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We calculate electron impact partial and total ionization cross sections of R-carvone (C10H14O), 2-butanol (C4H10O), imidazole (C3H4N2), and 2-nitroimidazole (C3H3N3O2). We have used the Binary Encounter Bethe (BEB) model to obtain total electron impact ionization cross sections (TICSs). The modified BEB method in combination with mass spectrum data of the molecules is used to calculate the partial ionization cross section (PICS) of the cationic fragments dissociating from the parent molecule. Our PICS data for R-carvone and 2-butanol are in good agreement with the experimental data for all the cation fragments along with the TICS data. For imidazole and 2-nitroimidazole, the estimates of the PICS are reported for the first time in the present study. We have found that both the modified BEB method and the mass spectrum dependence method work effectively to estimate PICS if we have information about the appearance energies and relative abundance data of the target under investigation. [ABSTRACT FROM AUTHOR]

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Mitigating the impact of fossil fuels in diesel engines is crucial for addressing environmental issues, and alcohol-based fuel additives play a pivotal role. As key carriers of hydrogen, these additives have attracted considerable attention for their potential to reduce our dependence on fossil fuels. This study investigates the impact of blending diesel with various alcohols—n-butanol, n-octanol, and ethanol—at blending ratios of 20 and 50 vol% on combustion characteristics, emissions, and soot nanostructure in a compression ignition (CI) engine. Blending with n-butanol and ethanol notably retarded ignition delay and shortened combustion duration, whereas n-octanol's influence was minimal. Emission analyses highlighted that alcohol additions generally curtail nitrogen oxides (NO x) emissions, with 20 vol% n-butanol or n-octanol effectively diminishing unburned hydrocarbon (HC) emissions. An in-depth analysis of particulate matter (PM) emissions revealed that incorporating 50 vol% n-butanol or 20 vol% ethanol can significantly reduce PM emissions, achieving a reduction of up to 68% under various engine conditions. The examination of soot characteristics via Raman spectroscopy analysis highlighted an increased oxidative reactivity in soot particles when using n-octanol and ethanol blends. Additionally, soot samples obtained from alcohol-diesel blends displayed a heightened presence of C O groups, as identified through Fourier-transform infrared (FT-IR) spectroscopy analysis. This research offers profound insights into the intricate effects of alcohol-diesel blending on engine combustion and emissions. • Comprehensive study of diesel blended with various alcohols at different conditions. • Significant effects of n-butanol and ethanol on gas emissions are distinctly observed. • Up to 68% reduction in PM emissions achieved with 50% n-butanol or 20% ethanol. • Raman and FTIR spectroscopy reveal detailed soot properties from engine emissions. • n-Octanol and ethanol blends enhance soot's oxidative reactivity, deepening insights. [ABSTRACT FROM AUTHOR]

[Display omitted] Switchable microemulsions (MEs) are those capable of adaptively responding to the action of internal or external stimuli. For redox-switchable MEs to obtain high-efficiency phase separation and surfactant recycling, it may be one of the keys to adequately turn off the interfacial activity of surfactants and reduce the solubility of the closed surfactants in the oil phase. Monophasic MEs consisting 11-butylselanyl-undecyl sulfate sodium (C 4 SeC 11 SO 4 Na), n -butanol, n -octane, and water were fabricated using the pseudo-ternary phase diagram method. Their structural features and droplets size were characterized by conductivity, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM), respectively. The redox response of MEs was studied using a combination of visual observations and DLS, cryo-TEM, nuclear magnetic resonance (NMR) and thin-layer tomography. The efficient recycling of C 4 SeC 11 SO 4 Na from a well-emulsified eluent is conceptually demonstrated. The reversible transition between C 4 SeC 11 SO 4 Na and C 4 SeOC 11 SO 4 Na is achieved under the alternating action of H 2 O 2 and N 2 H 4 , by which C 4 SeC 11 SO 4 Na-based monophasic MEs are able to efficiently demulsify and regenerate, respectively, regardless of their type. After H 2 O 2 -induced demulsification of the MEs, C 4 SeOC 11 SO 4 Na can be efficiently recycled with the water phase. We hope that such a redox-switching method may benefit some technological applications. For example, it offers exciting possibilities for simultaneous recycling C 4 SeC 11 SO 4 Na and removal of oil from a well-emulsified eluent. Around 97.1 ± 0.3 % of C 4 SeC 11 SO 4 Na could be recycled over five cycles with no apparent loss. After a simple and conventional treatment with anion-exchange resin and active carbon, the total organic carbon and chemical oxygen demand of the waste water were 17.4 ± 2.8 and 26.2 ± 1.4 mg/L, respectively. [ABSTRACT FROM AUTHOR]

Enset fiber is a promising feedstock for biofuel production with the potential to reduce carbon emissions and improve the sustainability of the energy system. This study aimed to maximize hydrogen and butanol production from Enset fiber through simultaneous saccharification and fermentation (SSF) process in bottles as well as in bioreactor. The SSF process in bottles resulted in a higher butanol concentration of 11.36 g/L with a yield of 0.23 g/g and a productivity of 0.16 g/(L h) at the optimal process parameters of 5% (w/v) substrate loading, 16 FPU/g cellulase loading, and 100 rpm agitation speed from pretreated Enset fiber. Moreover, a comparable result to the bottle experiment was observed in the bioreactor with pH-uncontrolled SSF process, although with a decreased in butanol productivity to 0.095 g/(L h). However, using the pre-hydrolysis simultaneous saccharification and fermentation (PSSF) process in the bioreactor with a 7% (w/v) substrate loading led to the highest butanol concentration of 12.84 g/L with a productivity of 0.104 g/(L h). Furthermore, optimizing the SSF process parameters to favor hydrogen resulted in an increased hydrogen yield of 198.27 mL/g-Enset fiber at atmospheric pressure, an initial pH of 8.0, and 37 °C. In general, stirring the SSF process to shift the product ratio to either hydrogen or butanol was possible by adjusting temperature and pressure. At 37 °C and atmospheric pressure, the process resulted in an e-mol yield of 12% for hydrogen and 38% for butanol. Alternatively, at 30 °C and 0.55 bar overpressure, the process achieved a yield of 6% e-mol of hydrogen and 48% e-mol of butanol. This is the first study to produce hydrogen and butanol from Enset fiber using the SSF process and contributes to the development of a circular bioeconomy. [ABSTRACT FROM AUTHOR]

Bio-oil produced via fast pyrolysis, irrespective of the biomass source, faces several limitations, such as high water content, significant oxygenated compound concentration (35–40 wt.%), a low heating value (13–20 MJ/kg), and poor miscibility with fossil fuels. These inherent drawbacks hinder the bio-oil's desirable properties and usability, highlighting the necessity for advanced processing techniques to overcome these challenges and improve the bio-oil's overall quality and applicability in energy and industrial sectors. To address the limitations of bio-oil, a magnetic bimetallic oxide catalyst supported on activated rice straw biochar (ZrO2-Fe3O4/AcB), which has not been previously employed for this purpose, was developed and characterized for upgrading rice straw bio-oil in supercritical butanol via esterification. Furthermore, the silica in the biochar, combined with the Lewis acid sites provided by ZrO2 and Fe3O4, offers Brønsted acid sites. This synergistic combination enhances the bio-oil's quality by facilitating esterification, deoxygenation, and mild hydrogenation, thereby reducing oxygen content and increasing carbon and hydrogen levels. The effects of variables, including time, temperature, and catalyst load, were optimized using response surface methodology (RSM). The optimal reaction conditions were determined using a three-factor, one-response, and three-level Box-Behnken design (BBD). The ANOVA results at a 95% confidence level indicate that the results are statistically significant due to a high Fisher's test (F-value = 37.07) and a low probability (p-value = 0.001). The minimal difference between the predicted R² and adjusted R² for the ester yield (0.0092) suggests a better fit. The results confirm that the optimal reaction conditions are a catalyst concentration of 1.8 g, a reaction time of 2 h, and a reaction temperature of 300 °C. Additionally, the catalyst can be easily recycled for four reaction cycles. Moreover, the catalyst demonstrated remarkable reusability, maintaining its activity through four consecutive reaction cycles. Its magnetic properties allow for easy separation from the reaction mixture using an external magnet. [ABSTRACT FROM AUTHOR]

