Pure Gasoline Research Articles

Investigation into ethanol effects on combustion and particle number emissions in a spark-ignition to compression-ignition (SICI) engine

Spark assistance along with oxygenated components addition is a promising method to achieve stable compression ignition, high thermal efficiency and low particle emission. To this end, ethanol blended with non-oxygenated gasoline was fueled to an engine working with spark-ignition to compression-ignition (SICI) mode under air dilution and exhaust-diluted conditions. The effects of ethanol addition on engine performance including combustion characteristics, fuel economy, particle number (PN) emissions, were studied in two categories: changing research octane number (RON) by varying ethanol content and maintaining RON by changing fuel type. The results showed that ethanol addition by splash blending suppressed knock tendency, and the knock intensity could be lowered by up to 65–75% with increasing ethanol content. However, when maintaining the same RON, the ethanol-gasoline blend exhibited higher knock intensity than pure gasoline due to synergistic effects between ethanol and aromatics on auto-ignition. Compared to pure spark ignition with high-RON gasolines, using ethanol-gasoline blends under SICI could reduce the minimum fuel consumption rate by up to 25 g/(kW·h). To characterize the high-efficiency cycles under SICI, two dimensionless parameters were proposed by considering the ratios of heat release amount and duration between the flame propagation stage and auto-ignition stage. The two parameters showed good exponential correlation. As for emissions, blending ethanol could basically reduce PN emissions under SICI mode except for the cases with significant increase in nucleation particles, such as those with high knock intensity under stoichiometric condition and poor combustion quality under heavily exhaust-diluted conditions. The total PN reduction by blending ethanol is mainly due to the decrease of accumulation mode particles, during the stage of flame propagation rather than auto-ignition. Blending ethanol into non-oxygenated gasoline will directly increase unburned hydrocarbons and nitrogen oxides due to the low auto-ignition propensity of ethanol under stoichiometric or moderately lean conditions according to the temperature-pressure trajectory. Therefore, a dedicated combustion system with higher compression ratio and lean-boosted mixture is required to enhance ethanol's reactivity and achieve better fuel economy along with low PN emission for diluted SICI combustion.

Effects of Compression Ratio of Bio-Fueled SI Engines on the Thermal Balance and Waste Heat Recovery Potential

In internal combustion engines, a significant share of the fuel energy is wasted via the heat losses. This study aims to understand the heat losses and analyze the potential of the waste heat recovery when biofuels are used in SI engines. A numerical model is developed for a single-cylinder, four-stroke and air-cooled SI engine to carry out the waste heat recovery analysis. To verify the numerical solution, experiments are first conducted for the gasoline engine. Biofuels including pure ethanol (E100), E15 (15% ethanol) and E85 (85% ethanol) are then studied using the validated numerical model. Furthermore, the exhaust power to heat loss ratio (Q˙ex/Q˙ht) is investigated for different compression ratios, ethanol fuel content and engine speed to understand the exhaust losses potential in terms of the heat recovery. The results indicate that heat loss to brake power ratio (Q˙ht/W˙b) increases by the increment in the compression ratio. In addition, increasing the compression ratio leads to decreasing the Q˙ex/Q˙ht ratio for all studied fuels. According to the results, there is a direct relationship between the ethanol in fuel content and Q˙ex/Q˙ht ratio. As the percentage of ethanol in fuel increases, the Q˙ex/Q˙ht ratio rises. Thus, the more the ethanol in the fuel and the less the compression ratio, the more the potential for the waste heat recovery of the IC engine. Considering both power and waste heat recovery, the most efficient fuel is E100 due to the highest brake thermal efficiency and Q˙ex/Q˙ht ratio and E85, E15 and E00 (pure gasoline) come next in the consecutive orders. At the engine speeds and compression ratios examined in this study (3000 to 5000 rpm and a CR of 8 to 11), the maximum efficiency is about 35% at 5000 rpm and the compression ratio of 11 for E100. The minimum percentage of heat loss is 21.62 happening at 5000 rpm and the compression ratio of 8 by E100. The minimum percentage of exhaust loss is 35.8% happening at 3000 rpm and the compression ratio of 11 for E00. The most Q˙ex/Q˙ht is 2.13 which is related to E100 at the minimum compression ratio of 8.

