Recent Researches in Engineering Mechanics, Urban & Naval Transportation and Tourism
Mixtures of Gasoline-ethanol and gasoline –methanol in a two stroke outboard low output engine.
CHARALAMPOS ARAPATSAKOS, MARIANTHI MOSCHOU
Department of Production and Management Engineering Democritus University of Thrace V. Sofias Street, 67100, Xanthi GREECE [email protected]
Abstract: - This work deals with the examination of a two stroke outboard low output engine from the viewpoint of pollution and consumption, using as fuel gasoline-ethanol and gasoline-methanol mixtures. A series of laboratory instruments were used for the realisation of the experiments
Key-Words: - Gasoline - ethanol, Gasoline –methanol, Gas emissions, Two stroke outboard engine
1 Introduction understanding of the use of these two alcohols we The possible increases of the price of crude oil, the must examine them separately. Fuel ethanol is an abrupt oil market changes, the finite of reserves, as alternative fuel that is produced from biologically well as the environmental pollution led to the renewable resources that it can also be used as an reevaluation of the importance of the rural and octane enhancer and as oxygenate. Ethanol (ethyl forestall factor as a renewable resources supplier. alcohol, grain alcohol, ETOH) is a clear, colorless Important quantities of ethanol are produced every liquid alcohol with characteristic odor and as year to be used as fuel [1]. Ethanol has a high octane alcohol is a group of chemical compounds whose number, which means it can be used as a fuel molecules contain a hydroxyl group, -OH, bonded additive, or as a substitute either as pure alcohol or to a carbon atom. It is produced by the process of as mixture of gasoline-alcohol [2]. fermentation of grains such as wheat, barley, corn, Alcohol is produced in laboratories in many ways. wood, or sugar cane. In the United States ethanol is Practical interest occurs in producing ethanol from made by the fermentation of corn [5,6]. By the the rich in sugar plants. ‘‘Alcoholic fragmentation’’ reaction of fermentation simple sugars change into ethanol and carbon dioxide with the presence of is the splitting of single sugars, type C6H12O6, zymase, an enzyme from yeast. Ethanol can also be mainly glucose and fructose, to CO2 which is catalysed by the zymasse enzyme. Raisins, molasses made from cellulose that is obtained from and starchy roots or fruits like potatoes, corn, barley agricultural residue and waste paper [6]. It is a and others are used for this purpose. high-octane fuel with high oxygen content (35% Nowadays mixtures of gasoline - alcohol are used oxygen by weight) and when blended properly in in USA mainly as car fuel (gasohol), either to fight gasoline produces a cleaner and more complete the energy crisis or to decrease environmental combustion. Ethanol is used as an automotive fuel pollution, because of the limited CO, HC emissions. either by itself or in blends with gasoline, such as Compared to pure gasoline, the gasoline-alcohol mixtures of 10% ethanol and 90%gasoline, or 85% mixtures produce smaller calorific output. This is ethanol and 15% gasoline [9,10,11]. Many countries due to the fact that the use of these mixtures in around the world use ethanol as fuel. For example, petrol engines reduces the power of the engine [2,4]. in Brazil ethanol is produced by using as raw The power decreases in principle, increases in material sugarcane and many vehicles use ethanol as proportion to the alcohol percentage in gasoline. fuel. Also in Canada and in Sweden ethanol is The question is how a two stroke low output highly promoted as fuel because of the many outboard engine behaves, from the viewpoint of environmental benefits that ethanol has. When pollution and consumption, when mixture of gasoline is used as fuel hydrocarbons (HC) escape gasoline-alcohol has been used as fuel. Ethanol and to the atmosphere. Many hydrocarbons are toxic and methanol are alcohols that can be used as fuels some, such as benzene, cane cause cancer to instead of gasoline in automobile engines. For better humans. If ethanol is used as fuel hydrocarbons are not being produced because ethanol is an alcohol
ISBN: 978-1-61804-071-8 268 Recent Researches in Engineering Mechanics, Urban & Naval Transportation and Tourism
