Increasing Ethanol Concentration Research Articles

Statistical optimization of bioethanol production from giant reed hydrolysate by Candida tropicalis using Taguchi design

The economic production of bioethanol as a sustainable liquid fuel is particularly needed and attractive. Giant reed as a low-cost and renewable biomass can be utilized as a sustainable feedstock for bioethanol development. The current research focuses on optimizing the fermentation parameters to increase ethanol concentration while lowering production costs. In this work, the giant reed was hydrolyzed thermochemically using HCl; cellulose and hemicellulose fractions were maximally converted at optimized hydrolysis conditions (5% HCl, 30 min, and 120 °C), resulting in a high sugar concentration (≈ 55 g/L), which were fermented by Candida tropicalis Y-26 for bioethanol production (≈ 15 g/L). Taguchi design was used to optimize the fermentation parameters (temperatures, pH, incubation period, and nitrogen sources). Under optimum fermentation conditions (25 °C; 24 h.; pH 5.5; and ammonium nitrate as a nitrogen source), the ethanol concentration at flask level accomplished ≈ 21 g/L, while its scale-up to bioreactor level contributed ≈ 25 g/L (equivalent to 250 kg ethanol/ton biomass) with ≈ 67% increase than the fermentation under unoptimized conditions. Overall, these findings proved that optimizing the fermentation parameters by Taguchi design and scaling up at a bioreactor could improve bioethanol production from giant reed biomass.

Effects of solid–liquid interaction and mixture concentration on wettability of nano-droplets: Molecular dynamics simulations

The wetting of droplets plays a critical role in engineering applications. Intensive study on nano-droplets is of great significance in revealing the wetting characteristics of droplets. The wetting behavior of ethanol/water mixture nano-droplets on a smooth substrate was investigated through molecular dynamics simulation in this paper. Five nano-droplets of the ethanol/water mixture with different mass fractions placed on a copper surface with different surface energies were simulated to equilibrium at 298.15 K. The contract angle, wetting limit (the minimum and the maximum surface tension of droplets make the surface completely wetted or completely non-wetted by the droplet), and density distribution at the solid–liquid interface of the nano-droplet were analyzed. The effects of ethanol concentration and solid–liquid interaction (corresponding to the droplet’s surface tension and the substrate’s surface energy, respectively) on droplet wettability were intensely discussed. Results revealed that the contact angle of nano-droplets decreased with the increase in ethanol concentration and the interaction between droplets and the substrate. In addition, the critical and ultimate surface tension increased with the increase in the substrate surface energy. The peak density values of the droplets were proportional to the interaction between the droplets and substrate and not related to the droplet concentration. The research also indicated that solid substrates with different surface energies and droplets with various components affected the contact angle of droplets in different ways: the former not only increased the surface tension of droplets at the solid–liquid interface but also increased the separation energy of solids and droplets, while the latter only had a great influence on the surface tension of droplets at the solid–liquid interface.

Microbiome-derived ethanol in nonalcoholic fatty liver disease.

To test the hypothesis that the gut microbiota of individuals with nonalcoholic fatty liver disease (NAFLD) produce enough ethanol to be a driving force in the development and progression of this complex disease, we performed one prospective clinical study and one intervention study. Ethanol was measured while fasting and 120 min after a mixed meal test (MMT) in 146 individuals. In a subset of 37 individuals and in an external validation cohort, ethanol was measured in portal vein blood. In an intervention study, ten individuals with NAFLD and ten overweight but otherwise healthy controls were infused with a selective alcohol dehydrogenase (ADH) inhibitor before an MMT. When compared to fasted peripheral blood, median portal vein ethanol concentrations were 187 (interquartile range (IQR), 17-516) times higher and increased with disease progression from 2.1 mM in individuals without steatosis to 8.0 mM in NAFL 21.0 mM in nonalcoholic steatohepatitis. Inhibition of ADH induced a 15-fold (IQR,1.6- to 20-fold) increase in peripheral blood ethanol concentrations in individuals with NAFLD, although this effect was abolished after antibiotic treatment. Specifically, Lactobacillaceae correlated with postprandial peripheral ethanol concentrations (Spearman's rho, 0.42; P < 10^-5) in the prospective study. Our data show that the first-pass effect obscures the levels of endogenous ethanol production, suggesting that microbial ethanol could be considered in the pathogenesis of this highly prevalent liver disease.

