Potential Ethanol Research Articles

Efficient stabilizing agent-free synthesis of gold nanoparticles via square-wave pulse deposition for enhanced catalytic performance in ethanol electrooxidation

The pressing environmental concerns and the depletion of fossil fuel reserves necessitate a transition toward sustainable energy sources. Ethanol, a renewable biomass-derived fuel, is a promising alternative due to its availability and high energy density. This study investigates the synthesis of gold nanoparticles (AuNPs) via a square-wave pulse deposition technique, aiming to enhance catalytic activity for ethanol electrooxidation. By varying pulse durations, we were able to exert precise control over AuNP size and distribution without stabilizing agents. Characterization using field emission scanning electron microscopy and X-ray diffraction techniques confirmed the formation of clustered nanoparticles of metallic gold phase. Electrochemical characteristics analyses revealed that AuNPs synthesized with a 900 ms pulse duration exhibited the lowest charge transfer resistance and the highest electrochemically active surface area. The electrocatalytic performance test of these AuNPs demonstrated an anodic current density of 2.5 mA cm-2 and a Tafel slope of 78 mV dec-1, indicating superior catalytic performance and reaction kinetics. Additionally, the AuNPs showed high resistance to poisoning, as evidenced by a low jb/jf ratio of 0.28 and stable chronoamperometric response. These findings underscore the potential of this synthesis method for producing high-performance electrocatalysts utilized in exploiting ethanol's potential as an environmentally friendly energy carrier.

Hydrothermal liquefaction of southern yellow pine with downstream processing for improved fuel grade chemicals production

The hydrothermal liquefaction (HTL) technique for liquefying lignocellulose biomass feedstock is often associated with low biocrude yield and poor fuel properties. This study examined the HTL of southern yellow pine sawdust and the hydrotreatment (HYD) of produced biocrudes in an effort to address these challenges. Pine HTL treatment was performed within water and water–ethanol mixed reaction medium at 250, 300, and 350℃ temperatures using metallic iron (Fe) as a catalyst. The rising reaction temperature in a water medium and increasing ethanol content in a mixed reaction medium were found to be effective in enhancing the biocrude yield from the non-catalytic pine HTL process. Maximum non-catalytic biocrude yield of 18 wt.% was produced in water at 350℃, whereas the ethanol and water (1:1 on mass basis) mixture generated the highest biocrude yield of 34 wt.% at 300℃ without any catalyst. The iron catalyst facilitated a maximum of 29 wt.% of biocrude yield as opposed to 18 wt.% without the catalyst at 350℃ in water. The use of an iron catalyst also raised the calorific value of produced biocrudes by 2.5–14 % within 250-350℃ in both water and water–ethanol media. The catalytic and non-catalytic biocrude products were chosen to undergo HYD treatment at 400 °C under high hydrogen pressure (initial 1000 psi) using an alumina-supported cobalt-molybdenum catalyst. The HYD treatment reduced the oxygen content of upgraded oils by 36–60 % compared to the parent HTL biocrudes with 35–37 MJ/kg calorific values. The simulated distillation detected the maximum gasoline range compounds in upgraded oil from catalyst and water–ethanol conditions, whereas the GC–MS analysis revealed the production of increased aromatic hydrocarbons in all upgraded HYD oils. This work has demonstrated the potential of ethanol and inexpensive iron catalyst in enhancing the biocrude production from pine, which could be upgraded to better fuel using the HYD process.