The novel heterogeneous catalyst, Bimetallic-organic framework (Fe, Cu)/carbon nanotubes encapsulated Ni nanoparticles, has been introduced for efficient degradation of acid orange 7 (AO7) via Fenton-like process. Optimizing and modeling of the heterogeneous degradation process were performed using response surface methodology (RSM) based on a five-level central composite design (CCD). The study on the individual and interaction effect of four operating parameters including pH, H2O2 concentration (mM), catalyst dose (mg L−1) and reaction time (min) revealed that the maximum AO7 degradation efficiency (93.94%) was achieved under optimal conditions of pH = 4.0, H2O2 concentration = 25 mM, catalyst dose = 200.0 mg L−1 and reaction time = 27 min (k = 0.1024 (min−1)). Analysis of scavenging revealed that tertiary butyl alcohol (TBA) led to a notable reduction in the degradation of AO7 under optimal conditions. The degradation of AO7 dropped from 93.94% to 14.28% as TBA concentrations varied from 0 to 9 mmol L−1. Consequently, the rate constant of the degradation reaction decreased from 0.1002 to 0.0058 min−1 as the concentration of the quenching agent increased. Interestingly, it was found that besides the role of Fe, Cu and Ni species in the Fe0.6Cu0.3Ni0.1(BDC)@CNT, surface oxygen-functional groups on the CNT provides faster and efficient Fe(III)/Fe(II) cycle over a broader pH range. Furthermore, concerning the importance of economic and environmental issues, the possibility of regenerating the Fe0.6Cu0.3Ni0.1(BDC)@CNT catalyst for four consecutive cycles has been confirmed. The concluding observations of this study provide favorable outcomes in the development and utilizing the advanced MOF-based catalysts with the aim of effective environmental remediation. [ABSTRACT FROM AUTHOR]

Using renewable fuels for diesel engines can reduce both air pollution and dependence on fossil fuels. A computer simulation was constructed to predict the performance, combustion characteristics, and NOx emissions of a diesel engine fuelled with diesel–biodiesel–butanol blends. The simulation was validated by comparing the modelling results against experimental data and a good agreement between the results was found. The fuels used for the validation were diesel (B0), biodiesel (B100), diesel–biodiesel blend (B50), and two diesel–biodiesel–butanol blends with 45% diesel–45% biodiesel–10% butanol (Bu10) and 40% diesel–40% biodiesel–20% butanol (Bu20) by volume. Experimental results showed that the addition of butanol reduced NOx emissions but deteriorated the engine performance. The aim of the current work was the numerical optimization of the different parameters to enhance the engine performance while using butanol to decrease NOx emissions. The engine compression ratio (CR) varied from 14 to 24, in increments of 2. Fuel injection timing (IT) was reduced from 30° before top dead centre (bTDC) to 5° bTDC in increments of 5°. Also, the fuel injection duration (IDur) was extended from 20° to 50° in increments of 10°. Results showed that the increase in the CR improved engine performance for the two investigated fuels, Bu10 and Bu20. The maximum engine brake power (BP), thermal efficiency (BTE), and minimum brake-specific fuel consumption (BSFC) of 1.46 kW, 32.3%, and 0.273 kg/kWh respectively, were obtained when the Bu10 fuel was injected under the optimum conditions of 24 CR, 15° bTDC IT, and 40° IDur. Under these optimum conditions, the BP, BTE, and BSFC improved by 3%–3.5% for Bu10 and Bu20 fuel blends compared with the base engine conditions of a CR of 22, 30° IDur, and 10° bTDC IT. The heat release rate during the premixed phase increased when the IT was advanced, while the mixing-controlled combustion phase was enhanced when the IT was reduced. NOx emissions increased with increasing CR, while both an increase in IDur at constant IT and the reduction of the IT decreased the engine NOx emissions. Under the optimum conditions, the NOx emissions for Bu10 and Bu20 were further decreased by 2.2% and 0.9%, respectively, compared with the experimental results under base engine conditions. Reducing the IT from 15° to 5° bTDC at a CR of 24 and IDur of 40° caused the NOx emissions for Bu10 and Bu20 to decrease by 16%. When the IDur was increased from 20° to 50° at a CR of 24 and an IT of 15°bTDC, the NOx emissions for Bu10 and Bu20 decreased by 12.3% and 11.8%, respectively. The addition of butanol to the diesel–biodiesel blend under optimum conditions showed results that were comparable to those of pure diesel, with a decrease in NOx emissions. [ABSTRACT FROM AUTHOR]

Constructing heterojunction composites is an effective method to enhance the gas-sensing performance of metal oxide semiconductors. In this paper, In 2 O 3 hierarchical microspheres were hydrothermally fabricated, and they were coated with SnO 2 nanoparticles by a liquid phase deposition method to improve the sensor response to n-butanol. The impact of deposition time on the morphology, structure and gas sensing performance were investigated. The results indicated that the In 2 O 3 /SnO 2 composite hierarchical microspheres with a deposition time of 60 min possessed the largest specific surface area of 137.6 m2/g and the best gas sensing properties. Its response toward 20 ppm n-butanol gas at 140 °C was 359, which was much higher than that of pure In 2 O 3 hierarchical microspheres (the response was 51–100 ppm n-butanol gas at 140 °C). In addition to enhanced sensitivity, this sensor showed quick recovery time, excellent selectivity, repeatability, and long-term stability for n-butanol, indicating its potential for practical applications. [ABSTRACT FROM AUTHOR]

This study investigated the effects of using ferric oxide nanoparticles (FO) and C2–C4 alcohols with diesel/biodiesel blend in a diesel engine. Optimum operating conditions were explored, and an engine speed of 1750 rpm was optimal. The concentration of FO was estimated to be 760 ppm, considering the best conditions for carbon nanotube (CNT) production. Ethanol was immiscible in diesel fuel; however, any biodiesel percentage in the blend made it miscible. The used engine was too small to run with a blend containing more than 3 % ethanol. Propanol and butanol were blended at the same ethanol concentration for comparative purposes. A blend with 30 % biodiesel (B30) was found to be the best diesel/biodiesel blend. This was detected by the best coefficient of variation (COV) with reasonable performance and emissions. Ferric oxide nanoparticles reduced COV and improved engine performance. The COV increased for tested alcohols. However, blending B30 with alcohols, especially butanol, improved thermal efficiency. FO and alcohol increased NOx emissions and decreased both CO and smoke opacity. They increased the peak pressure and the heat release rate while reducing the combustion duration. Nonetheless, no CNT traces were detected in the present study under any conditions. [ABSTRACT FROM AUTHOR]

Biobutanol is produced from the acetone-butanol-ethanol (ABE) fermentation. The major bottleneck of ABE fermentation is the self-inhibition of cells and the high energy consumption while recovering butanol. Several alternative techniques have been investigated, but the continuous recovery of butanol using the inexpensive and inert material could be a reliable choice. In the present study, the kraft lignin isolated from the novel lignocellulosic biomass, Sterculia foetida shells, was investigated for its selective adsorptive recovery of biobutanol from the simulated ABE solutions. SEM analyses of morphology and syringyl and guaiacyl units from FTIR show that the isolated lignin is in the softwood category. The XRD analysis shows 76.99% of the crystallinity index, which shows the crystalline features of kraft lignin. High thermal stability and surface area from TGA–DSC and BET analysis shows that the isolated lignin can be wisely used as an adsorbent. The isolated lignin maximum butanol adsorption capacity and the rate constant is 393.700 mg/g and 0.0954, respectively. The results show that Sterculia foetida lignin can be used commercially as a potential adsorbent for continuous biobutanol recovery in the ABE fermentation process. Using renewable lignin as an adsorbent is a sustainable approach for the circular bioeconomy as part of the lignocellulosic biorefinery. [ABSTRACT FROM AUTHOR]

In this study, we investigated the metabolic behavior of the engineered Clostridium acetobutylicum ATCC 824 (pCD07239) strain during the acidogenic phase under varying glucose concentrations and pH conditions. Unlike the wild-type C. acetobutylicum ATCC 824, the engineered strain exhibited negligible butyrate production and simultaneous butanol production during the acidogenic phase under limited glucose condition of 25 g/L. Specifically, batch fermentations of the engineered strain with 25 g/L glucose at a pH of around 5.0 (initially uncontrolled) demonstrated butanol production of 2.99 g/L, while butyrate remained below 0.30 g/L. Separately, in batch fermentations at pH 6.0 with 90 g/L glucose, acetate production nearly doubled compared to fermentations at pH 5.0 with the same glucose concentrations, reaching a maximum concentration of 11.43 g/L, while butyrate production remained relatively low at 4.04 g/L. Under these pH 6.0 and 90 g/L glucose conditions, butanol production reached 9.86 g/L. These findings indicate that C. acetobutylicum ATCC 824 (pCD07239) maintained low butyrate production, even under conditions favoring acidogenesis, and consistently produced butanol. Additionally, the negligible production of acetone at pH 6.0 further indicates that the traditional phase transition was not prominent, suggesting altered regulation mechanisms in the engineered strain. These findings highlight C. acetobutylicum ATCC 824 (pCD07239) strain's unique metabolic profile and its potential for efficient biobutanol production under diverse conditions. [ABSTRACT FROM AUTHOR]

