Testing of Biofuels on an SI EngineThesis Report submitted in partial fulfillment of the requirement for the degree ofB.S.InMechanical EngineeringUnder the Supervision ofDr.Mohy MansourByAbdelrahman AbdelrahmanAhmed El TayebieAmr Hamed RedaMazen El BarawyAmerican University in CairoDecember 2014

Acknowledgement We would like to thank our friends, family members and all the doctors that helped us during our thesis. Also special thanks to our advisor Dr. Mohy Mansour who supported us during our research.

Table of ContentsList of TablesList of FiguresAbstract 1. Introduction1.1. Problem Statement1.2. Background1.3. Objectives and Outcomes1.4. Project Plan 2. Methodology2.1. Sugarcane and Rice straw production2.2. Pollution2.3. Fuel Characteristics2.4. Engine2.5. Operating Characteristics2.6. Modifications3. Preliminary Results4. Conclusion5. References

List of tables

List of figures

AbstractOur world today is facing a major energy crisis and the demand for energy is consciously increasing. The world is depending heavily on fossil fuels as a source of energy and Egypt is no exception. We this rate of consumption we are expected to run out of energy sources soon. Even if we dont run out of fossil fuels soon there will come a point in time where there are alternatives to oil that are less expensive, and the process of extracting oil will become very uneconomical. This also means that the prices of oil will rise to the point where people will use less of it. Egypt produces a lot of agricultural crops that can be used to produce biofuels which is considered a renewable and sustainable type of energy. This project aims to give a brief introduction about the importance of biofuel. The main objective is testing blends of gasoline and ethanol produced form rice straw and sugarcane and find out which best suits us in Egypt.

IntroductionProblem StatementThe world today depends heavily on fossil fuel and crude oil as our primary sources of energy. There is an ongoing debate about when will the non-renewable be diminished.research has conducted that the world is going to run on out of oil in approximately 35 years, coal in 107 years and gas in about 37 years. Other studies have also suggested that the earth will run out of oil in 30-40 years. [1] It is estimated there are 1.3 trillion barrels of oil proven to exist. By the consumption rate we have now it, the world will be left without oil around year 2040. [2] Because of the increase in demand and decrease in supply the price of the fossil fuel which rise dramatically during the next few years. This also means that the prices of oil will rise to the point where people will use less of it. Others will look for alternatives. Either way, research has shown that alternative fuels would benefit the world and would make it possible to avoid a crisis if oil does in fact diminish. The best option now is to turn to renewable types of energy which are sustainable and most of them produce less green house emissions than the fossil fuels.

The table below also shows the amount of giga tonnes of oil equivalent and also the fossil fuel reserve (%) according to each region in the year 2006.Table 1: Fuel reserve of some of the region in 2006 [1]Fuel fossil reserves in 2006Fossil fuel reserve (gteo)Fossil fuel reserve (%)

Region

OilCoalGasSumOilCoalGasSum

North America817071850.8618.20.7519.81

South America15136341.611.390.643.64

Europe2405470.214.280.545.03

Africa163413631.713.641.396.75

Russia18152522221.9316.275.5723.77

Middle East10106616710.8107.0717.88

India1621640.116.640.116.85

China2762800.218.140.218.57

Australia and East Asia26010720.216.421.077.71

Total16560716293417.6764.9917.34100

Background Research

The term sustainable energy development broadly means being able to live and produce energy and consume such energy in a way that we can meet our needs. Also we need to consume the energy in a manner that does not affect the needs of our future generations. [3] There are many types of energy, the main types that are used nowadays are oil, coal, gas, renewable energy and nuclear energy. Nowadays the world is depending heavily on fossil fuels as our primary source of energy and this is a non-renewable type of energy and this means that we are far away from energy sustainability and sustainable energy development. According to a research done in the year 2011 oil consumption accounts for 31.5% of our worlds energy consumption, where as coal account to about 28.8%, gas with about 21.3%, renewable energy with about 13.3% and finally nuclear energy with about 5.1%. [4]

In order to read this level of sustainability the world needs to shift its consumption from non- renewable types of energy such as oil, coal and gas towards other types of renewable energy.

Figure 1: percentages of energy used in 2011 [4]

2.2 Renewable energyRenewable energy also known as Green Energy or Sustainable Energy is a type of energy that can be obtained from sources that are naturally replenished around us such as wind energy, solar energy, biomass energy, geothermal energy, hydropower energy and tidal energy.All these examples are considered alternative types of energy that can produce clean energy with low green house emissions. Many of these alternative types of energy are being implemented in the world today such as solar cells converting the suns energy into electric and heat energy and also dams to obtain hydropower. On the other hand some of these sources are currently un feasible such as nuclear energy.

2.2.1 Solar energySolar energy is a type of energy that can be produced using energy taken from the sun to provide different services. It can be used for personal or business matters. Here are the different ways that solar energy can be used:

Photovoltaic Systems: is a solar energy technology where electricity is produced from sunlight directly. For this process to take place, solar cells must be used, the same kind used for different applications such as watches. The photovoltaic effect occurs when these solar cells extracts sunlight and loosens electrons from atoms.

