Engine and Winter Road Test Performances
Content
Energy Conversion and Management 46 (2005) 1279–1291 www.elsevier.com/locate/enconman
Engine and winter road test performances of used cooking oil originated biodiesel Merve Mer ve C ¸ etinka eti nkaya ya a, Yahya Ulusoy b, Yu¨ cel Tekın b, Fılız Karaosmanog˘ lu
a
a,*
Department of Chemical Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey b Vocational School of Technical Sciences, Agricultural Equipments and Machinery Program, ˘ University, 16059 Go¨ ru Uludag ¨ ru¨ kle, ¨ kle, Bursa, Turkey Received 15 October 2003; received in revised form 3 March 2004; accepted 13 June 2004 Available online 11 September 2004
Abstract
Biodiesel Biodiesel is a renewable renewable and environmen environmentally tally friendly friendly alternative alternative fuel that can be used in Diesel engines with little or no modification. Low cost feedstocks, such as waste oils, used cooking oil and animal fats, are important for low cost biodiesel production. The objective of this study was to investigate the engine performance and the road performance of biodiesel fuel originated from used cooking oil in a Renault Me´ Me´ gane automobile and four stroke, four cylinder, F9Q732 code and 75 kW Renault Me´ Me´ gane Diesel engine in winter conditions for 7500 km road tests in urban and long distance traffic. The results were compared to those of No. 2 Diesel fuel. The results indicated that the torque and brake power output obtained during the used cooking oil originated biodiesel application were 3–5% less then those of No. 2 Diesel fuel. The engine exhaust gas temperature at each engine speed of biodiesel was less than that of No. 2 Diesel fuel. The injection pressures of both fuels were similar. Higher values of exhaust pressures were found for No. 2 Diesel fuel at each engine speed. As a result of the No. 2 Diesel fuel application, the engine injectors were normally carbonized. After the first period, as a result of winter conditions and insufficient combustion, carbonization of the injectors was observed with biodiesel usage. As a result of the second period, since the viscosity of the biodiesel was decreased, the injectors were observed to be cleaner. Also, no carbonization was observed on the surface of the cylinders and piston heads. The catalytic converter was plugged because
*
Corresponding author. Tel.: +90 212 285 6837; fax: +90 212 285 2925. E-mail address: fi[email protected] (F. Karaosmanog˘ lu).
0196-8904/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.enconman.2004.06.022
1280
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
of the viscosity in the first period. At the second period, no problem was observed with the catalytic converter. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Biodiesel; Used cooking oil; Used cooking oil methyl ester; Diesel engine; Engine performance test; Road test; Durability test
1. Introduction
Biodiesel is an environmentally friendly alternative for petroleum based Diesel fuel. It has proven itself as a technically sufficient alternative Diesel fuel in the fuel market since the beginning of the 1990s [1]. Its reducing characteristic for greenhouse gas emissions, its help on reducing a country s reliance on crude oil imports, its supportive characteristic on agriculture by providing a new market for domestic crops, its effective lubricating property that eliminates the need of any lubricating additive and its wide acceptance by vehicle manufacturers can be listed as the most important advantages of the fuel [2]. Many studies have shown that the properties of biodiesel are very close to those of No. 2 Diesel fuel. Therefore, biodiesel can be used in Diesel engines with little or no modification [3,4]. The first application of vegetable based oils for engine performance was in World War II. Although vegetable oil applications have been available since the 1950s, it was necessary to research on engine design and fuel technology. Geyer et al. [5] used a mixture of No. 2 Diesel fuel and cotton oil, sunflower oil and their methyl esters in a one cylinder Diesel engine and compared engine performances and emission values. According to the results, it was reported that the thermal efficiencies of vegetable based fuels were equal to or much higher than those of No. 2 Diesel fuel. The temperatures of the exhaust gases and emission values were equal to or much higher also [5]. Schafer researched the application of vegetable based oils in Diesel engines as an alternative fuel [6]. For this aim, during the research in Daimler Benz AG, it was observed that carbonization and stratification in the combustion chamber and the fuel consumption were similar to those of No. 2 Diesel fuel, and the values were more suitable. The amount of wear occurring due to the engine working for long hours was observed to be similar to that with conventional Diesel fuels [6]. In his study, Ko¨rbitz [7], worked on the use of vegetable based fuels that were cultivated in Austria for the purpose of biodiesel production. As a result, biodiesel was found to