The conversion of biomass derived ethanol into Sustainable Aviation Fuel (SAF) is gaining attention as aviation seeks practical routes to lower its carbon footprint. Yet, the current alcohol-to-jet (ATJ) pathway still carries several technical and economic burdens. This review looks closely at how process intensification can reshape each stage of this route, from fermentation to catalytic conversion. On the biological side, efforts such as consolidated bioprocessing (CBP), high gravity fermentation (HGF), and in situ product recovery (ISPR) show clear advantages for higher ethanol concentrations, with reduced water use and less strain on downstream purification. In the catalytic steps, recent progress in dehydration with zeolites (HZSM-5, SAPO-34, gamma-Al2O3), metal modified catalysts, and hybrid structures has improved activity and selectivity while slowing catalyst deactivation, particularly by limiting coke formation. These advances are crucial for producing the light olefins needed for jet-range hydrocarbons. Further improvements in oligomerization and hydrogenation guided by better control of acidity, pore structure, and metal sites help steer products toward the C8-C16 range required by aviation standards. Reactor designs such as fluidized beds and membrane-assisted systems provide additional gains by improving heat management and continuous catalyst renewal. Together, these developments at different steps can bring alcohol derived biojet fuel closer to commercial competitiveness.

This study demonstrates the urgent need for sustainable solutions to reduce the environmental pollution caused by plastic waste and domestic wastewater discharge. To address this challenge, the microalga Spirulina has been shown as an effective resource for sustainable bioproduct production while simultaneously enabling the valorization of domestic wastewater (DWW). The algae was cultivated for a period of 16-days in DWW, restuls revealed that the biomass productivity increased steadily reaching a maximum of 0.83 g L-1 on day 12. Meanwhile, the methanol-water solvent combination supported for the highest phycocyanin extraction of about 22.5 mg L-1 from the Spirulina biomass. The residual algal biomass further utilized for the production of polyhydroxyalkanoates (PHAs) and biochar. Fourier transform infrared (FTIR) spectroscopy analysis of Spirulina-derived PHA revealed characteristic O-H and C-H stretching bands at 3270.1 and 2979.2 cm(-1), respectively. The band at 1626 cm(-1) attributed to C=O stretching, though partial purification. The presence of CHs bending at 1387 cm(-1) and strong ester C-O-C vibration in the 1241.6 cm(-1) region confirms the presence of polymer, indicating functional groups of PHA. The PHA-bioplastic film shows a uniform thickness of 0.12 +/- 1 mm, water absorption 16%, water solubility 33.27% and balanced chemical resistance, indicating the biodegradability of the material. In addition, torrefaction of the residual biomass produces biochar yield of 31%, demonstrating effective biomass valorization. Thermogravimetric analysis shows that the torrefied biochar contained lower volatile matter, higher fixed carbon content and improved thermal stability. This integrated approach shows the potential of DWW as an efficient medium for sustainable Spirulina cultivation, enabling pigment recovery and valorization of residual biomass into bioplastic and biochar.

This comprehensive review examines nitrosamine impurities, potent carcinogens formed through amine-nitrite reactions, which are predominantly found in pharmaceuticals, food, cosmetics, and environmental sources. Given recent pharmaceutical recalls and growing concerns about developmental toxicity, this review consolidates current knowledge on nitrosamine sources, detection methods, and health effects, with a special focus on at-risk maternal-fetal-infant groups. Recent evidence indicates widespread nitrosamine contamination, resulting in over 1,400 drug recalls for exceeding the acceptable level of 26.5 ng/day. The FDA's August 2023 guidelines introduced five potency categories, each with an adequate intake limit ranging from 26.5 to 1,500 ng/day. Maternal nitrosamine exposure has been linked to neural tube defects, limb deficiencies, and heart malformations. New electrochemical sensors can now detect levels as low as 1.47 nM, although traditional chromatographic methods remain the most common. Nitrosamines can cross the placental barrier, and tobacco-specific nitrosamines (TSNAs) are particularly associated with fetal alcohol spectrum disorder (FASD). Multiple exposure routes during pregnancy include contaminated medications, drinking water (NDMA levels between 2 and 51.8 ng/L), processed foods, and secondhand smoke. Nitrosamine exposure is a significant yet modifiable risk factor for adverse developmental outcomes. The review highlights critical knowledge gaps, including human dose-response relationships, long-term developmental effects, and optimal prevention strategies. Recommendations include expanding surveillance of pediatric medications, establishing age-specific exposure limits, promoting maternal education programs, and adopting nitrite-free manufacturing processes. By integrating toxicological, analytical, and public health perspectives, this work presents an evidence-based framework to protect maternal and child health, and underscores urgent research priorities in this evolving field.

