Hydrous Ethanol Gasoline Research Articles

Prospects of performance, emissions and cost of methane-based fuels in a spark-ignition engine compared to conventional Brazilian fuels

Brazil has a long history of using biofuels in the transport sector, especially due to the 40 years widespread use of ethanol and almost 20 years of biodiesel. Nevertheless, more efforts are needed to reduce even further the carbon emissions of the transport sector. In addition to ethanol, gaseous fuels such as biogas and biomethane are gaining ground due to their great potential to be obtained through biomass processing. To prospect the potential use of biomethane as a vehicle fuel in Brazil, compressed natural gas (CNG), another methane-based fuel with similar composition to biomethane, was tested and had its performance and emissions compared to hydrous ethanol and Brazilian gasoline at three different operating conditions in two different compression ratios: 3.0 bar, 6.0 bar and 9.0 bar IMEP at 1800 rpm, exploring compression ratios of 11.6:1 and 14.3:1. With CNG, engine operation at MBT was possible with both compression ratios. Ethanol presented border knock near MBT for the highest compression ratio and load, while the gasoline spark timing was knock-limited for both compression ratios at the highest load. Indicated efficiency of CNG was higher than that of gasoline and lower than that of hydrous ethanol. ISCO emissions were lower for CNG, while ISTHC and ISNOX were similar to gasoline. Due to the lower LHV of biomethane, a reduction in the ISNOX value could be expected with possible increase in methane slip. Regarding cost, biomethane is the fuel with the cheapest operating cost per kWh when considering the final price for industrial consumers in Brazil. It is still difficult to estimate large-scale production cost of biomethane, but its use in partial replacement of CNG would still be able to keep fuel market competitiveness, while reducing the carbon footprint.

Experimental and Simulation Analysis on Spray Characteristics of Hydrous Ethanol–Gasoline Blends

Abstract Hydrous ethanol application in engines can not only improve combustion and reduce emissions but also save energy consumption in the production process, which is a potential alternative fuel for engines. However, little research has been conducted on the influences of hydrous ethanol, gasoline, and hydrous ethanol–gasoline blends on spray characteristics, especially the phenomenon of flash boiling. In this investigation, the spray characteristics of hydrous ethanol and gasoline have been conducted using a constant volume chamber system, and the spray characteristics of hydrous ethanol–gasoline blends have been simulated using validated models. The results show that hydrous ethanol fuel is more likely to enter a flash-boiling state in comparison with gasoline. In addition, the spray penetration of hydrous ethanol is higher than that of gasoline, which increases by 10% approximately under the same temperature. Moreover, the spray cone angle of test fuels is between 32 deg and 43 deg and decreases with the increase of back pressure in trend. Besides, the spray projection area of hydrous ethanol and gasoline decreases significantly with the increase of back pressure. In terms of simulation, the spray penetration of E10w, E20w, E50w, and E85w fuels decreases with the increase of back pressure.

Experimental Investigation of Hydrous Ethanol Gasoline on Engine Noise, Cyclic Variations and Combustion Characteristics

Nowadays, the noise pollution of internal combustion engines is a very important factor influencing human health and is the main noise source of urban environmental noise. Additionally, the main source of gasoline engine noise consists of combustion noise in the cylinder, where the combustion noise is influenced by the combustion processes within the combustion chamber, especially the cyclic variation in the engine combustion. Thus, the inter-relationship between engine noise, cyclic variation and combustion is of great interest to be explored. Moreover, despite the environmental advantages of clean energy, the impact of different fuels on the internal combustion engine’s noise emissions cannot be ignored. As a result, in this work, three blends were prepared and used as test fuels, namely pure gasoline (E0), 10% hydrous ethanol (E10W) and 20% hydrous ethanol (E20W) by volume, accompanied by engine operating at a steady speed of 2000 r/min under various loads. The experimental results show that lower engine noise was observed for both E10W and E20W compared to E0. Upon the addition of hydrous ethanol, the peak in-cylinder pressure increased while the maximum pressure rise rate ((dp/dφ)max) decreased at the low and medium loads. Furthermore, the coefficients of variation in indicated mean effective pressure (COVimep) and COV(dp/dφ)max for the two blended fuels were higher than those for pure gasoline. Compared with those of E20W, E10W has lower COVimep and COV(dp/dφ)max at low and medium loads. The (dp/dφ)max and noise emission have a positive relation when the engine is fueled with the hydrous ethanol–gasoline blends, whereas the cyclic variation parameters vary in the opposite direction of the noise emission level for all the blend mixtures. Moreover, (dp/dφ)max has an essential effect on the combustion noise from a gasoline engine.

