Increasing Ethanol Concentration Research Articles

Wearable threads for monitoring sanitizer quality using dye displacement assay.

This study employs zero-cost (≈0.01 $) and durable thread-based devices to evaluate the quality of simulated and commercial sanitizer samples through dye displacement assay (DDA). A diverse range of sanitizer compositions, including ethanol concentrations of 55%, 75%, and 95% (v/v), were analysed. This investigation encompasses an assessment of the marker type (Doms and Hauser brands) on the migration distance of the dye region marked on thread devices. Our results demonstrate a proportional increase in the migration distance of the dye with increasing ethanol concentrations due to a decrease in the coefficient of viscosity and solvation power of ethanol on dye molecules. Additionally, a field trial for the thorough assessment of commercial sanitizer quality using thread-based devices further underscores the efficacy of this methodology. A calibration plot for a braided thread with Doms marker dye provides a reliable means to quantitatively assess the ethanol content in different commercial sanitizer compositions. Our findings collectively highlight the significance of this innovative method as a valuable tool for quality control and assessment for public health and hygiene as well as for preparing us for another pandemic.

Understanding of Wetting Mechanism Toward the Sticky Powder and Machine Learning in Predicting Granule Size Distribution Under High Shear Wet Granulation.

The granulation of traditional Chinese medicine (TCM) has attracted widespread attention, there is limited research on the high shear wet granulation (HSWG) and wetting mechanisms of sticky TCM powders, which profoundly impact the granule size distribution (GSD). Here we investigate the wetting mechanism of binders and the influence of various parameters on the GSD of HSWG and establish a GSD prediction model. Permeability and contact angle experiments combined with molecular dynamics (MD) simulations were used to explore the wetting mechanism of hydroalcoholic solutions with TCM powder. Machine learning (ML) was employed to build a GSD prediction model, feature importance explained the influence of features on the predictive performance of the model, and correlation analysis was used to assess the influence of various parameters on GSD. The results show that water increases powder viscosity, forming high-viscosity aggregates, while ethanol primarily acted as a wetting agent. The contact angle of water on the powder bed was the largest and decreased with an increase in ethanol concentration. Extreme Gradient Boosting (XGBoost) outperformed other models in overall prediction accuracy in GSD prediction, the binder had the greatest impact on the predictions and GSD, adjusting the amount and concentration of adhesive can control the adhesion and growth of granules while the impeller speed had the least influence on granulation. The study elucidates the wetting mechanism and provides a GSD prediction model, along with the impact of material properties, formulation, and process parameters obtained, aiding the intelligent manufacturing and formulation development of TMC.

Experimental and kinetic study of methanol/ethanol assisted oxidative degradation of ammonia in supercritical water

Ammonia is a refractory intermediate during supercritical water oxidation (SCWO) of nitrogen-containing wastes, and alcohols are usually introduced as auxiliary fuels to accelerate its degradation. The kinetics of methanol/ethanol assisted oxidative degradation of ammonia in supercritical water have been investigated in a flow reactor, covering alcohol-to-ammonia ratios of 0.2–2.0. During SCWO of ammonia-methanol mixtures, ammonia was mostly converted to N2, with N2O as the main by-product. Increasing methanol concentration facilitated effectively the degradation of ammonia. For the cases with ethanol assistance, high concentrations of HCN were detected at the investigated temperature. Increase in ethanol concentration enhanced ammonia conversion, but had a non-monotonic influence on N2 production. A detailed chemical kinetic model was developed by integrating the nitrogen chemistry with methanol/ethanol mechanisms. The model performance was further validated by comparing to the present and literature data. The model reproduced the ammonia conversions at different conditions fairly well, but overpredicted the N2 yield and underpredicted the NO2 and HCN yields slightly. Based on the model, reaction mechanism was inferred and important elementary steps were identified through kinetic analyses. Finally, the influence of process parameters on ammonia degradation rate was numerically explored. This study is expected to facilitate the application of SCWO technology for N-containing wastes treatment.

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.

