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AbstractThis work designed a continuous-flow tubular reactor for rapidly and scalably harvesting the metal-organic framework (MOF) of UiO-66(Zr)-NH2. The experimental conditions, including temperature (110–140 °C), holding time (10–30 min), and CH3COOH/H2N-BDC molar ratio (100–250), were carried out to survey their impacts on the product yield and quality. The highest yield and production rate of ∼72% and ∼1.55 g h−1 were obtained at 130 °C, 20 min, and CH3COOH/H2N-BDC ratio 200. The temperature and modulator content significantly influenced MOFs’ crystal morphology, crystallinity, and porosity. Besides, the adopted method also successfully produced UiO-66 and UiO-67 MOFs with high production rates. The adsorptive denitrogenation (ADN) performances were carried out using liquid fuel models containing quinoline (QU) and 2-methyl pyrrole (MP). In batch mode adsorption, the UiO-66-NH2-130-200 sample showed the highest adsorbing quantities of ∼199 and ∼163 mg g−1 for QU and MP, respectively. Furthermore, the prepared MOFs efficiently removed NCCs from liquid fuel under a continuous fixed-bed column process. These demonstrate that modulator-assisted continuous-flow synthesis can be a potential strategy for the scalable harvest of Zr-MOFs with good qualities and high performance in getting rid of NCCs from liquid fuel. [ABSTRACT FROM AUTHOR]

The escalating demand for plastic presents an immense peril to both the environment and humanity. Not only have there been notable advancements in the creation of advanced biodegradable polymers, but there has also been a lack of attention towards tackling the current issue of plastic waste. Processing fuels via plastic waste valorization provides a feasible approach to recycle plastics and mitigating pollution for the improvement of society. This review addresses a comprehensive analysis of various heterogeneous catalysts in the context of plastic pyrolysis to produce fuel, intending to identify an eco-friendly method for recycling garbage. The choice of catalyst has a substantial effect on the disintegration process of waste plastic, dictating the properties of the resulting fuel, encompassing both the amount and the quality. Pyrolysis, an alternative method for addressing the increasing waste disposal issue, is a non-toxic process that does not release hazardous pollutants, in contrast to incineration. The waste plastic serves as a feedstock for pyrolysis process, employing innovative, environmentally friendly catalysts derived from natural and other sources, to generate fuel oil that possesses similar physical characteristics to the diminishing petroleum-based fuels. This critical review analyzes the impact of different heterogeneous catalysts on the process of transforming waste plastic to produce fuel through pyrolysis. Heterogeneous catalysts are crucial to the process of turning discarded plastics into oil, offering significant potential for improving not only economic and environmental conditions but also benefiting both industry and society. [ABSTRACT FROM AUTHOR]

The corrosion and material evaluation study in (a) water‐based simulated black liquor and (b) water‐based simulated black liquor at super‐critical conditions was successful. The conclusion from the testing program was that the most resistant alloy for the defined conditions is the chromium‐rich carbon steel candidate P91 (UNS K91560). This is a type of creep strength‐enhanced ferritic alloy, which is steel designed to retain strength at high temperatures. The P91 abbreviation represents the material's chemical composition, that is, 9 wt% chromium (Cr) and 1 wt% molybdenum (Mo). Further work is required to conclude the corrosion resistance for the P91 quality at supercritical conditions in the welded condition and to better understand caustic corrosion mechanisms. [ABSTRACT FROM AUTHOR]

Boron is a potential fuel for energetic materials due to its high volumetric and gravimetric energy density. However, its application has long been constrained by ignition difficulties and insufficient combustion. In this study, a mixture of NGO and GF was introduced as an additive to boron particles. We prepared NGO/GF-coated B complexes and performed several characterizations, showing that NGO combined with GF had a good coating effect on B. The combustion heat was measured by an oxygen bomb calorimeter, while the combustion mechanism was proposed. Its effect on the thermal decomposition behavior of AP was also analyzed. The results showed that the combustion efficiency of NGO/GF-modified B was significantly improved, which was 14.34% higher than that of pure B. This enhancement was attributed to the synergistic effect of NGO and GF, which promoted ignition and combustion by releasing heat, gases, and fluorocarbon radicals. In addition, both boron and NGO/GF-modified boron accelerated the decomposition of AP, especially, in the presence of NGO/GF, the decomposition temperature of AP was advanced by 73.2 °C compared to that in the presence of boron alone. These findings may provide valuable theoretical guidance for the design and potential application of NGO/GF modified boron in energetic materials. [ABSTRACT FROM AUTHOR]

Brick manufacturing is a major global industry employing millions of workers, yet it remains heavily reliant on outdated, polluting technologies. This study aims to categorize the brick kilns according to the way each of them functions. Also, it focuses on the fuel used and its properties. Another goal of the current research is to bring out the effects brick industry has on the environment and the people who work and live near the brick kilns. Conclusively, the current study underscores the urgent necessity for improvement and for the adoption of the strategies outlined to guide the brick manufacturing field towards a more sustainable future. [ABSTRACT FROM AUTHOR]

This article investigates non-price determinants of fuel choice and consumption decision of households in rural India. Fuel consumption varies at household levels from traditional fuels like firewood and chips to modern fuels such as LPG. Fuel consumption is based on two-stage decisions: (a) whether households participate or not; and (b) how much they consume if they participate. Significant factors might be different in the first stage and the second stage due to certain socio-economic or non-price factors. Applying Cragg's double hurdle model on NSSO data, this article finds determinants of fuel choice and its consumption at the household level in rural India. Empirical findings indicate that income significantly determines quantity consumption, not choice decision. The role of assets in determining fuel choice and quantity decision is also considered through a comparative study including and excluding landholding, a major asset in rural India. Bottom and top quintile results suggest that advancement of the economic position of the households changes their attitude towards dirty fuel selection and consumption. Firewood fuel consumption decreases with the rising education level of the household head, especially women-headed households. Increased awareness through education and removing social barriers might help to reduce dirty fuel consumption, and India might move towards Sustainable Development Goal. JEL Codes: C20, C13, C34, O13, Q23, Q40, Q56 [ABSTRACT FROM AUTHOR]

Coal water slurry (CWS) has been considered a cleaner and sustainable alternative to coal. However, the challenging suspension of coal particles in CWS has created a major obstacle to its use in industry. This study presents a novel approach to enhance the stability and rheological properties of coal water slurry (CWS) through the utilization of carboxyalkylated lignin (CL) as a dispersant. The generated CL samples had high water solubility of around 9 g/L and a charge density of around 2 mmol/g. All CLs were able to stabilize the coal suspension, and their performance decreased due to the increase in the alkyl chain length of carboxyalkylated lignin. Carboxymethylated lignin (CL-1) improved the stability of the coal suspensions with the lowest instability index of less than 0.6. The addition of CLs reduced the contact angle of the coal surface from 45.3° to 34.6°, and the increase in the alkyl chain length hampered its effect on contact angle changes. The zeta potential measurements confirmed that the adsorption of CL enhanced the electrostatic repulsion between coal particles in suspensions, and the zeta potential decreased with the increased alkyl chain length of CLs due to increased steric hindrance. The rheology results indicated that CLs demonstrated shear thinning behavior. This innovative method showcases the affinity of carboxyalkylated lignin to improve the performance of CWS, offering an environmentally friendly alternative for producing a cleaner product, i.e., sustainable coal water slurry, with improved suspension stability. [ABSTRACT FROM AUTHOR]

Hydrogen mobility embodies a promising solution to address the challenges posed by traditional fossil fuel-based vehicles. The use of hydrogen in small heavy-duty road vehicles based on internal combustion engines (ICEs) may be appealing for two fundamental reasons: Direct electrification seems less promising in heavy-duty transport systems, and fuel cell-based hydrogen vehicle implementation may not proceed at the expected pace due to higher investment costs compared to ICEs. On the other hand, hydrogen combustion is gaining attractiveness and relies on robust and cheap technologies, but it is not the only renewable solution. In this framework, this work presents a methodology to assess the Well-to-Wheel primary energy consumption and CO2 emissions of small heavy-duty vehicles. The methodology is applied in a real case study, namely a passenger coach traveling on a 100 km mission in non-optimized conditions. Therefore, the suitability of hydrogen is compared with standard diesel and other alternative diesel-type fuels (biodiesel and synthetic diesel types). Hydrogen shows competitivity with standard diesel from the point of view of CO2 emission reduction (−29%) while it hides a higher primary energy consumption (+40%) based on the current power-to-hydrogen efficiency declared by electrolyzer manufacturers. Nonetheless, HVO brings the highest benefits both from the point of view of primary energy consumption and emission reduction, namely −35% and 464–634 kgCO2/100km avoided compared to hydrogen. Moreover, the availability of HVO—like other biofuels—does not depend on carbon from CO2 capture and sequestration systems. [ABSTRACT FROM AUTHOR]