The persistent trade-off between carbohydrate digestibility and preservation of the native lignin structure hampers integrated lignocellulose valorization. Herein, we designed a reactive ternary deep eutectic solvent (DES) that integrated fractionation and in situ lignin arylation into a single solvent platform under mild conditions. The ternary DES redirected benzylic reactivity toward selective α-arylation, suppressing unordered condensation and yielding well-defined arylated lignin with 85.5% β-O-4' retention. Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (1H NMR), density functional theory (DFT), and an independent gradient model based on Hirshfeld partition analyses consistently supported a reconfigured local hydrogen-bonding topology. The feature is a cooperative dual-donor O-H···Cl environment that likely contributed to enhanced lignocellulose fractionation efficiency and increased arylated lignin yield. The system yielded 21.4 wt % arylated lignin, versus 15.8 wt % for the formic acid-syringol control, together with 92.8% cellulose recovery. This work establishes a solvent-engineering strategy for coupling controlled lignin transformation with high carbohydrate recovery.

Microwave-assisted pyrolysis (MAP) has emerged as a promising thermochemical conversion route for sustainable bioenergy production from different biomass. MAP has recently seen widespread applications in the pyrolysis industry due to its fast-heating rate and ease of handling. However, the potential of MAP to convert various biomasses into biofuel remains largely underexplored. Besides that, new strategies to increase the overall efficiency and scalability of MAP technology are still being identified. This review critically analyses recent advancements in MAP for biomass conversion to biofuels. It summarizes the fundamentals of MAP, including microwave heating, pyrolysis pathways of different biomasses, and the influence of operating parameters on product distribution. Major limitations, such as high equipment cost, scalability challenges, and safety concerns, are highlighted. The review further identifies key research gaps in catalyst development, reactor design, and process optimization, while also incorporating techno-economic assessments from lab- and pilot-scale studies to evaluate the commercial potential of MAP technology. In the future, Techno-economic analysis (TEA), Life cycle assessment (LCA) of MAP, and machine learning need to be employed to improve process performance and commercial viability. More research is required to understand heat transfer mechanisms and overall energy efficiencies of MAP. Addressing these areas can improve process performance and facilitate its commercial implementation. The review provides the most modern and advanced level of development of MAP and would help to understand the fundamentals and bottlenecks of this technology.

Lactic acid (LA) is a top platform chemical with diverse applications in various industrial sectors. Sugarcane bagasse (SCB) is a significant waste stream during sugarcane processing. Our previous work was focused on the biomanufacturing of LA using fermentable sugars from SCB and techno-economic analysis. The current study evaluated the life cycle assessment (LCA) of SCB-based LA manufacturing for three different routes using the process models based on industrial-scale biorefinery-acid pretreatment & fermentation integrated with reactive distillation (ARD), alkali pretreatment & fermentation integrated with reactive distillation (AkRD), and alkali pretreatment & fermentation integrated with distillation (AkD). The environmental impacts were evaluated using attributional and consequential life cycle assessment (aLCA and cLCA). While aLCA was used to identify process hotspots by proportionally allocating environmental impacts, long-term impacts were assessed through cLCA by accounting for avoided products and additional burdens resulting from the upstream and downstream consequences of the processes. The aLCA analysis indicated that ARD had a 30-36 % superior environmental performance compared to AkRD and AkD, based on midpoint & endpoint impacts. The cooling water (45-47 %) and steam (27-29.1 %) during distillation, along with chemicals (18.4-24.2 %) in pretreatment and fermentation, were identified as environmental hotspots, with the respective values representing their proportionate contributions to the midpoint impacts across all scenarios. The cLCA depicted that LA recovered from the processes could offset environmental impacts by 34-44.2 %, emphasizing the long-term benefits of replacing the conventional LA manufacturing process. Moreover, valorisation of CO2, gypsum, and steam as by-products could significantly reduce environmental impacts. The process heat integration pinch technology further reduced steam and cooling water demands, cutting the impact by 26-27.5 %. These findings emphasize the importance of water recycling and energy integration for improving the overall sustainability of SCB to LA valorisation.

