Ethanol-gasoline Blends Research Articles

A comparison of the exhaust emission of a vehicle fuelled with different ethanol-petrol blends

Due to limited fossil fuel resources and a need to reduce anthropogenic CO2 emissions, biofuel usage is increasing in multiple markets. Ethanol produced from the fermentation of biomass has been of interest as a potential partial replacement for petroleum for some time; for spark-ignition engines, bioethanol is the alternative fuel which is currently of greatest interest. At present, the international market for ethanol fuel consists of E85 fuel (with 85 percent ethanol content), as well as lower concentrations of ethanol in petrol for use in standard vehicles (e.g. E5, E10). The potential for reduced exhaust emissions, improved security of fuel supply and more sustainable fuel production makes work on the production and usage of ethanol and its blends an increasingly important research topic. This paper evaluates the possibility of using petrol-ethanol blends in a modern Euro 5 vehicle without substantial engine modification. The influence of different quantities of ethanol in ethanol-petrol blends (E5, E10, E25, E50 and E85) on the emission measurement of the gaseous pollutants carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx) and carbon dioxide (CO2) for a passenger car were analysed over the New European Driving Cycle (NEDC) on a chassis dynamometer. The results obtained revealed that exhaust emissions are affected by the proportion of ethanol in the blend. The air:fuel ratio (λ) and exhaust temperature also varied. Increased fuel consumption was found to broadly correlate with blend energetic content for all blends. The experimental work presented in this paper was performed at BOSMAL Automotive Research and Development Institute as part of a test program evaluating biofuels’ influence on light-duty petrol engines for passenger cars and light commercial vehicles.

GC-MS/FID analysis of aldehyde and hydrocarbon emissions from exhaust gases of a spark ignition engine fueled with different ethanol-gasoline blends

In this paper the influence of changes in ethanol concentration in gasoline-alcohol blend on the concentrations of aldehydes and hydrocarbons emitted from a spark-ignition automotive engine is described. Results of the exhaust gas analysis with E0, E5, E10, E25 and E50 blends tested in a car meeting the Euro 5 emission standard are presented. It was found that an increase of the ethanol concentration in the fuel blend leads to an increase in the acetaldehyde concentration in the exhaust gas. TD-GC-FID/MS analysis of exhaust gases collected on two different, complementary sorbents (Carbograph 1TD, Tenax TA) allowed for identification of the large number of hydrocarbons.

Evaluación de la corrosión de un duraluminio en mezclas de gasolina y bioetanol

Nowadays, different countries use ethanol as a self-propulsion fuel. However, this biofuel is aggressive for metal parts in the fuel system of an automobile. In this study, we determined the corrosion rate of duralumin, a material used in the production of piston engines, in ethanol-gasoline blends at concentrations of 5 to 20%, through electrochemical impedance spectroscopy (EIS), Tafel polarization and Gravimetry. It was shown that the corrosion process control was mixed with a tendency towards localized corrosion. It is generally observed that the corrosion rate of duralumin decreases during the exposure time.

Study of the knocking propensity of 2,5-dimethylfuran–gasoline and ethanol–gasoline blends

Measurements of the knocking propensity of two biofuels blended at low levels with a gasoline fuel were performed in a single-cylinder direction-injection research engine at three load conditions. Blends tested included three blends containing 2,5-dimethylfuran (DMF) blended by volume with gasoline at concentrations of 5%, 10%, and 15%. A blend of 10% DMF/10% ethanol with a balance of gasoline was also tested. The knocking propensity of the blends using the potential advanced biofuel were compared to the performance of E10 and gasoline. Knocking intensity was quantified using in-cylinder pressure measurements. A comparison of the improvement in the knock-limited spark advance (KLSA) relative to the baseline gasoline was performed for the fuels tested, where the knock limit was defined as the spark crank angle where more than 10% of the cycles knock with a knocking intensity greater than 100kPa. All of the blends using either DMF or ethanol showed improvement in the KLSA relative to the baseline gasoline fuel. The blend with 10% ethanol and 10% DMF showed the best performance for the fuels tested and gave an improvement in the KLSA of 7 crank angle degrees at the full load condition. Ethanol showed a greater ability to reduce knocking tendency than DMF for the same volumetric blend percentage. The higher autoignition resistance of the ethanol blends is hypothesized to be due at least in part to the higher latent heat of vaporization reducing the in-cylinder temperature.