Numerical Analysis of the Effect of Ethanol-Gasoline Blends on a Single-Cylinder Spark-Ignition Engine Performance and Emissions

— With the rapid increase in the number of vehicles fueled by gasoline plying on the roads, there has been a rising need in the search for alternative fuels, which are more environmental friendly in order to reduce the amount of vehicular exhaust emissions. This can be achieved by using blended mixtures of gasoline with alcoholic fuels among which, ethanol is found to be most suitable due to its easy availability, low costs, safety and low impact on the engine performance. This study aims to investigate the performance of a single-cylinder, four-stroke spark-ignition engine using different ethanol-gasoline blends, namely E0, E10, E20 and E30. The engine's torque, brake power, brake thermal efficiency, brake-specific fuel consumption, and exhaust emissions were analysed using numerical simulation. Results revealed that raising the proportion of ethanol in the fuel mixture resulted in reduced brake power and torque upto 16% as a result of decrease in calorific value of the mixture. The engine's brake thermal efficiency decreased by upto 3% while the brake-specific fuel consumption increased upto 12% with increase in ethanol concentration. Exhaust emissions, including NOx and HC, were found to be influenced by engine speed, with NOx emissions increasing and HC emissions decreasing as speed increased. The study also revealed that increasing ethanol concentration in the fuel resulted in reduced engine exhaust emissions by upto 47% and 10% for NOX and HC emissions respectively. The study concluded that among all the blends used, optimum performance was obtained for E30 blend with reduction in exhaust emissions but at the expense of slight reduction in engine performance.

Effect of ethanol on the elasticities of double-stranded RNA and DNA revealed by magnetic tweezers and simulations.

The elasticities of double-stranded (ds) DNA and RNA, which are critical to their biological functions and applications in materials science, can be significantly modulated by solution conditions such as ions and temperature. However, there is still a lack of a comprehensive understanding of the role of solvents in the elasticities of dsRNA and dsDNA in a comparative way. In this work, we explored the effect of ethanol solvent on the elasticities of dsRNA and dsDNA by magnetic tweezers and all-atom molecular dynamics simulations. We found that the bending persistence lengths and contour lengths of dsRNA and dsDNA decrease monotonically with the increase in ethanol concentration. Furthermore, the addition of ethanol weakens the positive twist-stretch coupling of dsRNA, while promotes the negative twist-stretch coupling of dsDNA. Counter-intuitively, the lower dielectric environment of ethanol causes a significant re-distribution of counterions and enhanced ion neutralization, which overwhelms the enhanced repulsion along dsRNA/dsDNA, ultimately leading to the softening in bending for dsRNA and dsDNA. Moreover, for dsRNA, ethanol causes slight ion-clamping across the major groove, which weakens the major groove-mediated twist-stretch coupling, while for dsDNA, ethanol promotes the stretch-radius correlation due to enhanced ion binding and consequently enhances the helical radius-mediated twist-stretch coupling.

Valorizing Arthrospira cell residues into polysaccharides: Characterization and application in yogurt

This study aimed to extract and characterize polysaccharides from Arthrospira cell residue and evaluate their application in yogurt. Four Arthrospira polysaccharides (APP-50, APP-60, APP-70, and APP-80) were obtained by different ethanol concentrations. With the increase in ethanol concentration, the component peaks of polysaccharide became less and the components were simpler. The results showed that APP-60 had the highest neutral sugar content and the densest spherical structure. APP-50 had the highest protein content, the strongest antioxidant capacity, the porous structure, and the structure was incomplete. The addition of polysaccharides increased the viscosity, storage modulus, loss modulus, and particle size of yogurt, and improved the stability of yogurt during long-term storage. The microstructure of yogurt with added polysaccharides was tighter and more orderly than that of the control yogurt. This study demonstrated that Arthrospira polysaccharides could be used as functional ingredients to enhance the quality and nutritional value of yogurt.

Adaptive laboratory evolution of Thermoanaerobacterium aotearoense for enhanced ethanol production from raw cassava starch

