Chapter 2 CHAPTER 2 REVIEW OF LITERATURE, OBJECTIVES AND SCOPE

Transcription

1 CHAPTER 2 REVIEW OF LITERATURE, OBJECTIVES AND SCOPE

2 C haptci Literature survey on fuels, ethanol, internal combustion engines, pollution. Usage of a vegetable oil was conducted as early as 1853 by scientists E. Duffy and J. Patrick, many years before the first diesel engine became functional. Rudolf Diesel's prime model, a single iron cylinder with a fly wheel at its base, ran on its own power for the first time in Augsburg, Germany, on August 10, 1893, in remembrance of this event, August 10 has been declared "International Biodiesel Day" The French Otto Company demonstrated a Diesel engine running on peanut oil at the World Fair in Paris, France in 1900, where it received the Grand Prix, this engine stood as an example of Diesel's vision because it was powered by peanut oil - a biofuel, though not biodiesel. since it was not transesterified, he believed that the utilization of biomass fuel was the real future of his engine. In 1912 Speech and Diesel said, "the use of vegetable oils for engine fuels may seem insignificant today but such oils may become in the course of time, as important as petroleum and the coal-tar products of the present time". During the 1920s, diesel engine manufacturers altered their engines to utilize the lower viscosity of petrodiesel (a fossil fuel) rather than vegetable oil l56 -> 98, the petroleum industries were able to make inroads in fuel markets because their fuel was much cheaper to produce than the biomass alternatives. The result, for many years was a near elimination of the biomass fuel production infrastructure. Only recently have environmental impact concerns and a decreasing price made biomass fuels such as biodiesel a growing alternative. Despite the widespread use of fossil petroleum-derived diesel fuels, interest in vegetable oils and ethanol as fuels in internal combustion engines is reported in several countries, during the 1920s 's later in World War II and also in Belgium, France, Italy, the United Kingdom, Portugal, Germany, Brazil, Argentina, Japan. As a fuel ethanol can be mass-produced by fermentation of the starch or sugar in a wide variety of crops (bio-ethanol) or by hydration of ethylene from petroleum and other sources and there is a considerable debate about how useful bio-ethanol will be in replacing fossil fuels in vehicles and concerns relate to the large amount of arable land required for crops, as well as the energy and pollution balance from the ethanol production cycle Ethanol fuel is the same type of alcohol found in alcoholic beverages, can be used as a fuel, mainly as a biofuel alternative to gasoline and is widely used by light vehicles in Brazil and as an oxygenate to gasoline in the United States, -4-

3 together both countries were responsible for 89 percent of the world's ethanol fuel production in 2008, because it is easy to manufacture and process and can be made from very common crops such as sugar cane, potato, corn. In several countries ethanol fuel is increasingly being blended as gasohol or used as an oxygenate in gasoline. Bioethanol unlike petroleum, is a renewable resource that can be produced from agricultural feedstocks. Anhydrous ethanol (ethanol with less than 1% water) can be blended with gasoline in varying quantities up to pure ethanol (El00) and most modern gasoline engines will operate well with mixtures of 10% ethanol (E10). Most cars on the road today in the U.S.are running on blends up to 10% ethanol and the use of 10% ethanol gasoline is mandated in some cities. Ethanol can be mass-produced by fermentation of sugar or by hydration of ethylene (ethene CH 2 =CH 2 ) from petroleum and other sources. Current interest in ethanol mainly lies in bio-ethanol, produced from the starch or sugar in a wide variety of crops, according to the International Energy Agency, cellulosic ethanol could allow ethanol fuels to play a much bigger role in the future than previously thought. Cellulosic ethanol offers promise as resistant cellulose fibers, a major and universal component in plant cells walls can be used to generate ethanol. Ethanol-based engines Ethanol is most commonly used in automobiles, though it may be used to power other vehicles such as farm tractors and aeroplanes. Ethanol (El 00) consumption in an engine is approximately 51 % higher than for gasoline, since the energy per unit volume of ethanol is %) lower than for gasoline. However, the higher compression ratio's in ethanol increases power output and better fuel economy that could be obtained with lower blending mixtures. In general, ethanol based engines are tuned to give slightly better power and torque output than gasoline-powered engines. In flexible fuel vehicles, the lower compression ratio requires tunings that give the same output when using either gasoline or hydrated ethanol. For maximum use of ethanol's benefits, a much higher compression ratio should be used, which would render that engine unsuitable for gasoline use. so due to its high combustion, ethanol diesel blends gives high-compression, high fuel efficiency which is equal to or greater than current gasoline engines. -5-