Control-oriented modelling of combustion phasing for a fuel-flexible spark-ignited engine with variable valve timing

In an effort to reduce dependence on petroleum-based fuels and increase engine efficiency, fuel-flexible engines with advanced technologies, including variable valve timing, are being developed. Fuel-flexible spark-ignition engines permit the increased use of ethanol–gasoline blends. Ethanol, an alternative to petroleum-based gasoline, is a renewable fuel, which has the added advantage of improving performance in operating regions that are typically knock limited due to the higher octane rating of ethanol. Furthermore, many modern engines are also being equipped with variable valve timing, a technology that can increase engine efficiency by reducing pumping losses. Through control of valve timings, particularly the amount of positive valve overlap, the quantity of burned gas in the engine cylinder can be altered, eliminating the need for intake throttling at many operating points. However, the presence of elevated levels of in-cylinder burned gas and ethanol fuel can have a significant impact on the combustion timing, such that capturing these effects is essential if the combustion phasing is to be properly controlled. This paper outlines a physically based model capable of capturing the impact of the ethanol blend ratio, burned gas fraction, spark timing and operating conditions on combustion timing. Since efficiency is typically tied to an optimal CA50 (crank angle when 50% of fuel is burned), this model is designed to provide accurate estimates of CA50 that can be used for real-time control efforts – allowing the CA50 to be adjusted to its optimal value despite changes in ethanol blend and burned gas fraction, as well as the variations in engine thermodynamic conditions that may occur during transients. The proposed control-oriented model was extensively validated at over 500 points across the engine operating range for four blends of gasoline and ethanol. Furthermore, the model was utilized to determine the impact of ethanol blend and burned gas fraction on the CA50, as well as their impact on the optimal spark timing. This study indicated that the burned gas fraction could change the optimal spark timing by over 20° at some operating conditions and that ethanol content could further affect the optimal spark timing by up to 6°. Leveraging the model in this manner provides direct evidence that accounting for the impact of these two inputs is critical for proper spark-ignition timing control.

High octane number ethanol–gasoline blends: Quantifying the potential benefits in the United States

Ethanol provides a significant contribution to road transportation fuel in the US, Brazil, and elsewhere. Renewable fuels regulations in the US and EU imply that ethanol use will continue to increase in the near future. The high octane rating of ethanol could be used in a mid-level ethanol blend to increase the minimum octane number (Research Octane Number, RON) of regular-grade gasoline. Higher RON would enable greater thermal efficiency in future engines through higher compression ratio (CR) and/or more aggressive turbocharging and downsizing, and in current engines on the road today through more aggressive spark timing under some driving conditions. Such an approach would differ from the current practice of blending ethanol into a gasoline blendstock formulated with lower octane rating such that the net octane rating of the resulting final blend is unchanged from historical levels.Developing scenarios of future ethanol availability, we estimate that large increases (4–7points) in the RON of US gasoline are possible by blending in an additional 10–20%v ethanol above the 10% already present. Keeping the blendstock RON at 88 (which provides E10 with ∼92.5RON), we estimate RON would be increased to 94.3 for E15 to as much as 98.6 for E30. Even further RON increases may be achievable assuming changes to the blendstock RON and/or hydrocarbon composition. For example, an increase in blendstock RON from 88 to 92 would increase the RON of E10 from 92.5 to 95.6, and would provide higher RON with additional ethanol content (e.g., RON of 97.1 for E15 to 100.6 for E30). Potential CR increases are estimated for the different estimates of future octane number, including the effect of increased evaporative cooling from ethanol in direct injection engines. For the ethanol and blendstock RON scenarios considered, CR increases were estimated to be on the order of 1–3CR-units for port fuel injection engines as well as for direct injection engines in which the greater evaporative cooling of ethanol can be fully utilized. Impacts to the fuel refining and blending sector and transition considerations are discussed. While additional work is needed to quantify and optimize the costs and benefits for both the automotive and refining sectors and for consumers, it appears that substantial societal benefits may be associated with capitalizing on the inherent high octane rating of ethanol in future higher octane number ethanol–gasoline blends.

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.