This study introduces a novel method for hydrogen fuel generation using ultrasound technology through the disassociation of water into hydrogen and oxygen. The proposed experimental setup comprises several key components: a power supply, an ultrasonic generator, two transducers, a reactor vessel, two vapor traps, a condenser, a valve, a hydrogen storage, a humidity sensor and a hydrogen measurement sensor. The system operates at a power of 100 W and a frequency of 40 kHz, and the reactor vessel contains 2L of solution. The study results show a variability in hydrogen production rates under different experimental conditions. The distilled water used in the experiments at 25 °C produces hydrogen at a rate of 0.05 μmol/min, which increases to 0.066 μmol/min at 70 °C. The tap water gives hydrogen production rates ranging from 0.044 μmol/min at 25 °C to 0.06 μmol/min at 70 °C. The lake water produces hydrogen at rates between 0.036 μmol/min and 0.054 μmol/min, while the wastewater ranges from 0.028 μmol/min to 0.044 μmol/min. The present study investigates the effect of CO 2 injection into the sonoreactor on the system performance and shows that hydrogen production rates increase over a 20-min period for the water resources, with higher CO 2 flow rates leading to improved production rates. These findings demonstrate the potential of ultrasound technology for eco-friendly hydrogen production, marking a promising alternative to conventional methods and contributing valuable insights to the field of sustainable energy. [Display omitted] • The study investigates an innovative sonic method of hydrogen generation. • The present system is proposed for clean hydrogen generation. • The experiments are conducted at a frequency of 40 kHz and power of 100 ± 10 W. • The hydrogen generation is tested under various water sources at different temperatures. • The hydrogen generation is assessed by injecting CO 2 into the sonoreactor solution. [ABSTRACT FROM AUTHOR]

This study investigates the performance and environmental impact of n-butanol blended with Jet-A fuel in turbo engines, aiming to assess its viability as a sustainable aviation fuel (SAF). The research involves the experimental testing of various blends, ranging from low to high concentrations of n-butanol, to determine their effects on engine performance and emissions. The experimental setup includes comprehensive measurements of engine parameters such as thrust, fuel consumption rates, and exhaust gas temperatures. Emissions of sulfur dioxide (SO2), and carbon monoxide (CO) are also analyzed to evaluate environmental impacts. Key findings indicate that n-butanol/Jet-A blends can significantly enhance combustion efficiency and reduce emissions compared to conventional Jet-A fuel. Higher n-butanol concentrations lead to improved thermal efficiency and lower SO2 and CO emissions. This study underscores the potential of n-butanol as an SAF for turbo engines, highlighting its ability to mitigate environmental impacts while maintaining or improving engine performance. This research supports the feasibility of integrating n-butanol into Jet-A blends for turbo engine applications, emphasizing their role in achieving more environmentally friendly aviation operations. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) emerges as an environmentally sustainable oxidant with great potential in diverse fields. However, the efficiency of H2O2 generation via photocatalysis remains suboptimal. Fundamentally, this inefficiency stems from the rapid recombination of photogenerated electron–hole pairs, limited surface or interface activity, restricted solar light absorption, and poor selectivity. Here, we discuss the fundamental mechanisms of photocatalytic H2O2 generation over the key material systems and highlight the most effective design strategies to address the unmet challenges faced by these systems. This review not only discusses fundamental insights into the mechanisms of photocatalytic H2O2 generation but also provides perspectives on future directions for the development of photocatalytic materials with high-efficiency and stability in generating H2O2. [ABSTRACT FROM AUTHOR]

As electric vehicle (EV) adoption increases, transportation services will shift dependence from liquid fuel infrastructure to electric power infrastructure. Since transportation plays a major role in disaster response and recovery, this shift in dependence has important implications for coupling electrical grids and transport resilience. The implications for the electrical grid for southwestern British Columbia, Canada are examined, motivated by this region's high EV adoption rate and the potential for a catastrophic magnitude 9.5 earthquake. A comparison of the resilience of the electrical infrastructure compared to the fuel infrastructure is provided and approaches for increasing resilience in the region for EV power supply are discussed. This paper compiles lessons learned from past large earthquakes in Chile, Japan, and New Zealand with consideration given to successes and failures. While this paper was written with a focus on southwestern British Columbia, many of the suggestions for increasing power system resilience could be applied in other seismically active locations during the transition to EVs. This paper also considers integrated disaster resilience planning for the changing transport landscape from fuel vehicles to EVs. [ABSTRACT FROM AUTHOR]

CEA has manufactured a series of Fukushima Daiichi fuel debris simulants, either with depleted uranium oxide or with hafnium oxide as a surrogate of UO2. In ex-vessel compositions resulting from an interaction between corium and concrete, the oxidic phase density becomes lighter than that of the metallic phase, which segregates at the bottom. Three of these metallic phases have been mechanically cut at CEA Cadarache with handsaw and with core boring tool in FUJISAN facility. It appeared that two of these metallic blocks were extremely hard to cut (one from a fabrication with uranium oxide, the other from a simulant block) while the last one was more easily cut. The similarities and differences in metallographic analyses (SEM-EDS and XRD) of these three metal blocks will be presented and discussed. This experience provides useful learnings in view of the cutting and retrieval of fuel debris from Fukushima Daiichi. [ABSTRACT FROM AUTHOR]

A roadway path is most commonly perceived as a 3-D element structure placed within its surrounding environment either within or outside urban areas. Design guidelines are usually strictly followed to ensure safe and comfort transportation of people and goods, but in full alignment with the terrain configuration and the available space, especially in urban and suburban areas. In the meantime, vehicles travelling along a roadway consume fuel and emit pollutants in a way that depends on both the driving attitude as well as the peculiar characteristics of road design and/or pavement surface condition. This study focuses on the environmental behavior of roadways in terms of fuel consumption, especially of heavy vehicles that mainly serve the purpose of freight transportation within urban areas. The impact of horizontal and vertical profiles of a roadway structure is theoretically considered through the parameters of speed and longitudinal slope, respectively. Based on theoretical calculations with an already developed model, it was found that the slope plays the most critical role, controlling the rate of fuel consumption increase, as an increase ratio of 2.5 was observed for a slope increase from 2% to 7%. The variation was less intense for a speed ranging from 25 to 45 km/h. The investigation additionally revealed useful discussion points for the need to consider the environmental impact of roadways during the operation phase for a more sustainable management of freight transportation procedures, thereby stimulating an ad hoc development of fuel consumption models based on actual measurements so that local conditions can be properly accounted for and used by road engineers and/or urban planners. [ABSTRACT FROM AUTHOR]

The problem of increasing passenger traffic remains acute for municipal public transport. The value of this indicator is determined by the interest of citizens in this way of making their trips and determines the feasibility of the carrier's operation. The authors conducted a study of the problems of public transport services in large- and medium-sized cities, which found that the population's interest in public urban passenger transport has generally been significantly lost. More than 40% of the city population refuses to travel on public transport, half of the population has questions about the reliability of tariff formation, and the same number of people are not satisfied with the regular route network and schedule. City residents increasingly prefer personal vehicles or taxis for their trips, which negatively affects the revenue side of carriers, as well as the level of social comfort and the quality of life of citizens. Efforts to reduce the operating costs of the carrier are aimed at correcting the current situation with urban transport so that tariffs for transportation are more acceptable for passengers. The formation of tariffs for passenger transportation for transport companies is an urgent and complex task. It is necessary to formulate the tariff in such a way as to cover your own transportation costs in the near future and, at the same time, not exceed the psychological threshold for passengers so as not to cause their negative reaction. In addition, since the transportation of passengers by urban public transport is regulated by the authorities, it is also necessary to provide an economic justification for transportation tariffs. This is difficult in the absence of substantiated indicators of consumption rates of material resources in the transport process. To solve this problem, it is necessary to carefully analyze the current costs of operating the bus fleet, as well as forecast costs for future periods. At different periods, researchers have proposed various approaches for planning the cost of operating a bus fleet. The approach we propose is to use standardization of the consumption of material resources, considering the individual operating conditions of the bus fleet and the influence of various factors. [ABSTRACT FROM AUTHOR]