Hot Water: this system comes from the natural occurrence of the sun heating the bottom of a river or lake if it is shallow enough. Solar hot water systems basically have two main components. The first one would be the solar collector, which contains tubes that carry the water. These tubes are connected to the absorbing plate, which absorbs the heat and begin to heat the water in these tubes. The second component is the storage tank, which is responsible for holding the water after it has been heated. Pumps are used for moving the water through the tubes. This system can also be used for swimming pools.

Solar Electricity: this can be used to construct a power plant that runs on solar energy, using the sun as its source of energy. There are 3 types of solar power systems. The first one is the parabolic-trough, which uses U-shaped mirrors facing the sun and uses its light to heat oil, which is then used to boil a steam generator that produces electricity. The second type of system is the dish/engine, which uses a dish shaped surface that absorbs heat and transports it to a fluid inside an engine. This heat causes a mechanical system to initiate by making the fluid react and come in contact with a piston. The third type is the power tower system where a field of mirrors is used to absorb heat and this heat is applied to molten salt. The advantage of this system is that molten salt can preserve this heat inside it for a few days which means electricity can still be produced even if we are having a day where we have a little amount of sunlight (cloudy day).Solar energy produces about 0.6 MTOE (Million Tons of Oil Equivalent)which accounts for about 12% of its total potential. [5]

2.2.2 Wind energyWind Energy can be obtained from the moving air, which has huge amounts of kinetic energy that can be converted to electric energy that can be transferred to electrical energy. Wind energy produces about 0.2 MTOE (Million Tons of Oil Equivalent), which account to about 4% of its potential. [5]

The main advantage to wind energy is that it produces no kinds of harmful emissions.Today what is used for wind energy instead of a windmill is a wind turbine. These turbines are put onto a high tower and the reason for that the turbines can take advantage of faster winds as it goes higher. These blades go through a process called lift. Lift is where turbulence occurs with low pressure that pulls the blades towards it causing the rotor. This makes the shaft spin and generate electricity. Wind turbines on its own can be used for pumping water or communications. However wind turbines can be combined with other systems for more complicated applications. An example of this is using it with a photovoltaic system to make a power grid.

2.2.3 Geothermal EnergyThis is the energy that can be extracted from the earth itself. This geothermal energy can be taken from different layers from the earth. It can be extracted from shallow ground, hot rocks beneath the surface but close, or magma that is deep within the earth at very high temperatures. Geothermal energy can be used to heat or cool down. Using pumps that contain an air delivery system and a heat exchanger system can do this application. This process also contains pipes that are buried near the building that needs to be heated or cooled. Hot rocks, which are another source, can be found 3 to 5 miles deep from the surface. The process is done by using cold water and receiving hot water back due to the circulation on these hot rocks do this. The most powerful source for geothermal energy would be the magma that is found deep within the earth and at very high temperatures but the world does not have the technology for it until now.Geothermal produces about 0.2 Mtoe and this is about 4% of its total potential. [5]

2.2.4 Hydro PowerThis type of energy is obtained from water flowing. The high dam in Egypt is an example. The dam stores water from a river in a reservoir. The reservoir releases this water and makes it flow through a turbine that in turn spins and makes a generator produce electricity. Another system where hydropower is used is a pumped storage plant. The main advantage of this system is that it can store energy. Power grids are installed and send power to the electric generators, which cause the turbines to turn backwards when spinning. The water is then pumped from the lower reservoir to the upper reservoir, and that is where the power is stored. In order to use this power, the water must be released from the upper reservoir and cause to the turbine to spin forward to follow the standard procedure. hydropower energy 1.7 Mtoe -15%of total potential. [5]

2.2.5 Ocean EnergyThere are two types of energy that can be found in the ocean. They are thermal energy, which comes from the sunlight, and mechanical energy that comes from tides and ocean waves. The ocean covers most of the earth which is why if used for generating energy can prove very effective. As seen many times above in other processes, thermal energy from the ocean can be used for generating electricity. Turbines must be installed here with a generator as well. The second type of energy, which is mechanical energy, is obtained by tides, which are mainly caused by the gravitational pull of the moon. To convert this energy Mechanical energy can also be obtained by waves, which are caused by wind. To convert this mechanical energy to electricity, a dam must be installed in order for a generator to be activated. With waves, reservoirs can be used. Waves can also be used for hydraulic pumps.