Growing environmental concerns associated with the accumulation of petroleum-based plastics have intensified interest in sustainable materials derived from renewable and waste resources. Although numerous reviews have discussed individual biopolymers or specific aspects of biodegradable plastics, a comprehensive evaluation integrating waste feedstocks, material performance, environmental sustainability and commercialization remains limited. This review addresses this gap by providing a multi-criteria assessment of waste-derived biopolymers as sustainable alternatives to conventional petroleum-based plastics. Natural-source biopolymers, microbial biopolymers and chemically synthesized bio-based biodegradable polymers are critically evaluated with respect to their waste-derived feedstocks, production pathways, physicochemical properties, functional modifications and end-of-life management. Particular attention is given to the influence of plasticizers, nanofillers, polymer blends and bioactive additives on mechanical, thermal, barrier and degradation properties. The review further compares decentralized and centralized production strategies and critically examines life cycle assessment and techno-economic studies to identify environmental trade-offs, cost drivers and commercialization barriers. Current evidence demonstrates that waste-derived feedstocks can substantially improve resource efficiency and support circular bioeconomy objectives while reducing dependence on virgin biomass. However, large-scale implementation remains constrained by feedstock variability, production costs, performance limitations, inconsistent biodegradation under real disposal conditions and inadequate waste management infrastructure. Future progress will require standardized sustainability assessment methods, advanced material engineering and integrated waste valorization strategies to enable wider industrial adoption of waste-derived biopolymers. Waste-derived biopolymers from agricultural and industrial residues support circular resource utilization. Material modification through blending, plasticization and nanofillers significantly improves biopolymer performance. Selected waste-derived biopolymers achieved high biodegradation under controlled composting and soil conditions. Life cycle evidence supports waste-derived biopolymers as lower-impact alternatives to conventional petroleum-based plastics under optimized production systems.

Urban stormwater runoff is increasingly recognized as a key yet insufficiently characterized pathway for the dissemination of microplastics (MPs) and antibiotic resistance genes (ARGs), but their time-resolved co-occurrence during individual rainfall events remains poorly understood. Water quality indicators (SS, TN, TP, TOC), MPs, tire and road wear particles (TRWPs), and ARG abundances were monitored from runoff initiation to recession during a 90-min rainfall event. First, MPs and TRWPs showed an early-event first-flush pulse: MP counts declined from ∼3100 particles/L at 0 min to 480 particles/L at 10 min, whereas TRWPs increased from 3313.78 μg/L at 0 min to 3931.46 μg/L at 10 min and then fell to 62.96 μg/L at 90 min. Detected MPs were yielding an event mean concentration of 415.78 particles/L (total load: 1.3 × 108 particles). Second, ARG abundances ranged from 105 to 109 copies/L, and sul1 showed the highest event load (1.1 × 1014 copies). In addition, Pearson correlation and redundancy analyses revealed strong associations among MPs, TOC/TN, and several ARGs (sul1, qnrS, floR; r > 0.7), whereas TRWPs showed weaker links with ARG profiles. These results further indicate that a subset of ARGs co-varied with particulate organic matter and MPs during early runoff based on correlation analyses, while other genes (e.g., ermB) follow distinct pathways. Finally, the study provides field-based evidence of co-occurrence patterns between MPs and selected ARGs and suggests that routinely monitored indicators may enable proxy-based screening of micro-pollutant dynamics. Although derived from a single event, the dataset underscores the importance of first-flush control and multi-event validation for improved assessment of ARG dissemination via stormwater.