Thermophiles have the potential to utilize starch for bioethanol production in consolidated bioprocessing procedure, but they are usually limited by the intolerance of high ethanol titer. In this study, we performed adaptative laboratory evolution (ALE) on Thermoanaerobacterium aotearoense strain PRH-B3 (ΔldhΔrexΔhfsB::BCD), which produced ethanol as the only product. After hundreds of generations of domestication with the increasing ethanol concentration, two lineages of ethanol-tolerant mutants were gained and the effects of alcohol dehydrogenase (ADH) domain mutations in aldehyde/alcohol dehydrogenase AdhE were analyzed. The assay of ADH activities in vivo showed that the mutants exhibited reduced NADH-dependent ADH activities and increased NADPH-dependent ADH activities, compared to that from PRH-B3. AdhA was subsequently demonstrated to contribute to the increased NADPH-linked ADH activities in the mutants. This was accompanied by an increased expression level of NADH-dependent ferredoxin:NADP+ oxidoreductase and improved contents of NADP(H), indicating that the ethanol-tolerant strains preferred to use NADPH for ethanol synthesis with a potential regulatory mechanism. The maximum ethanol production (∼39 g/L) of the mutants had increased by 26 % after ALE from untreated cassava starch. The enhanced comprehension of the mechanisms underlying ethanol tolerance elucidated herein paves the way for the development of other ethanologenic strains with elevated ethanol titers.

Self-powered wearable biosensor based on stencil-printed carbon nanotube electrodes for ethanol detection in sweat

Herein we introduce a novel water-based graphite ink modified with multiwalled carbon nanotubes, designed for the development of the first wearable self-powered biosensor enabling alcohol abuse detection through sweat analysis. The stencil-printed graphite (SPG) electrodes, printed onto a flexible substrate, were modified by casting multiwalled carbon nanotubes (MWCNTs), electrodepositing polymethylene blue (pMB) at the anode to serve as a catalyst for nicotinamide adenine dinucleotide (NADH) oxidation, and hemin at the cathode as a selective catalyst for H2O2 reduction. Notably, alcohol dehydrogenase (ADH) was additionally physisorbed onto the anodic electrode, and alcohol oxidase (AOx) onto the cathodic electrode. The self-powered biosensor was assembled using the ADH/pMB-MWCNTs/SPG||AOx/Hemin-MWCNTs/SPG configuration, enabling the detection of ethanol as an analytical target, both at the anodic and cathodic electrodes. Its performance was assessed by measuring polarization curves with gradually increasing ethanol concentrations ranging from 0 to 50 mM. The biosensor demonstrated a linear detection range from 0.01 to 0.3 mM, with a detection limit (LOD) of 3 ± 1 µM and a sensitivity of 64 ± 2 μW mM−1, with a correlation coefficient of 0.98 (RSD 8.1%, n = 10 electrode pairs). It exhibited robust operational stability (over 2800 s with continuous ethanol turnover) and excellent storage stability (approximately 93% of initial signal retained after 90 days). Finally, the biosensor array was integrated into a wristband and successfully evaluated for continuous alcohol abuse monitoring. This proposed system displays promising attributes for use as a flexible and wearable biosensor employing biocompatible water-based inks, offering potential applications in forensic contexts.Graphical A novel water-based graphite ink modified with multiwalled carbon nanotubes designed for the development of a wearable self-powered biosensor enabling alcohol abuse detection through sweat analysis.

Construction of an amylolytic Saccharomyces cerevisiae strain with high copies of α-amylase and glucoamylase genes integration for bioethanol production from sweet potato residue.

Sweet potato residue (SPR) is the by-product of starch extraction from fresh sweet potatoes and is rich in carbohydrates, making it a suitable substrate for bioethanol production. An amylolytic industrial yeast strain with co-expressing α-amylase and glucoamylase genes would combine enzyme production, SPR hydrolysis, and glucose fermentation into a one-step process. This consolidated bioprocessing (CBP) shows great application potential in the economic production of bioethanol. In this study, a convenient heterologous gene integration method was developed. Eight copies of a Talaromyces emersonii α-amylase expression cassette and eight copies of a Saccharomycopsis fibuligera glucoamylase expression cassette were integrated into the genome of industrial diploid Saccharomyces cerevisiae strain 1974. The resulting recombinant strains exhibited clear transparent zones in the iodine starch plates, and SDS-PAGE analysis indicated that α-amylase and glucoamylase were secreted into the culture medium. Enzymatic activity analysis demonstrated that the optimal temperature for α-amylase and glucoamylase was 60-70°C, and the pH optima for α-amylase and glucoamylase was 4.0 and 5.0, respectively. Initially, soluble corn starch with a concentration of 100 g/L was initially used to evaluate the ethanol production capability of recombinant amylolytic S. cerevisiae strains. After 7 days of CBP fermentation, the α-amylase-expressing strain 1974-temA and the glucoamylase-expressing strain 1974-GA produced 33.03 and 28.37 g/L ethanol, respectively. However, the 1974-GA-temA strain, which expressed α-amylase and glucoamylase, produced 42.22 g/L ethanol, corresponding to 70.59% of the theoretical yield. Subsequently, fermentation was conducted using the amylolytic strain 1974-GA-temA without the addition of exogenous α-amylase and glucoamylase, which resulted in the production of 32.15 g/L ethanol with an ethanol yield of 0.30 g/g. The addition of 20% glucoamylase (60 U/g SPR) increased ethanol concentration to 50.55 g/L, corresponding to a theoretical yield of 93.23%, which was comparable to the ethanol production observed with the addition of 100% α-amylase and glucoamylase. The recombinant amylolytic strains constructed in this study will facilitate the advancement of CBP fermentation of SPR for the production of bioethanol.