Production of producer gas and its use as the supplementary fuel for SI engine

This study was completed in two phases. The first phase consists of the design and fabrication of a small-capacity updraft gasifier followed by the production of producer gas from the wood by biomass gasification and momentarily storing the gas in a tube. The second phase consists of the use of producer gas as a supplementary fuel in a petrol engine with minor modification on the engine’s suction side. The main objective of this study was to produce a producer gas via wood gasification process through the fabricated small updraft gasifier and find its potential as a supplementary fuel along with petrol fuel in conventional SI engine. Through the experimental investigation, the performance and emission characteristics of the engine running on dual fuel mode were evaluated; the result was compared with the engine running on pure petrol. The result reveals that a reduction in engine efficiency as 1–1.5% in the entire load spectrum but de-rating of engine power was compensated by an improved emissions level in dual fuel mode in terms of reduction in HC, CO, and NO emission of 27%, 22%, and 19% respectively.

Experimental investigation of the performance and emissions of a dual-injection SI engine with natural gas direct injection plus gasoline port injection under lean-burn conditions

Conventional gasoline SI engines have low efficiency and poor lean burn characteristics at lower loads. The objective of this study is to improve the combustion and emission performance of gasoline SI engines under lean burn conditions through dual-injection mode with gasoline port injection and natural gas direct injection(GPI + NDI). In this work, total fuel energy is kept constant for all investigated test points. The sole gasoline mode with port injection is used as the baseline and compared with the GPI + NDI mode. The results show that the proposed GPI + NDI mode provides stable and promising performance. In particular, the GPI + NDI mode achieves stable combustion with COVIMEP lower than 1.5 under the condition of λ = 1.4 where the sole gasoline mixture cannot stably combustion, which broadens the lean burn limit of the gasoline engine at low load. Compared with pure gasoline mode, GPI + NDI mode with appropriate RCNG and direct injection timing can increase efficiency by 0.7 and 0.94 percentage points at λ = 1 and 1.2, and BSFC drops by 3.1% and 3.6%. HC continues to decrease with the increase of RCNG. CO emissions at λ = 1 decrease first and then increases with the increase of RCNG, and when λ is higher than 1.2, CO emissions reach extremely low levels. Furthermore, there is a significant effect on the limitation of the total particle number(TPN)with the increase of RCNG. When λ = 1 and 1.2, the TPN has a downward trend with the RCNG increases. Since there is enough oxygen to ensure the complete oxidation of the particles, TPN is not sensitive to changes in RCNG at λ = 1.4.

Study on the utilization of low-grade bioethanol on SI gasoline engine as a mixture of pure gasoline fuel or with the addition of oxygenated additives to improve performance and reduce emissions

Utilization Currently, bioethanol has developed into additional fuel or substitute fuel for motorcars as a renewable energy source. Although Indonesia has great potential for developing bioethanol, its utilization continues to be very low. In certain areas in Indonesia, bioethanol is produced on a tiny low scale grade (hydrous) and is barely used as a drink; therefore research and development of the utilization of bioethanol in motorcars are needed, where the grade must be higher (anhydrous). Hydrous bioethanol has slightly different characteristics compared to anhydrous bioethanol. Octane is lower, heating value is lower, the heat energy of vaporization is higher, and the oxygen content is higher. However, the precise values for every characteristic rely on the mixture content and therefore the water content contained so a separate test of the hydrous bioethanol is required. This study could be a study of the utilization of hydrous bioethanol produced from low-grade bioethanol which is converted to high- grade bioethanol through a distillation process using motorcycle exhaust gas as a heat source which is applied to a compact-distillation system consisting of an evaporator, separator, and condenser to distil low-grade bioethanol (around 30%) becomes high-grade bioethanol (> 90%). Followed by testing the utilization of anhydrous bioethanol mixed with gasoline in SI gasoline engines, the composition of the mixture E0, E5, E10, and E15 and therefore the composition of the mixture with the addition of oxygenated additives (cyclohexanol) as secondary alcohols to further improve performance and reduce gas emissions throw it away.