2.2.6 BiomassOne of these alternatives that can be used is biofuel. A biofuel is a source of energy extracted from living things. There are two main type of biofuel which are biodiesel and ethanol. First biodiesel which is a type of fuel that can extracted from soya beans, oil and algae. The second type is ethanol which is an alcohol form of fuel that can be extracted form many crops such as rice straw, sugarcane, corn and wheat. Although some are against it because of the production of carbon dioxide, supporters of biofuel claim that growing the plants will remove the carbon dioxide. The production of biomass is 3.3 MTOE (65%) and it total potential is approximately equal to 5.1 MTOE (100%). [5]Objectives and Outcomes Introduction to the need of Biofuels

Substituting gasoline with an alternative fuel

Selecting biofuels that can be used in most SI engines without major modifications

Testing different compositions and types of biofuels that are available in Egypt

Determining the best biofuel based on performance characteristics

2.3 Bio-fuelBiofuels are energy sources made from living things. In order to order to use a fuel as an alternative for oil and use it in an engine, it needs to be in liquid form. Which brings us to a big advantage in biofuels. This makes it easy to handle and can be pumped smoothly.

Advantages and disadvantages of biofuels Advantages Biofuels is a kind of renewable energy, which means that it will always be available. It would decrease the dependence on oilDisadvantages It has a lower energy output than that of oil Its production has a higher cost due to a different process and certain modifications that might be needed. [6]

Uses of biofuelThere are 3 main usages of biofuel.1- Transportation: This is probably the most important use of biofuel. Transportation is one of the most things that consume energy. If the world does in fact run out of oil, it would be a major crisis and our society would suffer.

2- Power generation: without electricity, our modern world would cease to exist. There many means of creating electricity and oil here is not a big factor. But biofuels would also be here an efficient fuel because it would produce fewer pollutants than most other alternatives. Some examples of these other options are coal, hydro, and natural gas.

3- Heat: can also be produced using solid biofuels such as wood. Natural gas is widely used for this cause. Biofuels can also here prove a worthy alternative because of rising prices.

There are three types of biofuels:First generation biofuels: are biofuels extracted from food crops directly. This type can also be obtained from sugar, vegetable oil or animal fats.

Second generation biofuels: are biofuels that are not fit for human consumption, which means that the source can not be food crops, unless they have already been used and are currently a waste. Certain types of grass would be examples for second-generation biofuels.

Third generation biofuels: are biofuels extracted from algae. The reason algae are categorized all on its own is that it has yields much higher than that of second-generation biofuels and uses only a few resource inputs.

In our project, we chose to focus on the use of food crops (first generation biofuels). As mentioned above, there are many things that can produce first-generation biofuels. However we chose two specific kinds of first-generation biofuels that we will experiment with.

1-Biodiesel is a type of biofuel that is extracted from vegetable oils. It can also be made from seed oils or animal fats. Biodiesel are produced from the reaction of alcohol and triglycerides. For biodiesel to be used on engines, some modifications must be made. The reason for this is that biodiesel contains some content such as alcohol that might possibly react with rubber.

2-Bio-alcohol (Ethanol): is basically alcohol used as fuel. The famous automaker Ford planned originally to make all its cars run on bio alcohol but the drinking of alcohol made it more expensive than using oil. Another reason ethanol did not become used is that it takes 1.5 times the amount of ethanol than gasoline to produce the same amount of energy. We will be experimenting with ethanol specifically for our project.

In order to use these as our fuel we needed to find a source that is available in Egypt with abundance in order for bio fuels to be accessible for our project. That is the reason we chose to use sugar cane and rice as our source for biofuels. There are other reasons why using these two sources might be a great choice for Egypt specifically. Dessert region conditions facilitate the growth of sugarcane crops. Large amounts of water supply and shine are available which are necessities for the growth of our choice of biofuels. Another fact is that Egypt is a large producer of rice which would greatly improve our cause in producing biofuels through it.

2.4 Sugar Cane ProductionThe Sugar Crops Research Institute states that sugar cane is the main source for refined sugar in Egypt. It is also the only source in Egypt for the molasses industry. An advantage of using sugar cane for producing biofuel is that it is easily cultivated and processed. Another advantage is that sugarcane is considered a high-energy crop. Egypt produces 16 million tons of sugarcane annually.[7]

[7] http://www.fao.org/home/en/

2.4.1 Sugarcane ethanol production

1. Extraction: The first step for production of ethanol from sugarcane is the extraction of the substance that will be used which is sucrose by crushing the crops of sugarcane. After the crushing the sugarcane crops, we will have sucrose and bagasse; the bagasse is a waste, but we will use it later as a source of heat. [8]2. Fermentation:The second step is fermentation which is the most important step in the production in which we convert the components of sugar cane which is sucrose to cellular energy and then produce ethanol and carbon dioxide; this happens in yeast or bacteria. This process happens with the absence of oxygen.Sucrose consists of glucose and fructose, so first we the enzymes breaks the relation between them in the shown equation:C12H22O11+ H2O + invertase 2 C6H12O

Then we convert the glucose into ethanol by this equation:

C6H12O6+Zymase 2 C2H5OH + 2 CO2The ethanol that is produced from the fermentation process is not pure [9]

Distillation and dehydration: This step is done to purify the ethanol that is produced from the fermentation process. The process is used to purify the ethanol is distillation using cyclohexane.After this process the ethanol which is produced will be 100% ethanol. [10]

Extraction SucroseFermentation Ethanol, but it is not pure Distillation and dehydration Ethanol pure 100%

2.5 Rice straw production According to the Food And Agriculture Organization of the United Nations Egypt is largest producer of rice in the near East region. That is why it would be a good idea to use it as a source of biofuel since in Egypt it is found in abundance.

