Normal Butanol Additive in Methanol-Gasoline Blends Fired in a Spark Ignition Single Cylinder Engine : Effects on Combustion and Emission Characteristics

The effect of firing n-butanol additives in methanol-gasoline blends is compared with that of methanol-gasoline blends of total alcohol volume of 10 to 90 % in gasoline fuel (GF). The comparison was based on combustion and regulated remission characteristics. Tests were carried out on a BASF octane rating engine. Higher volatility and lower energy content of methanol-gasoline blends used were improved by the addition of n-butanol to the blends. Additives of n-butanol was recommended for the shortening combustion duration; reducing engine-out oxygen a benefit for downsizing the intake manifold and raising the heating value of fuel mixture.Добавление дозированной спиртовой добавки, которая используется в стандартных бензиновых топливах, ограничивается в связи с пониженной энергией (теплотой сгорания) спирта, однако энергия топлива возрастает при использовании в метанол-бензиновой смеси, помимо имеющейся, другой спиртовой добавки — н-бутанола. При этом благодаря пониженной летучести н-бутанола ослабляются проблемы с топливной системой двигателя, обусловленные повышенной летучестью метанол-бензиновых смесей. Цель работы состояла в определении преимуществ использования двойных спиртовых смесей с бензином (DAG) по сравнению с односпиртовыми смесями (SAG). Содержание спиртов в смеси превышало 30 % (об.). Воздействие горючих спиртовых добавок н-бутанола к метанол-бензиновым смесям (DAG) сравнивается с таковым при использовании метанол-бензиновых смесей (SAG) для случаев содержания спиртов от 10 до 90 % (об.) в бензиновом топливе. Сравнение основывалось на характеристиках горения по степени приближения к регламентируемым показателям вредных выбросов: NOx, CO, UHC (несгоревшие углеводороды). Испытания проводились на двигателе фирмы BASF с пересчетом мощности (по октану). Установлено, что выбросы UHC сокращались в большей степени при работе с SAG, чем при использовании DAG. Повышение доли спирта в бензиновом топливе сопровождается незначительным уменьшением выбросов NOx. При этом выбросы UHC для смесей минимальны, когда содержание NOx максимально, и наоборот. Установлено, что рост NOx ® (NOx)max при высоких температурах сопровождается минимизацией выбросов СО и UHC. Рекомендуется добавление н-бутанола для сокращения продолжительности горения и снижения содержания кислорода на выходе из двигателя как основа сокращения габаритов впускного (всасывающего) трубопровода и повышения теплоты сгорания топливной смеси.Додавання нормального бутанола до метанол-бензиновым сумішей, що спалюються в одноциліндровому двигуні з іскровим запаленням : Вплив на характеристики горіння та утворення шкідливих речовин Додавання дозованої спиртової домішки, яка використовується у стандартних бензинових паливах, обмежується у зв’язку зі зниженою енергією (теплотою згоряння) спирту, проте енергія палива зростає при використанні у метанол-бензиновій суміші, окрім тієї, що є, іншої спиртової домішки — н-бутанола. При цьому завдяки зниженій летючості н-бутанола ослаблюються проблеми з паливною системою двигуна, зумовлені підвищеною летючістю метанол-бензинових сумішей. Мета роботи полягала у визначенні переваг використання подвійних спиртових сумішей з бензином (DAG) у порівнянні з односпиртовими сумішами (SAG). Вміст спиртів у суміші перевищував 30 % (об.). Дія горючих спиртових домішок н-бутанола до метанол-бензинових сумішей (DAG) порівнюється з такою при використанні метанол-бензинових сумішей (SAG) для випадків вмісту спиртів від 10 до 90 % (об.) у бензиновому паливі. Порівняння грунтувалося на характеристиках горіння за мірою наближення до регламентованих показників шкідливих викидів: NOx, CO, UHC (незгорілі вуглеводні). Випробування проводилися на двигуні фірми BASF з перерахунком потужності (за октаном). Встановлено, що викиди UHC скорочувалися більшою мірою при роботі з SAG, ніж при використанні DAG. Підвищення долі спирту у бензиновому паливі су-проводжується незначним зменшенням викидів NOx. При цьому викиди UHC для сумішей мінімальні, коли вміст NOx максимальний, та навпаки. Встановлено, що зростання NOx → (NOx)max при високих температурах супроводжується мінімізацією викидів СО та UHC. Рекомендовано додавання н-бутанола для скорочення тривалості горіння та зниження вмісту кисню на виході з двигуна як основа скорочення габаритів впускного (всмоктуючого) трубопроводу та підвищення теплоти згоряння паливної суміші

Effects of injection timing of diesel fuel on performance and emission of dual fuel diesel engine powered by diesel/E85 fuels