be more benign ecologically and the emissions were similar to Diesel fuel emissions and some had better results. Besides special vehicles, trucks (lorry) and government vehicles have been tested, and no problem resulting from biodiesel use was observed [7]. Is ıg˘ıgu¨r et al. [8] investigated the ASTM fuel properties of different ratio blends of safflower seed oil methyl ester and No. 2 Diesel fuel. As a result of the study, the 20% blend had fuel properties close to the limits of specified No. 2 Diesel fuel, and the engine and emission performance of the 20% blend were found to be similar to those of No. 2 Diesel fuel [8]. Is ıg˘ıgu¨r et al. [9] studied the performance and emission characteristics of safflower seed oil methyl ester, and it was reported that the safflower seed oil methyl ester revealed similar engine performance characteristics to those of the reference No. 2 Diesel fuel. Lower CO and HC emissions were obtained when the methyl ester was used, and a negligible amount of sulfur content was another advantage of the methyl ester application [9]. Gomez et al. [10] investigated the Õ
ß
ß
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1281
exhaust emission and performance characteristics of a Toyota van powered by a 2 l indirect injection (IDI), naturally aspirated Diesel engine operating on vegetable based waste cooking oil methyl ester. The waste cooking oil methyl ester developed a significantly lower smoke opacity level and reduced CO, CO2 and SO2 values, whereas the O2, NO2 and NO levels were higher when compared to those of No. 2 Diesel fuel. The power values were comparable for the two fuels [10]. Al-Widyan et al. [11] investigated the performance of an ethyl ester of waste vegetable oil in a Diesel engine. The fuels tested were different ester/Diesel blends, including 100% ester, with No. 2 Diesel fuel. Variable speed tests were run on all fuels on a standard test rig of a single cylinder, direct injection Diesel engine. As a result, it was reported that the blends burned more efficiently with less specific fuel consumption and, therefore, resulted in higher engine thermal efficiency. The blends produced less CO and unburned HC than Diesel fuel [11]. The exhaust emissions of a Diesel direct injection Perkins engine fueled with waste olive oil methyl ester were studied by Dorado et al. [12] at several steady state operating conditions. Emissions were characterized for biodiesel from used olive oil and No. 2 Diesel fuel. The use of biodiesel resulted in lower emissions of CO, CO2, NO and SO2 with an increase in the emissions of NO2. Biodiesel also presented a slight increase in brake specific fuel consumption. Combustion efficiency remained constant using either biodiesel or No. 2 Diesel fuel [12]. Dorado et al. [13] also worked to determine the feasibility of running a 10% waste vegetable oil–90% Diesel fuel blend during a 500 h period in a three-cylinder, direct injection, 2500 cm3 Diter Diesel engine. Approximately 12% power loss, a slight fuel consumption increase and normal smoke emissions were observed. The Diter Diesel engine, without any modifications, ran successfully on a blend of 10% waste oil–90% Diesel fuel without externally apparent damage to the engine parts. As a result of the studies, it was concluded that the long term use of waste oil blended with Diesel fuel may need further testing before use as a viable energy solution [13]. C ¸ anakc¸i and Gerpen [14] investigated the performance and emissions of a John Deere 4276T model Diesel engine with biodiesel from yellow grease and soybean oil. Two different biodiesels from yellow grease and soybean oil were prepared, and their 20% blends with No. 2 Diesel fuel were studied at steady state engine operating conditions in a four cylinder turbocharged Diesel engine. Significant reductions in particulates, CO and unburned HCs were observed, whereas an increse of 11% and 13% in oxides of nitrogen were found for the yellow grease methyl ester and soybean oil methyl ester, respectively [14]. Leung [15] has studied the properties of biodiesel produced from used waste cooking oil and animal fats from restaurants as feedstock. Tests of the fuel with three different proportions, 0%, 10% and 15%, of Diesel have been conducted on various Diesel engines. A 7% reduction in smoke opacity at a blending ratio of 15% was observed without affecting the engine power, torque and fuel consumption. A reduction of air pollutants from 1.5% to 44% was observed for most of the pollutants other than NO, which had a slight reduction at the idle condition but increased by about 16% at 2500 rpm. The third test was conducted on a Diesel generator (Robin GS 3300RD) that consisted of a generator and a four stroke single cylinder Diesel engine with rated power 3.4 kW. CO levels decreased with increasing biodiesel percentages for both idle and loaded conditions. The NOX level showed a decreasing trend for the idling case, whereas at loaded conditions, the level fluctuated within a narrow range. The fuel consumption showed a slight increase with increasing biodiesel percentage for idle and loaded conditions [15]. Guo et al. [17] studied three different feed stocks for biodiesel production. The aim of their study was to investigate the optimum conditions for biodiesel production and to study the fuel properties and engine performance of the produced biodiesel samples in a light Diesel van on a chassis