Here is a table demonstrating some details about the biofuels that we will be using.FuelFeedstock Energy Density(megajoules/kilogram)Greenhouse GasCO2(kg/kg)

Bioalcohol:EthanolPropanolButanolStarches from wheat, corn,Sugarcane,Molasses, potatoesBy Type303436.6By Type1.91

2.37

Biodiesel produces slightly less energy than standard diesel. It also burns cleaner than diesel. However, an engine would need to be redesigned in order to take it in.

Ethanol contains only half the energy of gasoline. This means that more ethanol must be used in order to give the same amount of energy. Engines must be modified for ethanol too. [11]

2.5.1 Rice straw ethanol production The production of ethanol from rice straw is the same as sugarcane because rice straw has cellulose that can be converted to glucose.1- The first step in the production of ethanol from rice straw is the conversion of cellulose into glucose into two procedures a. The glucosidic linkage is broken tocellobiose using beta-1,4 glucanase. The cellabiose is a glucose dimer with a beta-1, 4 bond.b. this beta-1,4 linkage is broken by beta-glucosidase to glucose:

Cellulose b-1,4 glucanaseCellobiose b-glucosidaseGlucose

3. After the conversion of rice straw to glucose, the fermentation process begins to produce ethanol which is not pure and then purify the ethanol using dehydration process to produce ethanol 100% pure. [12]2.6 ComparisonThe aim of our thesis is to perform tests on SI Engine and to know the best biofuel that will be used according to the efficiency of the engine, but it is not our aim to provide cost analysis, so we tried to know approximately what is less expensive sugarcane or Rice Straw.Sugar canes production price is about 180 LE per ton and the production quantity in Egypt is about 16 million tons. [7][13] Sugarcane produces 19.5 gallons of ethanol pre one ton of sugarcane [14]. On the other hand Egypt produces 3.5 million ton of rice straw each year and the tonnes price is 97.25 LE/ton. [7] However rice straw produces 45 gallons of ethanol per ton. [14]

Rice straw Sugarcane

Production Price 97.25 LE/ton180 LE/ton

Production Quantity 3.5 million tons16 million tons

Gallons of ethanol/ton4519.5

As we can see from here that the sugarcane is more expensive in its production process, but the rice straw produces more ethanol than the sugarcane does.

Project Plan

Gant chartt

Methodology

Pollution

Burning gasoline has harmful products which affects our environment. Examples of the harmful products are listed below. As mentioned, our main goal for this thesis is to substitute gasoline with an alternative. This alternative is not only based on performance characteristics but also its affect on the environment. The following analysis will show us which one of both ethanol and gasoline will produce less harmful gases. Hydrocarbons (HC)Exhaust gases leaving the combustion chamber of an SI engine contain up to 6000 ppm of hydrocarbon components, the equivalent of 1-1.5 % of the fuel. About 40% of this is unburned gasoline fuel components. The other 60% consists of partially reacted components that were not present in the original fuel. [15]The amount of HC emissions depends on three factors. It depends on the fuel composition, chamber geometry and the performance characteristics of the engine.One of the causes HC is the equivalence ratio, the graph below shows the relation of Nitrogen Oxides, Carbon Monoxide and Hydrocarbons with the equivalence ratio.[15]The equivalence ratio is ratio between the actual air to fuel ratio to the stoichiometric air to fuel ratio. This means that the fuel with the greater actual air to fuel ratio compared to the stoichiometric value will have the greater equivalence ratio. As shown in the graph the greater the equivalence ratio value the greater the amount of HC and CO emissions, however NOX emissions is the largest near the equivalence ratio value of 1. The fuel that has rich fuel content will have the highest equivalence ratio value this is due to the insufficient oxygen available to react with carbon to produce carbon dioxide. So HC and CO are produced.An analysis of air and fuel was done below; gasoline had the highest air to fuel ratio value which means it is more probable that it will have the higher equivalence ratio value. However due to no practical experiment the actual air to fuel ratio value is missing so we can not specifically decide which fuel will produce the most HC. It is more probable that the ethanol will produce less.As mentioned above fuel consumptions is one the causes to amount of emissions of hydrocarbons. The graph below shows the relation between the two.[15]Carbon MonoxideTypically the exhaust of an SI engine will be about 0.2% to 0.5% carbon monoxide.[415 book page 285] As mentioned before, the cause of Carbon Monoxide formation is the incomplete combustion of the fuel due the low equivalence ratio (rich fuel mixture). Typically the exhaust of an SI engine will be about 0.2% to 0.5% carbon monoxide.(Pulkrabek)Since in this thesis we are comparing ethanol with gasoline or specifically the mixture of both, shown below is the incomplete combustion of 1mol of gasoline and 1 mol of ethanol with oxygen. Due to the insignificance nitrogen will removed from the equation.Gasoline (C8H15):C8H15 + 7.75O2 8CO + 7.5H2OEthanol (C2H6O):C2H6O + 2 O22CO + 3H2OOne mole of gasoline produces 8 moles of carbon monoxide and one mol of ethanol produces 2 moles of Carbon monoxide, assuming that Carbon monoxide and water are the only products. This means that using the higher percentage of ethanol mixture will reduce the amount of CO emissions.Carbon dioxideCarbon dioxide is the main product of combustion. Carbon dioxide is the cause of global warming and the greenhouse effect. Gasoline (C8H15):C8H15 + 11.75O2 8CO2 + 7.5H2OEthanol (C2H6O):C2H6O + 3 O22CO2 + 3H2O1 mole of gasoline produces 8 moles of CO2 while one mole of ethanol produces 2 moles of CO2.This gives the same conclusion as the carbon monoxide analysis.