The paper presents the results of the investigation of Dual Fuel (DF) diesel engines powered by high bioethanol contain fuel – E85. The object of the investigation is a three-cylinder Compression Ignition (CI) Internal Combustion Engine (ICE) powered by diesel oil and bioethanol fuel E85 injected into the intake port as a DF engine. With the increase in the share of E85 fuel the highest intensification of the combustion process takes place in the main stage of the combustion and the ignition delay increases as well. The researchers are conducted using Computational Fluid Dynamics (CFD) method; the results of the investigation are successfully verified based on the indicator diagrams, heat performance rate and emissions. Based on CFD results the cross sections investigation of the combustion chamber it can be seen that in case of the DF engine, the flame front propagates with a higher speed. The initial phase of the combustion starts in a different location of the combustion chamber than in the classic CI engine. Replacement of diesel fuel by E85 in 20% resulted in the shortening of the combustion duration more than 2-times. With the increase of energetic share in E85 the soot emission is decreased at all ranges of the analysed operations of the engine. The oppositerelationship was observed in case of NO emission. With the increase of E85 in the fuel, the emission of NO increased

Combustion and Emission Characteristics of Blends: -n-Butanol- Diesel (D2); and Dual Alcohols: n-Butanol-Methanol with Gasoline in Internal Combustion Engines

A study of the effects of oxygenated alcohol/gasoline/diesel fuel blends on performance, combustion, and emission characteristics in conventional reciprocating engines is reported. On the one hand, in alcohol-gasoline blends, dual alcohols-gasoline blends have not yet been sufficiently proven as suitable alternatives to single alcohol-gasoline blends in engines as far as performance is concerned. On the other hand, n-butanol-diesel, although it has a better miscibility factor in diesel than methanol or ethanol, is limited with regard to extensive application in the diesel engines due to its low cetane number. Engine performance was compared using single alcohol-gasoline and dual alcohol-gasoline blends, where the dual blends were constrained to meet the vapor issues regarding fuels and regulations. The blends were selected in terms of a combination by volume of one being higher alcohol (n-butanol) and the other, lower alcohol (methanol). The engines used for this study included a single-cylinder and a four-cylinder, naturally aspirated, four-stroke spark ignition engines and a four-cylinder, four-stroke compression ignition turbocharged diesel engine. In the n-butanol-diesel studies, a comparison was made with other studies in order to determine how suitable n-butanol-diesel blends were across the biofuel family such as the biodiesel-ethanol-diesel blends. The findings were as follows: The dual alcohols-gasoline blends performed better than the single alcohol-gasoline blends depending on certain compositional ratios of the alcohols in gasoline regardless of vapor pressure consideration. The n-butanol/diesel alcohol blend (B5, B10, and B20, where B5 represents 5% n-butanol and 95% diesel) significantly reduced the regulated emissions in a turbocharged engine compared to other studies using biodiesel-diesel blends. The significant decrease in NOx, CO emissions, and reduction of unburned hydrocarbons content using n-butanol/diesel fuel (DF) blends were found experimentally. The use of dual alcohol /gasoline blends was beneficial due to their shorter combustion duration in crank angles and their higher-energy content compared with single alcohol-gasoline blends. The n-butanol/diesel blend fired in the diesel engine showed a higher brake thermal efficiency and improved brake specific fuel consumption compared to the study by others where ethanoldiesel and methanoldiesel blends were used

n-Butanol-Diesel (D2) Blend Fired in a Turbo-Charged Compression Ignition Engine: Performance and Combustion Characteristics

The use of biofuels that include n-butanol in diesel fuel (DF) is attracting attention in the search for the reduction of emissions into the environment due to the burning of fossil fuel. The performance and combustion characteristics were evaluated in this study using blends B5, B10, and B20 (B5: 5% n-butanol and 95% DF) in a turbo-charged direct injection compression ignition engine. In the n-butanol diesel studies, a comparison was made with other studies that also included biodiesel in order to determine how suitable n-butanol-diesel blends were to use in internal combustion engines. Combustion characteristics of B20 (n-butanol 20% and 80% DF) improved when the study was compared with a similar study that included 40% biodiesel added to B20. A higher value of the standard deviation for DF than the blends was observed from the standard deviation diagram, indicating a more stable combustion process for the blends than DF. Soot reduction relative to DF at 1500 rpm at 75% load for B05, B10, and B20 mixtures was 55.5, 77.8, and 85.1%, respectively. This reduction is a significant advantage of blending DF with smaller shared volumes of bioalcohol

Impact of Antioxidant Additives on the Engine Performance and Exhaust Emissions Using Biodiesel made from Jatropha Oil of Eastern Africa Origin

