Percent Ethanol Research Articles

Recovery of Bioactive Compounds from Pomegranate (Punica granatum L.) Peel Using Pressurized Liquid Extraction.

Pressurized liquid extraction (PLE) is a clean and environmentally friendly alternative for the recovery of bioactive compounds from fruit by-products. Herein we focused on PLE for the extraction of bioactive compounds from pomegranate peel using a combination of pressurized water and ethanol. The main aim was to determine the optimal PLE conditions, i.e., ethanol percentage and process temperature, to obtain a pomegranate peel extract (PPE) with maximum total phenolic content (TPC), punicalagin content, and antimicrobial activity (AMA). The experimental design was conducted using a central composite design with axial points. Response surface methodology was applied to optimize the response variables using the desirability function. Multiple response optimization indicated a process temperature of 200 °C and ethanol of 77% as optimal conditions. The TPC and the punicalagin content of PPE-PLE obtained under optimal conditions were 164.3 ± 10.7 mg GAE/g DW and 17 ± 3.6 mg/g DW, respectively. Our findings support the efficacy of PLE on TPC recovery but not in punicalagin recovery. The AMA against S. aureus was 14 mm. The efficacy of PPE-PLE in food applications must continue to be studied in order to achieve adequate information on its potential for developing new food additives.

Selective Extraction of Sinapic Acid Derivatives from Mustard Seed Meal by Acting on pH: Toward a High Antioxidant Activity Rich Extract.

The aim of this paper is to study the effect of the pH on the extraction of sinapic acid and its derivatives from mustard seed meal. Solutions of acidic pH (pH 2), basic pH (pH 12) and distilled water (uncontrolled pH ~ 4.5) were tested at different percentages of ethanol. The maximum extraction yield for sinapic acid (13.22 µmol/g of dry matter (DM)) was obtained with a buffered aqueous solution at pH 12. For ethyl sinapate, the maximum extraction yield reached 9.81 µmol/g DM with 70% ethanol/buffered aqueous solution at pH 12. The maximum extraction yield of sinapine (15.73 µmol/g DM) was achieved with 70% ethanol/buffered aqueous solution at pH 2. The antioxidant activity of each extract was assessed by DPPH assay; the results indicated that the extracts obtained at pH 12 and at low ethanol percentages (<50%) exhibit a higher antioxidant activity than extracts obtained at acidic conditions. Maximum antioxidant activity was reached at pH 12 with buffer solution (11.37 mg of Trolox Equivalent/g DM), which confirms that sinapic acid-rich fractions exhibit a higher antioxidant activity. Thus, to obtain rich antioxidant extracts, it is suggested to promote the presence of sinapic acid in the extracts.

Free Swelling Behaviour of Bentonite-sand Mixtures in Presence of Pore Fluids of Different Dielectric Constants

The free swelling behaviour of bentonite sand mixtures have been studied using different percentage of ethanol-water and methanol-water solutions. Free swell index tests were conducted at different proportion of ethanol and methanol with distilled water(0%, 20%, 40%, 60%, 80% and 100%). Free swell index (FSI), modified free swell index (MFSI) and free swell ratio (FSR) were determined from the results obtained from the tests. FSI, MFSI and FSR decrease with the increase of ethanol as well as methanol percentage. Good linear correlation have been observed between the dielectric constants of the pore fluids and FSI and MFSI of the bentonite sand mixtures. The study focuses on the significant influence of dielectric constants of different percentage of ethanol and methanol water solution on the free swell of bentonite-sand mixtures. Keywords: Free swell index; modified free swell index; dielectric constant; bentonite; ethanol, methanol

Study on the Effect of Dual Solvent Proportions on Composition of Rosa x damascena Concrete Oil Obtained using Soxhlet Extraction Method

Concrete oil was extracted from Rosa x damascena using different percentage ratios of solvents (petroleum ether and ethanol) by the Soxhlet extraction method. The extraction was carried out using petroleum ether and ethanol in five different percentage ratios of (v/v) (100:0, 75:25, 50:50, 25:75, 0:100) (petroleum ether:ethanol). The rotary vacuum evaporator was used to separate concrete oil and the solvents. The extracted concrete oil was analyzed using gas chromatography-mass spectrometry (GC-MS) technique. The obtained results show that many new compounds were identified, at two different solvents and its ratios. Phenylethyl alcohol in the percentages of (61.71%), (10.07%) and (25.92%) was obtained as a major compound with the solvent percentages of (100:0), (50:50) and (75:25) (PE:E), respectively. Hexacosane (37.2%) was identified as a major compound when pure ethanol is used as a solvent. The highest number of components were identified (totally 93 components) when an equal percentage (50:50) of petroleum ether and ethanol were mixed. The usual monoterpenes components, e.g. geraniol, nerol, citronellol and linalool, were not found in the present extraction study. This study concludes that the compositions of concrete oil were mainly influenced by the type of solvents and its ratios used for the extraction