Nitrogen oxides (NOX)Nitrogen at high temperatures reacts with oxygen in different forms to form oxides of nitrogen. The emissions of nitrogen oxides depend on temperature, pressure and air to fuel ratio. Deduced from the stoichiometric combustion equation stated in the carbon dioxide section, the air to fuel ratio of gasoline is approximately 14.5 while gasoline has an air to fuel ratio of 2.47, which means the highest ethanol composition is favored to minimize the NOX emissions due to its lower air to fuel ratio. However due to no practical data (which will be supplied in thesis 2), we cannot decide which is the best composition of biofuel to use to minimize NOX emissions.O + N2 NO + NN + O2 NO + ON + OH NO + HNO + H2O NO2 + H2NO + O2 NO + OLooking at this section overall we can deduce that obviously ethanol is more environmentally friendly than gasoline. This means we will choose 0.8 gasoline and 0.2 ethanol mixture for fewer emissions.

3.1 Fuel characteristics

Octane numberOctane number or antiknock is an important fuel property. The higher the octane in a certain the fuel the more this fuel can resist knocking when the fuel is mixed with air and ignited inside the cylinders of an internal combustion engine . A research investigating three different blend of ethanol and gasoline which are (E0), (E10) and (E30) conducted that increasing the concentration of ethanol in gasoline increases the research octane number (RON) and motor octane number (MON). [16] This means that blending ethanol with gasoline can enhance the octane number of the mixed fuel and thus make the fuel more resistant to the effect of knocking. The table below shows the number of RON and MON of different blends of ethanol.

Figure #: RON (number vs gasoline and E10) [16]

Properties of ethanol blended gasoline fuels

Property itemsE0E10E30

Density (kg/l at19C)0.7360.7410.751

RON92.49599.7

MON81.282.386.6

Table #: Different properties of ethanol blended gasoline fuel [16]

Viscosity and lubricity Ethanol has a lower viscosity than gasoline this means that when blending ethanol with gasoline this results in a mixture of fuel that has a higher value of viscosity. The table below shows values of different blends of ethanol and gasoline. Viscosity is an important parameter in the internal combustion engine. When the viscosity is decreased this leads to problems in the engine such as pump and injector linkage this can reduce both the power output and the fuel delivery. This is a problem that might arise when mixing ethanol with gasoline is the lower kinematic viscosity of the blended fuel. Decreasing kinematic viscosity of the fuel causes the fuel to be less lubricant. This can cause major problems if the engine relays completely on fuel for lubrication thus modification on the engine must be made prior to the usage of fuel.[16]

Flash point and Fire pointFlash point is the lowest temperature that can ignite the fuel when exposed to an external ignition source such as the spark plug in the SI engines. Where as the fire point is the temperature point at which the fuel to continue out burning after removing the ignition source. Flash point and fire point of ethanol are higher than those of gasoline thus we might need to preheat the mixture of fuel before applying it in the engine. Value of fire point and flash point different blends of ethanol and gasoline is shown in the table.[16]

On blending ethanol with gasoline many characteristics of the fuel change. Some of the important fuel characteristics that change are the octane number, viscosity, kinematic viscosity, flash point and fire point. Some of these characteristics can have an effect on the engines performance and might need engine modifications. First when you increase the percentage of the ethanol in gasoline this increase the octane number and thus makes the fuel more resistant to the effect of knocking. Moreover the viscosity of ethanol is lower than the viscosity of gasoline, so a mixture of (E10) will have a lower viscosity than gasoline this might reduce both the power output and the fuel delivery because of problems in the engine. Also the (E10) has lower kinematic viscosity than gasoline. Kinematic viscosity plays an important role in lubrication of the engine. This is another problem that we need to take into consideration. E10 also has lower temperature values of flash and fire point than gasoline. So in order to use blended fuel of ethanol and gasoline we might need to preheat the fuel before introducing it to the combustion chamber. The table below shows some of the fuels properties of different compositions of gasoline and ethanol.