The inlet valve closing (IVC) timing plays a crucial role in engine combustion, which impacts engine performance and emissions. This study attempts to measure the potential to use n-butanol (Bu) and its blends with the neat diesel in a common rail direct injection (CRDI) engine. The computational fluid dynamics (CFD) simulation is carried out to estimate the performance, combustion, and exhaust emission characteristics of n-butanol-diesel blends (0%-30% by volume) for variable valve timings. An experimental study is carried out using standard valve timing and blends to validate the CFD model (ESE AVL FIRE). After validation, the CFD model is employed to study the effect of variable valve timings for different n-butanol-diesel blends. Extended coherent flame model-3 zone (ECFM-3Z) is implemented to conduct combustion analysis, and the kappa-zeta-f (k-ζ -- f) model is employed for turbulence modeling. The inlet valve closing (IVC) time is varied (advanced and retarded) from standard conditions, and optimized valve timing is obtained. Advancing IVC time leads to lower cylinder pressure during compression due to reduced trapped air mass. The brake thermal efficiency (BTE) is increased by 4.5%, 6%, and 8% for Bu10, Bu20, and Bu30, respectively, compared to Bu0. Based on BTE, optimum injection timings are obtained at 12° before the top dead center (BTDC) for Bu0 and 15° BTDC for Bu10, Bu20, and Bu30. Nitrogen oxide (NOx) emissions increase due to complete combustion. Due to IVC timing, further carbon monoxide and soot formation decreased with blends and had an insignificant effect. [ABSTRACT FROM AUTHOR]

Green deep eutectic solvents (DESs) are widely used to extract bioactive components from plant biomass; however, hydrophilic DES and bioactive component isolation methods have not been developed. In this study, we synthesized hydrophilic DES (CL‐CA‐DES) using citric acid and choline chloride. We combined this with environmentally friendly anion‐ and cation‐exchange resin column chromatographic isolation methods. This approach extracted and isolated four polyphenolic compounds (catechins, epicatechins, procyanidin B1, and procyanidin B2) from raspberry root and efficiently recovered the hydrophilic DES. CL‐CA‐DES extracted significantly higher contents of catechin and procyanidin B2 from raspberry root compared to other solvents. It also extracted substantially higher contents of epicatechin compared to butyl alcohol, 70% ethanol, and water, but there was no significant difference when compared with acetone and ethyl acetate. Additionally, CL‐CA‐DES extracted significantly higher contents of procyanidin B1 compared to butyl alcohol, water, and ethyl acetate, with no significant difference when compared with 70% ethanol and acetone. The isolation efficiency of the bioactive components in the raspberry root extract by anion‐ and cation‐exchange resin column chromatography was higher than that of the organic solvent extraction and precipitation generation methods, and the method was effective in recovering CL‐CA‐DES with a recovery rate higher than 60%. In conclusion, this study developed a new method for the efficient recovery of hydrophilic CL‐CA‐DES, which can be used for isolating polyphenolic compounds from raspberry root. [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]

In the era of decarbonization driven by environmental concerns and stimulated by legislative measures such as Fit for 55, the industry and transportation sectors are increasingly replacing petroleum-based fuels with those derived from renewable sources. For many years, the share of these fuels in blends used to power compression ignition engines has been growing. The primary advantage of this fuel technology is the reduction of GHG emissions while maintaining comparable engine performance. However, these fuel blends also have drawbacks, including limited ability to form stable mixtures or the requirement for chemical stabilizers. The stability of these mixtures varies depending on the type of alcohol used, which limits the applicability of such fuels. This study focuses on evaluating the impact of eight types of alcohol fuels, including short-chain (methanol, ethanol, propanol) and long-chain alcohols (butanol, pentanol, hexanol, heptanol, and octanol), on the most critical operational parameters of an industrial engine and exhaust emissions. The engines being compared operated at a constant speed and under a constant load, either maximum or close to maximum. The study also evaluated the effect of alcohol content in the mixture on combustion process parameters such as peak cylinder pressure and heat release, which are the basis for parameterizing the engine's combustion process. Determining ignition delay and combustion duration is fundamental for optimizing the engine's thermal cycle. As the research results show, both the type of alcohol and its concentration in the mixture influence these parameters. Another parameter important from a usability perspective is engine stability, which was also considered. Engine performance evaluation also includes assessing emissions, particularly the impact of alcohol content on NOx and soot emissions. Based on the analysis, it can be concluded that adding alcohol fuel to diesel in a CI engine increases ignition delay (up to 57%), pmax (by approximately 15–20%), HRRmax (by approximately 80%), and PPRmax (by approximately 70%). Most studies indicate a reduction in combustion duration with increasing alcohol content (by up to 50%). For simple alcohols, an increase in thermal efficiency (by approximately 15%) was observed, whereas for complex alcohols, a decrease (by approximately 10%) was noted. The addition of alcohol to diesel slightly worsens the stability of the CI engine. Most studies pointed to the positive impact of adding alcohol fuel to diesel on NOx emissions from the compression ignition engine, with the most significant reductions reaching approximately 50%. Increasing the alcohol fuel content in the diesel blend significantly reduced soot emissions from the CI engine (by up to approximately 90%). [ABSTRACT FROM AUTHOR]

In the current era there are huge quantities of waste organic matter available, creating a big burden to the environment. To address these issues, researchers started to apply effective and microbial induced biotechnological processes that can mitigate these waste matters. In this context, different nature of microbial systems are involved in hydrolysing the waste organic material into fermentable sugar. These can be easily consumed by specific microbial systems like Saccharomyces cerevisiae MTCC 3821 and Clostridium acetobutylicum that produced bioethanol and biobutanol, respectively. Saccharomyces cerevisiae was cultured in specific media and incubated at rotary shaker with 150 rpm at 30°C for 72 to 96 hours. Ethanol concentrations from different waste matters were found in the range of 1.2-1.5 g.L-1. Ethanol synthesis was done by shake flask experiment with addition of glucose (50 g.L-1) to waste organic hydrolyzed solution. Non-glucose media produced less than 3 g.L-1 ethanol but glucose media produced 4.5 g.L-1. Next, Clostridium acetobutylicum was grown in culture media containing waste organics as sole carbon substrate with pH 7 and then was incubated in anaerobic conditions at 35°C for 72 hours, produced butanol (0.7 to 1.25 g.L-1). This research work promoted biofuels synthesis by keeping a waste mitigation strategy. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the use of cranberry bush fruit pomace (CBFP) (Viburnum opulus L.), which has recently become popular raw material, as a substrate in the presence of a reducing agent to increase biobutanol production by Clostridium beijerinckii DSMZ 6422. For this purpose, some factors were optimized, including the pretreatment, initial concentration of CBFP (5–20%), different types of reducing agents (ascorbic acid, L-cysteine, sodium dithionite and sodium sulfite), different concentrations of sodium dithionite (2.5–15 mM), inoculum concentration (5%, 10%, and 20%), and fermentation time (24–96 h). The maximum biobutanol, total ABE, biobutanol yield, and biobutanol productivity were 9.45 g/L, 12.08 g/L, 0.21 g/g, and 0.13 g/L/h in the medium containing enzymatically hydrolyzed 10% CBFP, 10 mM sodium dithionite, and 20% inoculum at the end of 72 h, respectively. These findings demonstrate that CBFP can be considered as a sustainable, economical, and viable substrate on biobutanol production for the first time in the literature. [ABSTRACT FROM AUTHOR]

