the microalgal culture and subsequent processes are needed to allow large‐scale biofuel production competitive to mineral oil fuels. Here, we recapitulate approaches from current literature studies which increase the process efficiency by converting the classical two‐phase batch into a continuous cultivation. Three process categories were identified and evaluated, with a focus on productivity, applicability, and research gaps. The first approach makes use of continuous transfer between two separate reactors for biomass and lipid production, where a higher equipment demand is compensated for by maximal productivity. In the second approach, a trade‐off is generated by applying relatively low stress conditions in a single bioreactor, allowing simultaneous cell growth and lipid production, albeit at a lower productivity. The third approach is a repeated‐batch variant, that alternates between growth phases to high cell density and stress phases, followed by a partial harvest and cell recovery. This yields a high product concentration using a single reactor. A direct comparison between these three approaches allows selection of the most productive strategy for future microalgal processes, depending on requirements and application field.
Lemongrass ( Cymbopogon citratus ) is widely cultivated for essential oil production, generating substantial lignocellulosic biomass before and after distillation. This is particularly relevant in tropical regions and small island developing states (SIDS), where local renewable energy demand is high. Lemongrass has been explored as an energy crop and anaerobic digestion (AD) substrate, but earlier studies generally considered raw biomass and postdistillation residues separately. It was hypothesized that steam distillation, by removing essential oils, would not reduce – and might slightly enhance – the biochemical methane potential (BMP) of lemongrass residues at equivalent loadings. Both materials were expected to achieve maximum methane productivity without strong inhibition at an optimal substrate‐to‐inoculum ratio. This study compared AD performance of steam‐distilled and nondistilled lemongrass under identical conditions. Biochemical methane potential assays were conducted at several substrate concentrations using the same mesophilic inoculum, reactor configuration, and incubation regime. Methane yields and production rates were quantified alongside key physicochemical substrate properties. Nondistilled lemongrass achieved 114 ± 6 mL g −1 fresh matter (FM), comparable with distilled lemongrass (120 ± 10 mL g −1 FM) at 2.5% substrate concentration. On an organic dry‐matter basis, optimum yields for both substrates fell within the lower middle range for grass and energy crops, confirming lemongrass as a moderately reactive lignocellulosic feedstock. Higher loadings reduced yields, indicating mild inhibition; distilled residues were less affected, suggesting that oil removal mitigates inhibition. These findings demonstrate that steam‐distilled lemongrass is a viable AD substrate and support an ‘oil‐first, biomethane‐second’ biorefinery concept, relevant for renewable energy and residue management in SIDS.
This study proposes a microalgae biorefinery integrated with tannery wastewater treatment. Each step of the route is analyzed, together with its yields, using data from the literature. The process begins with tannery wastewater treatment, followed by biomass recovery and pyrolysis. The three pyrolysis products – bio‐oil, biochar, and gas – are evaluated, and potential applications are suggested based on the yields achievable with current processing technologies. The results indicate that 1000 m 3 of tannery wastewater can produce 11.58 t of dry microalgae biomass, yielding 109.6 L of diesel, 184.3 L of gasoline, and 68.79 kg of carbon dots.
The price of pure cellulase enzyme for the recovery of fermentable cellulosic sugars is one of the major challenges that limit the commercialization of second-generation biofuels and bio-based products. This work shows a means to greatly reduce the cost of cellulases. The abundant capacity of plants to synthesize and hyperaccumulate transgenic proteins in their plastids has been demonstrated for two gene constructs using either NPTII or TetC to regulate the expression of bacterial cellulase Cel6A. Previously, the expression of Cel6A to 20-35% of total soluble leaf protein in tobacco was shown in two consecutive field trials. Moving forward, the key challenge was the extraction of active enzymes from the transgenic tobacco leaves hyperaccumulating bacterial cellulases in a cost-effective manner. The study showed that unpurified crude extracts of NPTII and TetC transgenic tobacco leaves recovered similar to 23% and similar to 29% w/w cellulosic sugars from energycane bagasse, respectively. A supplementation of as low as 25% of purified commercial cellulase improved the glucose recovery by 2.9 times (similar to 85% w/w) compared to 100% crude extract, which is comparable to the glucose recovery obtained by commercial cellulases, thereby suggesting a reduced requirement of commercial cellulases leading to a cost reduction of 75% for biorefineries. Assuming a stable 40% cellulase yield in total soluble protein under field conditions and multiple harvests (one to three) a year, the study estimates that the potential cost for saccharification of 1 t of lignocellulosic biomass can be reduced to 67-200 USD by using crude leaf extracts of transgenic tobacco. (c) 2026 The Author(s). Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.
In this study, a green extraction strategy was developed for the recovery of antioxidant phenolics and flavonoids from Urtica dioica leaves using deep eutectic solvents (DESs). Seven DESs consisting of lactic acid (La) and ethylene glycol (Eg) at different molar ratios (1:1, 1:2, 2:1, 1:3, 3:1, 1:4, and 4:1) were prepared and screened based on the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Principal component analysis (PCA) identified La:Eg (1:4) as the best-performing DES. The homogenizer-assisted extraction process using La:Eg (1:4) was subsequently optimized using a Box-Behnken design with four variables (solid mass, water content, homogenization speed, and extraction time). Bioactivity was evaluated using TPC, total flavonoid content (TFC), and antioxidant activity determined by DPPH and 2,2 '-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. In addition to modeling and experimental validation, PCA was applied to evaluate the relationships between the optimized extraction conditions and bioactivity indicators, including TPC, TFC, DPPH, and ABTS.
Oxidation of furfural (FF), a bio-based platform chemical, was investigated using a range of iron-, vanadium- and iron-zinc-oxalates supported on silica gel (FeVOx@silica and FeZnOx@silica, respectively) as precursor for FeV@silica and FeZn@silica oxide catalysts and H2O2 as a green oxidant. Furfural oxidation offers a route to valuable C4 diacids and lactones serve as monomers for biodegradable plastics, providing greener alternatives to petrochemicals. FeVOx@silica catalysts containing 5 wt% metal were synthesized following an oxalic-acid-assisted in situ impregnation/deposition method and calcined at 150-300 degrees C All catalysts developed magnetically recoverable properties owing to the presence of the iron oxide phases. Catalysts showed high activity in mild liquid-phase FF oxidation (70 degrees C, 1 atm), achieving nearly complete substrate conversion within 3-4 h. Gas chromatography indicated the formation of two main products: maleic anhydride and 2-furoic acid, with minor observed quantities of 2(5H)-furanone. The addition of a small amount of formic acid (5 vol%), despite having little effect on FF conversion, notably impacted product ratios. Incorporating Zn cations into the Fe-based catalyst (FeZn@silica) led to noticeable improvement of catalyst durability and suppression of the unproductive rapid decomposition of H2O2. FeZn catalyst calcined at 200 degrees C exhibited the highest product yield, whereas patterns obtained upon calcination below 150 degrees C and above 300 degrees C, despite furfural consumption (mineralization), produced much less detectable liquid products (suggesting Fenton-like overoxidation and/or strong adsorption). This work demonstrates an effective green oxidation process for furfural under mild conditions using Earth-abundant metal-based catalysts.