Effect of H2 addition to methanol-gasoline blend on an SI engine at various lambda values and engine loads: A case of performance, combustion, and emission characteristics

The main purpose of this study was to investigate the effects of hydrogen and methanol addition on the engine performance, combustion, and emission characteristics of a spark-ignition engine. The experiments were performed with pure gasoline, methanol-gasoline, and hydrogen-methanol-gasoline fuel blend under various engine loads (25Nm, 50Nm, 75Nm, and 100Nm, 100%), different lambda values (0.8, 1, and 1.2), and a constant engine speed (2000 rpm). The hydrogen energy substitute rate method was applied for hydrogen enrichment that was constituted by 5% of the total input fuel energy. The experimental results indicated that the average values of brake specific fuel consumption were increased by 11.98% with the methanol-gasoline test fuel, while decreased 4.07% with the hydrogen-methanol-gasoline fuel blend. The average values of brake thermal efficiency were slightly increased by 0.07% and 0.61% with the methanol-gasoline and hydrogen-methanol-gasoline fuel blends, respectively. The combustion characteristics were improved after adding the methanol and hydrogen. In this respect, the average ignition delay values decreased by 6.45% with the addition of the methanol in gasoline, while the combustion duration, maximum cylinder pressure, and maximum heat release rate values increased by 0.85%, 1.66%, and 2.32%, respectively. Furthermore, the ignition delay and combustion duration values were substantially affected by the addition of the hydrogen and observed to be at rates of 21.10% and 6.93% reduction, respectively. In addition, the maximum cylinder pressure and maximum heat release rate values were increased by 2.02% and 4.13%. The combustion characteristics improved after the addition of hydrogen and methanol, which also considerably affected the engine performance and emission characteristics. The average values of exhaust gas temperature, hydrocarbon, carbon dioxide were increased by 0.92%, 2.26%, and 0.156% with methanol and the values of carbon monoxide and nitrogen monoxide were decreased by 1.09% and 11.82%, respectively. However, the hydrocarbon, carbon dioxide values were decreased by 13.06%, 3.90% with the hydrogen, while the carbon monoxide, exhaust gas temperature, and nitrogen monoxide were increased by 1.84%, 1.38%, and 31.68%, respectively. Although nitrogen monoxide was considerably decreased by the methanol, a drastic increase was observed with the hydrogen. The optimum brake specific fuel consumption and nitrogen monoxide values occurred between 68.61 Nm and 74.55 Nm of the engine loads for the methanol-gasoline and hydrogen-methanol-gasoline test fuels at λ = 1 and 1.2. Overall, the engine performance, combustion, and emission characteristics were improved by the addition of hydrogen and methanol in the test fuels due to their superior fuel properties compared to gasoline.

Utilisation of Chemical Waste Additives with Low Octane Commercial Gasoline Fuel to Enhance the Performance of SI Engines

In this study, fusel oil additive from the waste product has been used as an octane number enhancer to improve gasoline engine performance. The fusel additive was added at 10%, 20% and 30% ratios to prepare the investigated fuel samples (M10, M20 and M30, respectively, in addition to pure gasoline M0). Engine tests were conducted at constant half engine load and increasing speed from 1500 rpm to 4500 rpm at 1000 rpm increments. Response surface methodology has been used as a statistical technique to describe the relationship between the investigated input variables with their responses to achieve the optimum operating conditions. Engine cyclic variations were analysed using wavelet analysis of in-cylinder pressure based on indicated mean effective pressure (IMEP) calculated for 100 consecutive cycles. The results showed that the higher brake power was obtained with blended fuel M20 during the engine operating speeds. The maximum increase of brake power found to be 23.6% with M20 compared to gasoline at 1500 rpm, which accompanied by a 7.3% increase in brake specific fuel consumption. On the other hand, the highest increase in brake thermal efficiency is found to be related to the engine speed and fusel additive ratio. Wavelet analysis shows that the engine cyclic variations decrease as the fusel additive introduce with gasoline. Moreover, fusel additive has a pronounced effect on decreasing the cycle to cycle variations of the IMEP time series with the lowest overall engine cyclic variations for M30. Accordingly, 20% fusel additive (M20) can be considered as a valuable octane enhancer for better engine performance.

Temperature Dependence of Density and Viscosity of Biobutanol-Gasoline Blends

Butanol seems to be an eligible fuel for compensating for the increasing fuel consumption. Biobutanol could be produced from local sources in the place of use. Its properties show similar results to gasoline, so biobutanol could be added as a biocomponent into fuels. Important properties, in the case of blending biobutanol into gasoline, are its fluid properties and their dependence on the temperature. Therefore, in this paper, the volumetric mass density and viscosity of the selected ratios between biobutanol and gasoline (0, 5, 10, 85, 100 vol.%) were tested over the temperature range from −10 °C up to 40 °C. Gasolines with a 95 Research Octane Number (RON 95) and with a 98 Research Octane Number (RON 98) were used. It was observed that as the temperature increased, the viscosity and volumetric mass density of the samples decreased nonlinearly. Four mathematical models were used for modelling the viscosity. The accuracy of models was evaluated and compared according to the coefficient of determination R2 and sum of squared estimate of errors (SSE). The results show that blends with 5 vol.% and 10 vol.% of biobutanol promise very similar fluid properties to pure gasoline. In contrast, a blend with 85 vol.% of biobutanol shows different fluid properties from gasoline, especially in negative temperatures, a lot. For practical applications, mathematical polynomial multivariate models were created. Using these models, three-dimensional graphs were constructed.