Facile and innovation synthesis of Zn-Mn-Co-LDH/polypyrrole and its application in investigating ethanol oxidation in an alkaline medium

Overvoltage and low current are observed for ethanol electrooxidation on the surface of many unmodified electrodes. Therefore, it is desirable to use a suitable catalyst for ethanol electrooxidation to increase the current. This research introduces a new sensor to catalyze ethanol oxidation in an alkaline environment. This new Zn-Mn-Co LDH/PolyPyrrole/GCE nanocomposite sensor exhibits high catalytic activity for ethanol electrooxidation. It changes the oxidation potential of ethanol to a less positive potential. To identify this proposed sensor, X-ray diffraction (XRD), Brauner Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), FT-IR spectroscopy, field emission scanning electron microscopy (FESEM), thermal analysis (TGA), high-resolution transmission electron microscopy (HR-TEM) and cyclic voltammetry techniques were used. Ethanol electrooxidation was investigated by cyclic voltammetry technique. The effects of scan rate and ethanol concentration on the ethanol oxidation peak have been investigated. The proposed sensor showed long-term stability. This prepared nanocomposite can be used as an anode catalyst for ethanol fuel cells.

Exploring macroalgae biorefinery: Extraction of bioactive compounds and production of volatile fatty acids

Macroalgae have gained significant attention in recent research owing to their potential as novel food source and their noteworthy nutritional properties. However, a substantial amount of these macroalgae accumulates along the coast without being utilized, highlighting the need for proper treatment and disposal methods to mitigate secondary pollution effects. Previous studies on macroalgae have primarily focused on extracting bioactive compounds or anaerobic digestion processes to produce methane or volatile fatty acids (VFA), with observed improvements following different pre-treatments. In this study, three biorefinery options for macroalgae have been compared. Additionally, the extraction of bioactive compounds followed by VFA production is proposed as a promising new valorization strategy. Milled macroalgae exhibited a low methane production yield (138 ± 17 NmL CH4·g volatile solid−1), corresponding to 31 ± 4 % biodegradability, while the acidification percentage was higher (45 ± 1%). Among the three solvents applied (water, ethanol and acetone), ethanol (80%) at 25 °C was the most effective in recovering bioactive compounds, such as chlorophylls, sugars, and phenolic compounds with antioxidant activity. The extraction of chlorophylls and phenolic compounds was not influenced by particle size reduction. However, a more efficient extraction of sugars was observed with lower particle size. Moreover, ethanol treatment demonstrated the good efficiency in VFA production, reaching up to 3.6 ± 0.2 g VFA-(chemical oxygen demand, COD)·L−1, with a VFA spectrum (in COD basis) consisting of 51% acetic acid, 29% propionic acid, 5% i-butyric acid, 7% butyric acid, and 7% i-valeric acid. These findings highlight the potential of ethanol for efficient compound recovery and VFA production from macroalgae.

Impact of crop residue removal on crop production, feedstock quality, and theoretical ethanol production in the Mid‐Atlantic United States

AbstractCellulosic biomass‐to‐bioenergy systems provide fuel, reduce emissions, and offer economic benefits. Corn (Zea mays L.) and wheat (Triticum aestivum L.) residues could be used as feedstocks for biofuel production. However, the impact of residue removal on crop productivity in the Mid‐Atlantic region has not been thoroughly assessed. A trial was conducted to assess crop yield and quality response to different biomass retention rates in grain cropping systems during 2015–2017. Various combinations of corn stover (0–10 Mg ha−1) and wheat straw (0–3 Mg ha−1) were applied in a corn–wheat/soybean [Glycine max (L.) Merr.] rotation in New Kent, VA. In Blacksburg, VA, corn stover (0–20 Mg ha−1) was applied in the continuous corn system. Residues were applied after grain harvest over two production cycles for each system. Residue retention showed no significant impact on grain or crop residue yields or nutrient uptake in either system. Treatment minimally impacted feedstock quality, except wheat straw's sulfur (S) concentration, optimized at around 70% retention in New Kent. Theoretical ethanol potential (TEP) and yield remained unaffected by total residue rates in New Kent. In Blacksburg, over 2 years, a minimum TEP for corn stover corresponded to a retention rate of approximately 30%. A retention rate of more than 30% increased TEP, likely due to improved feedstock quality. Nutrient replacement costs for primary macronutrients and S uptake ranged from $18.3 to $36.9 ha−1 for corn stover and $6.1 to $11.8 ha−1 for wheat straw. Residue harvest or addition did not harm short‐term biomass yield in Virginia's grain‐based cropping systems.