Bioproduction of industrially relevant chemicals such as 1,2-propanediol (1,2-PD) is central to decarbonization of the economy. Currently, 1,2-PD is produced from fossil-derived feedstocks, contributing to CO 2 emission and generation of hazardous wastes. In this study, Clostridium beijerinckii NCIMB 8052 (Cbei) , C. pasteurianum ATCC 6013 (Cpas), and Clostridium tyrobutyricum ATCC 25755 (Ctyro) were screened for the ability to transform methylglyoxal and acetol—precursors of 1,2-PD—to 1,2-PD in cultures exogenously supplemented with both compounds. Only Cbei transformed methylglyoxal to 1,2-PD (0.08 g/L). Subsequently, multiple recombinant strains of Cbei were engineered to express methylglyoxal-targeting aldo-keto reductases [ mgR , yeaE , yhdN (from Cpas), yqhD , and ydjG (from Enterobacter hormaechei UW0SKVC1), and glycerol dehydrogenase (gldA ; from Ctyro ]. With exogenous supplementation of methylglyoxal, the growth of the control strain of Cbei was impaired. Conversely, Cbei_ydjG , Cbei_yqhD , and Cbei_gldA showed 19.3 %, 130 % and 162 % enhanced growth following methylglyoxal challenge, respectively, whilst producing 0.100, 0.032, and 0.042 g/L 1,2-PD. Wildtype or recombinant strains of Cbei , Cpas , and Ctyro transformed ∼100 % of exogenously supplemented acetol to 1,2-PD. Cbei _ mgsA + mgR co-expressing methylglyoxal synthase (mgsA) and mgR (both from Cpas) produced up to 88 % more butanol on both glucose and lactose than the control strains. [Display omitted] • Clostridium beijerinckii transformed a fraction of exogenously supplemented methylglyoxal to 1,2-propanediol. • Two aldo-keto reductases and a glycerol dehydrogenase that transform cloning and heterologous expression. • YdjG from Enterobacter hormaechei UW0SKVC1 exhibited the highest 1,2-propandiol production from exogenous methylglyoxal. • Heterologous expression of mgR from Clostridium pasteurianum in Clostridium beijerinckii enhanced butanol production. [ABSTRACT FROM AUTHOR]

One of the primary sources contributing to vibrations in operational marine diesel engines is the combustion process of fuel injected into the cylinders. Hence, alterations in the injection process and the quality and type of fuel supplied to the engine can modulate the combustion parameters, consequently impacting noise and vibration levels. A literature review on this subject suggests that while some research has been conducted, mainly focusing on small engines in the automotive sector, there's been a limited exploration in the marine domain. Despite the recent surge in manufacturers' interest in electrifying road transport vehicles, a similar trend has not been observed in sea transport besides short-range ferries, mainly due to the substantial range requirements of vessels. It is conceivable that the utilisation of liquid fuels in shipbuilding will persist. Presently, the predominant marine fuels are fossil-based, the reserves of which are progressively declining. However, the widespread adoption of alternative fuel additives like butanol holds promise in curbing fossil fuel consumption. One of the conditions to be met by a new commonly used fuel for marine engines is its good properties in limiting the parameters of accompanying processes like vibrations. The article delineates a comparative analysis of parameter values related to the vibrations of a marine engine fueled by different blends of butanol and diesel oil. Laboratory tests were conducted on a sixcylinder marine engine under load using a water brake, encompassing various engine loads to replicate real-world operating conditions accurately. [ABSTRACT FROM AUTHOR]

The biobutanol‐based biofuel fermentation is hindered by the challenge of inadequate fermentation broth concentration and the azeotropic systems of water. The application of eucalyptus oil in diesel fuel makes it a promising extractant for biobutanol extraction and dehydration, thus resulting in product recovery and the development of fuel blend technology. Eucalyptus oil‐derived 1,8‐cineole was applied to acetone‐butanol‐ethanol (ABE) and isobutanol systems to enhance the butanol recovery and dehydration. The recovery of n‐butanol and isobutanol reached 92% and 95%, respectively, while the water removal in a 2% butanol system exceeded 99%. These results demonstrated that 1,8‐cineole exhibited a high selectivity toward butanol, thus providing a robust theoretical foundation for the fermentation‐based biofuel recovery and the elimination of azeotropic systems. The introduction of high‐density diesel‐fuel‐like eucalyptus oil into low‐energy‐density biobutanol will increase the energy density of fermentation‐based alcohols, yielding linear and cyclic biofuel blends. [ABSTRACT FROM AUTHOR]

Abstract Enset fiber is a promising feedstock for biofuel production with the potential to reduce carbon emissions and improve the sustainability of the energy system. This study aimed to maximize hydrogen and butanol production from Enset fiber through simultaneous saccharification and fermentation (SSF) process in bottles as well as in bioreactor. The SSF process in bottles resulted in a higher butanol concentration of 11.36 g/L with a yield of 0.23 g/g and a productivity of 0.16 g/(L h) at the optimal process parameters of 5% (w/v) substrate loading, 16 FPU/g cellulase loading, and 100 rpm agitation speed from pretreated Enset fiber. Moreover, a comparable result to the bottle experiment was observed in the bioreactor with pH-uncontrolled SSF process, although with a decreased in butanol productivity to 0.095 g/(L h). However, using the pre-hydrolysis simultaneous saccharification and fermentation (PSSF) process in the bioreactor with a 7% (w/v) substrate loading led to the highest butanol concentration of 12.84 g/L with a productivity of 0.104 g/(L h). Furthermore, optimizing the SSF process parameters to favor hydrogen resulted in an increased hydrogen yield of 198.27 mL/g-Enset fiber at atmospheric pressure, an initial pH of 8.0, and 37 °C. In general, stirring the SSF process to shift the product ratio to either hydrogen or butanol was possible by adjusting temperature and pressure. At 37 °C and atmospheric pressure, the process resulted in an e-mol yield of 12% for hydrogen and 38% for butanol. Alternatively, at 30 °C and 0.55 bar overpressure, the process achieved a yield of 6% e-mol of hydrogen and 48% e-mol of butanol. This is the first study to produce hydrogen and butanol from Enset fiber using the SSF process and contributes to the development of a circular bioeconomy. Graphical Abstract

Abstract In this study, we investigated the metabolic behavior of the engineered Clostridium acetobutylicum ATCC 824 (pCD07239) strain during the acidogenic phase under varying glucose concentrations and pH conditions. Unlike the wild-type C. acetobutylicum ATCC 824, the engineered strain exhibited negligible butyrate production and simultaneous butanol production during the acidogenic phase under limited glucose condition of 25 g/L. Specifically, batch fermentations of the engineered strain with 25 g/L glucose at a pH of around 5.0 (initially uncontrolled) demonstrated butanol production of 2.99 g/L, while butyrate remained below 0.30 g/L. Separately, in batch fermentations at pH 6.0 with 90 g/L glucose, acetate production nearly doubled compared to fermentations at pH 5.0 with the same glucose concentrations, reaching a maximum concentration of 11.43 g/L, while butyrate production remained relatively low at 4.04 g/L. Under these pH 6.0 and 90 g/L glucose conditions, butanol production reached 9.86 g/L. These findings indicate that C. acetobutylicum ATCC 824 (pCD07239) maintained low butyrate production, even under conditions favoring acidogenesis, and consistently produced butanol. Additionally, the negligible production of acetone at pH 6.0 further indicates that the traditional phase transition was not prominent, suggesting altered regulation mechanisms in the engineered strain. These findings highlight C. acetobutylicum ATCC 824 (pCD07239) strain’s unique metabolic profile and its potential for efficient biobutanol production under diverse conditions.

One of the primary sources contributing to vibrations in operational marine diesel engines is the combustion process of fuel injected into the cylinders. Hence, alterations in the injection process and the quality and type of fuel supplied to the engine can modulate the combustion parameters, consequently impacting noise and vibration levels. A literature review on this subject suggests that while some research has been conducted, mainly focusing on small engines in the automotive sector, there's been limited exploration in the marine domain. Despite the recent surge in manufacturers' interest in electrifying road transport vehicles, a similar trend has not been observed in sea transport besides short-range ferries, mainly due to the substantial range requirements of vessels. It is conceivable that the utilisation of liquid fuels in shipbuilding will persist. Presently, the predominant marine fuels are fossil-based, the reserves of which are progressively declining. However, the widespread adoption of alternative fuel additives like butanol holds promise in curbing fossil fuel consumption. One of the conditions to be met by a new commonly used fuel for marine engines is its good properties in limiting the parameters of accompanying processes like vibrations. The article delineates a comparative analysis of parameter values related to the vibrations of a marine engine fueled by different blends of butanol and diesel oil. Laboratory tests were conducted on a six-cylinder marine engine under load using a water brake, encompassing various engine loads to replicate real-world operating conditions accurately.

