Abstract – The ever increase in global energy demand, consumption of a depletable fossil fuels, exhaust emissions and global warming, all of these led to search about alternative fuels. Bio diesel was produced from waste cooking oil (WCO) by transesterification process. Low speed diesel engine performance was studied experimentally, by burning waste cooking oil blends, and pure diesel. The experiments performed at constant load and various engine speed (400-800 rpm). The objective of this study, is to investigate the effects of biodiesel blends, extracted from used oil from (corn and sunflower), and pure diesel, and to utilize waste cooking oils and fresh oil to produce biodiesel fuel. The study reveals that Diesel engine can operate with biodiesel blends extracted from WCO without making any modifications on the engine, and .pure diesel produces higher brake thermal efficiency, and Brake Power than the bio diesel extracted from WCO, used in this study.
I. INTRODUCTION
In general, in most countries, the people would through away the cooking oil after usage. This oil is causing water pollution, and cannot follow down the drain system in the residence sectors.
Waste cooking oil (WCO), provides a means to convert waste to wealth, and reduce the competition between using edible oil for energy generation instead of food. Production. This reduces waste and increases wealth, in terms of direct and indirect jobs created when waste cooking oil is used to produce biodiesel. Biodiesel provide lower cost, lower gaseous emission levels of particulate matter, hydro carbon monoxide, and net carbon dioxide [1].
Biodiesel seems very suitable for many reasons, firstly, it is renewable source of energy, and secondly, it is the least toxic and most biodegrable. In addition, it is reasonable to use in boilers and diesel engines without major modifications. Biodiesel has more cetane number. In addition, it does not contain aromatics, which reduce the emission of carbon dioxide [2].
In recent studies, which examined waste cooking oil, as a tool to address social, technological, and economical challenges. It shows that WCO would save 10% of impartation costs in India, and it is suitable and sustainable as an alternative to diesel fuel. In addition, it is cheaper than conventional diesel fuel [3-5]. Naima et. al [6], Analyze the properties of oil derived from waste plastics, cooking and engine oil, and compared with petroleum products, and found that, its properties similar to that of diesel. The conversion process of each type of waste oil was presented.
Maksum et, al perform an experimental stud, staring from the fuel characterization, combustion process, engine emission, and engine performance. The results indicate the use of 100% cooking oil biodiesel reduce the duration of ignition delay until 4 degrees, and reduction of soot particulate emissions of 4-6% for each 25% increase in used cooking oil biodiesel [7].
The objective of this study, is to investigate the effects of biodiesel blends, extracted from used oil from (corn and sunflower), and pure diesel, and to utilize waste cooking oils and fresh oil to produce biodiesel fuel.
II. METHODOLOGY
A. Biodiesel Production:
The experiments were performed in the internal combustion engines laboratory, department of Mechanical engineering, faculty of engineering at Mutah University. The biodiesel blends employed in the present study, were obtained through the following steps:
(a) Pour 200 milliliters of methanol into a glass blender, then turn the blender on its lowest setting and slowly add 3.5 grams of sodium hydroxide.
(b) Mix the methanol and the sodium hydroxide until the sodium hydroxide has completely dissolved (about 2 minutes), then add 1 liter of used vegetable oil from (corn, or sunflower).
(c) Continue blending the mixture (on low speed) for 20 to 30 minutes.
(d) Pour the mixture in a glass jar, then the liquid starts to separate out into layers. The bottom layer will be glycerate, and the top layer is biodiesel.
(e)Allow a couple of hours for the mixture to fully separate, then carefully pour off the biodiesel (upper layer), in a large glass container.
B. Engine setup:
Experiments in this study were conducted with one cylinder, four-stroke engine. The specifications of the test engine are tabulated in Table 1. Low Speed Diesel Engine (Test set up) is shown in Figure 1.
Table 1. Technical data of PETTER PHIW diesel engine
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Technical dataSpecification
TypeLister LVI
Max. Power4 kW at 900 rpm
No. of cylinderssingle
Engine operationfour strokes
Speed range400-1000 rpm
Compression ratio17:1
Combustion chamberdirect injection
The engine operates at no load for 10 minutes using only diesel fuel, and then check the operation Status of the equipment measuring parameters. Next, the engine works at 50% load. Then the engine operates at various speeds using fuels: a mixture of biodiesel blends, and 100% pure diesel.