(Investigation of Ethanol/Gasoline Blends as Alternative Fuel for Spark Ignition Engine) Properties of ethanol compared with gasoline

Fuel propertyGasolineE10E15E20E25

Density (Kg/L) at 15.6 C0.73130.73340.73570.740720.74192

API gravity degrees62.7061.460.859.559.2

Viscosity mm2/sec0.490.52660.55620.60440,6448

Flash point C28.72929.429.529.6

Fire point C2531313132

Gross heat content4350041900410254000039375

Table #: Different properties of ethanol blended gasoline fuel [17]

3.2 Problems of blending ethanol and gasolineGeneral problems Water absorption as ethanol absorbs the moisture in the fuel tank Decrease in octane rating because of water absorption Vapour lock and fuel starvation Decrease in fuel efficiency because ethanol produce less energy than gasoline when burned Shell life of gasoline decreases Life cycle of parts and engine decreases

Engine Parts that can be damaged Metal, rubber and plastic parts of the fuel system Corrosion of metal parts in the engine and fuel system Carburettor damage Dirty and clogged fuel filters Deterioration of non-metallic parts Deterioration of plastic parts Unsuitable ignition timing resulting in ignition failureDrivability issues Lower energy of the blends causes engine performance problems Stalling at low speeds Lack of acceleration Hard starting and operating difficulties[18]EngineThere are two types of engines, spark ignition engines (SI) and compression ignition engines (CI). Spark ignition engines contain a spark plug which fires a spark by the use of two electrodes to ignite the air and fuel mixture inside the combustion chamber. Compression ignition engines doesnt contain a spark plug, however the high temperature and pressure in the chamber during the combustion process causes the air fuel mixture to self ignite.[15]We are mainly looking for biofuels that work on major cars in Egypt. The SI engine is widely found in Egypt because it is the one using gasoline not diesel like the CI engine. So in our thesis we are choosing the SI engine to test on. The exact type of Engine to use for our experiments will be stated in thesis 2.Operating CharacteristicsOne of the main aspects that determine which biofuel blend is most suitable for the SI engine is the operating characteristics. Operating characteristics will be tested against the rpm (revolutions per minute). The higher the value of whatever variable tested the better the fuel.[15]Mean Effective Pressure (mep)Pressure in an engine is continuously changing; the mean effective pressure is a measure of the constant pressure value of the engine that will give the work done by the piston over the length of the displacement volume of the cylinder.

Vd is the displacement volume of the cylinder and W is the work. Work is produced when the air and fuel mixture combust producing gases which produce a force that causes the piston to expand. Work is a parameter that measures a force that undergoes a certain distance.There are three types of mep to be measured. Which are break, indicated and friction mean effective pressures. Break mean effective pressure (bmep) comes from the work measured at the output shaft, Indicated mean effective pressure (imep) comes from the work done by the gases in the combustion chamber and the break mean effective pressure (fmep) comes from the difference between the two.Mean effective pressure is a good parameter to test upon because it doesnt depend on size or speed. Power will favor the high speed engines and torque will favor the larger engines.[15]To measure the break mean effective pressure of the engine the volume displacement of the engine must be known and the power from the output shaft of the engine must be measured using a dynamometer. Power is a measure of the rate of work done. The power value is then divided by the time of the engine during the experiment.

Torque and Break power ()Torque is a good indicator of an engines ability to do work. (Pulkrabek)In other words it is the force that causes the revolution of the output crankshaft.[15]

Break Power as mentioned before is the rate of work done by the output crank shaft.Both power and torque are measured by a dynamometer.Break Specific Fuel Consumption (BSFC)BSFC is measure of how much fuel is consumed to produce a constant value of power.

It is a good measure to see which blend will last longer in the engine to produce the same power output. In other words which blend is more economical?

[15]This graph shows the relation between the equivalence ratio and the bsfc. The stoichiometric air to fuel ratio can be calculated but the actual air to fuel ratio must be measured which is provided in thesis 2. The blend with the highest value of bsfc will be the better selection.BSFC is measured by measuring the mass of fuel rate into the cylinder and by measuring the power produced at the output shaft using the dynamometer.Combustion Efficiency and Thermal EfficiencyCombustion inside the cylinder does not always occur completely, a small fraction of the fuel will not be burnt which might affect the overall power output of the engine. The combustion efficiency equation gives the output power value of the combusted part of the fuel.

Where is the mass flow rate of the fuel, is heating value of the fuel and is the actual heat of the fuel. Thermal efficiency is the measure of the power output per one unit of the actual heat of the fuel.[15]

Specific EmissionsSpecific emissions are a measure of the rate of emissions coming out of the exhaust per unit of output work. In this thesis we will be measuring three types of emissions, hydrocarbons, carbon monoxide and nitrogen oxides emissions.