Sustainable waste management: a comprehensive life cycle assessment of bioethanol production from agricultural and municipal waste.

Biofuels have emerged as a promising and eco-friendly alternative to conventional fossil fuels. Biofuel sourced from rice straw (RS) and municipal solid waste (MSW), which are abundant residues from agricultural and municipal activities, present a sustainable solution to address waste management challenges. Utilizing life cycle assessment, this study quantifies the environmental advantages by assessing the reduction in greenhouse gas emissions, energy consumption, and other environmental impacts linked with employing these waste materials for biofuel production. Employing a cradle-to-gate approach as the system boundary for bioethanol production, with the functional unit set as per liter of bioethanol produced, the analysis reveals that the global warming potential (GWP) for ethanol from MSW is 4.4 kg CO2 eq., whereas for RS, it is 2.1 kg CO2 eq. per functional unit. The total environmental impacts were primarily due to enzymatic hydrolysis and electricity consumption for ethanol production from MSW and RS. Despite advancements, fossil fuel consumption remains a potential energy source for biofuel production. The cumulative energy demand stands at 18.6 MJ for RS and 71.5 MJ for MSW per functional unit, underscoring the potential to significantly reduce overall impacts by transitioning to a more environmentally sustainable energy source. The uncertainty analysis acknowledges the inherent uncertainties associated with data, assumptions, and methodologies, highlighting the crucial need for ongoing research and updates to enhance the accuracy of future assessments. This analysis forms the foundation for well-informed decision-making, providing valuable insights for policymakers, industry stakeholders, and consumers.

The PDE4 inhibitor apremilast modulates ethanol responses in Gabrb1-S409A knock-in mice via PKA-dependent and independent mechanisms

We previously showed that the PDE4 inhibitor apremilast reduces ethanol consumption in mice by protein kinase A (PKA) and GABAergic mechanisms. Preventing PKA phosphorylation of GABAA β3 subunits partially blocked apremilast-mediated decreases in drinking. Here, we produced Gabrb1-S409A mice to render GABAA β1 subunits resistant to PKA-mediated phosphorylation. Mass spectrometry confirmed the presence of the S409A mutation and lack of changes in β1 subunit expression or phosphorylation at other residues. β1-S409A male and female mice did not differ from wild-type C57BL/6J mice in expression of Gabrb1, Gabrb2, or Gabrb3 subunits or in behavioral characteristics. Apremilast prolonged recovery from ethanol ataxia to a greater extent in Gabrb1-S409A mice but prolonged recovery from zolpidem and propofol to a similar extent in both genotypes. Apremilast shortened recovery from diazepam ataxia in wild-type but prolonged recovery in Gabrb1-S409A mice. In wild-type mice, the PKA inhibitor H89 prevented apremilast modulation of ataxia by ethanol and diazepam, but not by zolpidem. In Gabrb1-S409A mice, inhibiting PKA or EPAC2 (exchange protein directly activated by cAMP) partially reversed apremilast potentiation of ethanol, diazepam, and zolpidem ataxia. Apremilast prevented acute tolerance to ethanol ataxia in both genotypes, but there were no genotype differences in ethanol consumption before or after apremilast. In contrast to results in Gabrb3-S408A/S409A mice, PKA phosphorylation of β1-containing GABAA receptors is not required for apremilast's effects on acute tolerance or on ethanol consumption but is required for its ability to decrease diazepam intoxication. Besides PKA we identified EPAC2 as an additional cAMP-dependent mechanism by which apremilast regulates responses to GABAergic drugs.

