Increasing Ethanol Concentration Research Articles

Subcritical liquefaction of lignocellulose for the production of bio-oils in ethanol/water system

Lignocellulose (20–40 mesh) was converted into bio-oils in ethanol with different concentrations (0, 20%, 40%, 60%, 80%, and 100%). The products were separated to obtain solid residues, heavy and light oils, and they were comprehensively characterized with a series of both chemical and spectral methods. Results indicated that the addition of ethanol enhanced the penetration of solvent into the rigid structure of lignocellulose. The highest bio-oil yield of 36.62% was obtained when the lignocellulose was liquified with 60% ethanol. The higher heating value of heavy oil decreased whereas that of light oil increased when more ethanol was used. 1H NMR analysis revealed that the addition of ethanol resulted in a high proportion of alcohols, ethers and esters, together with less aldehydes in the heavy oil. Meanwhile, the proportions of aldehydes in the light oil decreased with the increase of ethanol concentration.

Rapidly increasing ethanol concentrations in rainwater and air

Rainwater and gas phase ethanol concentrations increased approximately fourfold between 2010 and 2017 in Wilmington, NC, USA. This 8-year study demonstrates that the gas phase and rainwater concentrations of ethanol have risen due to increased production and use of ethanol as a biofuel. Rainwater ethanol concentrations are close to equilibrium with local atmospheric gas phase concentrations and have increased in proportion to increased air concentrations. Ethanol emissions are important because they impact the oxidizing capacity of the atmosphere due to the reactivity of the alcohol towards hydroxyl radical. Gas phase ethanol contributes to air pollution through oxidation to acetaldehyde, with subsequent production of ozone, and in high NOx regions production of peroxyacetyl nitrate (PAN). However, combustion of ethanol can also lower emissions of acetaldehyde precursors such as alkenes, suggesting that the potential impact of ethanol combustion is complex. The large increase in the concentration of ethanol in both the gas and condensed phases indicates that existing sinks are not sufficient to remove the excess alcohol being added to the atmosphere from biofuel use. This suggests that the projected growth of ethanol as a biofuel will result in considerable increases in atmospheric concentrations within the next few years with direct ramifications on a host of fundamentally important atmospheric processes.

Tracing of Chemical Components of Odor in Peels and Flesh from Ripe Banana on a Daily Basis Using GC-MS Characterization and Statistical Analysis for Quality Monitoring During Storage

A promising research to evaluate the quality of ripe banana during storage period by analyzing the variability of the volatile chemical components in odor from peels and flesh based on solid-phase microextraction-GC-MS characterization and statistical analysis has been discussed. A rapid increase of ethanol concentration in peels and flesh contributes to rotting of the banana. Specifically, occurrence of some compounds, including 1,2-dimethoxybenzene, 3,4-dimethoxybenzaldehyde, and isoeugenol, is an important feature of banana rotting. The decrease of 3-hydroxy-4-methoxybenzaldehyde concentration signifies a weakening of antiseptic, bactericidal, fungicidal, and antioxidant properties of banana. Besides, the principal component analysis (PCA) has been implemented in the discrimination of banana odor at different days of storage.

Qualitative alcoholic and dealcoholized wine vapor-phase stimuli perceptions using a citation frequency-based method

ABSTRACTRetronasal and orthonasal wine vapor-phase stimuli perceptions by 57 participants were obtained using a citation frequency-based method. Ariel Chardonnay (35.45%) and Ariel Rouge (35.19%) concentrates were used to create 5 ethanol concentrations (i.e. <0.5% abv, 3.75% abv, 7% abv, 10.25% abv, and 13.5% abv) for each type of wine. Overall, no significant differences were found among Chardonnay wine aromas and Rouge wine aromas. However, an increase in ethanol concentration significantly decreased the response probability for apple (p = 0.030) retronasally and significantly increased the response probability for alcohol (p = 0.013) orthonasally in Chardonnay wine. In Rouge wine, ethanol concentration significantly impacted response probabilities for ginger (p = 0.022) retronasally and bell pepper (p = 0.025) and wood (p = 0.039) orthonasally. Such findings suggest that the contributions of ethanol to the aroma of real wines may be subtle from a consumer perspective and orthonasal and retronasal qualitative descriptions for wines may not be equivalent. With further investigation and some modification, the use of a citation frequency-based method may be used in smell research to collect detailed, qualitative data from consumers or individuals with no or minimal sensory training.