4 C haptei 2 A 2004 MIT study and an earlier paper published by the Society of Automotive Engineers identify a method to exploit the characteristics of fuel ethanol substantially better mixing it with gasoline. This method presents the possibility of using alcohol to achieve definite improvement over the cost-effectiveness of hybrid electric. The improvement consists of using dual-fuel direct-injection of pure alcohol (or the azeo trope or E85) and gasoline in any ratio up to 100% of either in a turbocharged, high compression-ratio, small-displacement engine results in similar performance to gasoline engine. The high-compression (which increases efficiency) engine will run on ordinary gasoline under low-power cruise conditions and alcohol is directly injected into the cylinders only when necessary to suppress 'knock' such as when significantly accelerating and raises the octane rating of ethanol up to an effective. The calculated ethanol use brings over-all reduction of C0 2 emission is to 30%. The consumer cost payback time shows a 4% improvement over turbo-diesel and a 5% improvement over hybrid In addition, the problems of water absorption into pre-mixed gasoline (causing phase separation), supply issues of multiple mix ratios and cold-weather starting are avoided.ethanol's higher octane rating allows an increase of an engine's compression ratio for increased thermal efficiency based on this study it is used in diesel engines and thermal efficiency up to 40% approximately that for a diesel was achieved. Since 1989 there also been ethanol engines based on the diesel principle operating in Sweeden, they are used primarily in city buses, but also in distribution trucks and waste collectors. The engines made by Scania have a modified compression ratio and the fuel (known as ED95) used is a mix of 93.6 % ethanol and 3.6 % ignition improver, and 2.8% denaturants and it is one of the ignition improver which makes it possible for the fuel to ignite in the diesel combustion cycle. It is then also possible to use the energy efficiency of the diesel principle with ethanol. Ethanol contains approx. 34% less energy per unit volume than gasoline and therefore in burning pure ethanol in a vehicle will result in a 34% reduction exhaust. Since ethanol has a higher octane rating, the engine can be made more efficient by raising its compression ratio fact using a variable turbocharger, the compression ratio can be optimized for the fuel being used, making fuel economy almost constant for any blend.. For El 0 (10% ethanol and 90% gasoline), the effect is small (-3%) when compared to conventional gasoline and even smaller (l-2%o) when compared to oxygenated and reformulated blends. However for E85 (85% ethanol), actual performance may vary depending on the vehicle. Based on EPA tests for all 2006 E85 models, the average fuel economy for E85 vehicles resulted 25.56% lower than. In -6-

5 ( haptci 2 unleaded gasoline. The EPA-rated mileage of current USAflex-fuelvehicles should be considered when making price comparisons, but it must be noted that E85 is a high performance fuel with an octane rating of about 104. Brazil has ethanol fuel available throughout the country, a typical Petrobras filling station at Sao Paulo with dual fuel service, marked A for alcohol (ethanol) and G for gasoline. Typical Brazilian "flex" modelsfromseveral carmakers that run on any blend of ethanol and gasoline from E20-E25 gasohol to E100 ethanol fuel. The Honda CG 150 Titan Mix was launched in the Brazilian market in 2009 and became the first flex-fuel motorcycle sold in the world. Brazil has the largest and most successful biofuel programs in the world, involving production of ethanol fuel from sugar cane, and it is considered to have the world'sfirstsustainable biofuels economy. In 2006 Brazilian ethanol provided 18% of the country's road transport sector fuel consumption needs and by April 2008, more than 50% of fuel consumption for the gasoline market

