Showing papers on "Fusel alcohol published in 2022"

Determination of methanol and fusel oils in various types of wines distributed in Korea

Abstract: The contents of methanol and fusel oils in various types of wines were determined using headspace-gas chromatography (HS-GC). The HS-GC analysis method showed good linearity, high precision and accuracy, and low LOQ and LOD values. The methanol content in 289 types of wines ranged from not detected (ND) to 333.84 mg/kg, and was higher in Korean grape wines than in imported grape wines. Among fusel oils, the contents of 1-propanol (23.61–84.23 mg/kg) and isobutanol (34.98–111.39 mg/kg) were slightly higher in Korean wild grape wines, whereas that of isobutanol (ND to 55.26 mg/kg) was slightly lower in Korean black raspberry wine than in the other wines. The contents of amyl alcohol were lower in Korean plum wine and Korean black raspberry wine than in all of the wines included in the present study, and highest in imported grape wines.

Producing Natural Flavours from Isoamyl Alcohol and Fusel Oil by Using Immobilised Rhizopus oryzae Lipase

Abstract: Enzymatic synthesis of short-chain esters (flavours) might enable their labelling as natural, increasing their value. Covalently immobilised Rhizopus oryzae lipase (EO-proROL) was used to synthesise isoamyl butyrate and acetate. In cyclohexane, the best performer reaction solvent, 1.8 times higher yield of isoamyl butyrate (ca. 100%) than isoamyl acetate (ca. 55%) was obtained. Optimum initial acid concentration (410 mM) and acid:alcohol mole ratio (0.5) were established by a central composite rotatable design to maximise isoamyl butyrate single-batch and cumulative production with reused enzyme. These conditions were used to scale up the esterification (150 mL) and to assess yield, initial esterification rate, productivity and enzyme operational stability. Commercial isoamyl alcohol and fusel oil results were found to be similar as regards yield (91% vs. 84%), initial reaction rate (5.4 µM min–1 with both substrates), operational stability (40% activity loss after five runs with both) and productivity (31.09 vs. 28.7 mM h–1). EO-proROL specificity for the structural isomers of isoamyl alcohol was also evaluated. Thus, a successful biocatalyst and product conditions ready to be used for isoamyl ester industrial production are here proposed.

High-Level Production of Isoleucine and Fusel Alcohol by Expression of the Feedback Inhibition-Insensitive Threonine Deaminase in Saccharomyces cerevisiae

Abstract: Fruit-like flavors of isoleucine-derived volatile compounds, 2-methyl-1-butanol (2MB) and its acetate ester, contribute to a variety of the flavors and tastes of alcoholic beverages. Besides its value as aroma components in foods and cosmetics, 2MB has attracted significant attention as second-generation biofuels. ABSTRACT A variety of the yeast Saccharomyces cerevisiae with intracellular accumulation of isoleucine (Ile) would be a promising strain for developing a distinct kind of sake, a traditional Japanese alcoholic beverage, because Ile-derived volatile compounds have a great impact on the flavor and taste of fermented foods. In this study, we isolated an Ile-accumulating mutant (strain K9-I48) derived from a diploid sake yeast of S. cerevisiae by conventional mutagenesis. Strain K9-I48 carries a novel mutation in the ILV1 gene encoding the His480Tyr variant of threonine deaminase (TD). Interestingly, the TD activity of the His480Tyr variant was markedly insensitive to feedback inhibition by Ile, but was not upregulated by valine, leading to intracellular accumulation of Ile and extracellular overproduction of 2-methyl-1-butanol, a fusel alcohol derived from Ile, in yeast cells. The present study demonstrated for the first time that the conserved histidine residue located in a linker region between two regulatory domains is involved in allosteric regulation of TD. Moreover, sake brewed with strain K9-I48 contained 2 to 3 times more 2-methyl-1-butanol and 2-methylbutyl acetate than sake brewed with the parent strain. These findings are valuable for the engineering of TD to increase the productivity of Ile and its derived fusel alcohols. IMPORTANCE Fruit-like flavors of isoleucine-derived volatile compounds, 2-methyl-1-butanol (2MB) and its acetate ester, contribute to a variety of the flavors and tastes of alcoholic beverages. Besides its value as aroma components in foods and cosmetics, 2MB has attracted significant attention as second-generation biofuels. Threonine deaminase (TD) catalyzes the first step in isoleucine biosynthesis and its activity is subject to feedback inhibition by isoleucine. Here, we isolated an isoleucine-accumulating sake yeast mutant and identified a mutant gene encoding a novel variant of TD. The variant TD exhibited much less sensitivity to isoleucine, leading to higher production of 2MB as well as isoleucine than the wild-type TD. Furthermore, sake brewed with a mutant yeast expressing the variant TD contained more 2MB and its acetate ester than that brewed with the parent strain. These findings will contribute to the development of superior industrial yeast strains for high-level production of isoleucine and its related fusel alcohols.