The Effects of Ethanol Concentration during Isolation and Purity on the In Vitro Antioxidant Properties of Polysaccharides from the Winter Culinary-Medicinal Mushroom, Flammulina velutipes (Agaricomycetes) Stembase.

Natural products with high antioxidant activity have attracted great attention in recent years. A water extraction and alcohol precipitation method were used to extract polysaccharides from the Flammulina velutipes stem-base (FVSP). The series of samples including FVSP30, FVSP45, FVSP60, and FVSP75 were isolated by different concentrations of ethanol. The crude polysaccharides were purified by freeze-thaw; deproteinization; DEAE cellulose-52 chromatography; Sephadex G-100 size-exclusion chromatography; and another series of samples were found including FVSP-1, FVSP-2, and FVSP-3. Through 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, and superoxide anion scavenging experiments, the effects of ethanol concentration during isolation and the degree of purification on the in vitro antioxidant properties of the FVSPs were analyzed. The results showed that the polysaccharides isolated by different ethanol concentrations exhibited strong antioxidant activity. With increasing ethanol concentration in the isolation process, the antioxidant activity was progressively enhanced. In the experimental concentration range, FVSP75 showed the strongest antioxidant activity at a concentration of 1.0 mg/mL. The FVSPs of different purities exhibited excellent antioxidant activity. Within the experimental range, as the degree of purification of the polysaccharides increased, the antioxidant activity decreased accordingly. FVSP-1, with low purity, exhibited the highest antioxidant activity at a concentration of 1.0 mg/mL. These results should provide a foundation for the use of FVSPs as a nutritional functional food or food additive and provide a theoretical basis for the efficient use of FVSPs.

Ethanol Conditioned Taste Aversion in High Drinking in the Dark Mice.

Two independent lines of High Drinking in the Dark (HDID-1, HDID-2) mice have been bred to reach high blood alcohol levels after a short period of binge-like ethanol drinking. Male mice of both lines were shown to have reduced sensitivity to develop a taste aversion to a novel flavor conditioned by ethanol injections as compared with their unselected HS/NPT founder stock. We have subsequently developed inbred variants of each line. The current experiments established that reduced ethanol-conditioned taste aversion is also seen in the inbred variants, in both males and females. In other experiments, we asked whether HDID mice would ingest sufficient doses of ethanol to lead to a conditioned taste aversion upon retest. Different manipulations were used to elevate consumption of ethanol on initial exposure. Access to increased ethanol concentrations, to multiple tubes of ethanol, and fluid restriction to increase thirst motivation all enhanced initial drinking of ethanol. Each condition led to reduced intake the next day, consistent with a mild conditioned taste aversion. These experiments support the conclusion that one reason contributing to the willingness of HDID mice to drink to the point of intoxication is a genetic insensitivity to the aversive effects of ethanol.

Dynamic High-Pressure Microfluidization-Treated Pectin under Different Ethanol Concentrations.

We previously reported that dynamic high-pressure microfluidization (DHPM) can degrade pectin in aqueous solution. In this study, we further investigated the effect of DHPM on pectin in water-ethanol systems. In the absence of DHPM treatment, it was found that pectin exhibited increased average particle size and unchanged average molecular weight, but a decline in reducing-sugar-ends content with the increase of ethanol concentrations (0–10% v/v). These results indicated that the addition of ethanol induced aggregation of pectin. During DHPM treatment, pectin underwent disaggregation and degradation under all measured ethanol concentrations. Disaggregation was enhanced but degradation was weakened with the increase of ethanol concentration. FT-IR and UV spectra indicated that demethylation but no β-elimination occurred in the water-ethanol system during DHPM. Finally, the mechanism of DHPM-induced disaggregation and degradation of pectin under a water-ethanol system was updated. This work may help us to find a suitable condition for reducing the degradation of pectin during the process of homogenization.