Evaluation of eye irritation potential of experimental cosmetic formulations containing glycolic acid, salicylic acid and ethanol using the Bovine Corneal Opacity and Permeability Assay

Objective Prototype cosmetic formulations containing short-chain acids and alcohols intended to be applied in the proximity of the eyes are sometimes evaluated for ocular irritation potential using the validated Bovine Corneal Opacity and Permeability Assay (OECD TG 437). We evaluated the eye irritation potential of nine experimental cosmetic formulations designed and prepared by Avon Global Reserach and Development to differ only in the concentrations of Ethanol, Glycolic Acid and Salicylic Acid. Methods We analysed the data generated using the BCOP assay. The opacity and permeability values obtained following the exposure of bovine corneas to experimental cosmetic formulations were combined into a single In Vitro Irritancy Score used to rank eye irritation potential. Histopathological examination of treated corneas was used to provide additional information about the depth and degree of the injury and to support the prediction of eye irritation potential of each experimental cosmetic formulation. Results The In Vitro Irritancy Scores and histopathological analysis showed that experimental formulations containing only Ethanol, Glycolic Acid, or Salicylic Acid alone had, at most, a mild ocular irritation potential. The experimental formulations containing both Ethanol and Glycolic Acid had a mild ocular irritation potential, while the experimental formulations containing both Ethanol and Salicylic Acid had a moderate ocular irritation potential. Severe ocular irritation potential was induced by an experimental formulation containing a combination of Glycolic Acid and Salicylic Acid and it was further accentuated by the addition of Ethanol to the formulation. Our data indicate a possible synergistic effect on eye irritation potential of Ethanol, Glycolic Acid and Salicylic Acid in at least some experimental cosmetic formulations. Further, our results provide insight on an apparent concentration-dependent ocular irritation potential effect of combinations of Glycolic Acid, Salicylic Acid and Ethanol in at least one experimental cosmetic formulation. Conclusions The results presented herein emphasise the need to consider in vitro testing of prototype cosmetic formulations containing combinations of Ethanol, Glycolic Acid and Salicylic Acid rather than relying on any predicted additive effect on ocular irritation based solely on previously generated results of similar formulations containing Ethanol, Glycolic Acid or Salicylic Acid alone. Further work is required to understand the significance of these observations and to elucidate the mechanisms responsible for the apparent synergistic effects of Glycolic Acid, Salicylic Acid and Ethanol and eye irritation potential suggested by our results.

Loss of glycine receptors in the nucleus accumbens and ethanol reward in an Alzheimer´s Disease mouse model

Alterations in cognitive and non-cognitive cerebral functions characterize Alzheimer's disease (AD). Cortical and hippocampal impairments related to extracellular accumulation of Aβ in AD animal models have been extensively investigated. However, recent reports have also implicated intracellular Aβ in limbic regions, such as the nucleus accumbens (nAc). Accumbal neurons express high levels of inhibitory glycine receptors (GlyRs) that are allosterically modulated by ethanol and have a role in controlling its intake. In the present study, we investigated how GlyRs in the 2xTg mice (AD model) affect nAc functions and ethanol intake behavior. Using transgenic and control aged-matched litter mates, we found that the GlyRα2 subunit was significantly decreased in AD mice (6-month-old). We also examined intracellular calcium dynamics using the fluorescent calcium protein reporter GCaMP in slice photometry. We also found that the calcium signal mediated by GlyRs, but not GABAAR, was also reduced in AD neurons. Additionally, ethanol potentiation was significantly decreased in accumbal neurons in the AD mice. Finally, we performed drinking in the dark (DID) experiments and found that 2xTg mice consumed less ethanol on the last day of DID, in agreement with a lower blood ethanol concentration. 2xTg mice also showed lower sucrose consumption, indicating that overall food reward was altered. In conclusion, the data support the role of GlyRs in nAc neuron excitability and a decreased glycinergic activity in the 2xTg mice that might lead to impairment in reward processing at an early stage of the disease.