This study investigated the effects of using ferric oxide nanoparticles (FO) and C2–C4 alcohols with diesel/biodiesel blend in a diesel engine. Optimum operating conditions were explored, and an engine speed of 1750 rpm was optimal. The concentration of FO was estimated to be 760 ppm, considering the best conditions for carbon nanotube (CNT) production. Ethanol was immiscible in diesel fuel; however, any biodiesel percentage in the blend made it miscible. The used engine was too small to run with a blend containing more than 3 % ethanol. Propanol and butanol were blended at the same ethanol concentration for comparative purposes. A blend with 30 % biodiesel (B30) was found to be the best diesel/biodiesel blend. This was detected by the best coefficient of variation (COV) with reasonable performance and emissions. Ferric oxide nanoparticles reduced COV and improved engine performance. The COV increased for tested alcohols. However, blending B30 with alcohols, especially butanol, improved thermal efficiency. FO and alcohol increased NOx emissions and decreased both CO and smoke opacity. They increased the peak pressure and the heat release rate while reducing the combustion duration. Nonetheless, no CNT traces were detected in the present study under any conditions.

Abstract Hyperthermus butylicus is a hyperthermophilic crenarchaeon that produces 1‐butanol as an end product. A thermostable alcohol dehydrogenase (ADH) must be present in H. butylicus to act as the key enzyme responsible for this production; however, the gene that encodes the ADH has not yet been identified. A novel ADH, HbADH2, was purified from a cell‐free extract of H. butylicus, and its characteristics were determined. The gene that encodes HbADH2 was demonstrated to be HBUT_RS04850 and annotated as a hypothetical protein in H. butylicus. HbADH2 was found to be a primary–secondary ADH capable of using a wide range of substrates, including butyraldehyde and butanol. Butyraldehyde had the highest specificity constant, calculated as kcat/Km, with kcat and apparent Km values of 8.00 ± 0.22 s−1 and 0.59 ± 0.07 mM, respectively. The apparent Km values for other substrates, including ethanol, 1‐propanol, 2‐propanol, butanol, acetaldehyde, propanal, and acetone, were 4.36 ± 0.42, 4.69 ± 0.41, 3.74 ± 0.46, 2.44 ± 0.30, 1.27 ± 0.18, 1.55 ± 0.20, and 0.68 ± 0.04 mM, respectively. The optimal pH values for catalyzing aldehyde reduction and alcohol oxidation were 6.0 and 9.0, respectively, while the optimal temperature was higher than 90°C due to the increase in enzymatic activity from 60°C to 90°C. Based on its substrate specificity, enzyme kinetics, and thermostability, HbADH2 may be the ADH that catalyzes the production of 1‐butanol in H. butylicus. The putative conserved motif sites for NAD(P)+ and iron binding were identified by aligning HbADH2 with previously characterized Fe‐containing ADHs.

Abstract Background Inhibitors that are released from lignocellulose biomass during its treatment represent one of the major bottlenecks hindering its massive utilization in the biotechnological production of chemicals. This study demonstrates that negative effect of inhibitors can be mitigated by proper feeding strategy. Both, crude undetoxified lignocellulose hydrolysate and complex medium supplemented with corresponding inhibitors were tested in acetone–butanol–ethanol (ABE) fermentation using Clostridium beijerinckii NRRL B-598 as the producer strain. Results First, it was found that the sensitivity of C. beijerinckii to inhibitors varied with different growth stages, being the most significant during the early acidogenic phase and less pronounced during late acidogenesis and early solventogenesis. Thus, a fed-batch regime with three feeding schemes was tested for toxic hydrolysate (no growth in batch mode was observed). The best results were obtained when the feeding of an otherwise toxic hydrolysate was initiated close to the metabolic switch, resulting in stable and high ABE production. Complete utilization of glucose, and up to 88% of xylose, were obtained. The most abundant inhibitors present in the alkaline wheat straw hydrolysate were ferulic and coumaric acids; both phenolic acids were efficiently detoxified by the intrinsic metabolic activity of clostridia during the early stages of cultivation as well as during the feeding period, thus preventing their accumulation. Finally, the best feeding strategy was verified using a TYA culture medium supplemented with both inhibitors, resulting in 500% increase in butanol titer over control batch cultivation in which inhibitors were added prior to inoculation. Conclusion Properly timed sequential feeding effectively prevented acid-crash and enabled utilization of otherwise toxic substrate. This study unequivocally demonstrates that an appropriate biotechnological process control strategy can fully eliminate the negative effects of lignocellulose-derived inhibitors. Graphical Abstract

One promising oxygenate additive being considered as a fuel component for diesel engines is 1-butanol. However, since 1-butanol is characterized, like many other alcohols, by poor autoignition properties and, consequently, a low cetane number, the introduction of this additive into diesel fuel naturally worsens the autoignition properties of the blend so obtained. It is usual to consider a proportion of 1-butanol no higher than approx. 30% alcohol by volume. Thus, when considering the addition of 1-butanol to diesel fuel, it is necessary to improve the autoignition properties of such a blend. One such additive may be 2-ethylhexyl nitrate (2-EHN). This article determines the effect of the 2-EHN additive on the autoignition properties of a blend of 1-butanol and diesel fuel at an alcohol content of 30% (v/v). The tests were carried out using a constant volume combustion chamber method, which additionally made it possible to determine the effect of ambient gas temperature on the ignition delay (ID), combustion delay (CD) and derived cetane number (DCN), among other factors. The study showed, among other things, that with an increase in the mass proportion of 2-EHN in the 1-butanol–diesel blend (BDB) tested, the ignition and combustion delay were shortened, which resulted in an increase in the value of the derived cetane number. [ABSTRACT FROM AUTHOR]

Schinus terebinthifolius is a medicinal plant with biological in vitro activity against clinically relevant parasites such as Leishmania amazonensis and L. chagasi. Considering its antiparasitic activity, this work aimed to investigate the in vitro effects of S. terebinthifolius fractions against P. falciparum using SYBR fluorescence tests, its cytotoxicity towards monkey kidney cells and efficacy against malaria in a murine model of P. berghei infection. For the first time, screening results with several extracts and fractions are reported herein. Five out of 16 fractions obtained from leaves, flowers, unripe and ripe berries with dichloromethane, ethyl acetate and butanol solvents used in plant extraction were active against P. falciparum. Two ethyl acetate fractions with no cytotoxicity in vitro presenting selectivity indexes of ≥111 and ≥167 exhibited no antimalarial activity in mice at 500 mg/kg. Preliminary LCMS analysis of the ethyl acetate subfractions showed antiplasmodial effect in vitro with high specific index suggesting that such activity is related to polyphenolics in the fractions, mainly flavonoids. Additional studies should be undertaken to identify the compound(s) with anti-malaria activity. [ABSTRACT FROM AUTHOR]

Acrylate polymer is widely used to manufacture display films as an adhesive. Improper disposal of acrylate polymer-containing display film waste (a kind of E-waste) may cause serious environmental problems. As an effort to develop a display film waste treatment strategy, this study applied a solvent-based method to recover acrylate polymer from display film waste. The solubility of acrylate polymer (e.g. poly(tert -butyl acrylate)) in 18 different organic solvents was calculated using Hansen solubility parameters. As a result, 2-butanol and methyl acetate were chosen as organic solvents for the acrylate polymer recovery from the display film waste. Effects of various recovery parameters (e.g. temperature, time, and stirring speed) on the recovery of acrylate polymer in five different solvent systems consisting of 2-butanol and methyl acetate (2-butanol, methyl acetate, 1:1 mixture, 1:2 mixture, and 2:1 mixture) were explored. 2-Butanol was found to be a better solvent than any others because it is more hydrophobic than methyl acetate. The recovery condition at which the highest acrylate polymer recovery yield in 2-butanol was obtained was T = 30 °C, t = 1 h, and stirring speed of 250 r/min, reaching 8.28 wt%. This study would help to develop an E-waste recycling method that can be recovering value-added products from E-waste. [ABSTRACT FROM AUTHOR]