Use of non-<i>Saccharomyces</i> yeasts in the <i>pris de mousse</i> of Lambrusco. Microbial evolution through alcoholic fermentation and effect on wine volatile profile

Lambrusco is a sparkling wine largely produced in the north of Italy, especially in the Emilia region. The possible application of two non-Saccharomyces yeasts in the secondary bottle fermentation (Champenoise method) was tested in combination with a commercial strain of S. cerevisiae to obtain wines having a distinctive volatile profile. Our results demonstrated that the gradual increase of ethanol content in the pied de cuve ensured the adaptation of Hanseniaspora guilliermondii and Torulaspora delbrueckii at the bottle fermentation, with survival comparable with that of S. cerevisiae, in the order of 6 log units. The simultaneous presence of two yeast species reduced the maximum fermentation rate, without any relevant alteration in the main oenological parameters of resultant wines. GC MS-MS analysis of the volatile profile of wines (46 compounds) highlighted differences in wine made from a pure culture of S. cerevisiae from wines obtained by mixed yeasts. Acetates, esters, and fatty acids are the classes of volatile compounds mostly affected by using different yeasts in the bottle fermentation of Lambrusco wines. This work provided for the first time information about the volatile profile of Lambrusco and suggests an innovative application of non-Saccharomyces yeast in the production of sparkling wines by champenoise methods.

Study of the effect of ethanol on the properties of poloxamer 338 solutions by rotational viscometry and spin probe method

The aim. Study the properties of 20 % solutions of poloxamer 338 (P338) in water and mixed solvents water-ethanol using rotational viscometry and the spin probe method at various temperatures. Materials and methods. 20 % m/m solutions of P338 in water and water – ethanol mixtures were the objects of research. The solutions were studied by rotational viscometry at various temperatures; the flow behaviour, lower yield stress (t0) and dynamic or apparent viscosity (η) were determined. Spin probes based on fatty acids, which differ in molecular structure, solubility, and radical localization, were added to the solutions. Electron paramagnetic resonance (EPR) spectra were obtained to determine their type and parameters. Results. Depending on the content, ethanol affects the rheological properties of 20 % solution of P338. The solution was demonstrated to be able to thermally induce sol → gel transition at 32 °C when ethanol content is 5 % m/m. The rheological parameters of the gel at 32 °C and 37 °C exhibit an increase (in comparison to the gel without ethanol), accompanied by a reduction in the packing density of polypropylene oxide (PPO) chains within the cores of P338 micelles. At an ethanol content of 10 % m/m, the gel formation temperature rises to 40 °C. At ethanol content of 15 % m/m and above, 20 % P338 solutions do not form gels at temperatures between 25 °C and 40 °C. The values of rotational correlation times (τ) and the order parameter (S) of fatty acid-based spin probes were observed to decrease with increasing ethanol content up to 30 % m/m; in the case of the ammonium salt of 5‑doxylstearic acid (5-DSA NH4 salt), the anisotropic EPR spectra transform, becoming a superposition of two triplets and subsequently a triplet. P338 solutions retain their ability to undergo thermally induced sol ↔ gel transitions as long as the EPR spectra of this probe exhibit anisotropy at temperatures ranging from 25 °C to 37 °C. As the concentration of ethanol in the solution increases, the solvation of the cores of P338 micelles by the dispersion medium of the solution also increases. Conclusions. It was demonstrated that ethanol, when added to the 20 % P338 solution, results in changes to the rheological properties of this solution. However, at the ethanol content of 5-10 % m/m, the ability of P338 to thermally induce sol → gel transition remains unaltered. The rheological properties of the 20 % P338 solution exhibit a correlation with the observed change in EPR spectra types for the 5-DSA NH4 salt. As the ethanol content in the solution increases, the solvation of P338 micelle cores by the dispersion medium increases, accompanied by decreased density and orderliness of the PPO chains packing in the micelle cores

Histidine modified Fe3O4 nanoparticles improving the ethanol yield and tolerance of Saccharomyces cerevisiae.