The assessment of fusel oil in a compression-ignition engine in the perspective of the waste to energy concept: investigation of the performance, emissions, and combustion characteristics

Abstract: Abstract Fusel oil can be obtained from all agricultural products containing sugar, as well as from starchy products such as corn and potatoes, and from cellulosic products such as sulfite liquor, which is a wood and paper mill residue. Fusel oil is produced as a waste product during the production of bioethyl alcohol or biomethyl alcohol from sugar beet pulp remaining during sugar production in Turkey. In this study, alternative fuel blends prepared by infusing 5, 10, 15, and 20% of fusel oil to diesel (DF) by volume were tested in a single-cylinder, diesel engine at 1500 rpm and different loads, and thus, engine performance, pollutant emissions, and combustion characteristics were determined and compared with reference diesel. As a result, since fusel oil has lower calorific values than diesel, alcohol fuel blends caused a decrease in brake thermal efficiency (BTE) and an increase in brake specific fuel consumption (BSFC). It was observed that carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOX), and smoke emissions decreased significantly with addition of FUSEL oil to diesel while carbon dioxide (CO2) and oxygen (O2) emissions, which are an indicator of complete combustion, increased. This occurred since oxygen molecules in chemical structure of fusel oil improved emissions. Concerning combustion characteristics, it was observed that addition of fusel oil to baseline diesel generally increased in figures of in-cylinder pressure and net heat release rate. Moreover, it was determined that alcohol fuel blends generally increased ignition delay time compared to diesel due to their low cetane numbers. When all experimental results are evaluated, it can be said that fusel oil additive significantly reduces exhaust emissions without considerably affecting combustion and performance characteristics.

Improved Catalytic Performance of Lipase Eversa® Transform 2.0 via Immobilization for the Sustainable Production of Flavor Esters—Adsorption Process and Environmental Assessment Studies

Abstract: The aim of this study was to produce several flavor esters via esterification of octanoic acid with different commercial short-chain alcohols (methanol, propanol, isoamyl alcohol, hexanol and benzyl alcohol) and fusel oil in solvent-free systems. Lipase Eversa® Transform 2.0 immobilized via mechanism of interfacial activation on poly(styrenene-divinylbenzene) (PSty-DVB) beads was used as heterogeneous biocatalyst and its catalytic performance was compared with that of the soluble lipase. The heterogeneous biocatalyst was prepared by employing 5 mmol.L−1 buffer sodium acetate at pH 5.0 and 25 °C using an initial protein loading of 40 mg·g−1. The maximum amount of immobilized protein reached was 31 mg·g−1, corresponding to an immobilization yield of 80%. Mass transfer studies demonstrated that the lipase was preferentially adsorbed inside the pores of the support, which was confirmed by scanning electron microscopy analysis. Lipase immobilization can be described by a pseudo-first-order kinetic model via a physisorption process. When used as biocatalysts of the target reactions, the highest conversion percentage (between 65 and 85% of acid conversion after 60–90 min of reaction) values were achieved for esterification reactions catalyzed by immobilized lipase. Reusability tests revealed high retention of the original activity of the immobilized lipase after six successive batch reactions using isoamyl alcohol (47%) and fusel oil (72%). The proposed reaction systems can be considered green processes (EcoScale score above 80), with exception of methanol medium, classified as an acceptable green process (EcoScale score of 68). These results show that the heterogeneous biocatalyst prepared can be an economic and sustainable option for flavor esters production on an industrial scale.