Leveraging renewable carbon-based resources for energy and chemical production is a promising approach to decrease reliance on fossil fuels. This entails a thermo/biotechnological procedure wherein bacteria, notably Clostridia , ferment syngas, converting CO or CO 2 + H 2 into Hexanol, Butanol and Ethanol (H-B-E fermentation). This work reports of Clostridium carboxidivorans performance in a stirred tank reactor continuously operated with respect to the gas and the cell/liquid phases. The primary objective was to assess acid and solvent production at pH 5.6 by feeding pure CO or synthetic syngas under gas flow differential conditions. Fermentation tests were conducted at four different dilution rates (D L) of the fresh medium in the range 0.034–0.25 h−1. The fermentation pathways of C. carboxidivorans were found to be nearly identical for both CO and syngas, with consistent growth and metabolite production at pH 5.6 within a range of dilution rates. Wash-out conditions were observed at a D L of 0.25 h−1 regardless of the carbon source. Ethanol was the predominant solvent produced, but a shift towards butanol production was observed with CO as the substrate and towards hexanol production with synthetic syngas. In particular, the maximum cell concentration (0.5 g DM /L) was obtained with pure CO at D L 0.05 h−1; the highest solvent productivity (60 mg/L*h of total solvent) was obtained at D L 0.17 h−1 by using synthetic syngas as C-source. The findings highlight the importance of substrate composition and operating conditions in syngas fermentation processes. These insights contribute to the optimization of syngas fermentation processes for biofuel and chemical production. [Display omitted] • C. carboxidivorans was grown in a CSTR at pH= 5.6. • The effect of substrate gas and dilution rate was evaluated. • max cell concentration (0.5 g DM /L) was obtained with pure CO at D L 0.05 h−1. • max solvent productivity was 60 mg/L*h, at D L 0.17 h−1 using synthetic syngas. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effect of pretreatment and different technological conditions on the course of ABE fermentation of rye straw (RS) and the composition of volatile compounds in the distillates obtained. The highest concentration of ABE and butanol was obtained from the fermentation of pretreated rye straw by alkaline hydrolysis followed by detoxification and enzymatic hydrolysis. After 72 h of fermentation, the maximum butanol concentration, productivity, and yield from RS were 16.11 g/L, 0.224 g/L/h, and 0.402 g/g, respectively. Three different methods to produce butanol were tested: the two-step process (SHF), the simultaneous process (SSF), and simultaneous saccharification with ABE fermentation (consolidation SHF/SSF). The SHF/SSF process observed that ABE concentration (21.28 g/L) was higher than in the SSF (20.03 g/L) and lower compared with the SHF (22.21 g/L). The effect of the detoxification process and various ABE fermentation technologies on the composition of volatile compounds formed during fermentation and distillation were analyzed. [ABSTRACT FROM AUTHOR]

Few studies have reported on the continuous evolution of dual-linker zeolitic imidazolate frameworks' (ZIFs) structure and morphology during the crystal growth process. Herein, we report the synthesis of a novel ZIF material with CHA topology (ZIF-301-eIm) via the combination of a small-sized 2-ethylimidazole (eIm) with the large-sized 5-chlorobenzimidazole ligand. A series of derivative materials with distinct structures and morphologies were obtained via two pathways: (1) insufficient amount of eIm with prolonged crystallization time (pathway A) and (2) sufficient amount of eIm with prolonged crystallization time (pathway B). Various characterization techniques revealed the continuous evolution of structure and morphology during the crystal growth process. Insufficient amount of eIm and crystallization time (crystallization pathway A) led to ZIF-301-eIm derivatives with defective and open structures alongside an aggregated morphology of nanoparticles. Prolonging the crystallization time allowed small-sized eIm ligands to gradually fill into the framework, resulting in the formation of ZIF-301-eIm-A5 characterized by complete but dense structures with a perfect polyhedral morphology. Remarkably, a sufficient amount of eIm during synthesis (crystallization pathway B) formed ZIF-301-eIm-B1 with a similar structure and morphology to ZIF-301-eIm-A5 in just 1 day. ZIF-301-eIm-B3, with intact, dense structures, exhibits superior acetone/butanol separation performance compared to ZIF-301-eIm-A3 due to small pore windows and large cages facilitating selective adsorption of acetone through exclusion separation. [ABSTRACT FROM AUTHOR]

Self-assembly of M(ClO4)2 (M2+ = Ni2+, Cu2+, and Zn2+) with (1S,1′S,1′′S,2R,2′R,2′′R)-(benzenetricarbonyltris(azanediyl))tris(2,3-dihydro-1H-indene-2,1-diyl) trinicotinate (s,r-L) and the corresponding enantiomer (r,s-L) as a pair of chiral tridentate donors gives rise to the chiral cage pairs [M3(s,r- and r,s-L)2](ClO4)6. For the two pairs of [(Me2CO)(H2O)@M3(r,-s and s,r-L)2](ClO4)6 (M2+ = Ni2+ and Zn2+), the inner cavity is occupied by both an acetone and a single water molecule, whereas for the copper(II) pair of [Me2CO@Cu3(r,s- and s,r-L)2](ClO4)6 under the same conditions, the cavity is filled by only one acetone molecule. Thus, the encapsulation of guest molecules into the cages during self-assembly shows significant metal(II) ion effects. These chiral cages are effective for the enantio-recognition of chiral (S)-2-butanol and (R)-2-butanol via the shifts of the electrochemical oxidation potentials obtained by the linear sweep voltammetry (LSV) technique, density functional theory (DFT) calculations, and the chiral 2-butanol adsorption in the single-crystal-to-single-crystal (SCSC) mode. [ABSTRACT FROM AUTHOR]

The widespread application of electrochemical hydrogen production faces significant challenges, primarily attributed to the high overpotential of the oxygen evolution reaction (OER) in conventional water electrolysis. To address this issue, an effective strategy involves substituting OER with the value‐added oxidation of biomass feedstock, reducing the energy requirements for electrochemical hydrogen production while simultaneously upgrading the biomass. Herein, we introduce an electrocatalytic approach for the value‐added oxidation of isobutanol, a high energy density bio‐fuel, coupled with hydrogen production. This approach offers a sustainable route to produce the valuable fine chemical isobutyric acid under mild condition. The electrodeposited Ni(OH)2 electrocatalyst exhibits exceptional electrocatalytic activity and durability for the electro‐oxidation of isobutanol, achieving an impressive faradaic efficiency of up to 92.4 % for isobutyric acid at 1.45 V vs. RHE. Mechanistic insights reveal that side reactions predominantly stem from the oxidative C−C cleavage of isobutyraldehyde intermediate, forming by‐products including formic acid and acetone. Furthermore, we demonstrate the electro‐oxidation of isobutanol coupled with hydrogen production in a two‐electrode undivided cell, notably reducing the electrolysis voltage by approximately 180 mV at 40 mA cm−2. Overall, this work represents a significant step towards improving the cost‐effectiveness of hydrogen production and advancing the conversion of bio‐fuels. [ABSTRACT FROM AUTHOR]

Nicotinic acid derivatives have a wide range of biological activity and are widely used in medical practice as first-line drugs for the treatment of tuberculosis [1], pulmonary arterial hypertension [2], vitamin B6- dependent epilepsy [3], inhibitors of blood clotting factor IXa [4, 5], human immunodeficiency virus inhibitor [6,7], etc. It should be noted that the pyridine cycle is part of many vital organic compounds, which determines it's one of the dominant roles among heterocycles. Therefore, the development of convenient preparative methods for the synthesis of new nicotinic acid derivatives is an urgent task, since these compounds are of practical and theoretical interest. The purpose of this work is the targeted synthesis of nicotinic acid azide and its further modification in order to obtain new pharmacologically active compounds. In this work, the synthesis of nicotinic acid azide was carried out by the interaction of sodium nitrite with nicotinic hydrazide with a yield of 99%. The interaction of nicotinic acid azide with alcohols (isopropyl and butyl alcohols) and a secondary amine (cytisine alkaloid) has been studied. It has been shown that when heated in a dry benzene medium, nicotinic acid azide undergoes a Curcius rearrangement to form isocyanate, which reacts in situ with alcohols and the alkaloid cytisine to form the corresponding urethanes and urea. In order to synthesize 1,2,3-triazole derivatives, the interaction of nicotinic acid azide with terminal acetylene - prop-2-inyl ether of 3-tert-butyl-5-ethyl-2-hydroxybenzoic acid was carried out in a DMFA and heated (70-80 °C) in the presence of copper sulfate CuSO4×5H2O and sodium ascorbate (NaAsc). It was found that as a result of the reaction, not the expected 1,2,3-triazole compound is formed, but 3-aminopyridine and the initial acetylene compound. It is shown that when heated, the azide decomposes to form an intermediate particle, nitrene, and the subsequent migration of the pyridyl radical to the nitrogen atom (Curtius rearrangement) leads to isocyanate. As a result of hydration of isocyanate and subsequent decarboxylation of the resulting carbamic acid, 3-aminopyridine is obtained. Conclusion. The synthesis of nicotinoylazide was carried out by the interaction of sodium nitrite with nicotinic acid hydrazide. The interaction of nicotinic acid azide with terminal acetylen - prop-2-vinyl ester of 3-tert-butyl-5-ethyl-2-hydroxybenzoic acid did not lead to the formation of the expected 1,2,3-triazole compound. It was found that the initial azide undergoes Curcius rearrangement upon heating in situ with the formation of corresponding urethanes and urea. The structure of the synthesized compounds was confirmed by NMR 1H and 13C spectroscopy, as well as data from the two-dimensional spectra COZY (1H-1H) and HMQC (1H-13C). [ABSTRACT FROM AUTHOR]