AVALIAÇÃO ANALÍTICA DE ANALISADOR DE COMBUSTÍVEL COMERCIAL NO CONTROLE DE QUALIDADE DE ETANOL E GASOLINA COMUM

ANALYTICAL EVALUATION OF COMMERCIAL FUEL ANALYZER IN GASOLINE AND ETHANOL FUEL QUALITY CONTROL. Brazilian news media is full of examples about fuels out of the compliances and needs to control fuel quality. This work proposed an analytical validation of a commercial near infrared photometer (Xerloq, Tech Chrom Analytical Instruments, Brazil) able to identify percentage of ethanol in fuels comparing with NBR standards. Four procedures were selected: analysis of ethanol percentage in gasoline type C samples comparing with standard method ABNT 13992; analysis of ethanol percentage in fuel ethanol samples comparing with standard method ABNT 5992; linearity correlation and selectivity of standard solution analysis. Comparisons between the photometer and standards measurements were to determine the accuracy and precision of the device which presented a little variation from the norm (ER &lt; 1.3%, sR &lt; 0.4%). With regard to the test for linearity, Ethanol:water mixtures was analyzed with R-squared larger than 0.999 with RMSEV less than 1%. On selectivity tests, Gasoline:Ethanol:water and Methanol:Ethanol:water mixtures were measured with bias error not exceeding 5% for regulated samples. In conclusion, this fuel analyzer can be used to analyze ethanol content in Brazilian fuels with similar results comparing with classical standard volumetric and glass densimeter analysis and may indicate adulteration gasoline and ethanol samples by anomalous data.

Assessing the potential of lignocellulosic energy crops as an alternative resource for bioethanol production using ultrasound assisted dilute acid pretreatment

Abstract Nowadays, more research is directed towards the development of sustainable and eco-friendly technology for the bioethanol production using lignocellulosic biomass to address the global energy requirement. The present study was focused on evaluating the chemical composition and bioethanol production potential of four different lignocellulosic biomass viz., Typha angustifolia, Saccharum arundinaceum, Arundo donax, and Ipomoea carnea. The study exploits the application of ultrasound (US) assisted dilute acid pretreatment for delignification of lignocellulosic biomass. The compositional analysis of biomasses, before and after pretreatment, showed that lignin structure was degraded and more cellulose was exposed for enzymatic saccharification. During enzymatic hydrolysis, Saccharum arundinaceum yielded the highest value of 309.75 ± 3.98 mg/g for total reducing sugar (TRS) among all the biomasses. Typha angustifolia yielded a higher percentage of ethanol of 81.91 ± 8.17% when compared to other biomasses. After the pretreatment, the changes in the morphological features, functional groups, and cellulose crystallinity were examined using various characterization techniques. The variations in peak intensity of functional groups in FTIR and decrease in crystallinity index in XRD indicate that cellulose content was increased with a decrease in lignin content due to the synergistic effect of dilute acid and cavitational effect of US shock waves. Among the lignocellulosic biomass examined, Typha angustifolia resulted a maximum bioethanol production of 5.12 ± 0.87% (w/v) during fermentation. The outputs of the present study showed that the four lignocellulosic perennial energy crops could be utilized as a potential feedstock for the production of bioethanol.

Optimization and investigation the effects of using biodiesel-ethanol blends on the performance and emission characteristics of a diesel engine by genetic algorithm

The purpose of this research is to investigate the combined effects of biodiesel-ethanol fuel blends on the performance and emission parameters of a diesel engine by the response surface methodology (RSM). The genetic algorithm was also applied for optimizations of the parameters. According to the results, the brake power and torque were decreased by approximately 30% with increasing the amount of ethanol in the fuel mixture. On the other hand, the BSFC of fuel blends enhanced around 16% with a higher percentage of ethanol as a result of the lower calorific value of ethanol compared with biodiesel. However, higher viscosity and density of biodiesel cause more fuel injection; so there is no notable difference in BSFC values for all blends. About emission parameters, the more percentage of ethanol resulted in less amount of smoke level and NOx emission around 38% and 17%, respectively due to the high level of oxygen in the molecular structure of ethanol. However, there is an approximately 44% decrease in CO emissions for a high percentage of biodiesel contained blends. According to the GA optimization, the results showed that the biodiesel percentage in the fuel mixture, RPM, and engine load were converged to 94.65%, 2800, and 65.75%, respectively as the optimal conditions. It is concluded that ethanol is more effective to improve the emission characteristics than that of the performance characteristics.