III. RESULTS AND DISSCUSSIONS
Alternative fuels used in engines are normally evaluated based on engine performance. The most important performance parameter considered by the researchers on the field of internal combustion engines are power output, brake thermal efficiency, brake specific fuel consumption, and the exhaust gas temperature. This section presents and discusses the results obtained from the experiments performed on slow speed diesel engine fueled by various biodiesel blends.
A. EFFECTS ON TORQUE
Torque represents a fundamental performance parameter for the engine, and its magnitude of the rotational effort developed by the engine against a torque load applied to it [8]. In Figure 2 the variation in brake torque are shown, where it is observed that pure diesel has the maximum brake torque of 25.7 J. Generally, the brake torque for all WCO is less than pure diesel, because of its reduced heating value compared of that of pure diesel. Therefore, the higher the fuel is heating value, the higher the torque. The torque generally increases with increasing speed up to a maximum value and then decreases with an increase in speed.
B. EFFECTS ON BRAKE POWER (BP)
The core purpose of an engine is to produce the driving force from the engine power, where the power of the engine will be directly proportional to Torque and inversely proportional to engine speed. The BP is the available power in the crankshaft of an engine, the maximum brake power of 3 kW was obtained at 70 r.p.m. when pure diesel was used in the engine. In Figure 3 an increase in speed produces a corresponding increase in brake power. However, biodiesel blends show a relative reduction in terms of brake power when compared to pure diesel.
C. EFFECTS ON BRAKE MEAN EFFECTIVE PRESSURE (BMEP)
The BMEP is function of torque, and as expected it increases as brake power increases, reaching maximum then decreases. In Figure 4 the variation in BMEP are shown, where it is observed that pure diesel has the maximum BMEP of 1140 kPa. Generally, the BMEP for all WCO is less than pure diesel, because of its reduced heating value compared of that of pure diesel.
D. EFFECTS ON B.S.F.C. (BSFC)
The BSFC is the actual mass of fuel consumed to produce 1 kW in an hour. It is the best parameter to compare the economy performance of an engine, because it takes care of both mass flow rate and the heating value of the fuel. BSFC for various biodiesel blends and pure diesel is plotted in figure 5. BSFC of all tested fuels is found to be decreasing with increase with brake power, reaching a minimum value, which is usually called optimum point (the fuel burnt produce the maximum brake power), then increasing as the power output increases. This may be attributed to lower heating value, higher density, viscosities, and boiling point of biodiesels blends compared to the pure diesel. It is clear from the figure that BSFC for all biodiesel blends is higher that of pure diesel.
E. EFFECTS ON BRAKE THERMAL EFFICIENCY (BTE)
The BTE commonly known as fuel conversion efficiency that replicates the percentage of fuel energy converted into useful energy. If different fuels are to be compared for the same engine, brake thermal efficiency is the most suitable parameter instead of specific fuel consumption. Figure 6 shown as the variation of brake thermal efficiency with engine speed for diesel and the WCO blends indicated that BTE of all tests increased with an increase in speed and then decreased as the speed increased.
F. EFFECTS ON EXHAUST TEMOERATURE
Exhaust temperature is very important indicator of the combustion process and has a key in the formation of pollutants. Figure 7 show the variation of exhaust temperature with engine speed. All fuels are characterized of an increase of temperature with engine speed, whereas the WCO blends are lower values than pure diesel. This behavior is ascribed to lower heating value of biodiesels, which reduces the amount of total energy released, thus reducing the combustion peak temperature and then the exhaust temperature.
IV. CONCLUSIONS
The following conclusions can be drawn from this study:
(a) Diesel engine can operate with biodiesel blends extracted from WCO without making any modifications on the engine.
(b) Using bio diesel blends extracted from WCO has higher B.S.F.C. than using pure diesel.
(c) Pure diesel produces higher brake thermal efficiency, and Power than the bio diesel extracted from WCO, used in this study.
REFERENCES
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Keywords: waste cooking oil, alternative fuel, diesel engine, performance