OES diagnostic of radicals in 33 MHz radio-frequency Ar/C2H5OH atmospheric pressure plasma jet

Ar/C2H5OH plasma jet is generated at atmospheric pressure by 33 MHz radio-frequency power source. This RF excitation frequencies which are higher than 13.56 MHz had rarely been used in atmospheric pressure plasma. The plasma characteristics of ethanol are investigated. The introduction of ethanol leads to the generation of four excited carbonaceous species C, CN, CH and C2 in plasma, respectively. Optical emission intensities of four carbonaceous species were strengthened with ethanol content increasing in the range of 0−4600 ppm. The ethanol content increase results in all the Ar spectra lines decrease. The reason is that the electron temperature decreases when ethanol content is high. The emission intensity ratios of C/C2, CN/C2 and CH/C2 decrease with the increase of ethanol content, showing that the relative amount of C2 is increasing by increasing the ethanol flow. The emission intensity ratios of excited species did not change much with the increase of RF power in stable discharge mode.

Enhanced separation behavior of ephedrine in organic solution by nanofiltration mass transfer model

Based on the nanofiltration mass transfer model, the enhanced separation behavior of ephedrine in organic solution was studied. In the experiment, the sensitive region of ethanol concentration and pH on the rejection of ephedrine was screened out by Box-Behnken central composite experiment design. Furthermore, to analyze the separation regularity of ephedrine and organic solution, the correlation between mass transfer coefficient and concentration of organic solvent was fitted with the changed organic solution by nanofiltration mass transfer mathematical model. Experiments showed the enhanced separation behavior, the decrease in the mass transfer coefficient while the increase in ethanol concentration from 20% to 40%, MWCO at 450 and pH 6.0. Under the same conditions, the enhanced separation behavior was appeared as the solvent changed into methanol and acetonitrile, the enhanced effect was positively correlated with the concentration of the three common organic solvents, and the effect order was acetonitrile>ethanol>methanol. This study took ephedrine as an example, and explored the mechanism of nanofiltration separation in the environment of organic solution, so as to provide references for nanofiltration separation for heat-sensitive traditional Chinese medicine of alkaloid.

STABILITY OF COORDINATION COMPOUNDS OF SOME d-METAL IONS WITH SUCCINIC ACID ANION IN AQUEOUS-ETHANOL SOLVENTS

The paper provides an overview of own data on complexation of nickel (II), cobalt (II) and cooper (II) ions with succinic acid anion in water-organic mixed solvents. Proper data are compared with data reported in literature for d-metal complexes with anions of maleic and succinic acids. The effect of aqueous ethanol solvent compositions on the stability of coordination compounds of M2+ with succinic acid anion as well as on рК values of stepwise succinic acid dissociation was carried out by a potentiometric titration at ionic strength of 0.1 maintained with sodium perchlorate at 298.15 ± 0.10 K. Mono ligand complexes of Ni2+, Co2+ and Cu2+ ions with succinic acid anion become stronger when ethanol content rises. In aqueous solutions Cu2+ ion forms stronger complexes with succinic and maleic acid anions than Ni2+ and Co2+ ions. In the studied water - ethanol solution this ratio is maintained for complexes with succinic acid anion, but a water-isopropanol solvent exerts leveling effect on the stability of complexes of nickel (II) and cobalt (II). An increase in the stability of complexes of d-metal with anions of maleic and succinic acids is due to the destabilization of the ligand with increasing ethanol concentration. The principal contribution of the changes in the solvation state of ligand is a typical for the stability changes of d-metal complexes with amine, glycinate, and acetate type ligands in water-organic mixed solvents.&#x0D; For citation:&#x0D; Tukumova N.V., Usacheva T.R., Thuan Tran Thi Dieu, Sharnin V.A., Giancola C. Stability of coordination compounds of some d-metal ions with succinic acid anion in aqueous-ethanol solvents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 15-22&#x0D;

Characteristics of combustion and soot formation of ethanol-gasoline blends injected by a hole-type nozzle for direct-injection spark-ignition engines