Three-Dimensional Simulation Analysis of the Effect of Hydrous Ethanol and Exhaust Gas Recirculation on Gasoline Direct Injection Engine Combustion and Emissions

Abstract To analyze the influence of hydrous ethanol on the performance of the direct-injection engine, the three-dimensional simulation is carried out by using converge software coupled with the combustion mechanism of hydrous ethanol gasoline and the soot model. The combustion and soot generation characteristics of a direct-injection gasoline engine burning hydrous ethanol gasoline using exhaust gas recirculation (EGR) technology are investigated. It is found that the increase of the blending ratio of the hydrous ethanol can accelerate the flame propagation speed, shorten the combustion duration, and improve the combustion isovolumetric. The nucleation and growth of soot are jointly controlled by polycyclic aromatic hydrocarbons (PAHs) and the small molecular components such as C2H2. The oxygen content properties and high reactive OH of the hydrous ethanol-containing gasoline inhibit soot formation. Compared with pure gasoline, the carbon soot precursor mass is reduced by 60%, 54.5%, 73.3%, and 52.4% for 20% anhydrous ethanol blended with gasoline, A1, A2, A3, and A4, respectively, and the carbon soot mass is reduced by 63.6% and the carbon soot volume density is reduced by 40%. The introduction of EGR exhaust reduces the burning rate and leads to an increase in the production of carbon monoxide, hydrocarbon, and soot. However, the combination of EGR with hydrous ethanol gasoline can significantly improve the engine combustion environment and significantly reduce soot and PAHs concentrations. The impact of EGR also includes the ability to reduce combustion chamber temperatures and reduce NOx emissions from hydrous ethanol gasoline by 75%.

Study on combustion and emissions of a hydrous ethanol/gasoline dual fuel engine with combined injection

Hydrous ethanol has lower cost and energy consumption during the production process than anhydrous ethanol. Many researchers used hydrous ethanol instead of anhydrous ethanol to manufacture hydrous ethanol-gasoline. The water ratio in hydrous ethanol (ω) determines the energy consumption in the production process of ethanol. However, no one researched the effects of different ω on combustion and emissions of hydrous ethanol-gasoline. So, we prepared five kinds of ethanol with different ω (0, 5%, 10%, 15%, 20% vol.) to research the effects of ω on combustion and emissions. This study adopted combined injection with hydrous ethanol direct injection plus gasoline port injection (HEDI + GPI). The engine speed was 1500 rpm, and λ was 1, the intake manifold absolute pressure was 48 kPa, the direct injection ratio was 20%, five spark timings varied from 5 °CA BTDC to 25 °CA BTDC. The results showed hydrous ethanol prolonged flame development and propagation duration, decreased Tmax and Pmax, delayed APmax. Water increased COVimep, but using hydrous ethanol at the reasonable spark timing would not significantly affect the stability. Meanwhile, when the spark timing was MBT, compared with GE (gasoline/anhydrous ethanol dual fuel) fuel, as ω in GEW (gasoline/hydrous ethanol dual fuel) fuels increased, torque and brake thermal efficiency improved by 1.69%, 1.13%, −0.01%, −0.77%; HC increased by 2.13%, 9.02%, 23.89%, 37.15%; CO decreased by 41.95%, 28.56%, 5.59%, 2.46%; NOx decreased by 10.10%, −0.75%, −0.17%, 4.18%; total PN emissions decreased by 24.07%, 69.57%, 36.34%, 32.45%. Meanwhile, more water caused the size of particles to drop, made particles smaller.