Comprehensive Analysis of Antioxidant Compounds from Lippia citriodora and Hibiscus sabdariffa Green Extracts Attained by Response Surface Methodology.

Phenolic compounds have shown to have a high bioactive potential against various pathologies, postulating as an interesting alternative to manage some diseases. In this sense, both Lippia citriodora and Hibiscus sabdariffa are two botanical sources with a demonstrated high bioactive potential, in which their antioxidant capacity stands out. In this work, the optimization of the extraction conditions for the recovery of phytochemicals from L. citriodora leaves and H. sabdariffa calyces has been carried out using Response Surface Methodologies (RSM) considering their total polar compounds measured by HPLC-ESI-TOF/MS and Folin-Ciocalteu assay, and its antioxidant capacity evaluated by Ferric Reducing Antioxidant Power (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC) assays. The results showed that to maximize the antioxidant capacity in H. sabdariffa, a moderate temperature and high ethanol percentage are needed, while a low temperature and a high percentage of ethanol are needed in L. citriodora. In addition, with the results obtained in the multiple response analysis, it is possible to affirm the importance of this type of analysis to develop functional ingredients, taking into account both total content of phenolic compounds and their bioactivity. Furthermore, as confirmed in this study, these analyses can be extrapolated in different techniques and in different matrices, with phenolic compounds from different families being important to develop new high added value products for food, pharmaceutical or cosmetic industries.

Optimization of the extraction process of compounds with antioxidant activity of tommy atkins mango peel

It is well known that vegetable residues from the food industry can be used as a possible source for the extraction of compounds with antioxidant activity; in the case of mango, approximately 40 to 60% of the total mass of the fruit is considered as residue after processing. This work focused on the optimization of the extraction process of compounds with antioxidant activity from the rind of Tommy Atkins mango. Initially a Fractional Factorial Design 25-1 (FFD) was applied to study the effect of five variables on the extraction process, namely: extraction time (min), percentage of ethanol in aqueous solution (%), pH, dry/solvent mango peel ratio (g/mL) and ultrasound power range (%). The variables extraction time and dry/solvent mango peel ratio were selected, which were evaluated sequentially by the application of a Central Composite Rotatable Design (CCRD) to determine the conditions of maximum extraction of antioxidant compounds by the response surface analysis. The ABTS•+ and Folin-Ciocalteu methods were used for the quantification of the antioxidant activity. The maximum extraction occurred with the use of water, extraction time of 30 min, dry mango peel/solvent ratio of g/mL (1:100), at natural pH of the mixture (pH 4.6 ± 0.20) and sonication amplitude at 50%. It was possible to develop an extraction process of compounds with antioxidant activity from the mango peel, in order to maximize yield through the use of non-toxic solvents and using an agro-industrial residue as raw material.

A green and sustainable method for monitoring the chemical composition of soybean: an alternative for quality control.

Soybean is one of the most important crops in the world, an important source of isoflavones, and used to treat various chronic diseases. High-performance liquid chromatography (HPLC), associated with multivariate experiments and green solvents, is increasingly used to develop comprehensive elution methods for quality control of plants and derivatives. The work aims to establish a HPLC fingerprinting method for soybean seeds employing Green Chemistry Principles, a sustainable solvent with low toxicity, and a comprehensive experimental design that reduces the number of experiments. The fingerprinting method was optimised through Design of Experiments by evaluating seven chromatographic variables: initial percentage of ethanol (X1), final percentage of ethanol (X2), temperature (X3), percentage of acetic acid in water (X4), flow rate (X5), run time (X6), and stationary phase (X7). The dependent variable was the number of peaks (n). An initial factorial design for screening purposes indicated that the most significant quantitative parameters to separate soybean metabolites were X1 and X3. The conditions were optimised by a Doehlert design, to obtain a HPLC-PAD (photodiode array detector) fingerprinting of the polar extract of soybean seeds with the markers identified by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS). The optimum fingerprinting method was determined as 5-55% of ethanol in 30 min, at 35°C, and flow rate of 1 mL/min, by employing a phenyl-hexyl column (150 mm × 4.6 mm). The developed green method enabled markers of soybean to be separated and identified and could be an eco-friendlier alternative for soybean quality control that covered seven Green Analytical Chemistry Principles.