that does not produce HC when is burned. The The main advantage of methanol as fuel is that is reaction of hydrocarbons and nitrogen oxides that being produced from resources that can be found are produced from the gasoline burning, in the globally, while a large percentage of petroleum is presence of sunlight leads to the formation of located in Middle East. Furthermore, the materials photochemical smog. The use of ethanol as fuel can needed for methanol production such as natural gas contribute to the decrease of photochemical smog or biomass, are renewable. This means that since it does not produces hydrocarbons [11,12,13]. methanol can also be cheaper and more Vehicles that burn petroleum fuels produce carbon economically attractive than gasoline. When fossil monoxide (CO) because these fuels do not contain fuels are used in automobiles produce exhaust oxygen in their molecular structure. Carbon emissions of hydrocarbons, carbon dioxide and monoxide is a toxic gas that is formed by other gases that contribute to the greenhouse effect. incomplete combustion. When ethanol, which Methanol can give lower HC and CO emissions and contains oxygen, is mixed with gasoline the besides that the vehicles that use methanol emit combustion of the engine is more complete and the minimum particulate matter compared to gasoline, result is CO reduction [14,15]. which usually has damaging effect to humans. In Using renewable fuels, such as ethanol, addition, methanol has high-octane content that there is also a reduction of carbon dioxide (CO2) in promotes better the process of combustion. Another the atmosphere. Carbon dioxide is non-toxic but advantage of methanol is that if it does ignite can contributes to the greenhouse effect. Because of the cause less severe fires to the vehicle because is less fact that plants absorb carbon dioxide and give off flammable than gasoline [19,20]. Some oxygen, that balances the amount of CO2 that is disadvantages that methanol has are the lower formed during combustion absorbed by plants used energy content compared to gasoline, the fact that is to produce ethanol. This is why the use of ethanol not volatile enough for easy cold starting and can will partially offset the greenhouse effect that is damage plastic and rubber fuel system components. formed by carbon dioxide emissions of burning The vehicle that uses methanol for fuel must have a gasoline [16,17]. Ethanol, as an octane enhancer, large storage tank because pure methanol burns can substitute benzene and other benzene-like faster than gasoline, and besides that, materials that compounds, which are powerful liver carcinogens, are not corrosive must make the storage equipment and reduce their emissions to the atmosphere. [21,22,23]. Renewable fuels such as methanol and Besides the environmental benefits, production and ethanol will probably replace petroleum-based fuels use of ethanol, which is a renewable fuel, increases in the near future because petroleum reserves are not economic activity, creates job openings, stabilizes sufficient enough to last many years. Also, the prices and can increase farm income. As a result severe environmental problems around the world ethanol as an automotive fuel has many advantages. will eventually lead to the use of more Methanol (CH3OH) is an alcohol that is produced environmentally friendly technologies. The question from natural gas, biomass, coal and also municipal that is examined in this paper is how the mixtures of solid wastes and sewage. It is quite corrosive and gasoline-ethanol and gasoline-methanol behave in a poisonous. Methanol has lower volatility compared four-stroke engine from the aspect of emissions, to gasoline, which means that is not instantly function and fuel consumption. flammable. Usually methanol is used as a gasoline- blending compound, but it can be used directly as an automobile fuel with some modifications of the 2 Instrumentation and experimental automobile engine. Although there are many results feedstocks that are being used for the production of methanol, natural gas is more economic. Methanol The tests were realised on an engine, type is produced from natural gas with a technology of EVINRUDE 4HP and volume 50cc, which is used steam reforming. By this method natural gas is on small boats. For the measurement of exhaust transformed to a synthesis gas that is fed to a reactor gases, an exhaust analyser was used, type HORIBA vessel to produce methanol and water at the MEXA 574E infrared radiation (Non Dispersive presence of a catalyst. The reactions that represent Infra Red) with a 0 to 10% CO and 0ppm to methanol production are the following [18,19]: 10.000ppm HC range. The engine was placed in a container filled with tap water. The testings were 2CH4 + 3H2O CO + CO2 +7H2 (Synthesis gas) realised using different gasoline-alcohol CO + CO2 + 7H2 2CH3OH +2H2 + H2O mixtures(gasoline, gasoline-10%ethanol, gasoline- 20%ethanol, gasoline-30%ethanol and gasoline-