Operating Range, Performance and Emissions of an HCCI Engine Fueled with Fusel Oil/Diethyl Ether: An Experimental Study

Abstract: The main disadvantages of HCCI engines are the knocking tendency at high engine loads, the challenge of the start of the combustion, control of the combustion phase, and the narrow operating range. In this study, we aimed to control the combustion processes in HCCI engines and to expand their working range by improving the fuel properties of fusel oil by the addition of diethyl ether. Thus, the variations in the in-cylinder pressure, rate of heat release, indicated mean effective pressure, start of combustion, combustion duration, CA50, indicated thermal efficiency, mean pressure rise rate, hydrocarbon and carbon monoxide emissions were investigated. It was observed that the in-cylinder pressure and rate of heat release were taken into advance and the test engine could be operated for a wider range by increasing the diethyl ether ratio in the blend. The indicated mean effective pressure increased by 67.5% with DEE40 fuel compared to the DEE80. Under the same operating conditions, HC and CO emissions decreased by 41.6% and 56.2%, in use of DEE40. Furthermore, the highest indicated thermal efficiency was obtained as 42.5% with DEE60 fuel. Maximum hydrocarbon and carbon monoxide emissions were observed with DEE80 fuel as 0.532% and 549 ppm, respectively.

Study on the drunkenness of Chinese Baijiu with representative flavor based on behavioral characteristics

Abstract: The essential role of drunkenness on the healthy development of Chinese Baijiu was studied in this research. This study revealed the effects of Baijiu on the behaviors of mice and evaluated the degree of drunkenness of soy sauce-, strong-, light-, and light and soy sauce-flavored Baijiu. The parameters obtained from the open field test were transformed into the behavioral drunkenness index by mathematical statistical analysis and the drunkenness-associated key compounds of Baijiu were analyzed. The results showed that strong- and light-flavored Baijiu presented higher levels of drunkenness and sobriety than soy sauce-flavored Baijiu. Interestingly, light and soy sauce-flavored Baijiu showed low drunkenness but a high sobriety degree. Specifically, the degree of drunkenness was positively correlated with fusel alcohol and aldehydes but negatively correlated with esters and acids. This study will enrich references for Baijiu behavior studies and lay a foundation for the research and development of healthy Baijiu. Graphical Abstract There are key drunkenness compounds in Baijiu that can induce or reduce the degree of drunkenness, which lead to the differences in behavioral characteristics of mice after drinking Baijiu.

Experimental investigation on combustion behaviour, performance and emission of fusel oil-gasoline blends using turbocharged SI engine

Abstract: Because of rising energy demand and pollution concerns in the transportation and industrial sectors, alternative fuel development is critical. The fusel oil, which is a by-product of ethanol distillation molasses, is receiving a lot of interest. The combustion characteristics, performance, and emissions of a 1.8L turbocharged four-cylinder, port injection, spark-ignition engine will be used to compare fusel oil blends with gasoline in this study. The experiment was carried out at a constant engine speed of 2000 rpm with a throttle load of 10-40%. Four samples with various ratios of gasoline combined with fusel oil were tested (100% gasoline, 10%, 20%, and 30% are referred to as F0, F10, F20, and F30 respectively). As a result, compared to gasoline, fusel oil blends increase Brake Specific Fuel Consumption (BSFC) by 5-22%. In comparison to gasoline, the combustion behaviour of in-cylinder pressure, Rate of Heat Release (ROHR), Rate Of Pressure Rise (ROPR), and Mass Fraction Burn (MFB) shows an early 2-3 Degree Crank Angle (CAD). Due to differences in attributes and oxygen content, the Brake Thermal Efficiency (BTE) of combustion utilising fusel oil blends suffers a modest drop of 13-16%. When compared to gasoline, fusel oil blends emit 3-4% less hydrocarbon (HC), 7.5-24.5% less carbon monoxide (CO), and 18-36% less nitrogen oxide (NOx). To summarise, fusel oil blends without water extraction blended with gasoline have a substantial impact on turbocharger engine functioning.