Anaerobic digestion of chicken manure (CM) with high-solid content is typically constrained by ammonia nitrogen accumulation, which influences the microbial activity and methane yield (MY). A strategy of recycling stripped biogas and co-digestion was developed to reduce ammonia nitrogen accumulation and increase MY in a semi-continuously-stirred tank reactor (semi-CSTR) using CM as feedstock (total solid, 10%). The experimental results demonstrate that the stripping strategy can improve hydrolysis efficiency and reduce total ammonia nitrogen, free ammonia nitrogen, and total volatile fatty acids concentrations by 11%, 14%, and 20%, respectively. The soluble chemical oxygen demand (SCOD) removal efficiency and MY were improved by 23% and 37%, respectively compared to the no-stripping operation. In the integrated in-situ ammonia stripping with co-digestion study, with the addition of co-substrate (glucose, sunflower oil, and peptone), which was optimized by a central composite design (CCD) model, resulted in increased biogas yield and MY yield by 39% and 21% over the no-stripping method. The process also evidenced a lower TVFA concentration than the control, inferring the efficient conversion of metabolites towards methane production. This technology could be utilised in high-ammonia waste/wastewater digestion.

Bioenergy with carbon capture, utilization, and storage (BECCUS) is a competent technology with the potential to address global climate change challenges. However, its deployment faces significant hurdles across technological, economic, and policy domains. The production of biofuels including ethanol, methane, butanol, and biogas is accompanied by the release of carbon dioxide (CO2). This CO2 can be incorporated into organic molecules through various biochemical routes as part of the metabolic mechanisms of carbon absorption. The efficiency of these carbon assimilation pathways can be improved through ongoing developments in metabolic engineering, which can increase the production of valuable bioproducts, improve carbon sequestration, and support efforts to mitigate climate change. The present review recognizes critical avenues for advancing BECCUS, emphasizing market mechanisms, technological innovations, and cross-sector integration in both developed and developing countries such as India. The review recommends policy modifications aimed at establishing a transparent framework related to carbon pricing, emission trading systems, and proper certification mechanisms for biogenic carbon utilization. These modifications, coupled with the integration of renewable energy systems, would not only stimulate BECCUS adoption, but also foster its economic feasibility and sustainability. Additionally, promising technologies such as chemical looping and microalgae-based carbon capture should be technologically scaled up to ensure industrial-level applications. The integration of BECCUS with other sectors is also critical to optimize the impact of this technology on climate change mitigation. Therefore, the present review highlights the need for a robust policy framework, technology-driven innovation, and cross-sector research collaboration to resolve the challenges associated with BECCUS, boost its adoption, and ensure its economic feasibility and environmental sustainability. Moreover, providing regulatory support, augmenting market competitiveness, and aligning research on BECCUS play a transformative role in attaining the goals of the Paris Agreement and promoting environmental sustainability.

Beyond clothing, end-of-life technical textiles and nonwoven products are an additional source of fibre-based waste and environmental impact. Absorbent Hygiene Products (AHPs), i.e. single use, disposable diapers (nappies), adult incontinence and menstrual products, play an important role in supporting the personal hygiene and wellbeing of millions of people worldwide, but their disposal presents considerable waste management and environmental challenges due to their biological contamination, as well as mixed fibre and polymer composition. Despite high rates of consumption, used AHPs remain one of the hardest waste streams to recycle, and most are incinerated or landfilled. Internationally, very little used AHP recycling infrastructure exists, and generating high-value outputs from such waste is highly challenging, mainly due to its multifaceted nature. This review evaluates the potential for an alternative biotechnological approach to recycling based on mycoremediation and biocatalysis of used AHPs (containing cellulose, superabsorbent polymers and synthetic polymers) harnessing fungi to valorise the cellulosic and plastic components of the waste. We focus on the synergistic integration of mycoremediation and precision fermentation techniques as part of a biorefinery model to yield valuable material outputs from used AHPs, such as industrial chemicals and fibre-forming biodegradable polymers for industrial applications, as a basis for new circular economies.