We use case studies to explore the impact of changed fire regimes on vegetation structure and fuel risk in Southeast Queensland, Australia. Multiple studies report high intensity wildfires promote excessive shrub and sapling densities, which increase elevated fuel hazard. We argue asset protection burns in dry conditions can cause similar vegetation thickening to an intense wildfire, which increases fire severity risk due to increased elevated fuel loads. We demonstrate regular low intensity burning with adequate soil moisture can achieve fuel reduction objectives. This provides a longer-term solution that promotes risk reduction to communities, whilst leading to better ecological outcomes and reduced cost of implementation over the long-term. Case studies explore the impact of fire regimes on vegetation structure and fuel risk in Southeast Queensland, Australia. High intensity wildfires and asset protection burns can promote excessive shrub and sapling densities, increasing elevated fuel loads. We recommend burns are done under moist, mild conditions to maintain an open forest structure and minimise fire hazard. This article belongs to the Collection Fire and Climate. [ABSTRACT FROM AUTHOR]

Abstract Oleaginous green microalgae are often mentioned in algae-based biodiesel industry, but most of them belong to specific genus (Chlorella, Scenedesmus, Botryococcus and Desmodesmus). Thus, the microalgal germplasm resources for biodiesel production are limited. Mutagenesis is regarded as an important technology for expanding germplasm resources. The main purpose of this study is to screen microalgae strains with high carbon dioxide tolerance and high lipid content from mutants derived from indigenous non-oleaginous green microalgae species—Ulothrix SDJZ-17. Two mutants with high CO2 tolerance and high lipid content genetic stability were obtained from the mutants by high-throughput screening, named Ulothrix SDJZ-17-A20 and Ulothrix SDJZ-17-A23. In order to evaluate the potential of CO2 fixation and biofuel production, A20 and A23 were cultured under air and 15% CO2 (v/v) conditions, and their wild-type strains (WT) were used as controls. Under the condition of high CO2 concentration, the growth performance and lipid production capacity of mutant strains A20 and A23 were not only significantly better than those of wild strains, but also better than those of their own cultured under air conditions. Among them, A23 obtained the highest LCE (light conversion efficiency) (14.79%), Fv/Fm (maximal photochemical efficiency of photosystem II) (71.04%) and biomass productivity (81.26 mg L−1 d−1), while A20 obtained the highest lipid content (22.45%). Both mutants can be used as candidate strains for CO2 fixation and biofuel production. By ARTP (atmospheric and room temperature plasma) mutagenesis with high-throughput screening, the mutants with higher CO2 tolerance, photosynthetic efficiency and lipid productivity can be obtained, even if they are derived from non-oleaginous microalgae, which is of great significance for enriching the energy microalgae germplasm bank, alleviating the global warming and energy crisis.

Abstract Background Sweet sorghum (Sorghum bicolor) displays an excellent potential to serve as a non-food bioenergy feedstock for bioethanol production in China due to its high potential yield on marginal lands. However, few studies have been conducted on the potential of sweet sorghum yield and appropriate industrial models in different marginal regions in China. This study explored the spatial distribution of potential sweet sorghum production using the Decision Support System for Agrotechnology Transfer (DSSAT) model and proposed three typical industrial models of sweet sorghum industry to calculate their economic and ecological benefits. Results The results indicate that considering the factors of land use, annual precipitation, soil salinity, soil pH, and accumulated temperature, approximately 32.23 million ha of marginal land are suitable for sweet sorghum cultivation in China, and 130 million tonnes (t) of ethanol can be produced. Further, the development of the sweet sorghum industry under the three models can generate 1425.49 billion CNY potential, approximately accounting for 3.57% of industrial added value in China if measured against 2023 levels, and reduce CO2 emissions by 4.68 million t. Conclusions This study provides an innovative perspective for the multi-industry large-scale promotion of sweet sorghum in different marginal lands based on the high spatial resolution Geographic Information System (GIS) data by the DSSAT model with a Life Cycle Assessment (LCA) method, and this applies not only to China but also to the worldwide and other types of energy plants.

Abstract Glycolipid biosurfactant, sophorolipids (SLs) and rhamnolipids (RLs) can be widely used in agriculture, food and chemical industries. The different physicochemical properties of SLs and RLs, such as hydrophilic lipophilic value (HLB) and critical micelle concentration (CMC), determine they have different application focus. Researchers are still hoping to obtain new glycolipid surfactants with unique surface activities. In this study, we successfully transformed two rhamnosyltransferase genes rhlA and rhlB from Pseudomonas aeruginosa to the sophorolipid-producing Starmerella bombicola CGMGG 1576 to obtain a recombinant strain was Sb rhlAB . Two novel components with molecular weight of 554 (C26H50O12) and 536 (C26H48O11) were identified with the ASB C18 column from the fermentation broth of Sb rhlAB , the former was a non-acetylated acidic C14:0 glycolipid containing one glucose and one rhamnose, and the latter was an acidic C14:1 glycolipid containing two rhamnoses. With the Venusil MP C18 column, one new glycolipid component was identified as an acidic C18:3 glycolipid with one rhamnose (C24H40O7), which has not been reported before. Our present study demonstrated that novel glycolipids can be synthesized in vivo by reasonable genetic engineering. The results will be helpful to engineer sophorolipid-producing yeast to produce some specific SLs or their derivatives in more rational and controllable way.

Abstract Background Escherichia coli JU15 is a metabolically engineered strain capable to metabolize C5 and C6 sugars with a high yield of d-lactic acid production at its optimal growth temperature (37 °C). The simultaneous saccharification and fermentation process allow to use lignocellulosic biomass as a cost-effective and high-yield strategy. However, this process requires microorganisms capable of growth at a temperature close to 50 °C, at which the activity of cellulolytic enzymes works efficiently. Results The thermotolerant strain GT48 was generated by adaptive laboratory evolution in batch and chemostat cultures under temperature increments until 48 °C. The strain GT48 was able to grow and ferment glucose to d-lactate at 47 °C. It was found that a pH of 6.3 conciliated with GT48 growth and cellulase activity of a commercial cocktail. Hence, this pH was used for the SSF of a diluted acid-pretreated corn stover (DAPCS) at a solid load of 15% (w/w), 15 FPU/g-DAPCS, and 47 °C. Under such conditions, the strain GT48 exhibited remarkable performance, producing d-lactate at a level of 1.41, 1.42, and 1.48-fold higher in titer, productivity, and yield, respectively, compared to parental strain at 45 °C. Conclusions In general, our results show for the first time that a thermal-adapted strain of E. coli is capable of being used in the simultaneous saccharification and fermentation process without pre-saccharification stage at high temperatures.

Abstract Background Hydroxy fatty acids represent an emerging class of compounds with promising applications in the chemical, medicinal and functional food sectors. The challenges associated with their chemical synthesis have spurred exploration of biological synthesis as an alternative route, particularly through the use of fatty acid hydratases. Fatty acid hydratases catalyse the regioselective addition of a hydrogen atom and a hydroxyl group from a water molecule to the carbon–carbon cis-double bond of unsaturated fatty acids to form hydroxy fatty acids. Despite having been discovered in the early 1960s, previous research has primarily focused on characterizing single fatty acid hydratase variants with a limited range of substrates. Comprehensive studies that systematically examine and compare the characteristics of multiple variants of fatty acid hydratases are still lacking. Results In this study, we employed an integrated bioinformatics workflow to identify 23 fatty acid hydratases and characterized their activities against nine unsaturated fatty acid substrates using whole-cell biotransformation assays. Additionally, we tested a dual-protein system involving two fatty acid hydratases of distinct regioselectivity and demonstrated its suitability in enhancing the biosynthesis of di-hydroxy fatty acids. Conclusions Our study demonstrates that fatty acid hydratases can be classified into three subtypes based on their regioselectivity and provides insights into their preferred substrate structures. These understandings pave ways for the design of optimal fatty acid hydratase variants and bioprocesses for the cost-efficient biosynthesis of hydroxy fatty acids.