Effects of Water Ratio in Hydrous Ethanol on the Combustion and Emissions of a Hydrous Ethanol/Gasoline Combined Injection Engine under Different Excess Air Ratios.

Ethanol is usually combined with gasoline to manufacture ethanol–gasoline with excellent combustion characteristics. However, extracting water from hydrous ethanol to manufacture anhydrous ethanol consumed much energy, which increases the production cost of ethanol–gasoline. Many researchers have studied the combustion and emissions of hydrous ethanol–gasoline to explore the application of hydrous ethanol–gasoline as the fuel for spark-ignition engines. Most previous studies changed the hydrous ethanol ratio with fixed purity in hydrous ethanol–gasoline to study the effects of hydrous ethanol. Different from previous studies, this paper studied the effects of water ratio (Wr) in hydrous ethanol on the combustion and emissions of a hydrous ethanol/gasoline combined injection engine under different excess air ratio (λ) values. The ratios of ethanol and gasoline keep constant, while the purity of hydrous ethanol changes during the research. The experiment adopted the combined injection mode with hydrous ethanol direct injection plus gasoline port injection; the direct injection ratio was 20%. The experiment set three λ (0.9, 1, and 1.2) and five Wrs (0, 5, 10, 15, and 20%). The test engine’s speed was 1500 rpm, and the intake manifold absolute pressure was 48 kPa. Results showed that water inhibited combustion, prolonged CA 0-10 and CA 10-90, reduced Pmax and Tmax, and delayed APmax; larger λ made the deterioration on combustion more obvious, and the smaller λ had a larger tolerance to water. Water could increase torque and improve emissions, but different parameters corresponded to different optimal Wrs. For torque, the optimal Wr was 5%. For HC emissions, the optimal Wr was 0%; for CO emissions, the optimal value was 5%; and for NOx emissions, the best value was 20%. The best Wr was 10% for particle number (PN) emissions. Under the optimal Wr condition, when λ values were 0.9, 1, and 1.2, compared with pure gasoline, the torque increased by 7.5, 5.54, and 5.31%; HC emissions decreased by 21.37, 23.43, and 26.58%; NOx emissions decreased by 4.26, 11.47, and 12.55%; CO emissions decreased by 17.51, 34.56, −50%; and the total PN emissions decreased by 87.64, 89.64, and 76.07%.

Effect of operation under lean conditions on NOx emissions and fuel consumption fueling an SI engine with hydrous ethanol–gasoline blends enhanced with synthesis gas

For the purpose of creating a clean environment, achieving higher engine efficiency, and complying with increasingly strict emission regulations, many methods have been developed to enhance SI engines performance and decrease their pollutant emissions. In this study, the effects of using hydrous ethanol–gasoline blends and synthesis gas addition on NOx emissions and fuel consumption under lean and ultra-lean conditions (i.e. at air/fuel equivalence ratios (λ) = 1.13, 1.26 and 1.46) were investigated using a Spark-Ignition (SI) engine. The engine was fuelled with a Saudi Arabian gasoline grade (RON91), mixed with 5 % and 10 % of hydrous ethanol containing different water concentrations (5 %, 10 %, 30 %, and 40 %). An on-board plasma fuel reformer was employed for the production of hydrogen-rich syngas via the partial oxidation of gasoline. The results revealed the evident positive effect of operating under lean conditions using hydrous ethanol–gasoline blends on reducing the NOx emissions. In addition, NOx emissions decreased with increasing the air/fuel ratio to reach the minimum at the highest lean condition. However, fuel consumption increased with equivalence air/fuel ratio from low-lean at λ = 1.13 to high lean at λ = 1.46 conditions. Syngas addition to the fuel blend under lean conditions resulted in further reduction of NOx emissions but increased the overall fuel consumption. The results showed that up to 4 % of water enrichment of hydrous-gasoline blend can effectively enhance the engine thermal efficiency and reduce NOx emission.