Muconic acid (MA) is characterized by two reactive carboxylic acid groups and two conjugated double bonds, making it a highly valuable industrial platform chemical with significant market potential. It serves as a key intermediate in the manufacturing of important commercial chemical products such as adipic acid and terephthalic acid. The finite fossil-based resources and climate issues due to CO2 emission have necessitated the microbial routes for the production of MA, a potential alternative to fossil-based synthesis. This review provides a comprehensive overview of recent progress in the biological production of MA. The article begins with an outline of the present catalytic routes and known biochemical pathways for MA biosynthesis. The review then focuses on metabolic engineering strategies employed in various microbial hosts including Escherichia coli, Corynebacterium glutamicum, and Pseudomonas putida to enhance MA production from diverse feedstocks such as sugars, aromatic compounds, and lignin-derived substrates. Special attention is given to pathway optimization, host tolerance, and strategies enabling efficient conversion of lignin-derived intermediates within integrated biorefinery frameworks. Key challenges associated with scaling up bio-based MA production to industrial levels are discussed, along with potential strategies for developing robust and efficient microbial cell factories. The review concludes with future perspectives and recommendations to accelerate research progress and development in this field. Comprehensive review of biological muconic acid (MA) production pathways. Overview of biochemical routes for MA biosynthesis from different substrates. Metabolic engineering strategies in E. coli, C. glutamicum, and P. putida. Diverse feedstocks explored: sugars, aromatics, and lignin-derived substrates. Challenges and future perspectives for industrial-scale MA production.

Anaerobic digestion (AD) is widely applied to stabilize wastewater sludge and recover energy, but it increasingly operates in the presence of emerging contaminants such as antibiotics, per- and polyfluoroalkyl substances (PFAS), and plastic particles including microplastics (MPs, < 5 mm) and nanoplastics (NPs, < 1 µm), collectively referred to as micro- and nano-plastics (MNPs) in the substrates. These highly persistent pollutants are routinely detected in wastewater treatment plants and often resist conventional removal, raising concerns about their long-term impacts on public health, ecosystems, and AD performance. On the other hand, full-scale digesters rarely operate under optimal conditions. Inhibitory levels of ammonia, sulfite, heavy metals, and toxic organics frequently induce systems into an “inhibited steady-state”, characterized by reduced biogas production and microbial activity, but without complete system failure. This review explores current knowledge on the fate, transformation, and removal of antibiotics, PFAS, and plastic particles (MPs and NPs) in AD, with a specific focus on these inhibited steady-state regimes. The impact of inhibition on microbial community structure and function, alterations in contaminant sorption and degradation pathways, and its influence on process stability are comprehensively discussed. Particular attention is given to prevention and mitigation strategies, including process optimization, pretreatment, the addition of sorbents and conductive materials, and combined treatment options. By explicitly accounting for realistic, non-ideal operating conditions, this work provides a framework for more accurate risk assessment and for designing robust, economically viable AD systems that can simultaneously manage complex contaminant mixtures while maintaining high treatment performance.

The bioelectrochemical system (BES) is a cutting-edge electrochemical technology for bioremediation and resource recovery during industrial effluent treatment. Its success, however, depends on the urgent need for commercialization and industrial applications. Although there has been noteworthy progress in field trials and scaling up since the previous decade, there have only been a few attempts towards industrialization. The effective implementation of BES at an industrial scale is demonstrated by various companies in the sector, including efforts by multiple organizations focused on advancing BES technology for practical, industrial applications. The present review provides an up-to-date overview of BES implementation for the treatment of industrial effluent to identify existing challenges and industrial outlooks and to discuss the success stories. This represents an early effort to examine the current industrial advancements in BES technology, assessing its readiness for commercial application and future market potential. In the near future, BES will also have a high market value (approximately 2.8 billion USD), and such success stories will entice business partners and stakeholders to invest in commercialization by giving them a realistic view of the technology. Prior to commercialization, upscaling issues and the techno-economic viability of BES technology must be resolved.