Saccharomyces cerevisiae, the primary microorganism involved in ethanol production, is hindered by the accumulation of ethanol, leading to reduced ethanol production. In this study, we employed histidine-modified Fe3O4 nanoparticles (His-Fe3O4) for the first time, to the best of our knowledge, as a method to enhance ethanol yield during the S. cerevisiae fermentation process. The results demonstrated that exposing S. cerevisiae cells to Fe3O4 nanoparticles (Fe3O4 NPs) led to increased cell proliferation and glucose consumption. Moreover, the introduction of His-Fe3O4 significantly boosted ethanol content by 17.3% (p < 0.05) during fermentation. Subsequent findings indicated that the increase in ethanol content was associated with enhanced ethanol tolerance and improved electron transport efficiency. This study provided evidence for the positive effects of His-Fe3O4 on S. cerevisiae cells and proposed a straightforward approach to enhance ethanol production in S. cerevisiae fermentation. The mediation of improved ethanol tolerance offers significant potential in the fermentation and bioenergy sectors.

Interaction between methyl red and cetyltrimethylammonium bromide under the influence of sodium polystyrene sulphonate in ethanol-water binary solvent systems: A spectrophotometric investigation

This research aims to comprehensively investigate and analyze the UV–visible spectroscopic behavior of the methyl red (MR)-cetyltrimethylammonium bromide (CTAB) system under the influence of sodium polystyrene sulfonate (NaPSS) in aqueous and different volume fractions (v.f.) of ethanol (EtOH)–H2O (0.1, 0.2, and 0.3) at 298.15 ± 0.2 K. In EtOH–H2O solvent systems, the triple interactions of dyes-surfactants-polyelectrolyte (DSP) complex systems are entirely novel. MR interacts with CTAB in NaPSS in the binary solvent media (0.1, 0.2, and 0.3 v.f. of EtOH–H2O) resulting in the formation of ion-pairs at very low CTAB concentrations, far below their apparent critical micelle concentration (CMC*) reducing the absorbance, and the new complexes above the CMC* due to solubilization of the MR into CTAB micelles observed by distinct spectral shifts. The CMC* values obtained from spectroscopic data increase in the order: (CMC*)water< (CMC*)0.1< (CMC*)0.2< (CMC*)0.3. This is because of the reduced polarity or dielectric constant and increased degree of water structure disruption around the hydrophobic chains of CTAB, where micelle formation occurs at somewhat higher concentrations. The Gibbs energy of micellization (ΔGmo) increases in the order: (ΔGmo=−16.89)water <(ΔGmo=−16.17)0.1<(ΔGmo=−15.62)0.2<(ΔGmo=−15.38)0.3, which further supports the inhibitory effect of increasing ethanol content towards micellization. In the post-micellar region, the decrease in hydrophobic interactions and an increase in electrostatic interactions lead to a rise in the overall binding constant value. This means that, when NaPSS is present, the stronger electrostatic interactions in the post-micellar region contribute significantly to the increased binding of CTAB micelles with MR. The tautomeric activity of MR and the solvent composition played a prime role in affecting the interaction mechanism, as evidenced by the blue and red spectral shifts.

Dielectric Characterization of Solutions of Galactomannan Extracted from Adenanthera pavonina L.: Effects of Purification and Ethanol Concentration.