Heterogeneous Fenton technology was employed for the advanced treatment of Maotai-flavored Baijiu wastewater. Novel catalysts were prepared by loading different active ingredients (Mn, Fe, and Cu) on γ-Al2O3 using an impregnation method. The effects of active ingredient, reaction time, initial pH, H2O2 dosage, catalyst dosage, and other factors on the reaction were examined. The properties of the new catalysts were analyzed using BET analysis, XPS, and SEM. Moreover, the mechanisms of Fenton-like oxidation and its reaction kinetics were explored through experiments and analyses including GC–MS and intermediate active species scavenging by tertiary butyl alcohol (TBA) and/or para-benzoquinone. The results revealed that the most effective removal of organic matter was achieved with a Mn-Fe/Al (2:1 wt%) catalyst dosage of 30 g/100 g water, pH of 5.0, H2O2 dosage of 0.3 g/L, and reaction time of 60 min; the effluent COD value was 12 ± 1 mg/L, and the degradation rate was 65.7 ± 3%, approximately 14% higher than that of the conventional Fenton catalyst under similar conditions; moreover, the catalytic efficacy remained high after seven cycles. Kinetic analysis indicated that the heterogeneous Fenton oxidation reaction followed a third-order kinetics model, with R2 = 0.9923 and K = 0.0006 min−1. [ABSTRACT FROM AUTHOR]

The article "Chemical Constituents and Anti-Anxiety Active Sites from Stellaria dichotoma var. lanceolata" explores the medicinal properties of Stellariae Radix, a dried root used in traditional Chinese medicine. The extract from Stellariae Radix has been found to have antipyretic, anti-inflammatory, and anti-cancer effects. The article focuses on the anti-anxiety potential of Stellariae Radix and describes the isolation and identification of 16 compounds from the root. The study also conducted experiments on rats to confirm the anti-anxiety effects of the extract. The document provides detailed information on the extraction and isolation process, as well as the identification of the compounds obtained. The research was supported by the National Nature Science Foundation of China and the Natural Science Foundation of Ningxia. [Extracted from the article]

Cu/SiO2 catalysts were prepared by co-precipitation (CP), hydrothermal (HT), ammonia evaporation (AE), and sol–gel (SG) methods and tested for their performance in the dehydrogenation reaction of secondary butyl alcohol to methyl ethyl ketone. The results showed that the Cu/SiO2 catalyst prepared by the sol–gel method has the best performance. By BET and H2–TPR characterization, it can be found that the catalysts prepared by sol–gel method has the largest specific surface areas and lowest reduction temperatures. Based on the characterization results of XRD, XPS and XAES, it shows that the catalyst prepared by sol–gel method has a better dispersion of copper components and a higher content of Cu0 species after reduction, which leads to its higher catalytic activity. At a copper loading of 22.96% (w%), the conversion of secondary butyl alcohol was up to 99.0% and the selectivity of methyl ethyl ketone was up to 99.8% by using the Cu/SiO2 catalysts prepared by sol–gel (SG) methods. [ABSTRACT FROM AUTHOR]

Background: The biochemistry of secondary metabolites of marine origin has been identified as a promising area for obtaining new and potent pharmaceutical agents. These secondary metabolism molecules may have important functions such as anti-biotic and anti-parasitic activity, mediate symbiotic relationships between organisms and even have reproductive functions, representing a great ecological advantage for the survival of marine organisms. Aim: This study aimed to characterize the secondary metabolites of the sea squirt Diplosoma listerianum and its associated micro-organisms. Materials and Methods: The squirts were frozen, dried, weighed, roughly crushed and extracted using methanol and dichloromethane (1:1). The crude extract was dissolved in methanol and fractionated in four solvents of increasing polarity: saturated hexane, acetic ester, butyl alcohol and water. The active substances were isolated by liquid chromatography, purified and their structures determined. Bacteriostatic action against the crude extract was assessed using longitudinal in vitro growth in Müller-Hinton broth. Results: D. listerianum’s crude extract showed antibiotic activity against various pathogenic microorganisms. Analysis of variance and Tukey’s multiple comparison tests indicated significant differences among exposure times. Mouse fibroblasts exposed to the crude extract showed fragmented and sickle-shaped nuclei, visible centrosomes, abnormal multipolar mitotic spindles and endoplasmic reticulum vacuolization. The phytagel assay showed a correlation between the gel’s algal density and associated organism numbers. The protein tyrosine kinase assay showed that the crude extract had enzyme-inhibiting properties. Preparative high-performance liquid chromatography, Sephadex column chromatography, high-resolution electrospray ionization mass spectrometry and electron impact mass spectra identified zeaxanthin, tubastrine (an epidermal growth factor receptor inhibitor), inosine, guanosine, oxazolidin-2-one, LL-PAA216 and 2-aminododecan-3-ol. Conclusion: Marine biotechnology generates technological products from the diversity of marine organisms and their strategic adaptations to the extreme conditions of the seas and, in turn, presents itself as a promising source of bioproducts and processes, being able to solve issues in areas such as health, food safety, cosmetics, agriculture, pollution control, climate and industry, among others. [ABSTRACT FROM AUTHOR]

This study compared free and immobilized cells with palm oil and hexanol as an extractant in a large volume ratio of extractant to the broth. Fermentation was conducted using TYA (Tryptone-Yeast-Acetate) media, glucose as the substrate and the palm oil, hexanol, and a mixture of hexanol and palm oil with a composition of 1:1 v/v as an extractant in the fermentation with a large volume ratio of extractant to broth of 5. The strain was inoculated as free-suspended cells of C. saccharoperbutylacetonicum N1-4 and immobilized cells in calcium alginate. The best extractant results for the acetone fermentation process in the ratio of extractive fermentation of free cells and immobilized cells were using palm oil as extractants. This extractant harvested acetone well, with the acetone concentration in the extractant at 18.41 g/L in free cell fermentation and 17.07 g/L in immobilized cell fermentation. The maximum total acetone concentration was up to 93.72 g/L broth. Using palm oil as an extractant in a large extractant volume combined with immobilization is an alternative to enhance bioacetone production by effectively reducing the toxicity effect of the products and minimizing nutrient requirements. [ABSTRACT FROM AUTHOR]

Background: Inhibitors that are released from lignocellulose biomass during its treatment represent one of the major bottlenecks hindering its massive utilization in the biotechnological production of chemicals. This study demonstrates that negative effect of inhibitors can be mitigated by proper feeding strategy. Both, crude undetoxified lignocellulose hydrolysate and complex medium supplemented with corresponding inhibitors were tested in acetone–butanol–ethanol (ABE) fermentation using Clostridium beijerinckii NRRL B-598 as the producer strain. Results: First, it was found that the sensitivity of C. beijerinckii to inhibitors varied with different growth stages, being the most significant during the early acidogenic phase and less pronounced during late acidogenesis and early solventogenesis. Thus, a fed-batch regime with three feeding schemes was tested for toxic hydrolysate (no growth in batch mode was observed). The best results were obtained when the feeding of an otherwise toxic hydrolysate was initiated close to the metabolic switch, resulting in stable and high ABE production. Complete utilization of glucose, and up to 88% of xylose, were obtained. The most abundant inhibitors present in the alkaline wheat straw hydrolysate were ferulic and coumaric acids; both phenolic acids were efficiently detoxified by the intrinsic metabolic activity of clostridia during the early stages of cultivation as well as during the feeding period, thus preventing their accumulation. Finally, the best feeding strategy was verified using a TYA culture medium supplemented with both inhibitors, resulting in 500% increase in butanol titer over control batch cultivation in which inhibitors were added prior to inoculation. Conclusion: Properly timed sequential feeding effectively prevented acid-crash and enabled utilization of otherwise toxic substrate. This study unequivocally demonstrates that an appropriate biotechnological process control strategy can fully eliminate the negative effects of lignocellulose-derived inhibitors. [ABSTRACT FROM AUTHOR]