Estimating the urban environmental impact of gasoline-ethanol blended fuels in a passenger vehicle engine.

A large portion of urban emissions in developing countries come from old gasoline vehicles driven in metropolitan areas. The present study aimed to develop models to estimate the environmental impact of different contents of gasoline and ethanol mixtures (pure gasoline; 25, 50, 75% ethanol blended to gasoline; and 100% ethanol) in a flex-fuel engine. We tested the blended fuel using three different speeds and recorded the GHG emissions and engine output data. The data mining approach was used to develop environmental impact predictive models. The ethanol content in gasoline; the engine rotational speed 900, 2000, and 3000 rpm; and λ were used as attributes. The classification target was the environmental impact concerning the CO2 emission ("low," "average," and "high"). We employed the Random forest algorithm to develop predictive models. The mean values of CO2 concentrations for all studied fuel content were above 2.47% of the volume. The trees' models (accuracy 73%, κ =0.61) showed three alternatives for predicting the environmental impact based on the ethanol blend, the engine rotation, λ, and the air-fuel ratio. Such models might help policymakers develop educational campaigns to reduce short- and medium-term urban commuter traffic pollution in countries that lack suitable urban transportation.

Fuel performance for stable homogeneous gasoline-methanol-ethanol blends

The advantages of methanol as a fuel for Internal Combustion (IC) engines includes the latent heat of evaporation that increase volumetric efficiency, high flame speed for increasing the engine power, low combustion temperature, and high hydrogen to carbon ratio which reduces harmful exhaust gases. One of the most critical aspects of gasoline-methanol is the stability during storage and distribution. This study aims to determine the fuel performance of stable homogeneous gasoline-methanol-ethanol blends. The following fuels were used, namely G-95, G-90, G-80, G-70 and G-10, where G-XX blend means that the mixture consists of gasoline XX% v/v. The gasoline-methanol blending was carried out in a 10 cm3 reaction glass, stirred manually and left for 24 h in closed conditions. The blend was then opened and allowed to stand for 12 h. Observations were made to identify a separated gasoline-methanol blend. The results showed that the mixture of G-95, G-90, G-80, G-70, and G-60 occurred in separation. Then, each was given 0.1 cm3 ethanol sustainably, and stirred manually in a reaction glass. The ethanol addition was carried out until the gasoline-methanol blend was inseparable in the mixture. The performance test of the homogeneous and stable gasoline-methanol-ethanol blend was conducted on a single-cylinder engine, and tested on the dynamometer chassis to determine the engine curve characteristics of each mixture. The results of the fuel mixture showed that the G-90 and G-95 blend produced the highest maximum and average torque, respectively. In the engine power test, the fuel blend of G-70, G-80, G90, and G-95 produced higher power than the pure gasoline in all working conditions, because it has more laminar combustion speed.

Analysis of water-ethanol-gasoline (RON 88) compositions in one phase substance-using triangular graph

The present work is aimed at analysing the compositions of the water, ethanol, and gasoline which has Research Octane Number/RON was 88 forming a stable emulsion (one phase) employing a ternary graph. When the mixture process, the blended fuels consisted of water-ethanol-gasoline were successfully prepared in which they were formed in one phase. Ethanol was derived from Arenga pinnata liquor which is locally called cap tikus using a home-made reflux distillation filled by packing materials. Ethanol obtained were differing their concentration that depended on the column temperature set. It was found that the purities were ranged from 80 to 96% and the higher column temperature was chosen the lower concentration was obtained. Each aqueous ethanol was blended with gasoline to obtain a homogenous solution. For ethanol 80%, compositions of water, pure ethanol, and gasoline were observed at 18, 74, and 8 (%v/v), and 22, 70, and 7 (%w/w). While ethanol 96%, the compositions ratios were 1:22:77 (%v/v) and 1:23:76 (%w/w). The ranges of pure ethanol, gasoline, and water in which they formed one phase solution were recorded at 23-70%, 7-76%, and 1-22%. The work found that substance was in one phase if the wet ethanol keeps being added. When the ethanol composition has decreased the substance was separated into wet ethanol and gasoline. The minimum ethanol dissolved completely into gasoline was of 80%.