Galactomannans are polysaccharides obtained from legume seed extraction. They present a chemical structure consisting of D-mannose chains linked by glycosidic bonds and galactose branches. The main focus lies in their use as thickeners in the food industry, aimed at improving the dielectric properties of food during heating processes within the radiofrequency and microwave ranges. In this work, the prepared galactomannan samples were electrically analyzed through impedance spectroscopy, which is a powerful physical technique. From the experimental measurements, the dielectric permittivity and loss tangent of the galactomannan solutions were analyzed and the electrical modulus formalism was used to study the dielectric relaxations. Crude galactomannans exhibited higher values of permittivity, conductivity, and losses compared to purified galactomannans. Increasing ethanol concentration in galactomannan purification causes an increase in the permittivity and conductivity of galactomannan solutions. In a 1% solution, at 1 kHz, the permittivity increased from 378.56 to 538.09, while in the 2% solution, this increase was from 656.22 to 1103.24. Regarding the conductivity, at the same frequency, the increase was from 1.6 × 10-3 to 3.3 × 10-3 Ω-1m-1 and from 2.9 × 10-3 to 5.5 × 10-3 Ω-1m-1, respectively. The rise of the ethanol concentration in galactomannan purification led to a decrease in the relaxation time, from 448.56 to 159.15 μs and from 224.81 to 89.50 μs in the solution with 1 and 2%, respectively. The results suggest that galactomannan from Adenanthera pavonina L. has potential for use in the food industry.

Effect of Ethanol and Iso-Octane Blends on Isolated Low-Temperature Heat Release in a Spark Ignition Engine

&lt;div&gt;Low-temperature heat release (LTHR) is of interest for its potential to help control autoignition in advanced compression ignition (ACI) engines and mitigate knock in spark ignition (SI) engines. Previous studies have identified and investigated LTHR in both ACI and SI engines before the main high-temperature heat release (HTHR) event and, more recently, LTHR in isolation has been demonstrated in SI engines by appropriately curating the in-cylinder thermal state during compression and disabling the spark discharge. Ethanol is an increasingly common component of market fuel blends, owing to its renewable sources. In this work, the effect of adding ethanol to iso-octane (2,2,4-trimethylpentane) blends on their LTHR behavior is demonstrated. Tests were run on a motored single-cylinder engine elevated inlet air temperatures and pressures were adjusted to realize LTHR from blends of iso-octane and ethanol without entering the HTHR regime. The blends were tested with inlet temperatures of 40°C–140°C at equivalence ratios of 0.5, 0.67, and 1.0 with boosted (1.5 barA) conditions. The measured LTHR decreased with increasing ethanol content for all conditions tested; iso-octane–ethanol blends with above 20% ethanol content (by volume) showed minimal LTHR under engine conditions. These net effects resulted from the combination of thermal effects (charge cooling) and chemical effects (reactivity changes at low temperatures). The effect of temperature, pressure, fuel composition, and equivalence ratio on ignition delay times calculated from chemical kinetic modeling are presented alongside pressure–temperature trajectories of the in-cylinder gases to explain the trends. The underlying cause of the trends is explained by using a sensitivity analysis to determine the contribution of each reaction within the chemical kinetic mechanism to first-stage ignition, revealing the effect of introducing ethanol on the OH radical pool and resulting LTHR intensity.&lt;/div&gt;

Experimental Study on Evaporation and Micro-Explosion Characteristics of Ethanol and Diesel Blended Droplets

In this study, the constant temperature control system of a heating plate was established, ethanol–diesel fuel with different proportions was prepared, and a series of experiments were carried out. The experimental system was used to observe, summarize, and analyze four evaporation and crushing modes of mixed droplets, which were explosion, liquid filament stretching, exocytosis, and ejection mode. The evaporation process of four kinds of mixed droplets in their life cycle was analyzed by normalizing the diameter square. It was proposed that the evaporation process of droplets could be divided into the following three stages: a heating stage, a fluctuating evaporation stage, and an equilibrium evaporation stage. It was also pointed out that the expansion, ejection, and micro-explosion of droplets were the causes of fluctuating evaporation. The concept of expansion and crushing intensity was put forward and the expansion and crushing intensity of ethanol/diesel mixed droplets with different proportions were calculated. The reasons why expansion and crushing intensity first increased and decreased with the increase in ethanol blending ratio were analyzed. Finally, the time proportion of ethanol–diesel mixed droplets in each evaporation stage was calculated, which explained that the time proportion of the instantaneous heating stage showed a parabolic law with the increase in ethanol content.