In this study, the combustion and soot formation processes of mid-low level ethanol-gasoline blends (E0, E20 and E50) sprays injected by a hole-type nozzle were examined in a quiescently high-temperature and high-pressure constant volume vessel by various ignition strategies (e.g. ignition position, ignition timing and spark energy). High-speed imaging of OH* chemiluminescence and two-color pyrometry were employed to clarify the flame propagation and soot formation. The results show that a relatively favorable flame area is potential to achieve for both E20 and E50 at the EOI or slightly after EOI timing. Higher ethanol content blends show more sensitivity to the ignition energy due to the physical properties. The soot level tends to decrease with increasing ethanol content at EOI middle ignition, possibly attributed to the dilution effect of ethanol and the increase of oxygen content. At EOI downstream ignition, however, the soot formation increases in both E20 and E50, possibly as a consequence of the downstream fuel heterogeneity consisting of the inhomogeneous mixture and liquid droplets of highly sooting hydrocarbons. Retarding ignition timing can help to decrease the soot formation. Moreover, E20 shows not only comparably intense combustion to E0 but also less soot formation at EOI middle ignition.

Meta‐analysis of the effects of Lactobacillus plantarum and Lactobacillus buchneri on fermentation, chemical composition and aerobic stability of sugarcane silage

AbstractWe conducted a meta‐analysis to investigate the impact of Lactobacillus plantarum or Lactobacillus buchneri on the fermentation, chemical composition, and aerobic stability of sugarcane silage. Two databases that included 15 and 27 published articles (81 and 83 silages evaluated) were used to evaluate L. plantarum and L. buchneri, respectively. For each database, the means of the treatments compiled from the studies were classified into two categories: (a) sugarcane silage without inoculant (untreated) and (b) sugarcane silage inoculated with L. plantarum (1 × 105–1.8 × 106 cfu/g of fresh forage) or with L. buchneri (2.5 × 104–1 × 106 cfu/g of fresh forage; inoculated). Sugarcane silage inoculated with L. plantarum displayed increased ethanol concentration (+43.8%, p &lt; 0.01) and dry matter (DM) loss (+9.6%, p = 0.03). In contrast, inoculation with L. buchneri increased the acetic acid concentration (+30.8%, p = 0.01), and decreased ethanol concentration (−58.8%, p &lt; 0.01) and DM loss (−19.7%, p &lt; 0.01). In vitro DM digestibility decreased following inoculation with L. plantarum (−5.7%, p = 0.05) or L. buchneri (−3.3%, p &lt; 0.01). Aerobic stability was unaffected by inoculation with L. plantarum (p = 0.16) or L. buchneri (p = 0.48). The results show that L. plantarum impairs the fermentation of sugarcane silages; therefore, its utilization might not be recommended for ensiling this crop. Conversely, even with no additional gain on silage digestibility and aerobic stability, L. buchneri may be recommended for sugarcane ensiling because it reduces alcoholic fermentation and DM loss.

Impact of ethanol blending on particulate emissions from a spark-ignition direct-injection engine

Particulate formation due to combustion of a wide range of ethanol-gasoline blends was investigated in a spark-ignition direct-injection (SIDI) engine. This study is a follow-up to a previous study done by the authors in which particulate formation for ethanol-gasoline blends was examined under fully premixed combustion, eliminating physical effects of the fuel. In this study, fuel was injected directly into the cylinder to investigate how the physical properties of the blended fuels influence particulate formation. The engine was operated at a fixed load, phasing, and equivalence ratio while end of injection timing was varied. The results of this work show that increasing ethanol content leads to a decrease in engine-out particulate in spite of, sometimes significant, changes in fuel properties. However, it was also shown that particulate results can be affected by engine operating history which, if not taken into account, could have implications for research and real world applications.