Detection of Ethanol Concentration in Liquid Using a Double-Layered Resonator Operating at 5G-mm-Wave Frequencies

A new sensing technique for rapidly detecting ethanol concentration in aqueous solutions based on electromagnetic resonance is discussed. The sensor has two substrate layers and operates at 5G-mm-wave frequencies. An experimental study of the new resonator's configuration determines the sensor's sensitivity. During the measurements, 6 samples were modeled with varying amounts of ethanol concentration in the water. The results showed that S11 resonance moves linearly towards higher frequencies as the ethanol content increases. The resonant frequency shifted at 0.178 GHz per 10% increase in ethanol towards higher frequencies. As a result, the proposed 5G-mm-wave-sensing technique based on a replaceable sensing layer was proved to be suitable for rapid, accurate, and low-cost alcohol content detection in liquids.

Influence of Ethanol on the Acid-Induced Flocculation of Casein Micelles

The influence of ethanol (0–10%, v/v) on the acid-induced flocculation of casein micelles was examined using diffusing wave spectroscopy. For this purpose, samples containing 10% (w/w) reconstituted skim milk powder and 0–10% (v/v) ethanol were acidified with glucono-delta-lactone and acid-induced coagulation was monitored by diffusing wave spectroscopy. The pH at which acid-induced flocculation of the casein micelles commenced (pHf) increased near-linearly with increasing ethanol content, whereas the rate of flocculation was not affected by ethanol. The results are discussed in terms of the steric stabilisation of casein micelles by a polyelectrolyte brush in a medium of high ionic strength. Ethanol-induced increases in pHf are probably primarily due to an ethanol-induced reduction in solvent quality; an ethanol-induced reduction in dissociation of carboxylic acid groups in the brush is likely to contribute.

Growth of Nanostructured Antibacterial Zeolitic Imidazolate Framework Coatings on Porous Surfaces

Morphological tailoring of crystalline nanomaterials such as zeolitic imidazolate frameworks (ZIFs) is essential for various applications, including oil-water separations, molecular sieving, and antibacterial applications. However, precise control of the morphology of these crystals is challenging. Herein, the morphological evolution map of ZIF-L to ZIF-8 nanocrystals on porous polymer supports was constructed in terms of ethanol content and processing temperature variation. Subsequently, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analyses demonstrated that an increase in the temperature in low ethanol content led to the formation of ZIF-L nanocrystals with decreased lateral size and increased crystal thickness. Comparatively, increased ethanol content typically increases crystal thickness with a greater degree of crystal intergrowth. However, an increase in both parameters exhibited a preferential formation of its three-dimensional (3D) structural analog, ZIF-8, and consequently resulted in a ZIF-L/ZIF-8 mixed phase at midrange temperatures (50–60 °C) and ethanol content (10 v/v%). The mixed phase demonstrated the stacking of ZIF nanosheets, with the morphology change significantly impacting the properties of the ZIF nanocrystals. As one example, the antibacterial performance of the as-prepared materials of different morphologies was analyzed to investigate the morphological impact on antibacterial efficiency. It was found that crystals with reduced crystal size and increased surface area resulted in improved antibacterial performance. Meanwhile, the nanostructured ZIF coating’s hydrophilicity and hydrostability were also enhanced with increased ethanol content and elevated temperatures. Overall, we reported a very useful method to conveniently control the morphology of ZIF nanocrystals for improved applications.

Kombucha: Determining the likelihood of secondary fermentation and increased ethanol content via stated sugar content on product labels

Kombucha products are now a common, and popular beverage. Increasingly, Kombucha beverages are outpacing popularity of other carbonated beverages on the market, such as soda pop. This increase is seen by many as a positive change of consumer interests, as Kombucha has much less sugar content than many soda pop alternatives. However, Kombucha products are fermented beverages, and therefore are apt to contain ethanol, which may be a hazard for certain at risk populations. This study aims to investigate how information provided on product labels may or may not allow for increased consumer control by making an educated guess about potential ethanol content.