Utilization of additive from waste products with gasoline fuel to operate spark ignition engine

Abstract: Impacts of blending fusel oil with gasoline on fuel combustion have been investigated experimentally in the current research to evaluate engine performance improvement and exhaust emission. Tested fuel include F10, F20 (10% and 20% of fusel oil by volume) and pure gasoline as baseline fuel have been used to operate 4-cylinder SI engine at increasing engine speed and constant throttle valve of 45%. The present results reveal a shorter combustion duration and better engine performance with F10 over engine speeds with maximum value of 33.9% for the engine brake thermal efficiency. The lowest BSFC of 251 g/kW h was recorded at 3500 rpm engine speed also with F10. All blended fuel have almost similar COVIMEP. Less NOx emission was measured with F10 at 4500 engine speed compared to gasoline. However, CO emissions reduced while higher CO2 was observed with introducing fusel oil in the blend. Moreover, HC emission increased an average by 11% over speed range and the highest value was achieved with 10% fusel oil addition compared to 20% and pure gasoline. Accordingly, higher oxygen content of fusel oil and octane number contribute to improve combustion of fuel mixture.

Monitoring of organic volatile compounds in craft beers during fermentative process

Abstract: The present study aimed to evaluate the formation of volatile organic compounds (VOCs) during the fermentation process of three different craft beers, using gas chromatography with headspace sampling. The production of VOCs, which are largely responsible for the flavors of the drink, makes up unique organoleptic characteristics for each beer. In this work, it was possible to observe the different profiles for the Pilsen, Witbier and IPA style beers, when quantifying the analytes methanol, ethanol, n-propanol, iso-butanol, 3-methyl-1-butanol (iso-amyl alcohol), acetaldehyde, ethyl acetate and iso-amyl acetate. Pilsen beer, with low fermentation, presented the ethanol content in the same concentration range as Witbier beer, as expected, but with higher alcohols and lower esters than the other two. Witbier and IPA beers, both of high fermentation, presented isoamyl alcohol concentration above expectations, while IPA beer, present higher concentrations of n-propanol, ethyl acetate and isoamyl acetate in relation to Pilsen and Witibier, which is related to the complexity of its recipe.

Maximizing net fuel economy improvement from fusel alcohol blends in gasoline using multivariate optimization

Abstract: Fusel alcohol mixtures containing ethanol, isobutanol, isopentanol, and 2-phenylethanol have been shown to be a promising means to maximize renewable fuel yield from various biomass feedstocks and waste streams. We hypothesized that use of these fusel alcohol mixtures as a blending agent with gasoline can significantly lower the greenhouse gas emissions from the light-duty fleet. Since the composition of fusel alcohol mixtures derived from fermentation is dependent on a variety of factors such as biocatalyst selection and feedstock composition, multi-objective optimization was performed to identify optimal fusel alcohol blends in gasoline that simultaneously maximize thermodynamic efficiency gain and energy density. Pareto front analysis combined with fuel property predictions and a Merit Score-based metric led to prediction of optimal fusel alcohol-gasoline blends over a range of blending volumes. The optimal fusel blends were analyzed based on a Net Fuel Economy Improvement Potential metric for volumetric blending in a gasoline base fuel. The results demonstrate that various fusel alcohol blends provide the ability to maximize efficiency improvement while minimizing increases to blending vapor pressure and decreases to energy density compared to an ethanol-only bioblendstock. Fusel blends exhibit predicted Net Fuel Economy Improvement Potential comparable to neat ethanol when blended with gasoline in all scenarios, with increased improvement over ethanol at moderate to high bio-blendstock blending levels. The optimal fusel blend that was identified was a mixture of 90% v/v isobutanol and 10% v/v 2-phenylethanol, blended at 45% v/v with gasoline, yielding a predicted 4.67% increase in Net Fuel Economy Improvement Potential. These findings suggest that incorporation of fusel alcohols as a gasoline bioblendstock can improve both fuel performance and the net fuel yield of the bioethanol industry.