Cold start characteristics of an ethanol-fuelled engine with heated intake air and fuel

Abstract The conventional cold start system of flexible fuel engines introduces gasoline in the intake system when the vehicle is fuelled with hydrous ethanol or with high ethanol content gasoline-ethanol blends. The system is necessary to allow for ignition of the fuel-air mixture under low temperatures due to the high ethanol evaporation temperature, in comparison with gasoline. This works presents a new cold start system for flexible fuel engines with heating of intake air and ethanol injector. The removal of the gasoline reservoir for cold start is the main benefit of the new system, and it is an awaited evolution of flexible fuel engines. The experimental results demonstrate that the new system provides hydrous ethanol-fuelled engine start in less than 2 s under temperatures as low as 0 °C.

Experimental study of hydrous ethanol gasoline blend (E10) in a four stroke port fuel-injected spark ignition engine

SUMMARY Performance, emissions and combustion characteristics of a port-injected engine fuelled with hydrous ethanol gasoline blend (E10 - 10% of hydrous ethanol by volume in gasoline) were compared with gasoline operation. Hydrous ethanol blend produced higher power output with lean mixtures at part throttle condition. Higher flame velocity and wider flammability limits of the blend resulted in lower cycle-by-cycle variations in indicated mean effective pressure as compared to gasoline. Hydro carbon emission was also lower due to the oxygen available in the fuel (E10), which enhanced the combustion rate. Higher latent heat of evaporation of the ethanol blend and water present in it resulted in lower in-cylinder temperature, which in turn led to lesser NOx emissions. Thermal efficiency with the blend was higher in the leaner operating conditions than gasoline. Not much difference in performance, emission and combustion characteristics between neat gasoline and E10 were observed at full throttle operation. On the whole, hydrous ethanol blends can be used as a fuel with good performance and low emissions at part load condition. Copyright © 2012 John Wiley & Sons, Ltd.

Application of Near-infrared Spectroscopy to the Quality Assurance of Ethanol and Butanol Blended Gasoline

The authors recorded near-infrared spectra of ethanol and butanol blended gasoline in the range of 5–30% of alcohol content. The major peaks in the spectra were assigned to the first CH overtone (~5670, ~5770, ~5810, and ~5870 cm−1), first OH overtone of alcohol (~6320 cm−1, 6720 cm−1), and second CH overtone (~8285, ~8400, and ~8690 cm−1). The OH overtone peak of the recorded spectra was subjected to the partial least squares (PLS) procedure to obtain calibration plots. The correlation coefficients (R 2) of .9938 and .9634 were obtained for the ethanol and butanol PLS calibrations, respectively. Recently there has been a great interest in butanol as a better gasoline blending alternative to ethanol. To understand the alcohol-gasoline interactions the integrated area of the polymeric OH alcohol band (~6320 cm−1) was plotted against the percentage of the alcohol content and the abrupt changes in the area were explained in terms of the viscosity of the fuel. Based on the OH integrated area plots the authors suggest that between 10 and 15% butanol can be blended with gasoline without compromising the viscosity of the fuel for optimum combustion. The results reveal that the near-infrared spectroscopy technique is a good alternative to the chromatographic methods for the quality assurance of the ethanol blended gasoline and in the future may find its application in the quality control of the butanol blended gasoline. The precision of the near-infrared quantification of ethanol and butanol is ±1%.

EFFECT OF LOWER ETHANOL GASOLINE BLENDS ON PERFORMANCE AND EMISSION CHARACTERISTICS OF THE SINGLE CYLINDER SI ENGINE

Alcohols, basically ethanol is considered as a leading alternative fuel for automotive application because of its ability to reduce the air pollution and cost of the fuel. This paper investigates the effect of lower ethanol gasoline blends (up to 20% by volume) on performance and emission characteristics of the single cylinder four stroke SI engine. Tests were carried out for power, torque, fuel consumption and brake mean effective pressure, while exhaust emissions were analyzed for CO, CO2, and HC by using different ethanol gasoline blends on volume basis at wide open throttle and variable engine speed from 4000 to 8000 rpm. Results were compared with the pure gasoline. It showed that as the ethanol content increases the power, torque, fuel consumption, brake mean effective pressure and CO2 emission while reduces HC and CO emission.