6 ( hapici 2 Fuel Fuel is any material that is burned or altered to obtain energy and to heat or to move an object. Fuel releases its energy either through a chemical reaction means such as combustion or nuclear means, such as nuclear fission or nuclear fusion. An important property of a useful fuel is that its energy can be stored to be released only when needed and that the release is controlled in such a way that the energy can be harnessed to produce work. Fuel can be broadly defined as solid, liquid and gas fuel derived from biomass. Biomass can also be used directly for heating or power known as biomass fuel. Biofuel can be produced from any carbon source that can be replenished rapidly e.g. plants. Many different plants and plantderived materials are used for biofuel manufacture. As a fuel, wood has remained in use up until the present day, although it has been superseded for many purposes by other sources. Wood has an energy density of MJ/kg. Recently biofuels have been developed for use in automotive transport (for example El 0 fuel), but there is widespread public debate about how carbon efficient these fuels are. The burning of fossil fuels by humans is the largest source of emissions of carbon dioxide, which is one of the greenhouse gases that enhances radiative 289 forcing and contributes to global warming. The atmospheric concentration of CO,, a greenhouse gas is increasing, raising concerns that solar heat will be trapped and the average surface temperature of the earth will rise in response. Coal was first used as a fuel around 1000 BC in China, with the development of the steam engine in 1769, coal came into more common use as a power source. Coal was later used to drive ships and locomotives. By the 19th century, gas extracted from coal was being used for street lighting in London. In the 20th century, the primary use of coal is for the generation of electricity, providing 40% of the 23 V58 world's electrical power supply in " Alternative fuels also known as non-conventional fuels, are any materials or substances that can be used as fuels other than conventional fuels. Conventional fuels include: fossil fuels (petroleum, coal, propane, and natural gas) and nuclear materials such as uranium. Some well known alternative fuels include biodiesel, bioalcohol (methanol, ethanol, butanol),chemically stored, electricity (batteries and fuel cells), hydrogen, non-fossil methane, non-fossil natural gas, vegetable oil and other biomass sources. The main purpose of fuel is to store energy in a form that is stable and can be easily transported from the place of production to the end user. Almost all fuels are chemical fuels, which store chemical potential energy. The end user may consume the fuel at will and release energy, usually in the form of heat for a variety of applications, such as powering an

7 engine or heating a building. In 2007, there were 2.3 million alternative fuel vehicles sold in the all over the world indicating an increasing popularity of alternative fuels". There is growing perceived economic and political need for the development of alternative fuel sources. This is due to general environmental, economic and geopolitical concerns of sustainability. The major environmental concern, according to an IPCC report is that "Most of the observed increase in globally averaged temperatures since the mid-20th century is due to the observed increase in anthropogenic greenhouse gas concentrations". Since burning fossil fuels is known to increase greenhouse gas concentrations in the atmosphere, they are a likely contributor to global warming.

8 Esters Esters are organic compounds in chemistry, in which an organic group replaces a hydrogen atom. An ester can be thought of as a product of a condensation reaction of an acid (usually an organic acid) and an alcohol (or phenol compound) although there are other ways to form esters. Condensation is a type of chemical reaction in which two molecules with -OH groups are joined with eliminating a water molecule from their -OH groups. A condensation reaction to form an ester is called esterification. Esterification can be catalysed by the presence of H + ions. Esters can be produced by an equilibrium reaction between an alcohol and a carboxylic acid. The ester is named according to the alkyl group (the part from the alcohol) and then the alkanoate. " Esters participate in hydrogen bonds as hydrogenbond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding makes them more water-soluble than their parent hydrocarbons. However, the limitations on their hydrogen bonding also make them more hydrophobic than either their parent alcohols or parent acids. Their lack of hydrogen-bonddonating ability means that ester molecules cannot hydrogen-bond to each other, which makes esters generally more volatile than an carboxylic acid of similar molecular weight. This property makes them very useful in organic analytical chemistry unknown organic acids with low volatility can often be esterified into a volatile ester, which can then be analysed using gas chromatography, gas liquid chromatography or mass spectrometry. Esters may undergo hydrolysis - to breakdown an ester by water. This process can be catalyzed both by acids and bases. The base-catalyzed process is called saponification. The hydrolysis yields an alcohol and a carboxylic acid or its carboxylate salt. -10-