ISBN: 978-1-61804-071-8 269 Recent Researches in Engineering Mechanics, Urban & Naval Transportation and Tourism
10%methanol, gasoline-20%methanol, gasoline- methanol 30%methanol), keeping the oil quantity stable, at 2 1:50. For each of the above mixtures, the engine 1,8 gasoline operated with different revolutions (500-1000-2000- 1,6 10% 3000rpm) and there was a continuous monitoring of 1,4 the exhaust gases, CO and HC, for each mixture and 1,2 20% number of revolutions separately. The second series 1 30% of experiments dealt with the fuel consumption, CO%0,8 which was measured separately for each mixture 0,6 always in relation to the different engine speed. 0,4 The environmental conditions, for all of the testings 0,2 0 above, were temperature 200C and pressure 1atm with negligible fluctuations. The experimental 0 500 1000 1500 2000 2500 3000 results are shown at the following figures: rpm
Figure 3. CO variation in relation to revolutions for ethanol 2 the different gasoline-methanol mixtures 1,8 gasoline 1,6 10% 1,4 20% methanol 1,2 4500 1 30% 4000 CO%0,8 3500 0,6 0,4 3000 2500 0,2 gasoline 0 2000 10% 0 500 1000 1500 2000 2500 3000 H C1500 (p p m ) 1000 20% rpm 500 30% 0 Figure 1. CO variation in relation to revolutions for 0 500 1000 1500 2000 2500 3000 the different gasoline-ethanol mixtures rpm
ethanol Figure 4. HC variation in relation to revolutions for 4500 the different gasoline-methanol mixtures 4000 3500 3000 In figures 1,3, it is noticed that the increase in the 2500 gasoline fuel alcohol percentage results in the CO reduction. 2000 10% Figures 2, 4 presents the HC variation in relation to H C1500 (p p m ) motor engine speeds separately for each fuel 20% 1000 mixture. The increase in the alcohol fuel percentage 500 30% results in a HC increase, contrary to the CO 0 reduction illustrated figure 1and figure 3. The 0 500 1000 1500 2000 2500 3000 increase of HC is probably caused by the production rpm of aldehydes during the combustion . The results of the second series of experiments, shown on figure 5, Figure 2. HC variation in relation to revolutions for refer to the engine consumption in relation to the the different gasoline-ethanol mixtures revolutions and the fuel mixture.
ISBN: 978-1-61804-071-8 270 Recent Researches in Engineering Mechanics, Urban & Naval Transportation and Tourism
9
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3 consumption(ml/min)
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0 500rpm 1000rpm 2000rpm 3000rpm gasoline 4,9 5,4 6,2 7,1 10% 5,3 5,6 6,4 7,4 20% 5,7 5,9 6,6 7,6 30% 6,1 6,3 6,9 8,9
Figure 5. The variation of fuel consumption in relation of engine rpm and fuel (ethanol and methanol) mixtures
in consumption. Also, it must be mentioned that the In figure 5 it can be noticed that the engine adjustment of the engine (air/fuel ratio) was that consumption increases in proportion to the % which referred to the use of gasoline as fuel. alcohol fuel percentage. This is the result of ethanol Comparing the mixtures of gasoline-ethanol and and methanol low calorific value, which means that gasoline-methanol it can be concluded that the in order to achieve the same number using pure mixture of gasoline-methanol appeared better gasoline, the fuel quantity in the combustion behavior regarding to gas emissions, but the same chamber must be increased when we use a gasoline- behavior regarding to fuel consumption. ethanol and gasoline- methanol mixtures. It is important to mention that there was no difference in References: the fuel consumption among the mixtures of gasoline-ethanol and gasoline-methanol. [1]. M. Kirik, “Alcohol as an Alternative Fuel “ The Ontario Digest and Engineering Digest , pp. 29-31, 3 Conclusion September 1997. [2]. C I. Arapatsakos and P D. Sparis. “ Bioethanol - The use of gasoline-ethanol and gasoline-methanol Premium Gasoline Mixture Tests in Otto Engines” mixtures, from the pollution viewpoint, results in a Meeting of the Greek Section of Combustion CO reduction and a HC increase. These effects Institute, Athens, 1997 increase with the ethanol and methanol percentage in the fuel. Finally, from the consumption [3].Swedish Motor Fuel Technology Co., Alcohol viewpoint, it was noticed that the increase in the and Alcohol Blends as Motor Fuel, Vol IIB, p. 8:39, alcohol fuel percentage has as a result the increase STU Information No. 580, 1986.