Experimental investigation on operating light-duty diesel engine using ethanol–gasoline blends in a homogeneous charge compression ignition combustion mode

The advanced diesel combustion mode of homogeneous charge compression ignition (HCCI) provides simultaneous lessening of soot and oxides of nitrogen (NOx) emissions. However, HCCI operations with low volatility and high reactivity diesel fuel require energy-intensive vaporizers and suffer from a restricted operating load range. In this work, high volatility, and low reactivity ethanol–gasoline blends were utilized as fuels in a port fuel injected light-duty diesel engine operated in HCCI mode to address this limitation. To study the effect of adding ethanol to the test fuels, its content was progressively increased from 10% to 60% by simultaneously reducing the gasoline content. 6% of an ignition improver, 2-ethylhexyl nitrate (2-EHN), was added to test fuels to attain stable HCCI combustion in the test engine at lower engine loads. A combined experimental and statistical approach was followed to characterize the HCCI engine combustion, performance and emissions. The impact of independent operating factors of ethanol–gasoline fuel blend composition and engine load on the various response parameters was estimated using multi-regression models developed based on the response surface method (RSM). The optimization of engine parameters was performed using the desirability approach of RSM to maximize performance and minimize emissions. The engine operating load range was extended from 23% (1.22 bar BMEP) to 86% (4.63 bar BMEP) with ethanol–gasoline–2-EHN-fuelled HCCI, which was a substantial improvement over the achievable load range only up to 38% (2.02 bar BMEP) with diesel-fuelled HCCI. All the multi-regression models developed were statistically significant at a 95% confidence level. The results showed that the indicated thermal efficiency improved, and soot and NOx emissions reduced with increased ethanol content in the test fuels. The test engine showed optimal working conditions when operated using 49% ethanol in the test fuels at 75% engine load. To benchmark the HCCI engine performance under optimal operating conditions, it was compared with conventional diesel combustion at 75% engine load. The NOx and soot emissions decreased by 76% and 98%, respectively, while indicated thermal efficiency increased by 20% for HCCI than conventional mode. The optimal fuel reactivity was determined at various engine loads by using the model equation developed for combustion phasing. According to the findings of this study, the fuel management strategy of using ethanol and gasoline blends is a viable method to enhance the performance and emission metrics of HCCI engines.

Numerical investigations on the performance and emissions of a turbocharged engine using an ethanol-gasoline blend

Due to a scarcity of fossil fuel supplies and concerns about pollution, the use of ethanol in gasoline has become a priority in the automobile industry. This paper aims to investigate the effect of different ethanol-gasoline fuel blend ratios, namely E20 (% ethanol + % gasoline), E50 (% ethanol + % gasoline), and E75 (75% ethanol + 25% gasoline) on a 1.6 L turbocharged, 4-cylinder, 2017 Proton Preve Premium CFE CVT engine, where E0 (pure gasoline) is taken as reference fuel. In addition, different speed intervals, which include 1000 RPM, 2000 RPM, and 5000 RPM, are employed for each fuel blend. The production of four major emissions, NOx, CO, CO2, and HC, and performance parameters such as thermal efficiency, volumetric efficiency, and brake-specific fuel consumption, are evaluated using SolidWorks for CAD modelling. This then is transferred to ANSYS for emission and performance analysis. According to the findings, increasing ethanol concentration and engine speed increases volumetric efficiency and brake-specific fuel consumption by up to 12.89% and 6.59%, respectively. It was also discovered that ethanol and increasing engine speed had an 11.39% reduction in thermal efficiency. Furthermore, the addition of ethanol occurs, along with an increase in speed, exhaust gas emissions are reduced by up to 21.74% compared to pure gasoline.

Extractability of Curcuminoids Is Enhanced with Milk and Aqueous-Alcohol Mixtures.