HC2-2 Study on Auto-ignition Characteristics of Ethanol and ETBE Blended Fuels in a Gasoline HCCI Engine(HC: HCCI Combustion,General Session Papers)

Bio-fuels such as ethanol (EtOH) and ethyl tert-butyl ether (ETBE) are used as blending components in gasoline for carbon neutralization. These oxygenates are also recognized as high octane number fuels, which are acceptable for spark ignition (SI) combustion, as they inhibit end-gas auto-ignition (partly leading to knocking). However, for homogeneous charge compression ignition (HCCI) combustion, excess delay in ignition timing may occur as an undesirable effect, leading to misfiring or incomplete combustion. In this work, knocking phenomenon and HCCI combustion characteristics of ethanol and ETBE blended gasoline fuels with same octane numbers have been experimentally studied. Chemical reaction simulations were also conducted for further understanding. Experimental work was performed in a single cylinder gasoline engine with compression ratio set to 14.0. Intake air was heated at HCCI combustion operation. SI combustion test results show that when the same octane number fuels are used, ethanol and ETBE have no effect on knocking limit. On the other hand, HCCI combustion results indicate that ethanol retards ignition timing at low intake temperature condition, whereas ignition advancement is observed at high intake temperature condition. ETBE acted as an ignition accelerator for all intake temperatures. Based on these results, an empirical equation is proposed for HCCI timing prediction of the tested blended fuels.

Degradation and Recovery of Reforming Catalyst in Ethanol-Blended Gasoline Steam Reforming

Degradation and Recovery of Reforming Catalyst in Ethanol-Blended Gasoline Steam Reforming

Fuel Consumption Improvement by Engine EGR Reforming with Ethanol-Blended Gasoline Steam Reforming

Fuel Consumption Improvement by Engine EGR Reforming with Ethanol-Blended Gasoline Steam Reforming

Revisión y estado del arte de la corrosividad del etanol y sus mezclas con gasolina

Ethanol is currently an important source of renewable combustible for the automotive sector. It is known that traditional fuels such as gasoline have not caused corrosion problems due mainly to low miscibility with water. On the other hand, the alcohol based biofuels can contain a considerable amount of water, and in addition, partial oxidation of their components might be produced by exposition to the atmosphere, and this may lead to corrosion and subsequent failure of any metallic component in contact with the ethanol-gasoline blends. In consequence, all the industrial sectors related to this fuel, producing companies, logistics, dispensers and manufacturers of vehicles might be affected by this problem. This makes this topic very interesting, both from a scientific and an industrial point of view. This paper systematically reviews all aspects related to the corrosive behaviour of ethanol and ethanol-gasoline blends, with the aim of assessing the current state-of the-art as well as serving as a guide for further works that take the study of this subject matter.

Corrosion behaviour of aluminium alloys in ethanol fuels

In this study, the corrosion behaviour of several aluminium alloys in ethanol fuels was investigated by immersion and polarization tests. The corrosion properties of cast aluminium alloys (Al–17wt%Si–4wt%Cu–Mg, Al–8wt%Si–3wt%Cu, Al–7wt%Si–Mg and Al–17wt%Si–4wt%Cu–Mg with a chemically deposited nickel layer) in ethanol blended gasoline fuels were examined at various ethanol and water contents and various temperatures. Electrochemical and gravimetric measurements revealed a pronounced acceleration of the corrosion process above the boiling point. Additions of water restrain the corrosion. Increasing the ethanol content and the temperature leads to a higher corrosion sensitivity of the aluminium alloys. Furthermore, the nickel layer is very protective in all tested fuels. For aluminium alloys, a theory of the corrosion process in ethanol blended gasoline fuels is proposed.

The Effects of Ethanol and Propanol Additions Into Unleaded Gasoline on Exhaust and Noise Emissions of a Spark Ignition Engine

Exhaust and noise emissions of a four-stroke spark ignition engine were investigated by using ethanol–gasoline blends and propanol–gasoline blends. Ethanol and propanol were added to unleaded gasoline at volume percent levels of 4, 8, 12, 16, and 20%. Higher octane number, lower sulphur content, and higher oxygen content were important advantageous of the blend fuels. In general, exhaust emission profile of the engine improved when ethanol and propanol were added into the unleaded gasoline. The CO and HC emissions with ethanol–gasoline blends and propanol–gasoline blends decreased by 65.56 and 33.92%, respectively. NO and CO2 emissions with the blend fuels showed a trend of increasing. In addition, noise emissions with gasoline–ethanol blends decreased slightly at low loads. However, at the other tests, noise levels showed a trend of increasing with the blend fuels.