Quantitative assay for farnesol and the aromatic fusel alcohols from the fungus Candida albicans

Abstract: The dimorphic fungus Candida albicans is a commensal and opportunistic fungal pathogen of humans. It secretes at least four small lipophilic molecules, farnesol and three aromatic fusel alcohols. Farnesol has been identified as both a quorum sensing molecule (QSM) and a virulence factor. Our gas chromatography (GC)-based assay for these molecules exhibits high throughput, prevention of analyte loss by avoiding filtration and rotary evaporation, simultaneous cell lysis and analyte extraction by ethyl acetate, and the ability to compare whole cultures with their cell pellets and supernatants. Farnesol synthesis and secretion were separable phenomena and pellet:supernatant ratios for farnesol were high, up to 12:1. The assay was validated in terms of precision, specificity, ruggedness, accuracy, solution stability, detection limits (DL), quantitation limits (QL), and dynamic range. The DL for farnesol was 0.02 ng/µl (0.09 µM). Measurement quality was assessed by the relative error of the whole culture versus the sum of pellet and supernatant fractions (WPS). C. albicans strain SC5314 grown at 30 °C in complex and defined media (YPD and mRPMI) was assayed in biological triplicate 17 times over 3 days. Farnesol and the three aromatic fusel alcohols can be measured in the same assay. The levels of all four are greatly altered by the growth medium chosen. Significantly, the three fusel alcohols are synthesized during stationary phase, not during growth. They are secreted quickly without being retained in the cell pellet and may accumulate up to mM concentrations. KEY POINTS: • Quantitative analysis of both intra- and extracellular farnesol, and aromatic fusel oils. • High throughput, whole culture assay with simultaneous lysis and extraction. • Farnesol secretion and synthesis are distinct and separate events.

The Consumption of Amino Acids and Production of Volatile Aroma Compounds by Yarrowia lipolytica in Brewers’ Wort

Abstract: The yeast Yarrowia lipolytica is well known for its versatile production of metabolites from various substrates, but, although isolated from, e.g., wild-fermented Belgian Sour beers, it is rarely considered a starter culture in fermented beverages. In this study, we aimed to elucidate the ability of Y. lipolytica to ferment brewers’ wort containing iso-α-acid for 7 days at low and high aeration and at 20 °C and 30 °C, with a special focus on amino acid consumption and production of volatile aroma compounds. Y. lipolytica was able to grow in the wort under all four conditions, although the growth was inhibited. Furthermore, it only consumed glucose and fructose, and no ethanol was formed. Moreover, under high aeration conditions, Y. lipolytica consumed 75–80% of the amino acids in the wort. Interestingly, no esters were produced during the fermentations, and only five higher alcohols (1-propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, 3-methyl-3-buten-1-ol, and 2-phenylethanol), two aldehydes (3-methylbutanal and (E)-2-nonenal), two ketones (cyclopentanone and 9-oxabicyclo [6.1.0]nonan-4-one), one fatty acid (3-methyl-butanoic acid), and one benzene derivate (1,2,4-trimethyl-benzene) were produced. These results may contribute to the potential use of Y. lipolytica in a traditional brewery for the production of novel beers; e.g., alcohol-free beer.

Improvement of Fusel Alcohol Production by Engineering of the Yeast Branched-Chain Amino Acid Aminotransaminase