In order to alleviate the aging phenomenon of Baijiu cellar pits, acid urease producing bacteria were isolated from pit mud of Sichuan Swellfun Co., Ltd. The isolated strain was mixed with Clostridium kluyveri S008 for solid-state fermentation to investigate the effect of acid urease producing bacteria on the pH value and volatile flavor compounds of simulated pit mud. The results showed that a total of 4 strains of acid urease producing bacteria were screened and identified, named as Lactobacillus buchneri S162, Staphylococcus cohnii S163, Rummeliibacillus pycnus S164, and Rummeliibacillus suwonensis S165. The urease activities of the four strains were ranged from 0.45 to 1.51 U/ mL. These four strains could raise the pH of pit mud models. The pH value of the simulated pit mud showed a trend of upper > middle > lower, with the highest pH value observed for S163 group (P < 0.05). Among the flavor substances analyzed, S163 + S008 group had the highest acetaldehyde content (2.38 mg/100 mL), while S162 + S008 group had the highest aldehyde acetal content (2.50 mg/ 100 mL); The content of n-propanol, n-butanol, n-hexanol, and isoamyl alcohol after co-fermentation were 1.41 - 1.97 times, 0.92 - 1.85 times, 0.66 - 1.58 times, and 1.13 - 1.69 times higher than that of single fermentation group, respectively. The synergistic fermentation of S164 and S008 showed the most significant increase in caproic acid content (P < 0.05). The synergistic fermentation of four strains of bacteria with S008 could increase the content of "four major esters" by 2.66 -- 5.02 times, 1.21 - 4.85 times, 1.33 - 3.31 times, and 1.27 - 2.86 times, respectively. The present study showed that the synergistic fermentation of these four acid urease producing strains with Clostridium kluyveri S008 could increase the pH and the production of major volatile flavor compounds in pit mud models. [ABSTRACT FROM AUTHOR]

Waste glycerol can be subjected to various processing operations, including purification and refining, to obtain glycerol of an appropriate purity. Alternative methods for utilising waste glycerol are also being sought, e.g., by converting it into other valuable chemical products or biofuels. Therefore, various technologies are being developed to ensure effective and sustainable utilisation of this type of waste. The production of value-added products from waste glycerol strongly determines the improvement of the economic viability of biofuel production and corresponds to the model of a waste-free and emission-free circular economy. This paper characterises the mechanisms and evaluates the efficiency of existing methods for microbiological utilisation of waste glycerol into liquid biofuels, including biodiesel, bioethanol and biobutanol, and identifies further production avenues of value-added products. In addition, it presents the results of a bibliographical analysis of publications related to the production of liquid fuels and economically valuable products from glycerol, assesses the progress of research and application work and, finally, identifies areas for future research. [ABSTRACT FROM AUTHOR]

Tequila production occurs in Mexico's designated area of origin, principally in the Jalisco State. Its residues are a challenge in treatment and tracking due to a lack of technology, non-economic treatments available, low environmental consciousness and incipient control from authorities. In 2021, average production was close to 1.5 million tequila litres per day with an estimated residue yield of 10–12 litres of stillage (tequila vinasses) per tequila litre produced, including volatile fractions. This research aims to reduce organic matter by electrooxidation (EO) from 5 distillation volatile residual effluents (two-stage still distillation) from three tequila distilleries, first and second-stage heads and heads and tails and second-stage non-evaporated fraction. Round 3 mm titanium (grade-1) electrodes (one anode and one cathode) were used, with fixed voltage to a value of 30 VDC at 0, 3, 6, 9 and 12 h with 75 experiments. Gas chromatography was used to analyse methanol, ethanol, acetaldehyde, ethyl acetate, n-propanol, sec-butanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate content. Treatment shows positive results, reducing organic matter content in all effluents in a Chemical Oxygen Demand COD range of 580–1880 mg/L.h, particularly useful in the second-stage non-evaporated fraction for water recovery. Residual effluent treatment is beneficial to environmental and resource sustainability. Process without adding materials achieving cleaner treated effluents. Process aimed as the final step to recover water. This process could help the Tequila industry to reach a higher sustainability level by reducing water usage and untreated residues. [ABSTRACT FROM AUTHOR]

Biobutanol has been perceived as a renewable green liquid fuel to replace fossil fuel due to its superior properties. Butanol production from waste resources is an ecologically viable and economically feasible approach. In this work, the potential of butanol fermentation from sweet potato processing waste was evaluated. Simultaneous viscosity reduction and fermentation (SVF) significantly improved fermentation performance of Clostridium acetobutylicum CICC 8012 from sweet potato waste (SW). Compared with the untreated group, viscosity reduction treatment increased the butanol concentration by 10.15% (from 8.87 to 9.77 g/L) at the optimal biomass loading of 395.91 gfresh SW/kgmedium (equivalent to 50 gglucose/kgmedium). As the substitute for yeast extract, soybean meal significantly increased the ABE yield by 9.68% (from 0.31 g/gglucose to 0.34 g/gglucose) when compared with unsupplied group. Then, the formulation of other supplements was obtained via response surface methodology. The maximum final butanol concentration, ABE concentration, yield, and fermentation efficiency of 11.39 g/L, 18.28 g/L, 0.37 g/gglucose, and 93.98% were respectively obtained at the optimal conditions of 0.26 g/kg, 0.17 g/kg, 0.24 g/kg, and 0.11 g/kg of ferrous sulfate, manganic sulfate, zinc sulfate, and potassium dihydrogen phosphate supplement. This study demonstrates the feasibility to utilize SW as feedstock for butanol fermentation, develops a one-step conversion approach of SW to butanol without pretreatment of liquefaction and saccharification, and provides a novel strategy for reducing environmental pollution and recycling waste biomass. [ABSTRACT FROM AUTHOR]

The biohydrogen production in Dark fermentation (DF) could be enhanced by ZnFe 2 O 4 nanomaterials (NPs). The optimum conditions were obtained by a response surface method. Eventually, a biohydrogen production of 2645 mL/L was obtained after 48 h of batch culture, which is 116% higher than control without ZnFe 2 O 4 NPs. The mechanism was investigated by a multi-scale method. In bioreactor scale, ZnFe 2 O 4 NPs could enhance the glucose metabolic ability of C. pasteurianum to promote cell growth and biohydrogen production. The metabolic pathways of biohydrogen production were shifted from the butyric acid-type to the ethanol-type. In cellular scale, ZnFe 2 O 4 NPs could reduce bacterial flagella assembly. In macromolecule scale, the activities of hydrogenase and ethanol dehydrogenase were increased. In genetic scale, the differentially expressed genes mainly involved in biohydrogen production, like those encoded Fe-only hydrogenase, ethanol dehydrogenase, and nitrogenase were up-regulated. The results could provide theoretical and technical supports for the development of commercial biohydrogen process. • ZnFe2O4 NPs can effectively promote biohydrogen production. • Optimal enhancement conditions determined through response surface optimization. • ZnFe2O4 NPs enhance glucose utilization by C. pasteurianum. • ZnFe2O4 NPs boost hydrogenase & ethanol dehydrogenase in C. pasteurianum. • Mechanism of NPs promoting biohydrogen production revealed by multi-scale analysis. [ABSTRACT FROM AUTHOR]

A one-pot method for the synthesis of 3-nitro-2H-thiopyrans starting from enamin-3-ones was developed. Reduction of the obtained 3-nitro-2H-thiopyrans with the benzaldehyde/o-phenylenediamine system in butanol led to 3-nitro-3,4-dihydro-2H-thiopyrans. [ABSTRACT FROM AUTHOR]

The n-butanol/low-carbon alcohol/diesel microemulsion system is a good alternative fuel to diesel. In this study, the microemulsions were formulated in four ways: ultrasonication, vortex oscillation, shaker mixing and spontaneous formation. The results reveal that the ultrasonication method is significantly influenced by temperature. Specifically, at 45 °C, the quantity of cosolvent added during the ultrasonic process can be reduced by a maximum of 25% compared to that at 25 °C. However, while the amount of cosolvent required is the lowest at 45 °C, the stability of the emulsion is the poorest. In all cases of this study, the stability of the microemulsion increases when the volume ratio of the lower carbon alcohol exceeds 60%. The lowest amount of co-solvent and high stability were achieved using the shaker mixing method at both 25 °C and 35 °C. Although the quantity of cosolvent required at 45 °C is second only to the lowest, its stability surpasses that of the ultrasonication method. Therefore, it is more effective to choose the shaker mixing method that provides uniform and ordered forces for the preparation of microemulsion liquids. [ABSTRACT FROM AUTHOR]

The demand for 2-ethylhexanol is rising in several sectors, yet this chemical is actually almost exclusively produced from petroleum resources, calling for sustainable alternatives. Here we review the production of 2-ethylhexanol from lignocellulosic biomass-derived chemicals with emphasis on 2-ethylhexanol synthesis and applications. 2-Ethylhexanol can be synthesized from ethanol, butanol, butyraldehyde, and syngas. Applications comprise biofuels, lubricants, plasticizers, and surfactants. [ABSTRACT FROM AUTHOR]