Hydroxy Gas (HHO) Supplement of Ethanol Fuel Mixture In A Single-Cylinder Spark-Ignition Matic-Engine

&lt;p class="TTPAbstract"&gt;Hydroxy Gas (HHO) has been identified as an efficient alternative energy source. HHO is considered an alternative fuel. It can be applied alone or mixed with other kind of fuels in different ratios. In this analysis, the composition of HHO-ethanol was mixed in different variations. Ethanol-HHO was chosen because of its high-octane rating yet low exhaust emissions, and ease of obtaining from engine products. It has been applied on fuel prepared by mixing it with gasoline in various ratios (E30-HHO, E40-HHO, and E50-HHO). The ethanol-HHO mixture has been used in a single-cylinder 4-stroke spark machine for performance, by varying speed of engine from 4000 to 9000 RPM and by applying a platinum spark plug electrode type. In experiments, engine power, average effective pressure (MEP), specific fuel consumption (SFC), and thermal efficiency have been analyzed. The analysis of combustion is accomplished by taking a pressure cycle in the chamber, monitoring the automatic control of engine control unit (ECU) and ensuring utilization in the same parameters of the various fuels tested, in addition to the fuel injection time, which increases with increasing ethanol percentage. Optimal power, MEP and thermal efficiency values are obtained with ethanol-gasoline (E50-HHO) mixture which is operated at 7200 rpm, an increase of about 5% compared to gasoline. Significant reduction in SFC was observed using HHO-ethanol mixture, reduced by about 6% compared to gasoline.&lt;/p&gt;

Modeling of polyphenols extraction from pomegranate by-product using rotatable central composite design of experiments

There is a growing request to find an effective method of polyphenols extraction from agro-industry by-product as pomegranate. In this study, response surface methodology (RSM) was used to explore the effect of three factors on ultrasonic assisted extraction (UAE) of total polyphenols (TP), total flavonoids (TF) and condensed tannins (CT) from pomegranate peels. The optimal conditions were determined for each phenolic compound using regression model equations and 3-D plots. The high TP, TF and CT content were obtained with, respectively, liquid/solid ratio of 20.00, 9.77, 9.77, extraction time of 36.38, 41.82, 30.39 min and 36.00, 83.64, 59.26% of ethanol percentage. In fact, liquid/solid ratio of 20, extraction time of 30.94 min and 59.26% of ethanol gives the highest contents of TP, TF and CT simultaneously. The experimental values using optimal conditions agreed with the predicted values. The pomegranate peels extract obtained under optimum conditions have an effective antioxidant activity as determined by ABTS and DPPH assays.

Final Endodontic Irrigation with 70% Ethanol Enhanced Calcium Hydroxide Removal from the Apical Third

IntroductionThe purpose of this study was to evaluate the cleanliness of root canal walls and dentinal tubules after attempting to remove the calcium hydroxide dressing with different irrigant solutions and the use of nonactivated irrigation or passive ultrasonic irrigation (PUI). MethodsAfter root canal instrumentation, 80 single-rooted teeth were filled with calcium hydroxide mixed with propylene glycol and 0.1% rhodamine B dye and inserted into canals with a Lentulo spiral. The calcium hydroxide dressing was initially removed with 10 mL saline solution and reinstrumentation with the master apical file. Then, the samples were randomly assigned into 8 experimental groups (n = 10) according to the irrigant solution with or without PUI: 2.5% sodium hypochlorite, 17% ethylenediaminetetraacetic acid + 1.25% sodium lauryl ether sulfate (EDTA-T), 37% phosphoric acid, or 70% ethanol. A final flush with 5 mL saline solution was performed. The percentage of clean root canal walls and the depth of clean dentinal tubules were measured with images of confocal laser scanning microscopy. The groups were compared using the 2-way analysis of variance test with the Bonferroni post hoc test for depth analysis and the Kruskal-Wallis with Dunn post hoc test for the perimeter analysis. ResultsIrrigation with 70% ethanol presented a significantly higher percentage of clean root canal walls and a higher depth of clean dentinal tubules when compared with irrigation with 2.5% sodium hypochlorite and 17% EDTA-T for both irrigation methods (P < .05). No differences were observed between nonactivated irrigation or PUI protocols (P > .05). ConclusionsSeventy percent ethanol enhanced calcium hydroxide removal from the apical root third compared with 2.5% sodium hypochlorite or 17% EDTA-T.