Abstract Biofuel production has emerged as a leading contender in the quest for renewable energy solutions, offering a promising path toward a greener future. This comprehensive state-of-the-art review delves into the current landscape of biofuel production, exploring its potential as a viable alternative to conventional fossil fuels. This study extensively examines various feedstock options, encompassing diverse sources such as plants, algae, and agricultural waste, and investigates the technological advancements driving biofuel production processes. This review highlights the environmental benefits of biofuels, emphasizing their capacity to significantly reduce greenhouse gas emissions compared to those of fossil fuels. Additionally, this study elucidates the role of biofuels in enhancing energy security by decreasing reliance on finite fossil fuel reserves, thereby mitigating vulnerabilities to geopolitical tensions and price fluctuations. The economic prospects associated with biofuel production are also elucidated, encompassing job creation, rural development, and the potential for additional revenue streams for farmers and landowners engaged in biofuel feedstock cultivation. While highlighting the promise of biofuels, the review also addresses the challenges and considerations surrounding their production. Potential issues such as land use competition, resource availability, and sustainability implications are critically evaluated. Responsible implementation, including proper land-use planning, resource management, and adherence to sustainability criteria, is emphasized as critical for the long-term viability of biofuel production. Moreover, the review underscores the importance of ongoing research and development efforts aimed at enhancing biofuel production efficiency, feedstock productivity, and conversion processes. Technological advancements hold the key to increasing biofuel yields, reducing production costs, and improving overall sustainability. This review uniquely synthesizes the latest advancements across the entire spectrum of biofuel production, from feedstock selection to end-use applications. It addresses critical research gaps by providing a comprehensive analysis of emerging technologies, sustainability metrics, and economic viability of various biofuel pathways. Unlike previous reviews, this work offers an integrated perspective on the interplay between technological innovation, environmental impact, and socio-economic factors in biofuel development, thereby providing a holistic framework for future research and policy directions in renewable energy.

Abstract Background Lignin is an aromatic polymer deposited in secondary cell walls of higher plants to provide strength, rigidity, and hydrophobicity to vascular tissues. Due to its interconnections with cell wall polysaccharides, lignin plays important roles during plant growth and defense, but also has a negative impact on industrial processes aimed at obtaining monosaccharides from plant biomass. Engineering lignin offers a solution to this issue. For example, previous work showed that heterologous expression of a coliphage S-adenosylmethionine hydrolase (AdoMetase) was an effective approach to reduce lignin in the model plant Arabidopsis. The efficacy of this engineering strategy remains to be evaluated in bioenergy crops. Results We studied the impact of expressing AdoMetase on lignin synthesis in sorghum (Sorghum bicolor L. Moench). Lignin content, monomer composition, and size, as well as biomass saccharification efficiency were determined in transgenic sorghum lines. The transcriptome and metabolome were analyzed in stems at three developmental stages. Plant growth and biomass composition was further evaluated under field conditions. Results evidenced that lignin was reduced by 18% in the best transgenic line, presumably due to reduced activity of the S-adenosylmethionine-dependent O-methyltransferases involved in lignin synthesis. The modified sorghum features altered lignin monomer composition and increased lignin molecular weights. The degree of methylation of glucuronic acid on xylan was reduced. These changes enabled a ~20% increase in glucose yield after biomass pretreatment and saccharification compared to wild type. RNA-seq and untargeted metabolomic analyses evidenced some pleiotropic effects associated with AdoMetase expression. The transgenic sorghum showed developmental delay and reduced biomass yields at harvest, especially under field growing conditions. Conclusions The expression of AdoMetase represents an effective lignin engineering approach in sorghum. However, considering that this strategy potentially impacts multiple S-adenosylmethionine-dependent methyltransferases, adequate promoters for fine-tuning AdoMetase expression will be needed to mitigate yield penalty.

Abstract Tryptophol (IET) is a metabolite derived from L-tryptophan that can be isolated from plants, bacteria, and fungi and has a wide range of biological activities in living systems. Despite the fact that IET biosynthesis pathways exist naturally in living organisms, industrial-scale production of IET and its derivatives is solely based on environmentally unfriendly chemical conversion. With diminishing petroleum reserves and a significant increase in global demand in all major commercial segments, it becomes essential to develop new technologies to produce chemicals from renewable resources and under mild conditions, such as microbial fermentation. Here we characterized and engineered the less-studied L-tryptophan pathway and IET biosynthesis in the baker’s yeast Saccharomyces cerevisiae, with the goal of investigating microbial fermentation as an alternative/green strategy to produce IET. In detail, we divided the aromatic amino acids (AAAs) metabolism related to IET synthesis into the shikimate pathway, the L-tryptophan pathway, the competing L-tyrosine/L-phenylalanine pathways, and the Ehrlich pathway based on a modular engineering concept. Through stepwise engineering of these modules, we obtained a yeast mutant capable of producing IET up to 1.04 g/L through fed-batch fermentation, a ~ 650-fold improvement over the wild-type strain. Besides, our engineering process also revealed many insights about the regulation of AAAs metabolism in S. cerevisiae. Finally, during our engineering process, we also discovered yeast mutants that accumulate anthranilate and L-tryptophan, both of which are precursors of various valuable secondary metabolites from fungi and plants. These strains could be developed to the chassis for natural product biosynthesis upon introducing heterologous pathways.

Abstract Background Ionizing radiation has been used for mutagenesis or material modification. The potential to use microalgae as a platform for antimicrobial production has been reported, but little work has been done to advance it beyond characterization to biotechnology. This study explored two different applications of ionizing radiation as a metabolic remodeler and a molecular modifier to enhance the antimicrobial activity of total protein and solvent extracts of Chlamydomonas reinhardtii cells. Results First, highly efficient transgenic C. reinhardtii strains expressing the plant-derived antimicrobial peptides, AtPR1 or AtTHI2.1, were developed using the radiation-inducible promoter, CrRPA70Ap. Low transgene expression was significantly improved through X-irradiation (12–50 Gy), with peak activity observed within 2 h. Protein extracts from these strains after X-irradiation showed enhanced antimicrobial activity against the prokaryotic bacterium, Pseudomonas syringae, and the eukaryotic fungus, Cryptococcus neoformans. In addition, X-irradiation (12 Gy) increased the growth and biomass of the transgenic strains. Second, C. reinhardtii cell extracts in ethanol were γ-irradiated (5–20 kGy), leading to molecular modifications and increased antimicrobial activity against the phytopathogenic bacteria, P. syringae and Burkholderia glumae, in a dose-dependent manner. These changes were associated with alterations in fatty acid composition. When both transgenic expression of antimicrobial peptides and molecular modification of bioactive substances were applied, the antimicrobial activity of C. reinhardtii cell extracts was further enhanced to some extent. Conclusion Overall, these findings suggest that ionizing radiation can significantly enhance the antimicrobial potential of C. reinhardtii through efficient transgene expression and molecular modification of bioactive substances, making it a valuable source of natural antimicrobial agents. Ionizing radiation can act not only as a metabolic remodeler of transgene expression in microalgae but also as a molecular modifier of the bioactive substances.

Abstract Switchgrass (Panicum virgatum L.) is a perennial C4 warm-season grass known for its high-biomass yield and wide environmental adaptability, making it an ideal bioenergy crop. Despite its potential, switchgrass seedlings grow slowly, often losing out to weeds in field conditions and producing limited biomass in the first year of planting. Furthermore, during the reproductive growth stage, the above-ground biomass rapidly increases in lignin content, creating a significant saccharification barrier. Previous studies have identified rhythm-related genes TOC1 and LHY as crucial to the slow seedling development in switchgrass, yet the precise regulatory functions of these genes remain largely unexplored. In this study, the genes TOC1 and LHY were characterized within the tetraploid genome of switchgrass. Gene expression analysis revealed that PvTOC1 and PvLHY exhibit circadian patterns under normal growth conditions, with opposing expression levels over time. PvTOC1 genes were predominantly expressed in florets, vascular bundles, and seeds, while PvLHY genes showed higher expression in stems, leaf sheaths, and nodes. Overexpression of PvTOC1 from the N chromosome group (PvTOC1-N) or PvLHY from the K chromosome group (PvLHY-K) in Arabidopsis thaliana led to alterations in circadian rhythm and hormone metabolism, resulting in shorter roots, delayed flowering, and decreased resistance to oxidative stress. These transgenic lines exhibited reduced sensitivity to hormones and hormone inhibitors, and displayed altered gene expression in the biosynthesis and signal transduction pathways of abscisic acid (ABA), gibberellin (GA), 3-indoleacetic acid (IAA), and strigolactone (SL). These findings highlight roles of PvTOC1-N and PvLHY-K in plant development and offer a theoretical foundation for genetic improvements in switchgrass and other crops.