Study on combustion, performance and exhaust emissions of bioethanol-gasoline blended spark ignition engine

This work focusses on a novel technique of producing bioethanol from fermented pomegranate fruits waste by using Saccharomyces cerevisiae, commonly known as baker's yeast. Four different blends of bioethanol, namely PE10, PE15, PE20, and PE25 were experimented at various operating speeds. It was inferred that the addition of ethanol enhanced the consumption of fuel as well as braking capacity. However, thermal performance was observed to be declined. PE15 blend exhibited optimum brake thermal efficiency at full load condition when compared with unleaded fuel. Brake specific fuel consumption of PE15 was noticed to be lower at different operating speeds among all the blends. Oxides of nitrogen as well as carbon dioxide emissions were increased as the proportion of ethanol in pure fuel was increased. Hydrocarbon and carbon monoxide emissions were reduced, while increasing the ratio of ethanol relative to pure gasoline, except PE10 blend. The combustion characteristics were also studied. Lower value of coefficient of variation revealed stable combustion. This study conclude that PE15 can be used as an alternative fuel.

Effect of ethanol-gasoline blends on SI engine performance and emissions

Negative effects of using traditional engine fuels on climate change and global warning have produced a scenario of high competition to find an alternative fuel more friendly and unharmful to the environment. Alcohol fuel was found very practical to be mixed with engine designed fuel. In the present work, ethanol was mixed with gasoline in different proportions (10% ethanol + 90% gasoline, 20% ethanol + 80% gasoline, 30% ethanol +70% gasoline, 40% ethanol + 60% gasoline) by utilizing ultrasonic bath to ensure perfect mixing which in turn will increase the fuel energy content.A one-cylinder, four-stroke and spark ignition engine was used to study and analyze the effect of ethanol's/gasoline blend on power, efficiency and exhaust gases. Results showed that power, brake specific fuel consumption and thermal efficiency are improved with the increase of ethanol concentration. On the other hand, ethanol was found to have negative effect on volumetric efficiency.Furthermore, adding ethanol reduce harmful exhaust gasses. It is found that more ethanol is an accompanied with less exhaust gasses. Finally, research octane number and motor octane number are found to be much with ethanol blends. Although lower heating value was found to be higher for pure gasoline, it's found that all other parameters are enhanced with adding ethanol to the engine fuel.

A study of bioethanol fuel characteristics in the combustion chamber of gasoline engine using magnetization technology

Bioethanol is a renewable energy that can replace gasoline, which will run out in the future. This study investigates the influence of magnetization of bioethanol fuel on the fuel combustion temperature in the combustion chamber of a gasoline motor. The fuel used is bioethanol with a composition of E0 (pure gasoline), E10 (10 % bioethanol+90 % gasoline), E20 (20 % bioethanol+80 % gasoline), E30 (30 % bioethanol+70 % gasoline), E40 (40 % bioethanol+60 % gasoline). The fuel passed through the magnet with a magnetic variation of 647.15 Gauss, 847.25 Gauss, 1419.57 Gauss. The temperature sensor used is a K-type thermocouple. The temperature sensor was inserted in the combustion chamber to measure the combustion chamber temperature. The thermocouple data were recorded in Microsoft Excel on a computer using the LabVIEW program via NI-USB 9213 interface. The temperature data recorded is 400 data/second. The results obtained without exposure to the magnetic field, the lowest peak temperature of 577.1998 °C at E40 and the highest peak temperature of 582.1786 °C at E0. The higher the bioethanol content, the lower the temperature of fuel combustion to the low bioethanol viscosity. The increasing magnetic field strength will increase the combustion temperature; hence the fuel burned quickly and the combustion process is more perfect. The result obtained with the magnetic field exposure, the lowest peak temperature of 577.8347 °C is at E40. The highest peak temperature of 587.36 °C is at E0. The use of a magnetic field in the bioethanol fuel mixture can increase the combustion temperature so that the fuel molecules move freely and the fuel is more easily mixed with oxygen. As more fuel is burned, the combustion of the fuel becomes complete

Emission Characteristics of Agricultural and Industrial Cellulosic Wastes Blended with Gasoline