Effect of cyclohexanol on phase stability and volatility behavior of hydrous ethanol-gasoline blends

Biofuels can contribute to reducing greenhouse gas emissions and bridging the gap between production and consumption. Ethanol is a renewable source of energy. It can reduce oil dependence and also can be appropriately used in gasoline as a blend. The high cost of dry ethanol has turned the researcher's attention to the more economic hydrous ethanol. However many works were focused on its impact on the engine performance and the exhaust emissions; few works were interested in the phase stability of those blends. This work aims to study the impact of blending cyclohexanol (CH) into hydrous ethanol-gasoline blends as a stabilizing agent. Four dual-alcohol (E5-3CH, E10-3CH, E15-3CH, and E20-3CH) blends were investigated besides their single hydrous ethanol (E0, E5, E10, E15, and E20) blends. The tests involved; water tolerance, distillation curve, and vapor pressure. Vapor lock protection potential, the area under the distillation curve (AUDC), and the area due to azeotrope formation (ADAF) were calculated. The obtained results show that cyclohexanol significantly increases the water tolerance of hydrous ethanol-gasoline blends. The blends of E5 and E10 which were separated at 30 °C converted into miscible and clear samples when they were blended with 3 vol% of cyclohexanol. These samples can also tolerate additional water. For E20, the addition of 3 vol% of cyclohexanol increased the water tolerance by about six times. Also, it was found that cyclohexanol does not have any negative effect on the volatility properties of the fuel blends. It was found that blending CH into the hydrous ethanol blends causes a significant increase in the AUDC and consequently, the area due to azeotrope formation (ADAF) decrease.

NOx Emission Reduction Using Hydrous Ethanol-Gasoline Blend with Syngas in SI Engine

This paper presents a comparatively experimental study of nitrogen oxide (NOx) emissions from an internal combustion engine fed by gasoline available in the Saudi Arabian market rating octane number (RON 91 and RON 95) with admixtures of syngas with 0% E0, 5% E5 and 10% E10—by volume of pure ethanol—and HE5 and HE10 with water concentrations of 5%, 10%, 30% and 40%—by volume of hydrous ethanol—at stoichio-metric mixtures. An on-board plasma system used to produce syngas through the partial oxidation of gasoline with air in a plasma-assisted fuel reformer. The syngas injected in a gasoline engine with a fuel injection system modified for operation with addition of some amount of syngas. The experimental results demonstrated a significant total reduction in NOx emissions and slightly increased in fuel consumption when mixing gasoline (RON 91 and RON 95), ethanol (E5 and E10) and hydrous ethanol (HE5 and HE10) with syngas. For the use of hydrous ethanol (HE5 and HE10) along with the addition of syngas, for both RON 91 and RON 95, the lowest NOx emissions are found 72% with a water concentration of 40%.

Combustion and Emission Characteristics of Hydrous Ethanol–Gasoline Blends with Co-solvents in Spark-ignited Single cylinder Engine

In Brazil, hydrous ethanol is blended with gasoline and is successfully implemented in flexi fuel engines and it has the potential to directly compete with fossil fuels. However, the Ethanol Blending Program of India has not been successful due to non-availability of sugarcane molasses and could not achieve its 5% blending target based on the literature review study. Hydrous ethanol with co-solvent is proposed in this work as a promising blending oxidant instead of energy-intensive anhydrous ethanol in gasoline. This research work also delves into the challenges of using hydrous ethanol in gasoline blended fuel such as water tolerance, fuel properties, and fuel selection. The selected fuel sample 2EW30TBA10, which contains 30% hydrous ethanol and 10% TBA (t-butyl alcohol), and gasoline was selected based on water tolerance of the blended sample and stability. The combustion and emission characteristics of the selected fuel sample 2EW30TBA10 are studied in 4-stroke, single cylinder, water cooled engine, and the performances are compared to base fuel (E0) and reference fuel (E10). The significant contributions of the present research work are the development of combustion model using MATLAB using: Apparent heat release model (Model1) and Combustion pressure method (Model-2) and the results are validated using modified Wiebe function. There was an increase in brake thermal efficiency by 5% compared to base fuel (E0) and the specific fuel consumption (sfc) for 2EW30TBA10 fuel sample is 290 g/KWh as compared to E10, which is 300 g/KWh and for Petrol (E0), sfc is 360 g/KWh. There was a reduction in CO and HC emission compared to base fuel (E0) and an increase in NOx emissions. The cyclic variations of experimental results are validated using a non-linear regression model.