Abstract Background The efficient use of softwood in biorefineries is hampered by its recalcitrance to enzymatic saccharification. In the present study, the fungus Thermothielavioides terrestris LPH172 was cultivated on three steam-pretreated spruce materials (STEX180°C/auto, STEX210°C/auto, and STEX210°C/H2SO4), characterized by different hemicellulose content and structure, as well as on untreated biomass. The aim of the study was to map substrate-induced changes in the secretome of T. terrestris grown on differently treated spruce materials and to evaluate the hydrolytic efficiency of the secretome as supplement for a commercial enzyme mixture. Results The cultivation of T. terrestris was monitored by endo-cellulase, endo-xylanase, endo-mannanase, laccase, and peroxidase activity measurements. Proteomic analysis was performed on the secretomes induced by the spruce materials to map the differences in enzyme production. Growth of T. terrestris on STEX180°C/auto and STEX210°C/auto induced higher expression level of mannanases and mannosidases of the GH5_7 CAZy family compared to cultivation on the other materials. Cultivation on untreated biomass led to overexpression of GH47, GH76, and several hemicellulose debranching enzymes compared to the cultivation on the pretreated materials. T. terrestris grown on untreated, STEX180°C/auto and STEX210°C/auto induced three arabinofuranosidases of the GH43 and GH62 families; while growth on STEX210°C/H2SO4 induced a GH51 arabinofuranosidase and a GH115 glucuronidase. All secretomes contained five lytic polysaccharide monooxygenases of the AA9 family. Supplementation of Celluclast® + Novozym188 with the secretome obtained by growing the fungus grown on STEX180°C/auto achieved a twofold higher release of mannose from spruce steam-pretreated with acetic acid as catalyst, compared to the commercial enzyme cocktail alone. Conclusions Minor changes in the structure and composition of spruce affect the composition of fungal secretomes, with differences in some classes explaining an increased hydrolytic efficiency. As demonstrated here, saccharification of spruce biomass with commercial enzyme cocktails can be further enhanced by supplementation with tailor-made secretomes.

Factorial experiment carried out in 2024 in southern Baghdad, for the aim of evaluation the performance of heavy disc harrow offset with tractor engine 120 horse power under different moisture soil (14 % and 8 %), depth of pulverization (8 and15 cm) speed of tractor (4.7 and 8.2 km.h-1) in medium texture soil which was silty clay loam, after soil tilted at 20 cm by used moldboard plow width 1.05 cm as a primary tillage. Pulverization the soil under moisture 8 % gave higher (best) soil pulverization rate was 70.49 %, productivity 1.5824 ha.h-1, specific productivity 5273 m.h-1, least number of clods < 0.05 was 7.83 clods.m-2 and fuel consumption 12.40 L.ha-1. Depth pulverization 8 cm gave on the best pulverization soil rate 71.51 %, number of clods < 0.05 was 5.08 clods.m-2, productivity 1.5992 ha.h-1 and least fuel consumption 12.04 L.ha-1. Speed of the tractor8.2 km.h-1 gave better soil pulverization rate 70.57 %, productivity 2.0151 ha.h-1, specific productivity 6715 m.h-1, least number of clods< 0.05 was 7 clods.m-2 and fuel consumption 11.81 L.ha-1. All interaction among the treatments was significant difference. Correlation were direct and inverse, significantly and non-significant. Concluded the most effected factors in the study was tractor speed then depth of tillage and both of them more than influent from moisture of soil, pulverization soil at low moisture level 8 % and used higher speed tractor 8.2 km.h-1 and pulverize depth 8 cm gave a better results comparing with the rest of the factors in this field experiment.

Abstract Background The ability of lignocellulose degradation for filamentous fungi is always attributed to their efficient CAZymes system with broader applications in bioenergy development. ADP-ribosylation factor GTPase-activating proteins (Arf-GAPs), pivotal in fungal morphogenesis, lack comprehensive studies on their regulatory mechanisms in lignocellulose utilization. Results Here, the orthologs (TgGlo3 and TgGcs1) of Arf-GAPs in S. cerevisiae were characterized in Trichoderma guizhouense NJAU4742. The results indicated that overexpression of Tggcs1 (OE-Tggcs1) enhanced the lignocellulose utilization, whereas increased expression of Tgglo3 (OE-Tgglo3) elicited antithetical responses. On the fourth day of fermentation with rice straw as the sole carbon source, the activities of endoglucanase, cellobiohydrolase, xylanase, and filter paper of the wild-type strain (WT) reached 8.20 U mL−1, 4.42 U mL−1, 14.10 U mL−1, and 3.56 U mL−1, respectively. Compared to WT, the four enzymes activities of OE-Tggcs1 increased by 7.93%, 6.11%, 9.08%, and 12.92%, respectively, while those decreased to varying degrees of OE-Tgglo3. During the nutritional growth, OE-Tgglo3 resulted in the hyphal morphology characterized by sparsity and constriction, while OE-Tggcs1 led to a notable increase in vacuole volume. In addition, OE-Tggcs1 exhibited higher transport efficiencies for glucose and cellobiose thereby sustaining robust cellular metabolic rates. Further investigations revealed that Tgglo3 and Tggcs1 differentially regulated the transcription level of a dynamin-like GTPase gene (Tggtp), eliciting distinct redox states and apoptotic reaction, thus orchestrating the cellular response to lignocellulose utilization. Conclusions Overall, these findings underscored the significance of TgArf-GAPs as pivotal regulators in lignocellulose utilization and provided initial insights into their differential modulation of downstream targets.

Abstract Background Production of cheese whey in the EU exceeded 55 million tons in 2022, resulting in lactose-rich effluents that pose significant environmental challenges. To address this issue, the present study investigated cheese-whey treatment via membrane filtration and the utilization of its components as fermentation feedstock. A simulation model was developed for an industrial-scale facility located in Italy’s Apulia region, designed to process 539 m3/day of untreated cheese-whey. The model integrated experimental data from ethanolic fermentation using a selected strain of Kluyveromyces marxianus in lactose-supplemented media, along with relevant published data. Results The simulation was divided into three different sections. The first section focused on cheese-whey pretreatment through membrane filtration, enabling the recovery of 56%w/w whey protein concentrate, process water recirculation, and lactose concentration. In the second section, the recovered lactose was directed towards fermentation and downstream anhydrous ethanol production. The third section encompassed anaerobic digestion of organic residue, sludge handling, and combined heat and power production. Moreover, three different scenarios were produced based on ethanol yield on lactose (YE/L), biomass yield on lactose, and final lactose concentration in the medium. A techno-economic assessment based on the collected data was performed as well as a sensitivity analysis focused on economic parameters, encompassing considerations on cheese-whey by assessing its economical impact as a credit for the simulated facility, dictated by a gate fee, or as a cost by considering it a raw material. The techno-economic analysis revealed different minimum ethanol selling prices across the three scenarios. The best performance was obtained in the scenario presenting a YE/L = 0.45 g/g, with a minimum selling price of 1.43 €/kg. Finally, sensitivity analysis highlighted the model’s dependence on the price or credit associated with cheese-whey handling. Conclusions This work highlighted the importance of policy implementation in this kind of study, demonstrating how a gate fee approach applied to cheese-whey procurement positively impacted the final minimum selling price for ethanol across all scenarios. Additionally, considerations should be made about the implementation of the simulated process as a plug-in addition in to existing processes dealing with dairy products or handling multiple biomasses to produce ethanol.