Agricultural and industrial wastes like sawdust and corncobs are definitely pollutants as they are disposed in dump sites and burnt in open air in most developing countries, like Nigeria. Proper utilization of these wastes could help reduce the environmental pollution arising from wastes disposal and combustion of fuels. Emissions generated from running an internal combustion (IC) engine with blends of gasoline and bio-ethanol produced from these wastes, as well as those of pure gasoline were compared in this work. A gas emission analyzer was placed at the exhaust of the IC engine and the readings were taken for each blend and for each round of testing period. The read out emissions were then compared with each other. The range of emissions for carbon monoxide (CO) were 1.45-2.75; 2.10-2.90; 2.00-2.62 and 3.0 % vol., for corncobs bio-ethanol/gasoline, softwood sawdust bio-ethanol/gasoline, hardwood sawdust bio-ethanol/gasoline and pure gasoline samples respectively while the emission ranges for hydrocarbon (HC) were 260-435; 328-360; 313-350 and 480 ppm for the same samples respectively. In the case of carbon dioxide (CO2), the samples gave 2.6-4.0; 2.2-3.9; 3.2-4.2 and 3.0 % vol. emissions. Thus all stakeholders considering the adoption of fuel blends in the country’s quest for increased energy mix can be properly guided on the pollutants associated with the investigated waste materials. This may help in the choice of appropriate waste to energy.

Agro-Residues for Clean Electricity: In-Lab Trial of Power Generation from Blended Cocoa-Kolanut Wastes

As a way of waste-to-voltage conversion, a laboratory-based test trial of electricity generation from a blend of cocoa and kola nut harvest by-products is presented in this study. Bioethanol obtained from the blend through a process of fermentation is mixed with gasoline at specific proportions and employed to fire a spark-ignition engine that serves as a prime-mover in driving a four-pole three-phase salient-pole synchronous machine. Performance of the driving machine as the fuel-mix proportion and its speed of rotation varies is studied. Likewise, the electric power output characteristic of the driven machine operated at its rated synchronous speed is examined. It is found that the driving machine performs better on mixed fuel than on pure gasoline as the machine develops a gradual increase in mechanical torque and power as the proportion of ethanol in the fuel-mix and the rotational speed increases. While the highest values of torque and power developed on using pure gasoline are 12.4Nm and 2574W respectively at 1900rpm, 13.1Nm torque and 2953W power are obtained from the machine when powered with 10%-bioethanol fuel-mix at the same speed. Also, with 90V excitation voltage and rotation at 1500rpm synchronous speed, the driven machine continuously generates electricity at 207.6Vrms (line-to-line), 1.169A, 0.698pf, 48.17Hz, 0.294kW output. Therefore, this investigation shows that the availability of cocoa and kola nut harvest wastes could be explored as a steady source of biofuel for off-grid microgrid electrification at locations with such agricultural wastes advantages.

Potential of hydrogen addition to natural gas or ammonia as a solution towards low- or zero-carbon fuel for the supply of a small turbocharged SI engine

Nowadays there is an increasing interest in carbon-free fuels such as ammonia and hydrogen. Those fuels, on one hand, allow to drastically reduce CO2 emissions, helping to comply with the increasingly stringent emission regulations, and, on the other hand, could lead to possible advantages in performances if blended with conventional fuels. In this regard, this work focuses on the 1D numerical study of an internal combustion engine supplied with different fuels: pure gasoline, and blends of methane-hydrogen and ammonia-hydrogen. The analyses are carried out with reference to a downsized turbocharged two-cylinder engine working in an operating point representative of engine operations along WLTC, namely 1800 rpm and 9.4 bar of BMEP. To evaluate the potential of methane-hydrogen and ammonia-hydrogen blends, a parametric study is performed. The varied parameters are air/fuel proportions (from 1 up to 2) and the hydrogen fraction over the total fuel. Hydrogen volume percentages up to 60% are considered both in the case of methane-hydrogen and ammonia-hydrogen blends. Model predictive capabilities are enhanced through a refined treatment of the laminar flame speed and chemistry of the end gas to improve the description of the combustion process and knock phenomenon, respectively. After the model validation under pure gasoline supply, numerical analyses allowed to estimate the benefits and drawbacks of considered alternative fuels in terms of efficiency, carbon monoxide, and pollutant emissions.