Sugarcane Water Productivity for Bioethanol, Sugar and Biomass under Deficit Irrigation

Knowledge of how certain crops respond to water stress is one of the prerequisites for choosing the best variety and best management practices to maximize crop water productivity (WPc). The selection of a more efficient protocol for managing irrigation depths throughout the cultivation cycle and in the maturation process at the end of the growth period for each sugarcane variety can maximize bioethanol productivity and WPc for bioethanol, sugar and biomass, in addition to the total energy captured by the sugarcane canopy in the form of dry biomass. This study aimed to evaluate the effect of four irrigation depths and four water deficit intensities on the maturation phase for eight sugarcane varieties under drip irrigation, analyzing the responses related to WPc for bioethanol, sugar and biomass. These experiments were conducted at the University of São Paulo. The plots were positioned in three randomized blocks, and the treatments were distributed in a factorial scheme (4 × 8 × 4). The treatments involved eight commercial varieties of sugarcane and included four water replacement levels and four water deficits of increasing intensity in the final phase of the crop season. It was found that for each variety of sugarcane, there was an optimal combination of irrigation management strategies throughout the cycle and during the maturation process. The RB966928 variety resulted in the best industrial bioethanol yield (68.7 L·Mg−1), WPc for bioethanol (0.97 L·m−3) and WPc for sugar (1.71 kg·m−3). The energy of the aerial parts partitioned as sugar had a direct positive correlation with the availability of water in the soil for all varieties. The RB931011 variety showed the greatest potential for converting water into shoots with an energy of 1.58 GJ·ha−1·mm−1, while the NCo376 variety had the lowest potential at 1.32 GJ·ha−1·mm−1. The productivity of first-generation bioethanol had the highest values per unit of planted area for the greatest water volumes applied and transpired by each variety; this justifies keeping soil moisture at field capacity until harvesting time only for WR100 water replacement level with a maximum ethanol potential of 13.27 m3·ha−1.

Investigating the Potential of Ethanol and Sugar Tolerant Yeast Strain Isolates from Fermented Cashew Apple Juice for Improved Feni Production

Investigating the Potential of Ethanol and Sugar Tolerant Yeast Strain Isolates from Fermented Cashew Apple Juice for Improved Feni Production

Regulation of the PFK1 gene on the interspecies microbial competition behavior of Saccharomyces cerevisiae

Saccharomyces cerevisiae is a widely used strain for ethanol fermentation; meanwhile, efficient utilization of glucose could effectively promote ethanol production. The PFK1 gene is a key gene for intracellular glucose metabolism in S. cerevisiae. Our previous work suggested that although deletion of the PFK1 gene could confer higher oxidative tolerance to S. cerevisiae cells, the PFK1Δ strain was prone to contamination by other microorganisms. High interspecies microbial competition ability is vital for the growth and survival of microorganisms in co-cultures. The result of our previous studies hinted us a reasonable logic that the EMP (i.e., the Embden-Meyerhof-Parnas pathway, the glycolytic pathway) key gene PFK1 could be involved in regulating interspecies competitiveness of S. cerevisiae through the regulation of glucose utilization and ethanol production efficiency. The results suggest that under 2% and 5% glucose, the PFK1Δ strain showed slower growth than the S288c wild-type and TDH1Δ strains in the lag and exponential growth stages, but realized higher growth in the stationary stage. However, relative high supplement of glucose (10%) eliminated this phenomenon, suggesting the importance of glucose in the regulation of PFK1 in yeast cell growth. Furthermore, during the lag growth phase, the PFK1Δ strain displayed a decelerated glucose consumption rate (P < 0.05). The expression levels of the HXT2, HXT5, and HXT6 genes decreased by approximately 0.5-fold (P < 0.05) and the expression level of the ZWF1 exhibited a onefold increase in the PFK1Δ strain compared to that in the S. cerevisiae S288c wild-type strain (P < 0.05).These findings suggested that the PFK1 inhibited the uptake and utilization of intracellular glucose by yeast cells, resulting in a higher amount of residual glucose in the medium for the PFK1Δ strain to utilize for growth during the reverse overshoot stage in the stationary phase. The results presented here also indicated the potential of ethanol as a defensive weapon against S. cerevisiae. The lower ethanol yield in the early stage of the PFK1Δ strain (P < 0.001) and the decreased expression levels of the PDC5 and PDC6 (P < 0.05), which led to slower growth, resulted in the strain being less competitive than the wild-type strain when co-cultured with Escherichia coli. The lower interspecies competitiveness of the PFK1Δ strain further promoted the growth of co-cultured E. coli, which in turn activated the ethanol production efficiency of the PFK1Δ strain to antagonize it from E. coli at the stationary stage. The results presented clarified the regulation of the PFK1 gene on the growth and interspecies microbial competition behavior of S. cerevisiae and would help us to understand the microbial interactions between S. cerevisiae and other microorganisms.Key points• PFK1Δ strain could realize reverse growth overshoot at the stationary stage• PFK1 deletion decreased ethanol yield and interspecific competitiveness• Proportion of E. coli in co-culture affected ethanol yield capacity of yeast cells