In this study, we evaluated the extractability of three curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin) from turmeric powder in several solvents using high-performance liquid chromatography (HPLC) with the diode-array detection method. These solvents include water, milk (homogenized, 2% reduced fat, low fat, fat free, soy, almond, coconut, and milkadamia), and aqueous ethanols (0%, 4%, 10%, 20%, 30%, 40%, 50%, and 100%). Ambient water was able to extract only 0.55 mg/g of curcuminoids, whereas warm water extracted more than four-fold higher amounts (2.42 mg/g). Almond, coconut, and milkadamia milk were able to extract only small amounts of curcuminoids at ambient temperatures (0.01–0.07 mg/g). The extractability of curcuminoids in these milk types did not improve, even in warm conditions (0.08–0.37 mg/g). Whereas dairy and soy milk extracted 6.76–9.75 mg/g of curcuminoids under ambient conditions, their extractability increased significantly in warm conditions by 30–100% higher (11.7–14.9 mg/g). The solubility of curcuminoids also varied remarkably in different proportions of aqueous-alcohol mixtures. With 4% ethanol, only 1.7 mg/g of curcuminoids were extracted, and the amounts improved with the increase in ethanol content up to 50% (32.2 mg/g), while 100% ethanol extracted a similar amount as 50% ethanol (34.2 mg/g). This study suggests that the extractability of curcuminoids from turmeric will be dependent on the type of diets consumed with the turmeric supplements.

Influence of ethanol content and temperature in coagulation bath on the microstructure and performance of polyvinylidene fluoride ultrafiltration membranes

In this article, polyvinylidene fluoride (PVDF) ultrafiltration membranes were prepared via phase inversion method. The influence of different ethanol content and temperature in coagulation bath on the microstructure of PVDF membranes was discussed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM) measurements. Rejection experiment was conducted with the bovine serum albumin (BSA) solution. The FTIR and XRD analysis showed the higher ethanol content and temperature of coagulation bath promoted the α crystal form of PVDF membranes. The increase of ethanol content in coagulation bath led to a decrease in the mean pore size and porosity and the increase of BSA rejection rate and break strength of PVDF membranes. This was because of the increase of ethanol content in coagulation bath that resulted in the formation of the more sponge-like structures and the fewer finger-like structures, which enhanced the compactness of the membranes. The PVDF membrane prepared in ethanol/pure water (60/40) coagulation bath at 20 °C showed a greater BSA rejection rate of 91.87% and break strength of 1.89 MPa with a mean pore size of 29.26 nm. Meanwhile, the increase in temperature of coagulation bath had a positive effect on the mean pore size, porosity, and hydrophilicity of PVDF membranes to a certain extent.

Species-specific effects of ethanol concentration on host colonization by four common species of ambrosia beetles

Ambrosia beetles (Coleoptera; Curculionidae; Scolytinae and Platypodinae) can cause severe damage to trees growing in plant nurseries, orchards and natural forests. Ethanol is emitted by stressed trees and represents an important cue used by ambrosia beetles to locate suitable hosts to infest. Ethanol also favors the growth of ambrosia beetles’ nutritional fungal symbionts and suppresses the growth of antagonistic fungi. An optimal concentration of ethanol in host tissues might maximize fungal growth and offspring production, but it is unclear if this optimal concentration varies among ambrosia beetle species. To investigate this mechanism, we injected five different concentrations of aqueous ethanol solution (5%, 25%, 50%, 75% and 90%) into the stems of container-grown oak trees, Quercus robur L. Modified Falcon tube chambers were used to confine four species of field-collected ambrosia beetles to the injected stems, namely, Anisandrus dispar, Xyleborinus saxesenii, Xylosandrus germanus, and Xylosandrus crassiusculus. Incidence of boring, ejected sawdust, gallery development, and offspring production were then quantified. The incidence of boring generally increased with increasing ethanol concentration for all four Scolytinae species tested. Ejected sawdust and offspring production increased with increasing ethanol concentration up to 90% for A. dispar and X. saxesenii; by contrast, an increasing trend up to 75% ethanol followed by a decrease at 90% ethanol was associated with X. germanus and X. crassiusculus. Our study highlights the key role of ethanol for ambrosia beetles, and showed that the optimal concentration maximizing colonization and offspring production can vary among species.

Xylan, Xylooligosaccharides, and Aromatic Structures With Antioxidant Activity Released by Xylanase Treatment of Alkaline-Sulfite-Pretreated Sugarcane Bagasse.