Abstract: Recently, several studies have attempted to increase the production of branched-chain higher alcohols (BCHAs) in the yeast Saccharomyces cerevisiae. The key enzymes for BCHA biosynthesis in S. cerevisiae are the branched-chain amino acid aminotransaminases (BCATs) Bat1 and Bat2. ABSTRACT Branched-chain higher alcohols (BCHAs), or fusel alcohols, including isobutanol, isoamyl alcohol, and active amyl alcohol, are useful compounds in several industries. The yeast Saccharomyces cerevisiae can synthesize these compounds via the metabolic pathways of branched-chain amino acids (BCAAs). Branched-chain amino acid aminotransaminases (BCATs) are the key enzymes for BCHA production via the Ehrlich pathway of BCAAs. BCATs catalyze a bidirectional transamination reaction between branched-chain α-keto acids (BCKAs) and BCAAs. In S. cerevisiae, there are two BCAT isoforms, Bat1 and Bat2, which are encoded by the genes BAT1 and BAT2. Although many studies have shown the effects of deletion or overexpression of BAT1 and BAT2 on BCHA production, there have been no reports on the enhancement of BCHA production by functional variants of BCATs. Here, to improve BCHA productivity, we designed variants of Bat1 and Bat2 with altered enzyme activity by using in silico computational analysis: the Gly333Ser and Gly333Trp Bat1 and corresponding Gly316Ser and Gly316Trp Bat2 variants, respectively. When expressed in S. cerevisiae cells, most of these variants caused a growth defect in minimal medium. Interestingly, the Gly333Trp Bat1 and Gly316Ser Bat2 variants achieved 18.7-fold and 17.4-fold increases in isobutanol above that for the wild-type enzyme, respectively. The enzyme assay revealed that the catalytic activities of all four BCAT variants were lower than that of the wild-type enzyme. Our results indicate that the decreased BCAT activity enhanced BCHA production by reducing BCAA biosynthesis, which occurs via a pathway that directly competes with BCHA production. IMPORTANCE Recently, several studies have attempted to increase the production of branched-chain higher alcohols (BCHAs) in the yeast Saccharomyces cerevisiae. The key enzymes for BCHA biosynthesis in S. cerevisiae are the branched-chain amino acid aminotransaminases (BCATs) Bat1 and Bat2. Deletion or overexpression of the genes encoding BCATs has an impact on the production of BCHAs; however, amino acid substitution variants of Bat1 and Bat2 that could affect enzymatic properties—and ultimately BCHA productivity—have not been fully studied. By using in silico analysis, we designed variants of Bat1 and Bat2 and expressed them in yeast cells. We found that the engineered BCATs decreased catalytic activities and increased BCHA production. Our approach provides new insight into the functions of BCATs and will be useful in the future construction of enzymes optimized for high-level production of BCHAs.

Exergy analysis of fusel oil as an alternative fuel additive for spark ignition engines

Abstract: Abstract The present study conducted performance and exhaust emission tests of fuel blends prepared using gasoline and waste fusel oil at full load and different engine speeds in a spark-ignition engine. Additionally, energy, exergy, and exergoeconomic analyses were carried out using engine performance and exhaust emission values. In engine tests, the highest brake specific fuel consumption obtained was 433.12 g/kWh in F50 fuel at an engine speed of 3500 rpm. The brake specific fuel consumption of G100 fuel was 364.46 g/kWh at the same engine speed. Adding waste fusel oil into fuel blends was observed to reduce carbon monoxide, unburned hydrocarbon , and nitrogen oxide emissions. According to the thermodynamic analysis results, an increase in the ratio of fusel oil in fuel blends reduces thermal efficiency and exergy efficiency. The ratio of fusel oil in fuel blends positively affects exergy destruction. The lowest exergy destruction was calculated as 16.47 kW in F50 fuel at an engine speed of 1500 rpm. As the fusel oil ratio in fuel blends increases, the unit cost of exergy of useful work of the fuel blends decreases. The lowest cost is 6.195 $/GJ at 1500 rpm in F50 fuel. The low pump price of waste fusel oil indicates its advantages over gasoline in exergoeconomic analysis results.

Optimization of SI Engine Performance Operating with Low Octane Gasoline and Fuel Additives from Waste

Abstract: Fuel additives from waste have been suggested to enhance low octane commercial gasoline in this study. Four samples were prepared in addition to pure commercial gasoline and denoted as GF0, GF4, GF8, GF12, and GF 16 which refer to fusel oil addition ratio of 0%, 4%, 8%, 12, and 16% respectively. Engine speed was controlled and increased manually from 1000 rpm to 3000 rpm at an increment of 500 rpm. Design of experiments is used to indicate the optimum additive dosage through response surface method optimization. Obtained results show that increasing engine speed significantly impacts the engine brake power, brake-specific fuel consumption, and brake thermal efficiency with a slight change for fusel oil ratio. Accordingly, it can be concluded that the maximum increase in output variables is statistically linked with the engine speed. The output response values at optimized conditions were 2.61812 kW brake power, 0.2431 kg/kW.hr brake-specific fuel consumption, and 36.5303% brake thermal efficiency. Based on the P-value, ANOVA data indicate that engine speed was a significant factor influencing output responses, while the fusel oil ratio was insignificant. However, fusel oil ratio of 8% has a significant effect on the brake thermal efficiency and BSFC.