Cytogenotoxic and antimicrobial effects of Nezara viridula (L.) (Hemiptera: Heteroptera: Pentatomidae) alcoholic extracts

Due to their multifunctionality and the numerous fields of applicability, insects are extensively studied today for both their biomedical and nutritional properties. In the current study the cytogenotoxic and antimicrobial potential of ethanol and methanol extracts of Nezara viridula (Linnaeus 1758) was evaluated using the Allium test, respectively the disk diffusion test. A mitostimulatory effect of the extracts of N. viridula and a variation of the cytogenotoxic activity of the extracts in a gender-dependent manner was noticed. As well, significant variations of the mitotic index were determined through the type of solvent used and the concentration of the extracts. High frequency chromosomal aberrations and mitotic abnormalities were recorded with high concentration ethanolic extracts. Following the testing of four standard bacterial strains and two standard yeast strains, a slightly antimicrobial activity was observed when compared to control. The use of invasive species in such studies opens up new perspectives on the potential of organisms considered harmful.

Effect of gasoline-ethanol blends on the performance of a four stroke engine using Ricardo Wave software

Purpose The purpose of this study is to assess the performance of fuel blends containing ethanol and gasoline in spark ignition engines. The aim is to explore alternative fuels that can enhance performance while minimizing or eliminating adverse environmental impacts, particularly in the context of limited fossil fuel availability and the need for sustainable alternatives. Design/methodology/approach The authors used the Ricardo Wave software to evaluate the performance of fuel blends with varying ethanol content (represented as E0, E10, E25, E40, E55, E70, E85 and E100) in comparison to gasoline. The assessment involved different composition percentages and was conducted at various engine speeds (1,500, 3,000, 4,500 and 6,000 rpm). This methodology aims to provide a comprehensive understanding of how different ethanol-gasoline blends perform under different conditions. Findings The study found that, across all fuel blends, the highest brake power (BP) and the highest brake-specific fuel consumption (BSFC) were observed at 6,000 rpm. Additionally, it was noted that the presence of ethanol in gasoline fuel blends has the potential to increase both the BP and BSFC. These findings suggest that ethanol can positively impact the performance of spark-ignition engines, highlighting its potential as an alternative fuel. Originality/value This research contributes to the ongoing efforts in the automotive industry to find sustainable alternative fuels. The use of Ricardo Wave software for performance assessment and the comprehensive exploration of various ethanol-gasoline blends at different engine speeds add to the originality of the study. The emphasis on the potential of ethanol to enhance engine performance provides valuable insights for motor vehicle manufacturers and researchers working on alternative fuel solutions.