Parametric study on direct ethanol fuel cell (DEFC) performance and fuel crossover

A parametric study was carried out to investigate the effect of fuel concentration (0.5 M–3.0 M), operating temperature (ambient temperature to 85 °C), flow rate of ethanol (0.5–5.0 mL min−1) and air (100–600 mL min−1) on the direct ethanol fuel cell (DEFC) performance. The operations were conducted in three operational modes, namely, passive, semi passive, and active modes, and power generation were measured. Ethanol crossover was indicated by the carbon dioxide (CO2) concentration present at the cathode outlet and measured by using a CO2 analyzer. Results indicated that DEFC performance increased with the increase of ethanol concentration, and ethanol and oxidant flow rate increased with temperature until DEFC reaches the optimum conditions, i.e., concentration and flow rate. Meanwhile, the DEFC performance significantly and proportionally increased with operation temperature and reached values of up to 8.70 mW cm−2 and 85 °C at stable conditions. Furthermore, fuel crossover, that is, ethanol flux, increased in proportion to the ethanol concentration, i.e., 3.71 × 10−4 g m−2 s−1 and 8.79 × 10−4 g m−2 s−1 for 0.5 M and 3.0 M ethanol concentration, respectively. At different modes of operation, the active DEFC system exhibited the highest performance, followed by the semi passive and passive DEFC system. These results indicated that optimizing ethanol, oxidant flow rate and temperature would enhance the mass transport in anodes and cathodes, and hence improve the electrochemical reactions and DEFC performance.

Phase Separation of Amphiphilic Drug Amitriptyline Hydrochloride in the Presence of Additives: Role of Ethanol

In this work, the effect of ethanol (EtOH) at different weight percentages (wt %) (0, 5, 10, and 15% w/w) is accounted for in the clouding phenomena of the AMT drug with/without additives (inorganic salts and conventional and gemini surfactants). The critical micelle concentration (cmc) and degree of counterions dissociation (α) of AMT solution at 30 °C in SP buffer (pH 6.7), studied through conductometric studies, are found to be enhanced with the increase in ethanol content due to the reduction in the dielectric constant of mixed media. A dye solubilization study performed under identical physicochemical conditions exhibited supporting results. Clouding could not be observed in 20 wt % EtOH–WR mixed media at pH 6.7. The effects of additives on the CP in 15 wt % EtOH–WR at a pH of 6.95 were also studied. Furthermore, the effect of pH (range 6.7 to 7.15) on the CP in the presence of KCl at the same composition of the mixed media reduce the clouding temperature due to the deprotonation of AMT headgroups. F...

Production of medium-chain carboxylic acids by anaerobic fermentation of glycerol using a bioaugmented open culture

Biological production of carboxylic acids during glycerol fermentation via the chain elongation process was investigated. Glycerol is a by-product of the biodiesel production process and a convenient feedstock alternative for the carboxylate platform. In batch experiments, glycerol was used as substrate, whereas sludge (granular and flocculent) and ruminal liquid served as inocula. To improve the production of carboxylates, bioaugmentation with Clostridium acetobutylicum ATCC 824 was performed. Maximal production of n-caproic and n-caprylic acids was achieved with the use of the granular sludge. Bioaugmentation with C. acetobutylicum enhanced production of n-caproic acid in the presence of 100 mM ethanol. However, increasing ethanol concentration to 200 mM had no further enhancing effect on n-caproic production with or without bioaugmentation. The enhancement of n-caproic acid production was probably due to the increased production of n-butyric acid by C. acetobutylicum, because n-butyric acid is an important intermediate in the chain elongation process when ethanol is used as an electron donor.

Ethanol Measurement Using Hetero-Core Structured Optical Fiber Covered with Layer-By-Layer Thin Film.

Ethanol measurements are performed in an ethanol/water solution utilizing an ethanol sensor based on a hetero-core structured optical fiber covered with a layer-by-layer thin film. The layer-by-layer (LbL) thin film was prepared using poly (allylamine hydrochloride) and poly styrene sulfonate. When the sensor was immersed in water, the propagating light intensity decreased with increasing ethanol concentration. This behavior suggested that the LbL film contracted due to the presence of ethanol, and the refractive index of the film increased, resulting in increasing propagating light leaks at the hetero-core of the fiber. The ethanol sensor was applied to a variety of spirits, and the propagating light intensity decreased with increasing ethanol concentration.