Abstract Background The integration of anaerobic digestion into bio-based industries can create synergies that help render anaerobic digestion self-sustaining. Two-stage digesters with separate acidification stages allow for the production of green hydrogen and short-chain fatty acids, which are promising industrial products. Heat shocks can be used to foster the production of these products, the practical applicability of this treatment is often not addressed sufficiently, and the presented work therefore aims to close this gap. Methods Batch experiments were conducted in 5 L double-walled tank reactors incubated at 37 °C. Short microwave heat shocks of 25 min duration and exposure times of 5–10 min at 80 °C were performed and compared to oven heat shocks. Pairwise experimental group differences for gas production and chemical parameters were determined using ANOVA and post–hoc tests. High-throughput 16S rRNA gene amplicon sequencing was performed to analyse taxonomic profiles. Results After heat–shocking the entire seed sludge, the highest hydrogen productivity was observed at a substrate load of 50 g/l with 1.09 mol H2/mol hexose. With 1.01 mol H2/mol hexose, microwave-assisted treatment was not significantly different from oven-based treatments. This study emphasised the better repeatability of heat shocks with microwave-assisted experiments, revealing low variation coefficients averaging 29%. The pre-treatment with microwaves results in a high predictability and a stronger microbial community shift to Clostridia compared to the treatment with the oven. The pre-treatment of heat shocks supported the formation of butyric acid up to 10.8 g/l on average, with a peak of 24.01 g/l at a butyric/acetic acid ratio of 2.0. Conclusion The results support the suitability of using heat shock for the entire seed sludge rather than just a small inoculum, making the process more relevant for industrial applications. The performed microwave-based treatment has proven to be a promising alternative to oven-based treatments, which ultimately may facilitate their implementation into industrial systems. This approach becomes economically sustainable with high-temperature heat pumps with a coefficient of performance (COP) of 4.3. Graphical abstract

Addressing escalating energy demands and greenhouse gas emissions in the oil and gas industry has driven extensive efforts in carbon capture and utilization (CCU), focusing on power plants and industrial facilities. However, utilizing CO2 as a raw material to produce valuable chemicals, materials, and fuels for transportation may offer a more sustainable and long-term solution than sequestration alone. This approach also presents promising alternatives to traditional chemical feedstock in industries such as fine chemicals, pharmaceuticals, and polymers. This review comprehensively outlines the current state of CO2 capture technologies, exploring the associated challenges and opportunities regarding their efficiency and economic feasibility. Specifically, it examines the potential of technologies such as chemical looping, membrane separation, and adsorption processes, which are advancing the frontiers of CO2 capture by enhancing efficiency and reducing costs. Additionally, it explores the various methods of CO2 utilization, highlighting the potential benefits and applications. These methods hold potential for producing high-value chemicals and materials, offering new pathways for industries to reduce their carbon footprint. The integration of CO2 capture and utilization is also examined, emphasizing its potential as a cost-effective and efficient approach that mitigates climate change while converting CO2 into a valuable resource. Finally, the review outlines the challenges in designing, developing, and scaling up CO2 capture and utilization processes, providing a comprehensive perspective on the technical and economic challenges that need to be addressed. It provides a roadmap for technologies, suggesting that their successful deployment could result in significant environmental benefits and encourage innovation in sustainable practices within the energy and chemical sectors.

This work provides an extended description of the tools developed in the Wolfram Mathematica environment to characterize proton exchange membrane (PEM) fuel cells. These tools, with their user-friendly interface, facilitate the calculation of the main parameters required to obtain the PEM fuel cell polarization curve, offering a seamless and intuitive experience. Various mathematical models and algorithms are coded to accurately calculate the parameters needed for the polarization curve analysis. This study presents the development and validation of a computational tool designed to simulate the performance of proton exchange membrane (PEM) fuel cells. The tool integrates thermodynamic and electrochemical equations to predict key operational parameters, and was validated using experimental data from a commercial Ballard® PEM fuel cell to ensure its accuracy. The validation process involved comparing the numerical predictions with empirical measurements under various operating conditions. The results demonstrate that the computational tool accurately replicates the performance characteristics observed in the experimental data, confirming its reliability and instilling confidence in its use for simulating PEM fuel cell behavior. This tool offers a valuable resource for optimizing fuel cell design and operation, providing insights into the efficiency, output, and potential areas for improvement. Future work will expand the tool’s capabilities to include degradation mechanisms and long-term performance predictions. This advancement underscores the tool’s potential as a comprehensive solution for academic research and industrial applications in fuel cell technology.

Climate change and the growing demand for energy have prompted research on alternative eco-friendly energy sources. This study focused on the potential for biogas production from water hyacinth and banana peel waste through physicochemical characterization and batch anaerobic digestion tests. The water hyacinth and banana peel samples were dried, ground, and subjected to elemental, proximate, and fiber content analyses. Subsequently, banana peel waste, water hyacinth stems, and leaves were used for batch anaerobic digestion tests in 500 mL glass flask bottles for 21 days under mesophilic conditions in n = 3 trials. Kruskal–Wallis and Dunnett’s tests were performed to identify the significance of the differences in biogas yield among the samples. The analyses of the elemental, proximate, and fiber contents of water hyacinth and banana peels revealed that they possess a suitable chemical composition and essential nutrients for the production of high-yield biogas. The biogas yields from water hyacinth leaves, stems, and banana peels were 280.15, 324.79, and 334.82 mL/g VS, respectively. These findings indicate that water hyacinth and banana peel waste have significant potential for biogas production.

Nowadays, the mobility sector is assessing different technologies to substitute the internal combustion engines in order to reduce its CO2 emissions; one of these possible alternatives is the Polymer Electrolyte Membrane (PEM) fuel cell. So, the development of non-destructive diagnostic tools that could identify defective cells and/or any malfunctioning behavior and can be easily embarked on in any vehicle will expand the durability of PEM fuel cells, improve their performance, and enable them to carry out predictive maintenance. In this research, we use an in-house developed methodology that combines the polarization curve and electrochemical impedance spectroscopy (EIS) techniques to characterize different cells of a commercial PEM stack, identifying malfunctioning ones.

The aim of this work was to verify the possibility of forming Ni-Fe and Co-Fe alloys via topotactic ion exchange exsolution in Fe-infiltrated (La,Sr,Ce)0.9(Ni,Ti)O3-δ or (La,Sr,Ce)0.9(Co,Ti)O3-δ ceramics. For this purpose, samples were synthesized using the Pechini method and then infiltrated with an iron nitrate solution. The reduction process in dry H2 forced the topotactic ion exchange exsolution, leading to the formation of additional round-shape structures on the surfaces of grains. EDS scans and XRD analysis confirmed the formation of bimetallic alloys, which suggests that these materials have great potential for further use as anode materials for Solid Oxide Fuel Cells (SOFCs).

Dew point pressure (DPP) emerges as a pivotal factor crucial for forecasting reservoir dynamics regarding condensate-to-gas ratio and addressing production/completion hurdles, alongside calibrating EOS models for integrated simulation. However, DPP presents challenges in terms of predictability. Acknowledging these complexities, we introduce a state-of-the-art approach for DPP estimation utilizing advanced machine learning (ML) techniques. Our methodology is juxtaposed against published empirical correlation-based methods on two datasets with limited sizes and diverse inputs. With superior performance over correlation-based estimators, our ML approach demonstrates adaptability and resilience even with restricted training datasets, spanning various fluid classifications. We acquired condensate PVT data from publicly available sources and GeoMark RFDBASE, encompassing dew point pressure (the target variable), as well as compositional data (mole percentages of each component), temperature, molecular weight (MW), and specific gravity (SG) of heptane plus, which served as input variables. Before initiating the study, thorough assessments of measurement quality and results using statistical methods were conducted leveraging domain expertise. Subsequently, advanced ML techniques were employed to train predictive models with cross-validation to mitigate overfitting to the limited datasets. Our models were juxtaposed against the foremost published DDP estimators utilizing empirical correlation-based methods, with correlation-based estimators also trained on the underlying datasets for equitable comparison. To improve outcomes, pseudo-critical properties and artificial proxy features were utilized, leveraging generalized input data.