Ultrasound-microwave-assisted extraction of polyphenolic compounds from Mexican "Ataulfo" mango peels: Antioxidant potential and identification by HPLC/ESI/MS.

Mango is used in traditional medicine in many countries. However, the processing by-products are not currently used and generate large pollution problems and high handling costs. To study the effect of different parameters in the extraction of polyphenolic compounds from mango peels using modern and ecological ultrasound-microwave-assisted extraction technology. Various parameters of these processes were studied: the extract was recovered by liquid chromatography using Ambetlite XAD-16. The total polyphenol content was determined by Folin-Ciocalteu's and HCl-butanol methods. Antioxidant activity was determined by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS+), 1,10-diphenyl-2-20-picrylhydrazyl (DPPH), and lipid oxidation inhibition methods. The recovered compounds were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The best extraction conditions were solid/liquid ratio of 1/5 g/mL, ethanol percentage of 50%, and an extraction time of 10 min. Under these conditions, the total polyphenol content was 54.15 mg/g, and the antioxidant activities were greater than 90% inhibition in the three assays evaluated. According to the high-performance liquid chromatography/electrospray ionization/mass spectrometry (HPLC/ESI/MS) analysis, nine polyphenolic compounds were identified; most of them were gallotannins, such as pentagalloyl glucose. Ultrasound-microwave-assisted extraction was shown to be effective and allowed the recovery of antioxidant polyphenolic compounds. The results indicated that mango peel extracts can be used as natural antioxidant components in the pharmaceutical and functional food industries.

Optimization of Extraction Conditions for Gracilaria gracilis Extracts and Their Antioxidative Stability as Part of Microfiber Food Coating Additives.

Incorporation of antioxidant agents in edible films and packages often relies in the usage of essential oils and other concentrated hydrophobic liquids, with reliable increases in antimicrobial and antioxidant activities of the overall composite, but with less desirable synthetic sources and extraction methods. Hydroethanolic extracts of commercially-available red macroalgae Gracilaria gracilis were evaluated for their antioxidant potential and phenolic content, as part of the selection of algal biomass for the enrichment of thermoplastic film coatings. The extracts were obtained through use of solid-liquid extractions, over which yield, DPPH radical reduction capacity, total phenolic content, and FRAP activity assays were measured. Solid-to-liquid ratio, extraction time, and ethanol percentages were selected as independent variables, and response surface methodology (RSM) was then used to estimate the effect of each extraction condition on the tested bioactivities. These extracts were electrospun into polypropylene films and the antioxidant activity of these coatings was measured. Similar bioactivities were measured for both 100% ethanolic and aqueous extracts, revealing high viability in the application of both for antioxidant coating purposes, though activity losses as a result of the electrospinning process were above 60% in all cases.

Experiments, Correlation, and Modeling of Curcumin Solubility in Subcritical Water (Water/Ethanol)

The solubility of curcumin in the pure water subcritical and water–ethanol solution (water + (5–10) % (v/v) ethanol) subcritical is investigated for the first time. The design approach taken from this study is the response surface methodology due to the Box Behnken. The experiments were performed in the temperature range of (90–150) °C, (0–10) volumetric percent of ethanol and the flow rate of (0.2–0.8) ml/min. As the pressure effect is ignored in the subcritical conditions, the pressure is constant in 2 MP in the experiments. All analyses were carried out employing the high-performance liquid chromatography apparatus. The curcumin solubility data were correlated with the dielectric constant of solvent mixture. Curcumin solubility modeling in subcritical conditions was done due to cubic-plus-association equation of state. The present study indicated that the rise in temperature and ethanol percentage cause an increase in curcumin solubility. Other important finding was by increasing the flow rate, curcumin solubility rate increased with a very mild slope. The optimum conditions for the curcumin solubility were in the water flow rate of 0.8 ml/min, 10% (v/v) of ethanol, and the temperature of 150 °C.