Xylanase enzymes are useful to fractionate plant biomass, producing xylan, xylooligosaccharides (XOS), and antioxidant-derived XOS. In a biorefinery, pretreated biomass can be digested with xylanase prior to cellulose saccharification, enhancing the product portfolio in the process. With this vision, this study highlighted a wide range of new products attainable from alkaline-sulfite–pretreated sugarcane bagasse by treatments with endo-xylanase under controlled conditions. The developed process provided a crude extract corresponding to 29.7% (w/w) of pretreated sugarcane bagasse. The crude extract included a relatively polymeric glucuronoarabinoxylan fraction, DP2-DP6 xylooligosaccharides, and aromatic compounds. The enzymatically produced extract was fractionated with increasing ethanol concentrations [up to 90% (v/v)], providing precipitation of varied polymeric xylan fractions (48% (w/w) of the crude extract) with average molar masses ranging from 28 kDa to 3.6 kDa. The fraction soluble in 90% ethanol was subjected to adsorption on 4% (w/v) activated charcoal and eluted with an ethanol gradient from 10% to 70% (v/v), thus providing xylooligosaccharides and aromatic fractions. Most of the xylooligosaccharides (74% of the eluted sugars) were washed out in 10%–30% ethanol. DP2 and DP3 structures predominated in the 10% ethanol fraction, while DP5 structures were significantly enriched in the 30% ethanol fraction. Higher ethanol concentrations desorbed xylooligosaccharides associated with higher amounts of aromatic compounds. Total aromatics, phenolic structures, and p-hydroxycinnamates predominated in the fractions desorbed with 60% and 70% ethanol. The antioxidant activity of produced fractions correlated with their phenolic contents. Compiled results indicate that a wide variety of products can be prepared from pretreated biomass using xylanase-aided extraction procedures. Recovered fractions presented different features and specific application prospects. Beyond polymeric xylan with low lignin contamination, xylooligosaccharides or even lignin-carbohydrate complexes with antioxidant activity can be included in the biorefinery portfolio based on the currently developed fractionation studies.

Effects of extraction methods on antioxidants and methoxyflavones of Kaempferia parviflora

This research was aimed to determine the effects of extraction methods on antioxidant properties and methoxyflavone contents of Kaempferia parviflora (KP) rhizome extracts. The KP rhizomes were extracted by maceration using ethanol at the concentrations of 25, 50, 75 and 95% V/V for 7 days and 95% V/V ethanolic extraction with sonication-assisted extraction (SAE) for 15-45 mins. Antioxidant components (phenolics, flavonoids and anthocyanins) and antioxidant activities (DPPH and FRAP) were examined. Methoxyflavones of the KP extracts were identified by a GC-MS technique. It was found that extraction methods affected the antioxidant properties of the extracts. Increasing ethanol concentrations enhanced anthocyanins but not phenolics and flavonoids. Ethanol concentration at 75% V/V exhibited the greatest DPPH while 25% V/V ethanol showed the greatest FRAP values. In this study, 10 methoxyflavones from KP extracts were separated and identified by GC chromatograms. The content of 5,7-dimethoxyflavone increased from 1.1 g/100 mL extract to 48.10 g/100 mL extract as the ethanol concentrations increased from 25% to 95% V/V. SAE for 15-45 mins had little impact on antioxidant properties as well as methoxyflavone contents. In general, SAE enhanced the extraction of KP rhizomes by increasing 5,7-dimethoxyflavone contents.

Effects of using cationic exchange for reducing pH on the composition and quality of sparkling wine (Cava)