Influence of ethyl acetate addition on phase stability and fuel characteristics of hydrous ethanol-gasoline blends

Hydrous ethanol or commercial ethanol is regarded as a promising additive for gasoline. Its low cost and many other advantages, such as increasing the octane number and reduction of harmful emissions, motivate the researchers to investigate its use as an economic octane booster. The most common drawback of using hydrous ethanol as a gasoline additive is the phase separation problem. In this study, the effect of adding ethyl acetate (EA) on the phase stability, distillation curve, vapor pressure, vapor lock index and octane number of hydrous ethanol-gasoline blends was investigated. The reference fuel blends were formulated by mixing hydrous ethanol (96%) with hydrocarbon-based gasoline in different percentages (5, 10, 15 and 20 vol%). For studying the effect of ethyl acetate on the fuel specifications, it was mixed with 15% hydrous ethanol-gasoline blend in different percentage (3, 6, 9 and 12 vol%). The experimental results indicated that ethyl acetate has a good ability to increase the phase stability and the octane number of the hydrous ethanol-gasoline blends without causing adverse impacts on the other studied specifications.

Near-azeotropic volatility behavior of hydrous and anhydrous ethanol gasoline mixtures and impact on droplet evaporation dynamics

After fermentation, the concentration of bioethanol is only 8–12 wt%. To produce anhydrous ethanol fuel, a significant amount of energy is required for separation and dehydration. Once the azeotrope composition is reached, distillation can no longer be exploited for purification and more expensive methods must be used. Replacing anhydrous ethanol fuel with hydrous ethanol (at the azeotrope composition) can result in significant energy and cost savings during production. The goal of this study was to characterize the volatility behavior and the droplet evaporation dynamics of hydrous and anhydrous ethanol gasoline blends. Three hydrous ethanol-gasoline blends (10, 15, and 30 vol%) in which the hydrous ethanol was composed of the azeotropic proportions of ethanol and water, and three anhydrous ethanol gasoline blends (10, 15, and 30 vol%) were prepared and analyzed with the advanced distillation curve method. Distillation curves were obtained for all test fuels and distillate samples were taken during the distillation process. A droplet evaporation model validated with the distillation data was exploited to understand how the non-ideal volatility behavior of these blends, the high heat of vaporization of water, and altered fluid properties can affect the transient droplet evaporation phenomena and thus the fuel's potential to effectively mix with air in direct injection internal combustion engines. Minor differences in the distillation curves and vapor-liquid equilibrium between the hydrous and anhydrous fuels were measured. Droplet modeling results showed that the higher heat of vaporization and viscosity of water relative to ethanol can lead to significant differences in the net droplet evaporation time between the two types of blends, especially at the higher blending ratios evaluated. These results suggest that the presence of water in ethanol-gasoline blends may extend droplet lifetimes and increase the susceptibility of the fuel to form particulate matter emissions. This is the first study to use distillation methods to gain a better understanding of evaporation behavior and the role of water's non-linear vapor-liquid equilibrium on droplet evaporation dynamics.

Physiochemical Property Characterization of Hydrous and Anhydrous Ethanol Blended Gasoline

Water removal during the production of bioethanol is highly energy intensive. At the azeotropic point, the mixture can no longer be separated via fractional distillation, so expensive and energy intensive methods are required for further purification. Hence, there is an interest in using hydrous ethanol at the azeotropic point to improve the energy balance of ethanol fuel production. Currently there is a lack of available thermophysical property data for hydrous ethanol gasoline fuel blends. These data are important to understand the effect of water on critical fuel properties and to evaluate the potential of using hydrous ethanol fuels in conventional and optimized spark ignition engines. In this study, gasoline was blended with 10, 15, and 30 vol % of anhydrous and hydrous ethanol. The distillation curve, Reid vapor pressure, vapor lock protection potential, viscosity, density, haze and phase separation points, and lower heating value were measured for each blend, and the results were compared to ASTM D...