Abstract Background Laccases can oxidize a broad spectrum of substrates, offering promising applications in various sectors, such as bioremediation, biomass fractionation in future biorefineries, and synthesis of biochemicals and biopolymers. However, laccase discovery and optimization with a desirable pH optimum remains a challenge due to the labor-intensive and time-consuming nature of the traditional laboratory methods. Results This study presents a machine learning (ML)-integrated approach for predicting pH optima of basidiomycete fungal laccases, utilizing a small, curated dataset against a vast metagenomic data. Comparative computational analyses unveiled the structural and pH-dependent solubility differences between acidic and neutral-alkaline laccases, helping us understand the molecular bases of enzyme pH optimum. The pH profiling of the two ML-predicted alkaline laccase candidates from the basidiomycete fungus Lepista nuda further validated our computational approach, showing the accuracy of this comprehensive method. Conclusions This study uncovers the efficacy of ML in the prediction of enzyme pH optimum from minimal datasets, marking a significant step towards harnessing computational tools for systematic screening of enzymes for biotechnology applications. Graphical Abstract

Abstract From both economic and environmental perspectives, ethylene glycol, the principal constituent in the degradation of PET, emerges as an optimal feedstock for microbial cell factories. Traditional methods for constructing Escherichia coli chassis cells capable of utilizing ethylene glycol as a non-sugar feedstock typically involve overexpressing the genes fucO and aldA. However, these approaches have not succeeded in enabling the exclusive use of ethylene glycol as the sole source of carbon and energy for growth. Through ultraviolet radiation-induced mutagenesis and subsequent laboratory adaptive evolution, an EG02 strain emerged from E. coli MG1655 capable of utilizing ethylene glycol as its sole carbon and energy source, demonstrating an uptake rate of 8.1 ± 1.3 mmol/gDW h. Comparative transcriptome analysis guided reverse metabolic engineering, successfully enabling four wild-type E. coli strains to metabolize ethylene glycol exclusively. This was achieved through overexpression of the gcl, hyi, glxR, and glxK genes. Notably, the engineered E. coli chassis cells efficiently metabolized the 87 mM ethylene glycol found in PET enzymatic degradation products following 72 h of fermentation. This work presents a practical solution for recycling ethylene glycol from PET waste degradation products, demonstrating that simply adding M9 salts can effectively convert them into viable raw materials for E. coli cell factories. Our findings also emphasize the significant roles of genes associated with the glycolate and glyoxylate degradation I pathway in the metabolic utilization of ethylene glycol, an aspect frequently overlooked in previous research.

Abstract Background Clostridium autoethanogenum is an acetogenic bacterium that autotrophically converts carbon monoxide (CO) and carbon dioxide (CO2) gases into bioproducts and fuels via the Wood–Ljungdahl pathway (WLP). To facilitate overall carbon capture efficiency, the reaction stoichiometry requires supplementation of hydrogen at an increased ratio of H2:CO to maximize CO2 utilization; however, the molecular details and thus the ability to understand the mechanism of this supplementation are largely unknown. Results In order to elucidate the microbial physiology and fermentation where at least 75% of the carbon in ethanol comes from CO2, we established controlled chemostats that facilitated a novel and high (11:1) H2:CO uptake ratio. We compared and contrasted proteomic and metabolomics profiles to replicate continuous stirred tank reactors (CSTRs) at the same growth rate from a lower (5:1) H2:CO condition where ~ 50% of the carbon in ethanol is derived from CO2. Our hypothesis was that major changes would be observed in the hydrogenases and/or redox-related proteins and the WLP to compensate for the elevated hydrogen feed gas. Our analyses did reveal protein abundance differences between the two conditions largely related to reduction–oxidation (redox) pathways and cofactor biosynthesis, but the changes were more minor than we would have expected. While the Wood–Ljungdahl pathway proteins remained consistent across the conditions, other post-translational regulatory processes, such as lysine-acetylation, were observed and appeared to be more important for fine-tuning this carbon metabolism pathway. Metabolomic analyses showed that the increase in H2:CO ratio drives the organism to higher carbon dioxide utilization resulting in lower carbon storages and accumulated fatty acid metabolite levels. Conclusions This research delves into the intricate dynamics of carbon fixation in C. autoethanogenum, examining the influence of highly elevated H2:CO ratios on metabolic processes and product outcomes. The study underscores the significance of optimizing gas feed composition for enhanced industrial efficiency, shedding light on potential mechanisms, such as post-translational modifications (PTMs), to fine-tune enzymatic activities and improve desired product yields.

This study investigated the integrated valorization of defatted rice bran (DRB) by converting it into lactic acid (LA) and subsequently utilizing the residues from LA production for biomethane generation through anaerobic digestion (AD). Processing 480 kg of DRB resulted in the production of 70 L of pure LA and generated significant waste streams, primarily consisting of 572 kg of decanted hydrolysate pellet (Pellet DEC) and 220 kg of microfiltration retentate (Retentate MF). Exceptionally high methane yields of 374‒434 LN kgVS-1 were observed for residues from LA fermentation in biochemical methane potential tests, indicating their high potential for biogas production. During long-term semi-continuous AD, varying organic loading rates (OLRs) from 0.5‒2.5 kgVS m-3 d⁻¹ demonstrated feedstock- and OLR-dependent methane production. Reactor failure at higher OLRs was attributed to the accumulation of total ammoniacal nitrogen (TAN). The co-digestion of Pellet DEC and Retentate MF proved to be more resilient, with OLRs up to 2 kgVS m-3 d-1, mitigating TAN inhibition. Methane yields, ranging from 265‒334 LN kgVS-1 before reaching inhibitory OLR levels, were higher than those found in the literature. Process integration has emerged as a promising approach because the biogas generated from residues could effectively offset the energy demands of LA production. Supported by life cycle assessment, the integrated processes showed a 67% lower environmental impact at the midpoint and a 71% lower environmental impact at the endpoint, along with an 80% reduction in energy costs compared to the standalone LA production. Results proved a significant enhancement of the sustainability and economic viability of this integrated biorefinery approach.

Achieving quantitative conversion of biomass-derived feedstocks under ambient environmental conditions (20°C, atmospheric air, 0.1 MPa) is a critical milestone for sustainability in chemical processes. Herein, the quantitative conversion of glucose to gluconic acid was accomplished under ambient environmental conditions without any additives using a Pt-Zn intermetallic nanoparticle-supported biochar catalyst prepared from raw rice straw (Pt-Zn/strawC) via a straightforward one-pot solvothermal reaction with ethylene glycol solvent. Spectroscopic analyses verified the formation of the Pt-Zn intermetallic alloy and confirmed strong electronic metal-support interactions. The Pt-Zn/strawC catalyst (Pt:Zn molar ratio of 1:6) was highly selective for the conversion of glucose to gluconic acid, whereas yields as high as 99.9% (98.9% gluconic acid, 1.0% glucaric acid) were reached at 20 oC under base-free and additive-free conditions. Isotope measurements and density functional theory revealed synergistic interactions in the Pt-Zn alloy, wherein the alloy tended to absorb glucose and active O2 into superoxide radical (O2·). This work demonstrates a chemocatalytic method that is practical for environmental conditions and provides a new avenue for sustainable conversion of lignocellulosic biomass to chemical products.

Cassava, a staple food crop, is widely used for starch production, but its inconsistent supply, price volatility, and substantial waste generation pose challenges to the cassava industrial market's growth. This study aims to identify a sustainable biorefinery pathway by optimizing conventional cassava starch plants (business-as-usual, BAU) for economic and environmental benefits. Four scenarios were evaluated: animal feed from peel waste (Scenario 1), fungal protein from thippi waste (Scenario 2), fish feed from digested wastewater (Scenario 3), and conversion of all waste streams into animal feed, fish feed, and fungal protein (Scenario 4). Scenario 4 emerged as the best pathway using the multi-criteria decision-making (MCDM) approach, with a performance score of 0.282. Despite the highest energy consumption (18.91 MWh), Scenario 4 was favored for producing four value-added products alongside starch, yielding the highest profit at USD 8.85 million. In contrast, profits for BAU, Scenario 1, Scenario 2, and Scenario 3 were 1.91, 2.30, 5.01, and USD 8.79 million, respectively. Waste valorization in Scenarios 1, 2, 3, and 4 resulted in CO2 avoidance of 36.5., 42.6., 21.7, and 57.45 t CO2eq., respectively. However, producing value-added products increased energy consumption by 13, 73, 7, and 74% compared to BAU (4.58 MWh). The global warming potential analysis showed negative values for scenarios 2 and 4, at -436 and -434 kg CO2eq./t root, respectively. This study highlights the potential of a biorefinery approach for sustainable cassava starch production, providing insights for future research and policy development.

We explore here, through reactive force field (ReaxFF) molecular dynamics simulations, oleic acid upgrading on beta zeolite (BEA) regulated with nine silica-to-aluminium ratios (SARs) to investigate their acid-catalyzed deoxygenation and coking susceptibility. The selected computational descriptors involved conversion, hydrodeoxygenation, and decarboxylation/decarbonylation selectivity, biofuels yield, and coke deposition characteristics. Simulations were validated by 20.3 SAR available experimental data and used for the systematic study. High deoxygenation selectivity was found to be related to the structural sensitivity of BEA(100) on the upgrading mechanism. ReaxFF simulations revealed that altering the Al-substitution could greatly promote biofuel formation. Specifically, SARs towards the mid-region (SAR 47) favored gasoline production, while 31 SAR exploited diesel-like hydrocarbons. An optimum ratio of 37.4 SAR achieved maximum oleic acid conversion (69.8%), with high yields of gasoline and diesel fuels (15.6 and 20.4 wt%, respectively) and moderate coking (8.6 wt%). Density functional theory screening of metallic dopants allowed investigating of their deoxygenation and coke susceptibility, obtaining that Cu-BEA structure favored the optimal carbon and O moiety adsorption (-3.89 and -1.8 eV, respectively). Furthermore, the economic and environmental analysis showed that Cu-dopped BEA displayed the lowest market price and global warming potential (71 USD/kg and 2.8 kg CO2-eq/kg).