Climate change is affecting vine and grape physiology and consequently wine composition, causing a decrease in titratable acidity and an increase in ethanol content and pH. These effects are especially problematic in sparkling wines that need higher acidity to maintain an adequate freshness. Therefore, the wine industry is currently using certain procedures for reducing wine pH, among which cation exchange stands out as it is probably the most widely used. To study the influence of cation exchange treatment on the composition and quality of sparkling wines, a grape juice of Macabeo (pH 3.21 and titratable acidity 5.70 g of tartaric acid/L) after settling was treated to obtain a very acidic grape juice (pH 1.9 and titratable acidity 8.70 g of tartaric acid/L). The original grape juice was then blended in different proportions (0-45 %) with a treated grape juice. These different grape juices were used for obtaining their corresponding base wines which in turn were used for elaborating their corresponding sparkling wines using the traditional method. The cation exchange treatment reduced the pH from 3.15 (Control) to 2.87 (45 % of treatment) and increased the titratable acidity from 4.61 (Control) to 7.69 (45 % of treatment). No significant effects were observed on the concentration of any of the protein or polysaccharide fractions and the foaming properties of the base wine or young sparkling wines were not affected; however, cation exchange caused a decrease in foamability and persistence of the foam in older sparkling wines, especially when the proportion of treated grape juice was higher. A trained panel only found clear sensory differences in the acidity of the sparkling wines without the rest of the attributes being affected by the treatment.

Effectiveness of Tannin Removal by Alkaline Pretreatment on Sorghum Ethanol Production

Sorghum has been proposed as a complement or replacement for corn in ethanol production. One difference between sorghum and corn is the presence of tannins, which may affect enzymatic activity. High-tannin sorghum hybrid XM217 was used to analyze the effect of tannin removal by the alkaline pretreatment of sorghum for ethanol production. A laboratory-scale dry-milling process was used on treated sorghum/corn blends to generate mash that was fermented by Saccharomyces cerevisiae and then compared to a 100% untreated sorghum control. Cellulase was added to a similar set of mash to determine the feasibility of the tannin-removal treatment as a pretreatment method for cellulosic ethanol production. Theoretical ethanol yield increased from 68.2 ± 1.5% to 78.5 ± 2.5% for alkaline-pretreated sorghum vs. untreated sorghum, with a corresponding increase in mean ethanol concentrations from 8.02 ± 0.15 to 9.39 ± 0.26% w/v. The average theoretical ethanol yield increased from 69.8 ± 1.7% to 94.6 ± 1.9% when using cellulase with untreated and treated sorghum. The use of alkaline tannin removal resulted in a significant increase in the theoretical ethanol yield obtained when using 100% sorghum, when compared to the theoretical ethanol yield obtained when using 100% corn. The combination of cellulase and alkaline tannin removal improved the yield of ethanol in all cases compared to the experiments without cellulase.

Thermal and flow characteristics in a flat plate pulsating heat pipe with ethanol-water mixtures: From slug-plug to droplet oscillations

The thermal performance and the internal flow regimes of a closed-loop flat plate pulsating heat pipe (FPPHP) are experimentally investigated. Reports on the FPPHP using the ethanol-water mixtures as working fluids are scarce in the literature. The binary mixtures with different boiling point components are suitable for a wide range of heat fluxes. Therefore, the results are reported for the ethanol-water mixtures of ratios 3:1, 1:1, and 1:3, and the corresponding pure liquids filled in the range of [40–80] % with power inputs given from 40 to 200 W. The effect of different condenser cooling modes, such as forced convective water cooling, forced convective air cooling, and natural convective air cooling on the thermal performance of the FPPHP, is also reported. With the increase in the power input, the observed flow characteristics in the FPPHP channels are: no oscillations, slug-plug oscillations, droplet oscillations, and the evaporator dry out. The binary mixtures with increased ethanol content give better slug-plug flow oscillations with smaller thermal resistances and fewer evaporator drying out instances than the pure working fluids. For power inputs of less than 120 W, the ethanol:water mixture ratio of 3:1 at all filling ratios gives a larger slug departure frequency in the evaporator. The smallest thermal resistance measured is 0.1 K/W, a decrease of 27% over pure ethanol. For power inputs greater than 120 W, the mixture ratio of 1:1 at all filling ratios performs better with continuous droplet oscillations. The smallest thermal resistance measured at the 80% filling ratio is 0.12 K/W, a decrease of 22% over pure ethanol. When the condenser cooling mode is changed to air cooling, the evaporator temperatures reach around 100 °C for power inputs greater than 40 W and 80 W for natural and forced air convection. Thus, the FPPHP filled with ethanol-water mixtures with the water-cooled condenser gives a stable flow regime and better thermal performance for a long-range of power inputs.