This research article published by the Journal of the South African Institution of Mechanical Engineering, 2016Biodiesel’s chemical nature makes it more susceptible to oxidation in comparison to mineral diesel. Biodiesels are doped with antioxidants to increase oxidation stability for long term storage. However, it is quite possible that these additives may affect fuel related properties of biodiesel such as cetane number and kinematic viscosity and also the performance of engine and exhaust emissions. Therefore, this study investigated the effects of antioxidant on the oxidation stability, cetane number and kinetic viscosity of biodiesel made from jatropha oil of Eastern Africa origin. Also, the influence on the performance and exhaust emissions of a four cylinder turbocharged direct injection (TDI) diesel engine. Antioxidant 1, 2, 3 trihydroxy benzene (Pyrogallol, PY), as the most effective antioxidant based on the earlier work of the authors was mixed with the produced Jatropha Oil Methyl Ester (JOME) at different concentrations to improve the oxidation stability. The results showed that, the oxidation stability of JOME increased with the increase of PY dosage. Also, cetane number slightly increased with additional of antioxidant whereas kinetic viscosity was observed to decrease with PY dosage. The brake specific fuel consumption (BSFC) of JOME with antioxidants decreased more than that without antioxidants, but both were higher than that of diesel and diesel/biodiesel blends. No significant effects were observed on the exhaust emissions of a diesel engine running on biodiesel (JOME) dosed with antioxidant PY

Zero fluoroscopy catheter ablation for atrial fibrillation: a systematic review and meta-analysis

IntroductionCatheter ablation for atrial fibrillation (AF) is the most frequently performed cardiac ablation procedure worldwide. The majority of ablations can now be performed safely with minimal radiation exposure or even without the use of fluoroscopy, thanks to advances in 3-dimensional electroanatomical mapping systems and/or intracardiac echocardiography. The aim of this study was to conduct a meta-analysis to compare the effectiveness of zero fluoroscopy (ZF) versus non-zero fluoroscopy (NZF) strategies for AF ablation procedures.MethodsElectronic databases were searched and systematically reviewed for studies comparing procedural parameters and outcomes of ZF vs. NZF approaches in patients undergoing catheter ablation for AF. We used a random-effects model to derive the mean difference (MD) and risk ratios (RR) with a 95% confidence interval (CI).ResultsOur meta-analysis included seven studies comprising 1,593 patients. The ZF approach was found to be feasible in 95.1% of patients. Compared to the NZF approach, the ZF approach significantly reduced procedure time [mean difference (MD): −9.11 min (95% CI: −12.93 to −5.30 min; p < 0.01)], fluoroscopy time [MD: −5.21 min (95% CI: −5.51 to −4.91 min; p < 0.01)], and fluoroscopy dose [MD: −3.96 mGy (95% CI: −4.27 to −3.64; p < 0.01)]. However, there was no significant difference between the two groups in terms of total ablation time [MD: −104.26 s (95% CI: −183.37 to −25.14; p = 0.12)]. Furthermore, there was no significant difference in the acute [risk ratio (RR): 1.01, 95% CI: 1.00–1.02; p = 0.72] and long-term success rates (RR: 0.96, 95% CI: 0.90–1.03; p = 0.56) between the ZF and NZF methods. The complication rate was 2.76% in the entire study population and did not differ between the groups (RR: 0.94, 95% CI: 0.41–2.15; p = 0.89).ConclusionThe ZF approach is a feasible method for AF ablation procedures. It significantly reduces procedure time and radiation exposure without compromising the acute and long-term success rates or complication rates

Functional dynamics of a single tryptophan residue in a BLUF protein revealed by fluorescence spectroscopy

Blue Light Using Flavin (BLUF) domains are increasingly being adopted for use in optogenetic constructs. Despite this, much remains to be resolved on the mechanism of their activation. The advent of unnatural amino acid mutagenesis opens up a new toolbox for the study of protein structural dynamics. The tryptophan analogue, 7-aza-Trp (7AW) was incorporated in the BLUF domain of the Activation of Photopigment and pucA (AppA) photoreceptor in order to investigate the functional dynamics of the crucial W104 residue during photoactivation of the protein. The 7-aza modification to Trp makes selective excitation possible using 310 nm excitation and 380 nm emission, separating the signals of interest from other Trp and Tyr residues. We used Förster energy transfer (FRET) between 7AW and the flavin to estimate the distance between Trp and flavin in both the light- and dark-adapted states in solution. Nanosecond fluorescence anisotropy decay and picosecond fluorescence lifetime measurements for the flavin revealed a rather dynamic picture for the tryptophan residue. In the dark-adapted state, the major population of W104 is pointing away from the flavin and can move freely, in contrast to previous results reported in the literature. Upon blue-light excitation, the dominant tryptophan population is reorganized, moves closer to the flavin occupying a rigidly bound state participating in the hydrogen-bond network around the flavin molecule