Effects of ethanol-blended gasoline on emissions of regulated air pollutants and carbonyls from motorcycles

The emission characteristics of regulated air pollutants and carbonyls from motorcycles using gasoline blended with 3% ethanol (E3) and gasoline (E0) were investigated in this study. Nine motorcycles were operated on a chassis dynamometer and driven according to the ECE driving cycle for air pollutant measurements. In addition, durability testing was performed on two brand-new motorcycles of the same model, using E3 in one and E0 in the other, to assess the effects of E3 usage on motorcycle emissions. The results show that average emission factors of CO and THC decreased by 20.0% and 5.27%, respectively, using E3 fuel. However, NOx and CO2 emission increased by 5.22% and 2.57%. The results of paired t-tests indicate that only the reduction of CO emission is statistically significant (p-value=0.006). The emission factors of ∑15 carbonyls for the nine test motorcycles were 1289±502 and 1579±368μg/km for E0 and E3, respectively. Carbonyl emission increased by 22.5% using E3 substituted for E0. However, the differences in ∑15 carbonyl emission between E0 and E3 were not statistically significant (p-value=0.137). Among the 15 analyzed carbonyls, only the emission of acetaldehyde was significantly higher (p-value=0.014) with E3. The results of durability tests show that deterioration coefficients for E3 were 1.50, 1.45, 0.84, 0.94 and 1.06 for CO, THC, NOx, CO2 and carbonyls, respectively. Statistical tests exhibit that using E3 as fuel does not increase the regulated air pollutants, nor carbonyl emissions for the durability test.

E15 CONTROVERSY

RETURN TO ISSUEPREVNewsNEXTE15 CONTROVERSYProposed shift to HIGHER ETHANOL-BLENDED GASOLINE draws questions from industry, activist groups, and CongressRAJENDRANI MUKHOPADHYAYView Author Information C&EN WASHINGTONCite this: Chem. Eng. News 2011, 89, 33, 26–27Publication Date (Print):August 15, 2011Publication History Published online9 March 2012Published inissue 15 August 2011https://doi.org/10.1021/cen-v089n033.p026Copyright © 2011 AMERICAN CHEMICAL SOCIETYArticle Views21Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (674 KB) SUBJECTS:Bioethanol Get e-Alerts

Emissions from Ethanol-Gasoline Blends: A Single Particle Perspective

Due to its agricultural origin and function as a fuel oxygenate, ethanol is being promoted as an alternative biomass-based fuel for use in spark ignition engines, with mandates for its use at state and regional levels. While it has been established that the addition of ethanol to a fuel reduces the particulate mass concentration in the exhaust, little attention has been paid to changes in the physicochemical properties of the emitted particles. In this work, a dynamometer-mounted GM Quad-4 spark ignition engine run without aftertreatment at 1,500 RPM and 100% load was used with four different fuel blends, containing 0, 20, 40 and 85 percent ethanol in gasoline. This allowed the effects of the fuel composition to be isolated from other effects. Instrumentation employed included two Aerosol Time-of-Flight Mass Spectrometers covering different size ranges for analysis of single particle composition, an Aethalometer for black carbon, a Scanning Mobility Particle Sizer for particle size distributions, a Photoelectric Aerosol Sensor for particle-bound polycyclic aromatic hydrocarbon (PAH) species and gravimetric filter measurements for particulate mass concentrations. It was found that, under the conditions investigated here, additional ethanol content in the fuel changes the particle size distribution, especially in the accumulation mode, and decreases the black carbon and total particulate mass concentrations. The molecular weight distribution of the PAHs was found to decrease with added ethanol. However, PAHs produced from higher ethanol-content fuels are associated with NO2− (m/z—46) in the single-particle mass spectra, indicating the presence of nitro-PAHs. Compounds associated with the gasoline (e.g., sulfur-containing species) are diminished due to dilution as ethanol is added to the fuel relative to those associated with the lubricating oil (e.g., calcium, zinc, phosphate) in the single particle spectra. These changes have potential implications for the health effect impacts of particulate emissions from biofuel blends.