Emission and Performance Evaluation of a Diesel Engine Using Addition of Ethanol to Diesel/Biodiesel Fuel Blend

Many countries have adopted the addition of biodiesel to diesel as a way of inserting renewable content into mineral fuel and making a contribution to the environment. The addition of ethanol to the diesel/biodiesel blend to increase the renewable content of the added fuel blend and reduce the percentage of biodiesel could be a strategysince the demand for biodiesel production is high, and this fuel has a high production cost when compared to ethanol. Thus, this study evaluated the performance and the content of NOx, CO and CO2 exhaust gases from a diesel engine fueled with blends of diesel/biodiesel/ethanol: pure B7, B7E3 (B7 with 3% ethanol) and B7E10 (B7 with 10% ethanol). Emissions of fuel blends were evaluated using the engine speed variation and tested at a speed of 1500 rpm under constant load (185 Nm). Assays were performed at engine speeds of 1000, 1100, 1250, 1500 and 1750 rpm and with loads of 10, 25, 50, 75 and 100% of the maximum torque. Through the performance curves, the specific consumption and thermal efficiency were evaluated. The increase in speed and ethanol content in the diesel/biodiesel mixture increased approximately 5 to 7 and 1.4 times, respectively, in terms of the emission of exhaust gases. There was a 6% decrease in the maximum torque and power available at each speed with increasing ethanol content in the blend. However, in a vehicular application, this decrease would be perceived only at some points of the part-load regime, causing considerable reductions in thermal efficiency.

Anthocyanin Extraction from Jaboticaba Skin (Myrciaria cauliflora Berg.) Using Conventional and Non-Conventional Methods.

This study evaluated the effect of different extraction technologies and conditions in order to obtain jaboticaba skin extracts. Firstly, the skins were extracted by conventional extraction, according to a rotatable central composite design, varying ethanol concentration, solid:liquid ratio, and temperature. Next, ultrasound-assisted extraction was performed using different power densities and times. Finally, high-pressure extractions were performed with varying pressures and times. For agitated bed extraction, the highest anthocyanin content was observed for ethanol concentrations varying between 60% and 80%. Thus, the independent variables which more influenced anthocyanin content were ethanol concentration and solid:liquid ratio. Folin–Ciocalteu reducing capacity was linearly affected by the increase in temperature. Ethanol concentration was the variable that most influenced ABTS+. On the other hand, the increase in ethanol concentration decreased the antioxidant capacity by ABTS+. Considering the ultrasound extraction, increasing its power did not affect total monomeric anthocyanins content, while the increase in process time had better yields. The highest antioxidant capacity and total monomeric anthocyanins were found for the highest extraction time. Similarly, with ultrasound, the increase in high hydrostatic-assisted extraction time positively influenced anthocyanin content and antioxidant capacity. As a result, the ultrasound-assisted method was found to be the best extraction technology for anthocyanins recovery.

In Situ Corn Fiber Conversion for Ethanol Improvement by the Addition of a Novel Lignocellulolytic Enzyme Cocktail.

Corn mashes have high-viscosity and high-sugar characteristics, which hinders yeast-fermentation efficiency and the ethanol yield increase. The excessive viscosity of corn mash is caused by the unutilized cellulose in corn kernel fiber. A novel lignocellulolytic enzymes cocktail with strong substrate specificity was prepared for high-viscosity, high-sugar corn mash. The in situ conversion of corn mashes with novel lignocellulolytic enzymes at the optimum cellulase dosage of 50 FPU/L resulted in about 12% increased ethanol concentration compared with the reference mash at different batch-fermentation scales. Adding the lignocellulolytic enzymes caused the greatest decrease in viscosity of corn mash and residual sugars by 40.9% and 56.3%, respectively. Simultaneously, the application of lignocellulolytic enzymes increased the value of the dried distiller’s grain with solubles (DDGS) by increasing the protein content by 5.51%. The in situ conversion of cellulose can decrease the fermentation broth viscosity and improve the rheological property, thereby improving the ethanol yield. With the same amount of material, the application of the novel enzymes cocktail can enhance the ethanol yield by more than 12%. A quarter of the ethanol yield increase was due to the further hydrolysis of starch, while three quarters to cellulose. Thus, this technology will increase the net revenue of bioethanol industrialization.