ISBN: 978-1-61804-071-8 271 Recent Researches in Engineering Mechanics, Urban & Naval Transportation and Tourism
[4]. R.M Tillman, Blending, “ Distribution and [18]. Environmental Protection Agency ''Fact Sheet Marketing Aspects of Alcohols as Alternative CMS-7, EPA 400-F-92-009'', USA, August 1994 Fuels” Ontario , November 19, 1976. [19]. Methanol Institute, ''Methanol Production'', [5]. Koenig H Menrad and W. Bernhardt, “Alcohol Methanol Historical Pricing, Copyright 1996-2001 Fuels in Automobiles ”Alcohol Fuel Conference, Inst. Chem. Eng. , Sydney, 9-11 August 1978. [21]. E. R. Fanick, L. R. Smith, et al., '' Laboratory evaluation of safety-related additives for neat [6]. Timothy T. Maxwell and Jesse C. Jones methanol fuel'', SAE paper No 902156, 1990. ''Alternative fuels: Emissions, Economics and Performance'' Published by SAE, 1995. [22]. J. Panzer, ''Characteristics of primed methanol fuels for passenger cars'', SAE paper No 831175, [7]. Keith Owen and Trevor Coley ''Automotive 1983. Fuels Reference Book'' Second Edition, Published by SAE, 1995. [23]. M. Singh, '' A comparative analysis of alternative fuel infrastructure requirements'', SAE [8]. Fred Schafer and Richard van Basshuysen " paper No 892065, 1989. Reduced Emissions and Fuel Consumption in Automobile Engines" Published by SAE, 1995.
[9]. Swedish Motor Fuel Technology Co., '' Alcohols and alcohol blends as motor fuels'' Vol. II B, p.8:39, STU information No 580,1986.
[10]. H. Menrad and M. Haselhorst, "Alcohol fuels", Monograph. Springer, New York, ISBN 3211816968,1981
[11]. Harrington, I.A.; Shishu, R.C.: A Single- Cylinder Engine Study of the Effects of Fuel Type, Fuel Stoichiometry and Hydrogen-to-Carbon Ratio on CO, NO and HC Exhaust Emissions, SAE-Paper 730476.
[12]. K. Taschner, ''Who Needs Biofuels'' European Environment Bureau Brussels 1993.
[13].D.J Rickeard and N.D.Thompson. ''A review of the potential for biofuels as transportation fuels'' SAE paper No.932778, 1993.
[14]. U.E. Stumpf, "Brazilian Research on Ethyl Alcohol as an Automotive Fuel" Alcohols Fuels Conference, Inst. Chem. Eng., Sydney, 1978.
[15]. N.N.: U.S. EPA, Clean Air Facts, Nr. 3, 5, 9, 10, 15/1989, Washington, D.C.
[16]. N.N.: VDA-Jahresbeicht. Auto 89/90, Sept.1990
[17]. "The Clean Fuels Report" J.E. Sinor Consultants Inc., Niwot, Colorado, February 1991.
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