The purpose of the study was to determine the effect of the fuel used in the spark-ignition engine of the selected vehicle on the characteristics of maximum torque and power at the crankshaft of the engine as a function of crankshaft speed and the content of components in the exhaust gas. The vehicle engine was tested on a stand equipped with V-tech VT-2/B2 chassis dynamometer, MAHA MET 6.3 exhaust gas analyzer and engine parameter monitoring system using OBD standard. The tests used two commercial fuels with different test octane number (RON) values of 95 and 100 octanes. Measurement of the characteristics of the maximum torque, power on the crankshaft and the total power losses in the drive system, the contact of the wheels with the rollers of the dynamometer and the dynamometer as a function of the crankshaft rotational speed was carried out using the acceleration method with a dynamic load comprising the braking torque of the rotating masses and the electro-swirl brake. On the basis of the test results, engine and drive system parameters of the vehicle using the software for generating driving test runs “the calculation of gearshift points for the WLTC cycle”, a set of measuring points determining the values of the engine crankshaft speed and the torque generated by the engine crankshaft was determined. The parameters of the selected engine operating conditions are within the ranges specified by the software for generating the selected test runs. The content of selected exhaust gas components (carbon monoxide CO, carbon dioxide CO2, other hydrocarbons HC, oxygen O2, λ coefficient, nitrogen oxides NO and nitrogen dioxide NO2) was measured for the selected operating parameters of the vehicle for the tested fuels. On the basis of the results of the toxicity measurements, analytical models determining the content of individual components in the exhaust gases as a function of the crankshaft rotational speed and the torque generated on the crankshaft and software simulating the exhaust emissions of the selected vehicle moving under dynamic conditions were developed.

Efficient production of H2 by combined (steam/CO2; steam/O2) reforming of CH4 was comparatively studied over perovskite-derived promoted Ni catalysts. The process performance was improved by regulating the redox and structural properties of the LaNi0.99M0.01O3 catalysts through promotion (M = Pt, Pd, Re, Mo, Sn). The catalysts were synthesized using the citrate sol–gel method, tested in combined reforming of methane and studied by X-ray fluorescence analysis, thermal analysis, N2 adsorption, X-ray diffraction, electron microscopy, temperature-programed hydrogen reduction to elucidate the impact of catalyst properties on their activity and resistance to re-oxidation and formation of carbon deposits under reaction conditions. It was shown that LaNi0.99M0.01O3 catalysts after calcination at 850 °C in air have a perovskite structure that was destroyed after reductive activation with formation of metal Nio particles with an average size of ~ 25 nm on the surface of lanthanum oxide/hydroxide. The resistance to re-oxidation of Nio particles depends on the type of promoter and is maximum in the case of M = Re. It was established that the type of promoter affects the conversion of reagents (CH4, CO2) and the H2 yield, which at 700 °C increases in the series of promoters Sn < Mo < Pt < Pd < Re in the case of steam/CO2 reforming and Pt < Sn < Mo < Pd < Re with steam/O2 reforming. The optimal composition of catalyst was identified: among the studied samples, LaNi0.99Re0.01O3 is characterized by a higher specific surface area, average reduction ability and high resistance to re-oxidation and coking. At 850 °C it provides the H2 yield of 95 and 50% at complete CH4 conversion in steam/CO2 and steam/O2 reforming, respectively. [ABSTRACT FROM AUTHOR]

The research experimentally examines the viability of ethanol (E) as a sustainable aviation fuel (SAF) when mixed with kerosene (Ke) – Jet A aviation fuel + 5% Aeroshell oil. Various blends of ethanol and kerosene (10%, 20%, and 30% vol. of ethanol added in kerosene) were subjected to testing in an aviation micro turbo-engine under different operational states: idle, cruise, and maximum power. During the tests, monitoring of engine parameters such as burning temperature, fuel consumption, and thrust force was conducted. The study also encompassed the calculation of crucial performance indicators like burning efficiency, thermal efficiency, and specific consumption for all fuel blends under maximum power conditions. Physical-chemical properties of the blends, encompassing density, viscosity, flash point, and calorific power, were determined. Furthermore, elemental analysis and FTIR were used for chemical composition determination. The research delved into analyzing the air requirements for stoichiometric combustion and computed resulting emissions of CO2 and H2O. Experimental assessments were performed on the Jet Cat P80® micro-turbo engine, covering aspects such as starting procedures, acceleration, deceleration, and emissions of pollutants (CO and SO2) during diverse engine operational phases. The outcomes reveal that the examined fuel blends exhibited stable engine performance across all tested conditions. This indicates that these blends hold promise as sustainable aviation fuels for micro turbo-engines, presenting benefits in terms of diminished pollution and a more ecologically sound raw material base for fuel production. [ABSTRACT FROM AUTHOR]

Large-scale subsurface hydrogen storage is critical for transitioning towards renewable, economically viable, and emission-free energy technologies. Although preliminary studies on geochemical interactions between different minerals, aqueous ions, and other dissolved gasses with H2 have helped partially quantify the degree of hydrogen loss in the subsurface, the long-term changes in abiotic hydrogen–brine–rock interactions are still not well understood due to variable rates of mineral dissolution/precipitation and redox transformations under different conditions of reservoirs. One of the potentially understudied aspects of these complex geochemical interactions is the role of iron on the redox interactions and subsequent impact on long-term (100 years) hydrogen cycling. The theoretical modeling conducted in this study indicates that the evolution of secondary iron-bearing minerals, such as siderite and magnetite, produced after H2-induced reductive dissolution of primary Fe3+-bearing phases can result in different degrees of hydrogen loss. Low dissolved Fe2+ activity (−4) in the formation water can govern the transformation of secondary siderite to magnetite within 100 years, eventually accelerating the H2 consumption through reductive dissolution. Quantitative modeling demonstrates that such secondary iron mineral transformations need to be studied to understand the long-term behavior of hydrogen in storage sites.

This study aims to analyze the influence of adding Aeroshell 500 oil on physicochemical properties. It was found that the oil’s kinematic viscosity is much higher than that of diesel and Jet A, with a higher density and flash point as well. Elemental analysis revealed a higher carbon content and lower hydrogen content in Aeroshell oil compared to Jet A and diesel, with lower calorific power. Adding 5% oil increases the mixture viscosity, flash point, and density; decreases the calorific power; and increases the carbon content for both diesel and Jet A. In the second part, mathematical models determined the combustion temperatures for Jet A, diesel, Jet A plus 5% Aeroshell 500 oil, and diesel plus 5% Aeroshell 500 oil, based on an air excess from one to five. Elemental analysis determined the oxygen and air quantities for these mixtures and stoichiometric combustion reaction for CO2 and H2O. Regarding the CO2 quantity, adding 5% Aeroshell 500 to Jet A increases it from 3.143 kg to 3.159 kg for each kilogram of mixture burned in the stoichiometric reaction. Similarly, adding the oil to diesel in a 5% proportion increases the CO2 quantity from 3.175 to 3.190 in the stoichiometric reaction. Through experimentation with the Jet Cat P80 microturbine engine across four operating regimes, it was observed that the combustion chamber temperature and fuel flow rate are lower when using diesel with a 5% addition of Aeroshell 500 oil compared to Jet A with the same additive. However, the thrust is slightly higher with diesel + 5% Aeroshell 500 oil. Moreover, the specific fuel consumption is higher in regimes one and two for diesel + 5% Aeroshell 500 oil compared to Jet A + 5% Aeroshell 500 oil, while the differences are negligible in regimes three and four. At maximum operating conditions, the excess air was determined from the measured values, comparing the combustion chamber temperature with the calculated value, with a 7% error, extrapolating the results for the scenario when oil is not used. Also, during the testing campaign, the concentrations of CO and SO2 in the exhaust gas jet were measured, with higher concentrations of CO and SO2 observed for diesel compared to Jet A.