Exhaust noise, performance and emission characteristics of spark ignition engine fuelled with pure gasoline and hydrous ethanol gasoline blends

The exhaust noise, performance and emission characteristics of a gasoline engine fuelled by hydrous ethanol gasoline with 10%, 20% hydrous ethanol by volume (E10W and E20W) and pure gasoline (E0) were experimentally investigated. The tests were performed at full load and different engine speeds varying from 1500 rpm to 5000 rpm. The results showed that compared with E0, E10W and E20W had much lower exhaust noise at low engine speeds. With the increase of engine speed, E0 showed an advantage in low exhaust noise. However, engine fuelled with three fuels displayed comparable noise emissions at high speed. In addition, better thermal efficiency, significantly decreased CO and HC emissions were achieved by hydrous ethanol gasoline at all tested operating conditions. However, significant NOx emission and slight BSFC were observed for E10W and E20W. Compared with E20W, E10W showed decreased BSFC, HC and NOx emissions with the increase of engine speed, while CO emission was only slightly increased. Hydrous ethanol gasoline was capable of realizing comparable torque and power with E0 at all operating conditions. From the results above, hydrous ethanol gasoline could be considered as a promising alternative for SI engine. What's more, E10W exhibits enhanced performance.

The influence of hydrous ethanol gasoline on cycle-to-cycle variation of a spark ignition engine

The influence of hydrous ethanol gasoline on cycle-to-cycle variation of a spark ignition engine

Particulate Matter and Gaseous Emission of Hydrous Ethanol Gasoline Blends Fuel in a Port Injection Gasoline Engine

The industrialization that increases day by day needs more and more power/fuel sources that are commonly available, abundant, renewable, and environmentally friendly. Recently, nearly all of the cities in China (PRC) have been influenced by haze. However, the pollutants from automobiles have always been seriously considered to be the main contamination causes of the haze and that influence human health. This study concerns the impact of hydrous ethanol on in-cylinder pressure, particulate matter (PM), and gaseous emissions (oxides of nitrogen (NOx) and unburned hydrocarbon (HC)) from a port fuel injection (PFI) gasoline engine. Tests were conducted on a four-cylinder port injection gasoline engine at different engine loads at an engine speed of 2000 rev/min for commercial gasoline, hydrous ethanol-gasoline blends (10% and 20% hydrous ethanol by volume), and an anhydrous ethanol-gasoline blend (20% anhydrous ethanol by volume). The results show that the peak in-cylinder pressure with the use of gasoline was the highest compared with the hydrous ethanol and anhydrous ethanol blends. Compared with the anhydrous ethanol blend, the hydrous ethanol blends performed well at a high load condition, equivalent to a low load. In addition, the total particulate number (PN) declines with an increase in engine operating loads for all of the fuels tested. The outcome of this study is an important reduction in PM number, mass emissions, and mean diameters of particles as the use of hydrous ethanol blends increases, while the form of the particulate size distribution remains the same. Furthermore, the NOx emission is raised with a rise in engine load, and NOx and HC emissions are reduced with the use of hydrous ethanol and anhydrous ethanol blend as equated with pure gasoline. Moreover, the correlation between the total particle number against NOx and HC has been found; the number of particles increases when the NOx emission decreases, and the opposite trend is exhibited for the HC emission. Therefore, it can be concluded that hydrous ethanol blends look to be a good selection for PM, NOx, and HC reduction for gasoline engines.