This study explores integrating Bitcoin mining with lignocellulosic biorefineries to create an additional revenue stream. Profits from mining can help offset internal costs, reduce business expenses, or lower consumer prices. Using sensitivity analysis and Monte Carlo simulations, this study identifies key profitability drivers, such as electricity costs, hardware expenses, starting year, and operational time. Time emerged as an extremely sensitive factor and showed that delaying mining operations significantly raised production costs and the probability of profitable outcomes. In contrast, longer mining durations had a smaller yet sizable impact. Hardware costs, computational efficiency, and electricity prices also strongly influenced the outcomes. The majority of simulated events showed a loss. Moreover, the model showed that the marginal profitability of mining decreases over time. Nonetheless, the model demonstrated that under favourable conditions, it is possible to integrate Bitcoin mining into biorefineries and other productive ventures, thereby allowing for cost recovery using Bitcoin profits. For a biorefinery to mine Bitcoin and maximise cost recovery, it must start early, access low electricity prices, and preserve hardware capital characterised by low expenditure and high revenues. Finally, a discussion about the opportunities, risks, and regulations is highlighted.

The shift from fossil-derived energy to clean, renewable sources has accelerated due to the demand for sustainable and commercially viable energy solutions. Another possible clean fuel is biohythane, also known as HCNG, which is a blend of bio-CH4 and bio-H-2 with a concentration of 10 and 30 % v/v, respectively. The chemical industries have eventually been utilizing bio-CH4 and bio-H-2 extensively because of their high calorific values of 143 and 55 kJ g(-1), respectively. The bio-H-2 and bio-CH4 have been emerged as promising green energy carriers, offering a broad range of applications in chemical industries, owing to their high calorific value, renewability, and CO2 neutrality. In the pursuit of zero-emission technologies to mitigate the global warming, biohythane is gaining attraction as a potential future fuel. This study explores biohythane production through a sequential two-stage process that converts organic wastes into bio-H-2 and subsequently into bio-CH4, offering an ideal pathway for sustainable biohythane generation. Further, this study provides an overview of key developments and applications in two-stage microbial synthesis of bio-CH4 and bio-H-2, alongside insights into the demand, supply, and current global status of biohythane production. This study delves into the acidogenic phase, where bio-H-2 is produced, and the methanogenic phase, which yields bio-CH4. While detailing the biochemistry, critical factors, challenges, and limitations of an integrated bio-hythane production system are discussed. Finally, the strategies for enhancing bio-H-2 and biohythane production and an outlook on their commercialization potential are discussed.

External magnetic field technology has been utilized in wastewater treatment. In this study, a current-powered solenoid magnetic field is implemented beyond a dual-chamber cubed MFC to investigate the effects of various current strengths (0, 20, 40, 60, and 80 mA) on bioelectricity generation and microbial community diversity in the anode chamber. The results show that adding a solenoid magnetic field (MF) can increase both electricity performance and pollutant removal efficiency. Applying a solenoid MF powered by 80 mA (MF-80) resulted in a peak current density of 130 ± 18.2 mA/m² and a power density of 66.3 ± 16.8 mW/m², which are 2.1 times and 3.6 times higher, respectively, compared with the value from MF-0. Moreover, the coulombic efficiency can also be increased from 12.0 to 23.6