Substantiation of the choice of the feed stage of the rectification column when obtaining food ethyl alcohol by the method of mathematical modeling

Abstract: Проведены численные исследования работы ректификационной колонны по определению тарелки питания эпюрата методом математического моделирования в среде сложных химико-технологических систем Hysys. Расчет осуществляли по действительным тарелкам с эффективностью работы 0,5. Работа колонны организована следующим образом: головная фракция отбирается сверху колонны из конденсатора в виде непастеризованного спирта, сивушный спирт – из жидкой фазы с тарелки, расположенной выше тарелки питания, сивушное масло отбирается из паровой фазы с тарелки, расположенной ниже тарелки питания; лютер выводится снизу ректификационной колонны из ребойлера. Летучие примеси в эпюрате были представлены ацетальдегидом, 2.3-бутиленгликолем, этилацетатом, метанолом, 2-пропанолом, 2-бутанолом, 1-пропанолом, изобутанолом, 1-бутанолом, изоамилолом, 1-гексанолом, уксусной кислотой, этанолом и водой. Вычисление коэффициентов активности компонентов проведено по модели UNIQUAC. Технические параметры режима работы колонны и концентрации основных летучих примесей в эпюрате взяты при обследовании действующей брагоректификационной установки. Получены и проанализированы графические зависимости распределения примесей, этанола, выхода спирта и крепости спирта-ректификата при изменении тарелки питания, а также концентрации этанола в лютере от числа тарелок в колонне (от 60 до 100) для двух вариантов: при подаче эпюрата на 16-ю тарелку колонны и на тарелку, номер которой вычислен пропорционально увеличению или уменьшению числа тарелок в колонне от исходного, равного 80. Рассчитан профиль изменения концентрации этанола по высоте колонны при его концентрации в эпюрате 20, 30, 40 и 60% об. при подаче питания на 16-ю тарелку колонны. Показано, что 16-я тарелка питания является оптимальной при переработке эпюрата различной крепости с целью получения ректификованного спирта, очищенного от легколетучих и труднолетучих примесей с соблюдением показателей экологической безопасности к лютеру, сбрасываемому в канализацию. Рассчитан профиль изменения концентрации этанола по высоте колонны при его концентрации в эпюрате 20, 30, 40 и 60% об. при подаче питания на 16-ю тарелку колонны. Numerical studies of the operation of a distillation column to determine the feed stage of the epurate were carried out by the method of mathematical modeling in the environment of complex chemical-technological systems Hysys. The calculation was implemented on real plates with an efficiency of 0,5. The operation of the column is organized as follows: the head fraction is taken from the top of the column from the condenser in the form of unpasteurized alcohol, fusel alcohol is taken from the liquid phase from a stage located above the feed stage, and fusel oil is taken from the vapor phase from a stage located below the feed plate, luther is removed bottom of the distillation column from the reboiler. Volatile impurities in the epurate are represented by the following components: acetaldehyde, 2.3-butylene glycol, ethyl acetate, methanol, 2-propanol, 2-butanol, 1-propanol, isobutanol, 1-butanol, isoamylol, 1-hexanol, acetic acid, ethanol, and water. The calculation of the activity coefficients of the components was carried out according to the UNIQUAC model. The technical parameters of mode of operation of the column and the concentration of the main volatile impurities are taken during the examination of the operating distillation plant. The graphic dependences of the distribution of impurities, ethanol, alcohol yield and strength of rectified alcohol with a change in the feed stage, as well as the concentration of ethanol in luther on the number of stages in the column (from 60 to 100) are obtained and analyzed for two options: when feeding the epurate to the 16th stage of the column and to the stage, the number of which is calculated in proportion to the increase or decrease of the number of stages in the column from the original, equal to 80. The profile of the change in the concentration of ethanol along the height of the column at its concentration in the epuret of 20, 30, 40 and 60% vol. when feeding to the 16th stage of the column is calculated. It is shown that feed stage 16 is optimal for processing epuret of various strengths in order to obtain rectified alcohol, purified from volatile and non-volatile impurities in compliance with environmental safety indicators for luther discharged into the sewer.