Experimental Investigation on the Stability of Hydrous Ethanol Gasoline Blends and Emission Products from SI Engine

In this study, gasoline–ethanol–water mixtures were tested for stability, at two gasoline compositions (gasohol E10 and commercial gasoline E0) and five additives. Then, Comparative experiments were carried on a port injection gasoline engine fueled with hydrous ethanol gasoline (HE10), ethanol gasoline (E10) and commercial gasoline (E0). The effects of the engine loads and the additions of ethanol and water on exhaust emission (NOx, HC, CO2, CO) were analyzed deeply. The experimental results showed the phase separation temperature of hydrous ethanol gasoline made up by gasohol (E10) is lower than that made up by commercial gasoline by 14oC, at the same ethanol content and the same water content. The use of chemical additives can importantly decrease the phase separation temperature of E25 hydrous ethanol gasoline. The usage of HE10 decreased NOX, HC and CO emissions significantly at 20 N.m, 40 N.m and 60 N.m While CO2 emissions increased for HE10. From the results, it can be decided that HE10 fuel can be considered as a possible alternative fuel for gasoline engine applications.

The effects of hydrous ethanol gasoline on combustion and emission characteristics of a port injection gasoline engine

Comparative experiments were conducted on a port injection gasoline engine fueled with hydrous ethanol gasoline (E10W), ethanol gasoline (E10) and pure gasoline (E0). The effects of the engine loads and the additions of ethanol and water on combustion and emission characteristics were analyzed deeply. According to the experimental results, compared with E0, E10W showed higher peak in-cylinder pressure at high load. Increases in peak heat release rates were observed for E10W fuel at all the operating conditions. The usage of E10W increased NOX emissions at a wide load range. However, at low load conditions, E10W reduced HC, CO and CO2 emissions significantly. E10W also produced slightly less HC and CO emissions, while CO2 emissions were not significantly affected at higher operating points. Compared with E10, E10W showed higher peak in-cylinder pressures and peak heat release rates at the tested operating conditions. In addition, decreases in NOX emissions were observed for E10W from 5Nm to 100Nm, while HC, CO and CO2 emissions were slightly higher at low and medium load conditions. From the results, it can be concluded that E10W fuel can be regarded as a potential alternative fuel for gasoline engine applications.

Optimal Design of Preparation Parameters of Hydrous Ethanol Gasoline Fuel Based on Multi-Island Genetic Algorithm

The experimental program was designed with design of experiment (DoE) technology and a series of experiments were conducted, then an approximate surface model was established with the experimental results and the significant preparation parameters of hydrous ethanol gasoline with different ethanol proportion were optimized with multi-islands genetic algorithms, then the optimal results were verified. The results show that the ethanol proportion, emulsifier type and proportion in the ethanol gasoline has a great influence on the stability; the phase separation temperature of the hydrous ethanol gasoline prepared with the optimal formula (with 25% ethanol proportion, 1.73% emulsifier S+T) is -8°C which is very close to the predicted value. The fuel can maintain stability and with no phase separate for more than 60 days in the room temperature (10°C-30°C).

Hydrous ethanol–gasoline blends – Combustion and emission investigations on a Flex-Fuel engine

Flex-Fuel vehicles, launched in the Brazilian market in 2003, operate with gasoline blended with anhydrous ethanol (18–25% vol/vol), 100% hydrous ethanol (4.0–4.9% vol/vol of water) or any blend of these fuels. Dynamometer tests were conducted on a 1.4L, Flex-Fuel Otto engine. Gasoline with 25% vol/vol of anhydrous ethanol was blended with different ratios of hydrous ethanol. A programmable engine control unit was used to manage engine operation and spark timing calibration for maximum break torque at different speeds and torques. Combustion characteristics, such as mass fraction burned, heat release rate and combustion duration were calculated based on in-cylinder pressure curve data, measured by a special data acquisition system. Emissions of THC, NOX, CO, CO2, unburned ethanol and aldehydes were measured by a Fourier transform infrared analyzer. Hydrous ethanol addition reduced CO and THC, but increased CO2, aldehydes and unburned ethanol emissions. NOX results presented complex trends with ethanol addition, depending on the operating condition, spark advance timing and other parameters.