9 Pollution Global warming is a term having to do with the slow increase of the Earth's temperature. The average temperature at the surface of the earth has gone up by 0.6 Celsius, since the late 19 th century. There are several theories (ways) which try to explain this increase. Some scientists think that the warming of the last 50 years is believed to be a result of increases in the greenhouse effect caused by carbon dioxide (C0 2 ). Coal-burning power plants, automobile exhausts, factory smokestacks and other waste vents of the human environment give off about 23 billion tons of carbon dioxide and other greenhouse gases into the earth's atmosphere each year. The atmospheric concentration of C0 2 has increased by 31% above pre-industrial level. From less direct geological evidence, it is believed that C0 2 values is high were last attained 40 million years ago. About three - quarters of the antropogenic emissions of C0 2 to the atmosphere during the past 20 years are due to fossil fuel burning. The rest is predominantly due to land-use change, especially deforestation.the possible effects of global warming are frightening. The united nations environment program recently announced that severe weather around the world has made 2005 the most costly year on record. It would cost a lot of money to cut off human-caused greenhouse gases completely and that would not stop the warming that must come from the gases already in the atmosphere. 273

10 ( haptci 2 Internal combustion engine The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber. In an internal combustion engine, the expansion of the high temperature and pressure gases, which are produced by the combustion directly applies force to a movable component of the engine such as the pistons or turbine blades and by moving it over a distance and generate useful mechanical energy. The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines along with 149 variants, such as the Wankel rotary engine, which works on the same principle of diesel engines. The internal combustion engine (or ICE) is quite different from external combustion engines such as steam or Stirling engines in which the energy is delivered to a working fluid not consisting of mixed with or contaminated by combustion products. Working fluids can be air, hot water, pressurised water or even liquid sodium, heated in some kind of boiler by fossil fuel, wood-burning, nuclear, solar etc. A large number of different designs for ICEs have been developed and built with a variety of different strengths and weaknesses. Powered by an energy-dense fuel (which is veryfrequentlya liquid derivedfromfossil fuels) the ICE delivers an excellent power-to-weight ratio with few safety or other disadvantages, the real strength of internal combustion engines is in mobile applications and they dominate as a power supply for cars, aircraft, and boats, from the smallest to the biggest. Only for hand-held power tools do they share part of the market with battery powered devices. Internal combustion engines are most commonly used for mobile propulsion in vehicles and portable machinery. In mobile equipment, internal combustion is advantageous since it can provide high power-to-weight 152 ratios together with excellent fuel energy density. Generally using fossil fuel (mainly petroleum) these engines have appeared in transport in almost all vehicles (automobiles, trucks, motorcycles, boats, and in a wide variety of aircraft and locomotives). -12-

11 2.2 Objectives and scope of the present work Here in this present work ethanol and its ethanol oil derivative blends are commonly used in internal combustion engines, it is a renewable energy source produced from agricultural feed stocks and replaces the fossil fuels with good performance result as well as in reducing pollution. It can be used as a bio-fuel alternative to gasoline but it is not feasible to blend with diesel upto maximum extent. So we made ethyl esters of different edible and non-edible oils blends, these ethanol blends results in possible effects of reducing exhaust emission upto 70% and by increasing fuel effeciency, reducing specific fuel consumption by increasing its cetane number. Engine performance in automobiles creats major savings in costwise analysis. Scope of ethanol blends By using Diesel - Ethanol blends engine results less efficiancy, so benzene is used as a solubilize, thermal efficiency of diesel - ethanol blends has been increased, ethanol direct blending is not feasible upto maximum extent so only 40% efficiency in terms of performance, ethanol derivatives are renewable sources, it relates the properties in terms of physical and chemically with diesel, energy security issues will be prominent in needs, performance analysis are comparitively high with diesel due to its fatty acid composition of oils which increases oxidation stability, substantial reduction of exhaust emission, by 0.05% by weight of sulphur, based on biodiesel specification and testing procedures biodiesel is stored, improvement in Kmpl, Transport economy, high calorific value results in high efficiency, cetane number has been increased, knock rating decreased with high ignition quality, decrease in delay period increases compression ration, density of fuel air increases due to its high oxygenated high volatile, less fuel consumption, speed increases, consistency of fuel. -13-