3.4 Modifications of an Engine In order for an engine to operate using ethanol, there are modifications that must be made. This is because of certain properties that are different. Petrol has a lower octane than ethanol. Therefore, ethanol will need a higher compression ratio. Another reason is that the calorific value of ethanol is lower than that of petrol. This means that a larger amount of ethanol would be needed than the amount of petrol. Here are the major points of where modifications are needed.

Main Jet OrificeThe main jet orifice is a specific size hole in the center of a brass thread plug inside the carburetor. The diameter of the main jet orifice is the indicator of how lean or rich the air/fuel mixture will be when the car is in motion. As the hole of the diameter is decreased, the mixture becomes lean and as it is increased the air/fuel mixture becomes richer. Ethanol would require a richer air/fuel mixture and therefore the size of the hole must be increased by 20 to 40 percent.

Idle Orifice The idle orifice is another thing where the size must be increased. The circuit that is fed by the main jet operates fully only when the throttle plate inside the carburetor is opened and not in idle position. When it is in idle position, the air/fuel mixture passes only through the idle orifice. This means that it needs to be enlarged. With ethanol, the sufficient amount of the air/fuel mixture must pass through in order for the engine to continue to operate.

Power ValveThe carburetors that we use today allow additional fuel to be added to the air/fuel mixture when the accelerator is depressed by a component called a power valve. This is done in order to make the mixture richer under load conditions. This valve also closes in order preserve fuel when it is not needed. If the power valve is operating normally it might not be needed to be modify it. However if the power valves dimension is increased by 25 percent, the mixture can become rich enough to give the engine more power when needed.

Accelerator PumpThe accelerator pump is a mechanical plunger or diaphragm that is used to insert fuel directly to the throat of the carburetor when the accelerator is unexpectedly depressed. Accelerator pumps are added to the system because when the accelerator is depressed and the mixture enters, some of it sticks on the intake manifold, which makes the mixture leaner before reaching to the combustion chamber. The accelerator pump provides an extra amount of fuel as a replacement for the fuel lost.

Compression Ratio modification: In this modification we are trying to increase the ratio in the cylinder volume between the cases when the piston is at the bottom dead center to the case when it is at the top dead center. The standard ratio for the compression ratio in the engines is 8 or 8.5 to 1 and the optimum case is 15 to 1 so we will try to reach about 12 to 1 ratio.To reach this case one of these modifications can be done to the engine:1. Installing a set of high compression pistons to increase the compression in the combustion chamber of the air and fuel; we need also to change some components to withstand the high compression ratio which are bearings, connecting rods and relief notches. This method is inexpensive in comparison to other methods.[19[\]

[19]

2. Milling the surface of the cylinder head, but this method does not increase the ratio a lot.

[19]3. Using turbocharger, which is the most effective way because it highly increases the compression inside the combustion chamber and these increase is proportional to the rpm of the engine, but it is so expensive.

[19]

Changes towards cold weather:The problem of cold weather affects the engine that works by ethanol because the alcohol does not vaporize fast like the gasoline does, so there is a need for the preheating of the fuel before it enters the carburetor. There solutions for this problems are:a. Using fuel heater in which we use the heat that comes from the radiator to heat the fuel.b. Using the hot air that comes from the exhaust manifold to heat the fuel c. Integrate cold start dual fuel system in the engine Changing the thermostat:Because the ethanol fuel is less in temperature than the gasoline, there is a need for a more efficient thermostat that will control the coolant function inside the engine [19]

3.5 DynamometerA machine that is used to calculate the power and efficiency of an engine by measuring its rotational speed and torque.

[20]http://www.indydyno.com/what-is-a-dynamometer.phpComponents:1) The engine that we need to test2) A coupling : connects the engine to the dynamometer 3) Tachometer: a device to calculate the rotational speed 4) A scale to calculate the resultant force5) Torque arm6) Housing: the stator that supports the rotor7) Rotor: a shaft that is free to move according to the engine under test8) Turnnion: it makes the housing free to move Inside the dynamometer, there is a coolant to reduce the overheat produced[20]Dynamometer operation:When the engine operates, the rotor that is connected to it starts to rotate until it reaches the desired speed that is calculated using tachometer. When it reaches the desired speed a braking torque is initiated that is calculated using the force scale and torque arm.[20]Calculations:

P(HP) Power in HorsepowerTorque Usually measured in pound-feet (lbfft).RPM Revolutions Per Minute5252 Constant[20]

EthicsEthics Definition:According to the Merriam-Webster Encyclopedia the definition of Ethics, rules of behavior based on ideas about what is morally good or bad.[21]In other words, if were applying it to our situation, it means that if our thesis project is morally good to people, environment etc. In our project we are trying to find a substitute to gasoline due to the harmful gases released and the probable extinction of fossil fuels. Since Egypt is one of the leading areas in growing sugarcane and rice in the region, we chose these two crops to produce ethanol. Therefore, this will provide a solution of the problems of the shortage of gasoline in Egypt which means that our project is helping the environment.Despite the fact that the project is fruitful, but there are some ethical dilemmas that may harm the society. This dilemmas are linked to problems that may have an effect on people and environment, so we had to propose some solutions which will decrease the effect of those problems.