Quantifying the Effects of Ethanol and Temperature on the Fitness Advantage of Predominant Saccharomyces cerevisiae Strains Occurring in Spontaneous Wine Fermentations.

Different Saccharomyces cerevisiae strains are simultaneously or in succession involved in spontaneous wine fermentations. In general, few strains occur at percentages higher than 50% of the total yeast isolates (predominant strains), while a variable number of other strains are present at percentages much lower (secondary strains). Since S. cerevisiae strains participating in alcoholic fermentations may differently affect the chemical and sensory qualities of resulting wines, it is of great importance to assess whether the predominant strains possess a “dominant character.” Therefore, the aim of this study was to investigate whether the predominance of some S. cerevisiae strains results from a better adaptation capability (fitness advantage) to the main stress factors of oenological interest: ethanol and temperature. Predominant and secondary S. cerevisiae strains from different wineries were used to evaluate the individual effect of increasing ethanol concentrations (0-3-5 and 7% v/v) as well as the combined effects of different ethanol concentrations (0-3-5 and 7% v/v) at different temperature (25–30 and 35°C) on yeast growth. For all the assays, the lag phase period, the maximum specific growth rate (μmax) and the maximum cell densities were estimated. In addition, the fitness advantage between the predominant and secondary strains was calculated. The findings pointed out that all the predominant strains showed significantly higher μmax and/or lower lag phase values at all tested conditions. Hence, S. cerevisiae strains that occur at higher percentages in spontaneous alcoholic fermentations are more competitive, possibly because of their higher capability to fit the progressively changing environmental conditions in terms of ethanol concentrations and temperature.

The effect of the preparation method on the physical and chemical characteristics of propolis tinctures

The effect of the preparation method was examined with regards to the physical and chemical characteristics of the propolis tincture, namely the extraction time and the ethanol content of the extraction solvent to the dry matter, polyphenol, flavonoid, phosphorus, calcium and copper concentration, respectively. The dry matter, the polyphenol and the flavonoid content were the lowest in the water extract of the propolis; however, significant increase was noticed depending on the extraction time. Significantly higher concentrations were found in 50 V/V% tinctures. The highest dry matter and flavonoid contents were analysed in 100 V/V% tinctures, whereas highest polyphenol content was found in 80 V/V% tinctures. However, the differences were not significant in several cases between latter tinctures. Moreover, the increase was not determined in some cases depending on the extraction time. Phosphorus and calcium concentrations were decreased depending on the increasing ethanol content, whereas copper concentration was increased up to 80 V/V%. Higher increase was found in the case of 0 and 50 V/V% extracts than in 80 and 100 V/V% tinctures. Moreover, in latter cases, no significant differences were found on several occasions, depending on the extraction time. There was no connection between the flavonoids and the calcium as well as the phosphorus content, whereas flavonoids may be made complex with copper. However, the amount of the possible complex was negligible.

Persimmon peel deastringency by CO2 and ethanol combination: Product quality and polyphenols bioavailability

Persimmons are popular worldwide owning to their unique flavor and nutritional value, while for the astringent cultivars, deastringency treatment is needed before processing. The current deastringency methods are limited to CO2 and ethanol. The aim of this work was to select optimal deastringency methods and assess the bioavailability of polyphenols in persimmon peels treated with 12 different combination of CO2 and ethanol. The level of soluble and insoluble tannins, total polyphenols bioaccessibility, antioxidant properties, color, and soluble solids were also determined. Results indicated that soluble tannin contents decreased with increasing ethanol concentration, and with an increase in carbon dioxide concentration, the insoluble tannins content increased. Application of 30% ethanol solution and 80% carbon dioxide for 24 hr has a best deastringency effect, while this treatment does not show good phenolics bioaccessibility and antioxidant activity. Therefore, the combination of 30% ethanol solution with 70% CO2 fumigation for 24 hr at 10 °C is the best deastringency method. Practical applications This project invented a novel deastringency method by CO2 and ethanol combination, with a feature of applying to lower temperature. The aim of this work was to select optimal deastringency methods and assess the bioavailability of polyphenols in persimmon peels treated with 12 different combination of CO2 and ethanol.