Educational/Professional Partnership in the Development of a Novel Strain of S‐11 Saccharomyces cerevisiae Brewing Yeast

Abstract: Craft beers have revolutionized the beer industry. In 2018, the craft beer market made up 20% of the sales of beer in the United States, totaling over 26 billion dollars and experiencing significant growth during a period when many traditional breweries are reporting losses or shrinkage in their market values (Gaille, 2019). Survival in an increasingly competitive market is reliant on the ability to develop novel products that match the ever‐evolving tastes of consumers. I worked with the Three Roads Brewing Company of Farmville and Lynchburg, Virginia to meet this goal using molecular biology. My institution has a preexisting relationship with Three Roads Brewery, as my research advisor has been doing similar but less intensive projects to teach students about the fundamentals of genetic engineering. The Brewmaster uses a strain of baker’s yeast (Saccharomyces cerevisiae) called S‐11 to generate a French Saison beer, a highly carbonated pale ale. My research worked to modify the S‐11 strain to generate a French Saison beer that lacks fusel alcohols while still maintaining the complex flavor profile of the rest of the beer. Because fusel alcohols are “key contributors to the intoxicating effect [of alcohol products],” this request is very common in the brewing community (Xie 2018). By removing these fusel alcohols, the Brewmaster will have a product that he feels will be more enjoyable for his consumers to drink. During the fermentation process, fusel alcohols are produced through a process called the Ehrlich pathway, which is normally responsible for the catabolism of amino acids. There is a key divergence point within the Ehrlich pathway that is especially relevant to brewers during which the fusel aldehyde is either oxidized into a fusel alcohol or reduced into a fusel acid (Hazelwood, 2008). Using molecular genetics to disrupt key genes in this pathway, I eliminated relevant proteins, including ADH1, ADH2, ADH3, ADH4, ADH6, and AAD4 in this process to force reduction as opposed to oxidation, and thereby decrease the production of fusel alcohols. Two strains, S11‐ΔAAD4 and S11‐ΔADH4 produced fewer in fusel alcohols, a 104% and 87% decrease respectively. The Southside region of Virginia in which the brewery is located is one of the most historically disenfranchised regions of the state, and by generating a strain of yeast that better satisfies the needs of local businesses, my lab was able to make a tangible impact in the support of the long‐term high‐paying jobs generated by local businesses such as Three Roads Brewing Company.

Utilization of fusel oil as a fuel for gasoline engine, a review

Abstract: The essential issues facing the world are climate change, global warning, energy price, and energy supply crisis. The main responsible for these problems is the petroleum based energy supplement. Carbon dioxide amount increased in environment and the need to higher energy through alternative fuels are becoming important. This should meet through the increase of the sources of renewable and clean energy with limited fuel supplies. Many researchers are studies alcohol as alternative fuels. Fusel oil is produced from fermentation process with higher alcohol content as a byproduct. In spark ignition engine, potential usage of fusel oil is took care as a renewable fuel during the last decades. In the present study, the objective is to survey the impacts of fusel oil-gasoline mixture on the performance (break torque, break power, brake specific fuel consumption, efficiency, & effective) and also characteristics of combustion and emissions (CO, HC hydrocarbons, NOx)) of SI engine. The conducted literature survey finding from this study reveal that torque, thermal efficiency, and engine power have slightly improved and specific fuel consumption increased when using fusel oil fuel. Emissions of CO & HC were increased with a reduction in the nitrogen oxide NOx and knocking. Accordingly, fusel oil may be used as a fuel with high efficiency in SI engine.