Dilemmas:The first Dilemma (food shortage) According to the FAO, some studies are concerned that the increase in biofuel production would eventually draw the world in a food versus fuel battle. [22] This will happen because the crops that are used for the production of biofuels have other productions which may be food productions like the production of sugar from sugarcane; furthermore, if the interest of production of biofuels increased, this will increase the need for lands of biofuel crops which may affect other lands that produce food for the society.Solutions for this problem would be that a. Adequate lands must be ensured in order to protect farmers and their food production for themselves or local markets.b. Regulations must be adopted by the government on the production of biofuels by which the production of biofuels will not affect the food security.

Second Dilemma (carbon dioxide)Another problem that needs to be addressed with biofuels is creating carbon dioxide. Increasing the carbon dioxide that exists in the air would be a major disadvantage of producing biofuels. This also means that biofuels would increase global warming. [22]However, in order to produce biofuels, plants must be used. Growing plants for biofuel production would make it a sustainable system. It would mean that biofuels neutralize its own side effect since the plants grown would use any carbon dioxide produced by the process. Here is a simple diagram of the neutralization process:

Another advantage of using biofuels is that it reduces the emission of green house gases. This is done by replacing fossil fuels when biofuels are used.Third Dilemma If our thesis project will be used on a large scale, large amounts of water will be needed to grow large quantities of crops; for example, sugarcane needs a large amount of water for its irrigation. This means that the production of biofuels will definitely affect local water resources and according to International Water Management Institute, it is estimated that in the year of 2008 1% of water supply for global irrigation is used for the production of biofuels. [22]Solutions that would be proposed for this problem are:a. Regulations must be adopted in order to protect water supplies. b. Biofuels crops should not be grown in areas where water resources would overstretch and would not be able to satisfy the demand.

Conclusion

References [1] Shafiee, Shahriar, and Erkan Topal. "When Will Fossil Fuel Reserves Be Diminished?" Energy Policy (2008). The University of Queensland. Web. 8 Nov. 2014.[2] "When Will Oil Run Out?" Institution of Mechanical Engineers. Web. .[3] Serag El-din, Amr. "Principles of Renewable Energy." American University in Cairo. Web. 11 Nov. 2013.[4] OPAI, Bojana, Dragan OKALO, and Jasmina PEKEZ. "SUMMARY OF THE USING SOLAR ENERGY ON THE GLOBAL LEVEL AND IN THE REPUBLIC OF SERBIA." 7.3: 59-64. University of Novi Sad, Technical Faculty Mihajlo Pupin Zrenjanin, SERBIA. Web.[5] ????????[6] Advantages and Disadvantages of Biofuels."GreenLiving.LovetoKnow. Jared Skye. Web. .[7] http://www.fao.org/home/en/[8] "SUGAR PRODUCTION FROM SUGAR CANE." Web. 26 Dec. 2014. .[9] O G Palanna.ENGINEERING CHEMISTRY. Web. 25 Dec. 2014. Tata McGraw-Hill Education. Print.[10] Buzzi Ferraris. "Simulation of Ethanol Production from Sugarcane in Brazil: Economic Study of an Autonomous Distillery." Ed. Pierucci. Web. .[11]"Biofuels: What Are They?"Biofuel. Web.[12] "Cellulose Degradation."Cellulose Degradation. Ed. Nam Sun Wang. Web. 25 Dec. 2014. .[13] Abolabbass, Bassem. "Cultivation of Sugarcane Takes Toll on Egypt's Farmers." English.ahram.org. 31 Mar. 2014. Web.[14] Hossein Shapouri, Salassi, and Fairbanks. "THE ECONOMIC FEASIBILITY OF ETHANOL PRODUCTION FROM SUGAR IN THE UNITED STATES." 1 July 2006. Web. 25 Dec. 2014. .[15] Pulkrapek, Willard. "Emissions and Air Pollution."Engineering Fundamentals of the Internal Combustion Engine. Print.[16]He, Bang-Quan, Jian-Xin Wang, Ji-Ming Hao, Xiao-Guang Yan, and Jian-Hua Xiao. "A Study on Emission Characteristics of an EFI Engine with Ethanol Blended Gasoline Fuels." Atmospheric Environment 37.7 (2013). Web.[17] Ibrahim, Abou Baker, Lang Keir, Samuel Lino, and Victoria Joeshp. "Investigation of Ethanol/Gasoline Blends as Alternative Fuel for Spark Ignition Engine." Web.[18] ???????????[19] engine modification[20] "What Is a Dynamometer and How Does It Work?"Setra Systems Blog. Web. 25 Dec. 2014. .[21] Web. .[22] Aziz Elbehri, Anna Segerstedt, and Pascal Liu. "Biofuels and the Sustainability Challenge." Web. 25 Dec. 2014. .