Physicochemical Properties of Mucin Extracted from &lt;i&gt;Misgurnus mizolepis&lt;/i&gt; Epidermal Mucus

The purpose of this study was to investigate the extraction yield and physicochemical characteristics of mucin from the epidermal mucus of Misgurnus mizolepis. Ninety percent ethanol produced the highest yield of mucin. At higher concentrations, mucin had more elastic properties, as revealed by dynamic viscoelasticity measurements. Differential scanning calorimetry (DSC) demonstrated that mucin is a thermostable glycoprotein. Denaturation enthalpy increased as mucin concentration increased. Mucin inhibited the growth of both Escherichia coli and Bacillus cereus, but had better antimicrobial activity in the former. Mucin also exhibited antioxidant activity, equivalent to 66.64% of that of L-cysteine. Mucin inhibited elastase activity and MMP-1 & MMP-2 expression activity, and induced hyaluronic acid expression. It is indicating that mucin is effective in moisturizing and anti-aging the skin. Thus, mucin from the epidermal mucus of Misgurnus mizolepis could have great potential as a non-food material in various industries.

Optimization of solid-liquid extraction of polar substances from pitaya peel flour

Pitaya, or dragon fruit, (Hylocereus polyrhizus) contains in its pulp and peel a high concentration of phenolic compounds, flavonoids and high antioxidant activity. The pulp is used in industries and the peel can be a source of bioactive compounds. The aim of this study was to optimize the extraction of phenolic compounds from pitaya peel flour, dried through freeze-drying. Thus, a central composite rotatable design (CCRD) was performed with two variables (X1 = ethanol percentage, of 0 – 100% as extraction solvent; X2 = extraction time, of 5 – 120 minutes assisted by ultrasound) resulting in 11 experiments. The response variables were the content of total phenolic compounds by the methods of Folin-Ciocalteau and Fast Blue BB, total flavonoids and antioxidant activity by capture of radicals 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); 2,2- diphenyl-1-picrylhydrazyl (DPPH); reduction of iron III (FRAP). It was possible to design the response surface for the analysis of total flavonoids and ABTS. The region of optimal flavonoids extraction, where the extract also demonstrated greater antioxidant activity by the ABTS method, is comprised between 13 and 57% of the ethanol as a solvent and time above 86 minutes of extraction in ultrasonic bath.

Fast and cost-effective preparation of plant cells for scanning electron microscopy (SEM) analysis

The analysis of plant cell structure provides valuable information about its morphological, physiological, and biochemical characteristics. Nowadays, scanning electron microscope (SEM) is widely used to provide high-resolution images at the surface of biological samples. However, biological specimens require preparation, including dehydration and coating with conductive materials for imaging by SEM. There are several techniques for providing images with maximum maintenance of cell structure and minimum cellular damage, but each requires the use of expensive and hazardous materials, which can be damaging to the cell in many cases. Therefore, the provision of new and effective preparation methods based on maintaining cell structure for imaging can be very practical. In the present study, a fast and cost-effective protocol was first performed for chemical fixation and preparation of the plant cells for imaging by SEM. Taxus baccata and Zhumeria majdae cells were chemically fixed using glutaraldehyde and then successfully dried with different percentages of ethanol including 70, 80, 90, and 100%. In addition, SEM was performed for imaging the cell surface in different micro-scales. This protocol can be used by plant cell biologists and biotechnologists who are interested in studying structural and biochemical responses of treated or stressed plant cells by SEM.

Effects of gasoline composition on engine performance, exhaust gases and operational costs

New technologies to improve the performance and efficiency of internal combustion engines are related to enhance knock resistance in fuels. Aromatics, Paraffins and Lead-based additives in gasoline are used to increase octane rating, but some of these are toxic, carcinogenic or expensive. Nowadays, several alternatives for octane boosting is considered and oxygenated compounds are attracting interest, as ethanol. This compound is a renewable energy source, which can reduce the oil dependence and also can be appropriately used in gasolines as a blend. Ethanol use, widely noticed in Brazil and United States, increase octane rating, thermal efficiency and engine power due to the charge cooling effect and molar expansion capacity. For the same engine and operation conditions, octane rating and engine performance are directly correlated. The present study discusses about the influence of gasoline blend composition on the engine performance by the combustion process analysis. For this, samples of gasoline blends with different RON numbers were experimentally evaluated on a single cylinder research engine in high load and speed conditions. These conditions were selected as they are potential operation points for knock occurrence. The results show that despite the increase in aromatic content of gasoline samples and consequently the improvements in octane rating and engine performance, it is not compensated by the cost. For instance, the use of gasoline blend with higher ethanol percentage, resulted in reduction of more than 23% in net power (kW) cost and up to 32% of NOx specific emission.