Effect of Blends Gasoline with Oxygenated Additives in the Performance of Internal Combustion Engine

The objective of this study was to evaluate the effect of blends of different oxygenated additives on gasoline in SI engine Otto cycle. The formulations analyzed were: pure gasoline (type A), common gasoline (type C), gasoline type A + 15% (v/v) oxygenated additives (ethanol, ethyl octanoate, ethyl oleate). The experiments were performed using engine Branco 4-stroke and 2-cylinder, electric dynamometer, exhaust system, control unit composed of Multi-K unit, variable selector and load cell, stroboscope tachometer, fuel supply system and stopwatch. The rotation was conserved at 4400 rpm and wheel power varied from 3 kW to 12 kW, with intervals of 3 kW to obtain hourly consumption curves and brake specific fuel consumption. Even esters and ethanol having lower heat of combustion, hourly consumption was similar to pure gasoline (type A). In relation to the brake specific fuel consumption, increasing the wheel power had a better conversion of the mass of fuel burned into energy. Thus, this study showed that the mixture of gasoline and esters (ethyl octanoate and ethyl oleate) presented good efficiency in terms of consumption. This research contributes to the needs and to the current studies in which industries started to add renewable products to petroleum-derived fuels; in order to obtain more sustainable fuels at lower costs.

Hydro-catalytic isomerization of light gasoline fraction of Zhanazhol field’s oil

The purpose of the present work is to show that light straight-run gasoline fraction can be used as feedstock for hydro-catalytic isomerization process, and the isomerized product can serve as a component for obtaining pure ecological commercial gasoline brand Euro-4 and Euro-5. Transformation of n-alkanes of Zhanazhol oil’s light gasoline fraction with boiling temperature 180°C was studied. Isomerization was carried out in a flow unit with a stationary layer of modified sample of industrial aluminum-platinum catalyst at 200-300°C and 2.0-4.0 MPa, with volume feed rate of 1.0-3.0 h-1 and circulation ratio of hydrogen containing gas circulation 1000-1500 m3/m3 of catalyst feed. Light gasoline fraction are subjected to a number of chemical transformations: n-paraffins isomerization, five-membered and six-membered cycloalkanes dehydroisomerization and hydrocracking. n-Alkanes are isomerized in iso-alkanes, naphthenic hydrocarbons are first subjected to hydrocracking with opening the cycle and forming n-alkanes, which are then isomerized into iso-alkanes. Thus, the reaction products contain isopentane, 2,3-dimethylbutane with octane number 92 and 104 correspondingly, and other iso-paraffinic hydrocarbons that lead to raise of gasoline octane number. By study of individual hydrocarbon composition of feedstock and isomerizate it is possible to establish some regularities hydrocarbons in the process of hydro-catalytic isomerization of light gasoline fraction.

Impact of various lambda values on engine performance, combustion and emissions of a SI engine fueled with methanol-gasoline blends at full engine load

The aim of this study is to investigate experimentally the effects of methanol-gasoline fuel blend on engine performance, combustion process, and exhaust emissions of a spark ignition (SI) engine under various lambda values at full engine load. Firstly, the methanol was blended with gasoline by volume fraction of 20%, which renamed as M20. The experiments were performed a constant engine speed at 2000 rpm and full load conditions. Then, the M20 fuel blend effects on the engine performance, combustion and exhaust emission characteristics were compared with pure gasoline fuel in terms of brake engine torque, brake specific fuel consumption (BSFC), thermal efficiency, combustion process, CO, CO2, HC and NO emissions at three different lambda values such as 0.8, 1, 1.2. It was found that the addition of methanol substantially affected the engine performance, combustion process, and exhaust emissions at various lambda values. The methanol properties such as higher oxygen content, octane number, laminar flame speed (LFS), latent heat vaporization, and lower calorific value, and also the variation of the air-fuel ratio of the test fuels substantially influenced on the test results. Furthermore, these properties considerably affected the combustion characteristics such as ignition delay (ID), and combustion duration (CD). According to obtained results, the highest engine performance was observed for gasoline at λ=1. The M20 test fuel was exhibited a better combustion process when at λ=0.8 among other lambdas compared to gasoline. However, the best emission performance was obtained at λ=1 for the M20. Thus, the M20 test fuel can be used as a fuel considering the combustion and exhaust emissions. Overall, the engine performance, combustion, and exhaust emission characteristics are considerably affected by the variety of air-fuel ratio, oxygen content, octane number, LFS, and latent heat vaporization properties.