Heat Characteristics and Emission Effect of a Fuel-operated Auxiliary Air Heater Fed with Fuel E10, E30 and E100

In order to increase the comfort of vehicle passengers in specific vehicle categories, the heating of the passenger compartment is not provided by the heat from the engine driving the vehicle but by an additional heating device. The study examines the effect of auxiliary heaters that use liquid fuels to heat the passenger compartment of vehicles. The device was operated during the test with two different mixtures containing bioethanol (E30, E100) and the original motor gasoline (E10). It aimed to understand the effects of different fuels, particularly heating performance, operating time and emissions. Based on the results, as the ethanol content increases, the temperature of the device’s flame and heating air decreases. The experiments showed that in the case of E100 bioethanol, the average temperature measured in stable operating conditions was significantly lower than in the case of E10 motor gasoline. That suggests that an increase in the ethanol content reduces the heating performance. Another significant result of the study was that in the case of mixtures containing ethanol, a longer operating time is required to achieve the same amount of heat, which leads to additional fuel consumption. In addition, when using E100 bioethanol, the amount of harmful gases that are emitted increases significantly during the longer operating time. This observation can be important for evaluating the environmental impact and efficiency of vehicles.

Amine-free synthesis of high-silica ZSM-5 assisted with calcined silicalite-1 and ethanol with the investigation of mechanism

Amine-free synthesis of high silica ZSM-5 with high crystallinity and well-defined morphology was challenging. In this work, ZSM-5 with the fed silica-alumina ratio (SAR) of 100 was rapidly synthesized with the assistance of the calcined silicalite-1 seed and ethanol, and their crystal structures, morphology and microporous properties were characterized by XRD, SEM, FT-IR, ICP and N2 adsorption-desorption and so on. Firstly, the crystallization temperature was optimized between 140 and 180 °C at a certain alkalinity and ethanol content, and 160 °C was selected to not only provide high crystallization rate but also ensure the stability of high-silica skeleton. Secondly, the influences of the EtOH/SiO2 ratio, Na2O/SiO2 ratio and crystallization time on the crystallization of high-silica ZSM-5 were investigated at 160 °C. The results showed well-crystalline high-silica ZSM-5 could be synthesized within a wide range of the EtOH/SiO2 ratios (0.5–2.0) and the increase of ethanol content slightly inhibited the growth of ZSM-5 along b-axial of hexagonal prisms due to the preferential adsorption of excess ethanol on the {010} crystal plane and the formation of Si–O–C2H5; high alkalinity was favorable for the preparation of a small-sized and well-crystalline ZSM-5 due to the rapid depolymerization of calcined seed and the contribution of mass nucleation sites; meanwhile, excellent micropore characteristic of high-silica ZSM-5 further proved that the synthetic strategy of seed + ethanol was feasible. Finally, the synergistic action mechanism of calcined seed and ethanol for the synthesis of high-silica ZSM-5 was revealed that silicalite-1 with MFI structure unit combined with Na+(H2O/EtOH) with larger radius were very important for rapidly assembly of a large number of silica species into MFI framework.

Laminar and kinetic burning characteristics of ethanol/methane/hydrogen fuel: Experimental and numerical analysis

In this essay, the effects of ethanol addition on the fuels of Hydrogen methane mixing fuel were discussed. The laminar burning characteristics of ethanol/hydrogen/methane mixture under different ethanol content, pressure (1 bar, 2 bar), and equivalence ratios (0.7–1.4) were experimentally and numerically simulated. Results show that increasing ethanol content reduces the laminar burning velocity (LBV) and shifts the peak LBV towards higher equivalence ratios, attributed to the fuel mixture's decreased average combustion heat. For a 20 % ethanol content, the LBV peak appears at φ = 1.3, while for 50 % and 80 % ethanol content, it appears at φ = 1.2 locations. An empirical correlation for LBV as a function of ethanol concentration was developed, demonstrating predictions within a 4 % error margin compared to experimental data. High accuracy fittings of activation energy, ethanol concentration, and equivalence ratio were achieved, with correlation coefficients exceeding 0.9. Numerical simulations pinpointed key reactions and the relationship between free radicals and LBV, highlighting a pronounced correlation between OH radicals and LBV under lean conditions (coefficient of 1.0583), and a strong correlation with H radicals under rich conditions (coefficient of 1.01657), this indicates that OH and H are involved in the key chain reaction that promote the burning process.