Effect of aqueous and ethanol extracts of Cucurbita maxima seed on fasting blood glucose in alloxan-induced rats

Diabetes is a chronic disorder marked by hyperglycemia due to insulin resistance and insufficient insulin action, or both. Synthetic antidiabetic drugs available on the market are associated with severe effects, necessitating the need for alternative antidiabetic drugs. This investigation aimed to determine the antidiabetic potential and phytochemical profiles of aqueous and ethanol seed extracts of Cucurbita maxima. The seeds of C. maxima were airdried, milled, and extracted using distilled water and ethanol. The antidiabetic effect of the extracts was performed using Wistar rats weighing 160-180 g. Thirty-five rats were assigned to 7 groups: non-diabetic (control), diabetic, glibenclamide-treated, and aqueous or ethanol extract-treated (200 and 400 mg/kg body weight). Alloxan monohydrate was used to induce experimental diabetes. The treatments were orally administered for 28 days. Blood glucose levels and histopathological analysis were performed. The phytochemical screening was conducted utilizing liquid chromatography-mass spectrometry (LC-MS). In diabetic rats, the effects of the two extracts revealed a substantial reduction in levels of fasting blood glucose in a dose-dependent manner, suggesting an antidiabetic effect. The histopathological analysis revealed the restoration of pancreatic β-cells by the extracts. The LC-MS analysis identified phytocompounds in the extracts belonging to classes of flavonoids, phenolic acids, and fatty acids that are associated with antidiabetic effects. Interestingly, the ethanol extract had a better antidiabetic effect compared to the aqueous extract. In conclusion, the aqueous and ethanol extracts of C. maxima seed possess phytocompounds that can be used to develop novel antidiabetic agents with less severe effects.

The effectiveness of alkaline and thermo hydrolysis pretreatments in the bioethanol production from Calliandra calothyrsus wood

The demand in energy is increasing along with the development of technology. However, the utilization of fossil energy as the main current energy sources creates various environmental problems. Hence, it is important to search other energy sources which are environmentally friendly. One of the renewable energy sources is bioethanol produced from woody biomass. The purpose of this study was to investigate the suitability of Calliandra calothyrsus wood under development of alkaline and thermohydrolisis pretreatments. These pretreatments included the variations of 15, 30, 45 and 60 min at 121°C with NaOH concentration of 1, 2, and 3% (w/v). The chemical component analysis was conducted by using the TAPPI method, while the percentage of reducing sugar after saccharification was carried out by the Nelson-Somogy method. The results showed that the highest holocellulose content 60,62%, and the highest α-cellulose content was 64,30%. The highest pulp saccharification test results were obtained from 60 min pretreatment of 3% concentration of NaOH, which was 42,82% and 32,99% wood basis. The highest yield of ethanol potential was obtained from 36 hours saccharification, which was 139 L/Ton. Finally, it is suggested to do additional treatments with variations in concentration and temperature in order to obtain more optimal results.

Separation process and mechanism of cyclohexane/ethanol system using deep eutectic solvents based on betaine and choline chloride

The efficient separation of azeotropes is of great significance for the effective recovery and utilization of chemical raw materials and environmental protection. This study investigated the separation efficiency and mechanism of deep eutectic solvents (DESs) with different combinations and ratios of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD) for cyclohexane/ethanol azeotropic systems. Through vapor-liquid phase equilibrium experiments, the effects of different DESs and different HBD: HBA molar ratios as solvents on the phase behavior of cyclohexane/ethanol azeotropic system were studied, and different combinations and molar ratios of DESs with the best separation performance were obtained. The effective separation of azeotropes by DESs is primarily due to the stronger molecular surface electrostatic potential of ethanol compared to that of cyclohexane, which results in a stronger interaction between the DESs and ethanol. Finally, through process simulations, a cyclohexane/ethanol extractive distillation separation process using a DES as the main solvent was established. The results showed that the separation effect of DESs increased with the increase of the interaction force between DESs and ethanol, achieving efficient recovery of chemical raw materials. This study established a safe and efficient separation process using DESs, which is of great significance for environmental protection and the development of safety processes.