Per- or polyfluoroalkyl compounds (PFASs) are recognized as emerging contaminant, with perfluorooctane sulfonate (PFOS) being one of the most extensively utilized PFASs due to its great chemical stability. However, knowledge of the bio-chemical behavior, the toxicity of PFOS and its mechanisms of interfacial binding to microorganisms remain inadequately validated. In this study, the biotoxicity of PFOS and its molecular interfacial adsorption mechanism in anaerobic digestion were investigated. The results showed that the tightly bound EPS (TB-EPS) of anaerobic microorganisms could defend against the biotoxicity of PFOS to some extent by physical adsorption and chemical binding, the exposure to PFOS might produce a greater disturbance to methanogenic archaea. With the increase of PFOS, acid-producing bacteria (APB) and methanogenic archaea showed different resistance to PFOS, suppressing cumulative methane production by up to 91.64 %. On the contrary, APBs were more tolerant, and fatty acids accumulated up to 2194.27 mg/L. Metagenomics analysis further confirmed that functional genes associated with fatty acid biosynthesis (fas, FAS2, fabK, etc.) were significantly enriched (approximately 85.29 %) whereas the relative abundance of genes associated with methanogenesis (acs, comA, mcrB, etc.) were decreased (up to 65.96 %). Molecular docking results suggested a potential route for PFOS cellular entry, as it was observed to bind to the substrate-binding protein of the ATP-binding cassette (ABC) transporter and interact with key functional enzymes, which led to the inhibition of methanogens. This study provides novel insights into the molecular blocking mechanism by which PFOS disrupts carbon metabolic flux through the selective inhibition of methanogenic archaea, rather than through a general suppression of acidogenic bacteria.

A techno-economic assessment was performed for a multi-feedstock lignocellulosic biorefinery that converts Norwegian tomato and cucumber crop residues, spent coffee grounds, and brewers' spent grain into value-added chemicals. Scenario 1 integrates dilute oxalic-acid hydrolysis (DAH) with oxalic-acid-assisted ethanol-organosolv delignification (ORG) and co-produces ethanol, lactic acid, ethanol-organosolv lignin, furfural, 5-hydroxymethylfurfural, and electricity. Scenario 2 omits the lactic-acid train, whereas Scenario 3 employs DAH, only without the ORG or lactic acid sections. Mass and energy balance simulations informed discounted cash flow models for feedstock capacities of 25 and 250 kt/yr. At 25 kt/yr, all scenarios were unprofitable. Scaling to 250 kt/yr improved outcomes for Scenarios 1 and 3, yielding 11.5-12.6 % internal rate of return (IRR), US$ 183.7-185MM net present value (NPV). ORG inclusion reduced overall returns due to elevated capital and operating costs. Integrated operation produced negative net unit production costs, indicating internal cost crosssubsidization among co-products. Sensitivity analysis identified revenue and operating expenditures as primary determinants of NPV and IRR. Monte Carlo analysis estimated a 93.7 % probability of profitability in all simulated outcomes. The findings underscore the importance of scaling up and diversifying product portfolio in future biorefinery deployments.

The present work focuses on the depletion of fossil fuel stock, which is driving the search for alternative energy resources. In view of this, biomethane based on natural gas is an effective alternative for the reduction of fossil fuel resources such as oil, petroleum, natural gas and coal. Its production deals with increased concerns of proper disposal of organic waste as well as regulation of global emissions of greenhouse gases. Organic residues in anaerobic digestion (AD) and thermochemical processes producing biogas, which in turn is upgraded to biomethane that could be a viable path towards sustainability. Techniques such as co-substrate dosing could increase the yield of biomethane was addressed in detail. The findings of this research focus on biomethane importance, the type of materials utilized and technologies in their production. It also explores its application in transportation, electricity and heat generation, describing its participation towards reduction to emission of greenhouse gases. It is important to provide critical analysis of biomethane prospects and its associated difficulties, as well as the numerous advantages it offers as a prospective replacement for traditional energy sources. This includes the current and future responsibilities, new trends in renewal energy legislation and market development. As the world attempts to make sustainable energy systems, there can be no doubt that biomethane will play an integral part in the movement towards efficient and greener energy systems.