Hydrogen addition to ethanol-fuelled engine in lean operation to improve fuel conversion efficiency and emissions

This work applies computer simulation to investigate the combined approach of hydrogen (H2) addition with lean operation to enhance the potential of ethanol as a clean engine fuel for low-carbon transportation. To this end, this research evaluates how this operation regime impacts brake power, fuel conversion efficiency, and exhaust emissions. A dedicated software was used to perform a parametric study with varying amount of hydrogen addition and excess air ratio. The software combustion and performance parameters were calibrated against available experimental data and optimised for engine operation at the tested conditions. The results show that hydrogen addition does not produce noticeable effects on brake power and fuel conversion efficiency for lean operation with up to 20% air excess. However, for operation with 40% air excess, 6% H2 addition is necessary to keep the power at the same level of the engine baseline condition while simultaneously improving fuel conversion efficiency. Operation in the range of air excess between 10% and 30% together with hydrogen addition up to 2% can simultaneously produce noticeable improvements of fuel conversion efficiency, carbon monoxide (CO) and hydrocarbon (HC) emissions, without compromising brake power and oxides of nitrogen (NOX) emissions.

Bioethanol potential of switchgrass cultivars for rainfed and irrigated conditions in marginal lands

ABSTRACT Bioethanol is a climate-friendly alternative to conventional energy sources. This study was conducted to determine bioenergy potential of switchgrass cultivation in Central Anatolia where water scarcity limits the agricultural production. Field trials were conducted in a randomized blocks design with three replications under irrigated and rainfed conditions for three growing seasons (2019, 2020 and 2021). Biomass yield (BY), theoretical cellulosic ethanol yield (TEY), theoretical ethanol potential (TEP) with several quality parameters of 10 switchgrass cultivars were evaluated. Highest BY averages were obtained from Boomaster cultivar with 5.28 (rainfed) and 18.45 t ha−1 (irrigated) when Dacotah had the lowest BY averages of 1.55 (rainfed) and 5.29 t ha−1 (irrigated). ANOVA and Genotype Trait Biplot results revealed higher BY, TEY and TEP with lower ADF, NDF and ADL of lowland ecotype cultivars. Lowland ecotypes provided superior results in both rainfed and irrigated conditions with a higher response to irrigation. TEY of switchgrass were found as positively associated with BY, plant height and stem weight which could be used as indicators of TEY for genotype selection. In conclusion, lowland ecotype cultivars of switchgrass were recommended for bioethanol production in water limited environments.

Investigations on energy efficiency enhancement under knock threshold limit conditions for a turbocharged direct-injection spark-ignition engine fueled with wet ethanol

Wet ethanol is a promising biofuel whose properties fit with turbocharged direct-injection spark-ignition (DISI) engines for countries with yearly production capacity. Even though it has a higher life-cycle efficiency than regular ethanol, which reduces significantly the energy required on ethanol production, wet ethanol’s potential is wasted by the continuous dehydration process. In order to highlight such potential as a fuel for engines, this study investigates the early injection of different blends of wet ethanol (E100W0, E95W5, E90W10, and E80W20, respectively) via an in-house engine simulator to improve engine operating conditions — enhancing engine and ethanol’s life-cycle efficiencies. This study searched for the highest sustainable values of engine energy and exergy efficiencies based on the threshold value of the knock index number. The combustion phasing model used correlations obtained from a machine learning algorithm fed with experimental data for a DISI engine. This investigation provided 120 different cases under different compression ratios (r), engine speeds, relative air-fuel ratios, and wet ethanol blends. Results showed that E80W20 can operate with a turbocharger at r = 18. The highest efficiencies (43% and 40%, respectively) were found for E90W10 and E80W20 — values 30% higher than regular Brazilian FFV. Lastly, cases involving the best conditions for torque, lean air-fuel conditions at high compression ratios and water content, and downspeeding are presented as interesting alternatives to either stationary engines or hybrid vehicles, therefore highlighting the potential of wet ethanol for DI engines.