1282
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
dynamometer. Experiments showed that utilization of the produced biodiesel could reduce smoke and HC emissions, while the NOX emissions changed slightly. An unnoticeable drop in the maximum engine power output was observed even at 100% biodiesel [17]. The work of Zaher et al. [16] was done on the utilization of used frying oil as an alternative fuel for Diesel engines. Used frying oil was modified with thermal cracking in the presence of 2% CaO to reduce its viscosity. The fuel properties of the modified oil were determined, and the performance of the oil as 50% blend with No. 2 Diesel fuel was evaluated. The product obtained after thermal cracking showed similar properties to those of No. 2 Diesel fuel. The output power, brake thermal efficiency and brake specific fuel consumption of the Diesel engine were changed markedly by blending the cracked product and No. 2 Diesel fuel [16]. Ulusoy et al. [18] investigated the effects of used frying oil originated biodiesel on engine performance and emissions in a Fiat Doblo 1.9 DS, four cylinder, four stroke, 46 kW power capacity Diesel engine. Comparative measurements with No. 2 Diesel fuel were done on both engine power and emission characteristics for each of the fuels used. Biodiesel, when compared to No. 2 Diesel fuel, showed a reduction in wheel force of over 3.35% and it also reduced the wheel power by over 2.03%. In the acceleration tests, 40–100 km/h and 60–100 km/h acceleration periods were measured, and a reduction of 7.32% and 8.78% were observed, respectively. According to the emission tests, as a result of biodiesel consumption, a reduction of 8.59% in CO emission and an increase of 2.62% in CO2 emission were observed. Also, as a result of biodiesel consumption, the NOX emissions increased by 5.03%. HC emissions and particulate emissions have a significant effect on air pollution. As a result of biodiesel use, the HC and particulate emissions decreased by 30.66% and 63.33%, respectively. When the fuel consumption amounts are compared, it was observed that the biodiesel consumption was 2.43% less than that of No. 2 Diesel fuel [18]. In this study, used cooking oil, as a low cost feedstock, was used for biodiesel production, and the engine performance and road performance of biodiesel were investigated in a Renault Me´gane automobile and four stroke, four cylinder, F9Q732 code and 75 kW Renault Me´gane Diesel engine in winter conditions for 7500 km road tests. The measured results were compared to those of No. 2 Diesel fuel.
2. Experimental section
2.1. Materials and methods
Biodiesel production was conducted in a pilot scale reactor in the Vocational School of Technical Sciences, Agricultural Equipments and Machinery Laboratory, Uludag University in Bursa, Turkey, according to the methods chosen from the literature [18]. The fuel properties of biodiesel and No. 2 Diesel fuel, were determined according to the ASTM standard methods in the TUBITAK-MAM Laboratories, and they are given in Table 1. The biodiesel types utilized during the experiments can be defined as follows: used cooking oil originated biodiesel (BD), BD with viscosity improver additive (BDV) and BD with pour point improver additive (BDP). These additives were applied to the original used cooking oil originated biodiesel (BD) due to the cold winter conditions in Turkey and the authors aimed to measure the effects of these additives on the biodiesel engine performance and duration and vehicle performances. The viscosity improver additive, which was obtained from Adco Petroleum Product Additives Company, Turkey, and the
1283
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291 Table 1 Fuel properties of No. 2 Diesel fuel, BD, BDV, BDP and biodiesel ASTM standards Properties
Test method
No. 2 Diesel fuel
Used cooking oil originated biodiesel (BD)
BD with viscosity improver (BDV)
BD with pour point improver (BDP)
Biodiesel fuel standard ASTM D6751-02
Flash Point, °C Kinematic viscosity, cSt (40 °C) Pour point, °C Cetane number
D 93 D 445
58 2.5
148 5.18
148 4.92
148 5.18
130 min 1.9–6.0
D 2500 D 613
À33
À4
À4
À10
55
48
49
48
Report 47 min
Skot Diesel Treatment Fuel System Cleaner, a commercially available pour point additive, were applied to decrease the biodiesel viscosity and pour point for the engine performance and duration and vehicle performance and speed tests. 2.2. Engine performance test
Studies on the vehicle and engine were performed in the Renault Factory, Bursa. In this study, the Renault Test Laboratories were used for identification of the engine durability. For the performance tests, the Renault Me´gane F9Q732 type Diesel engine was used. The engine technical specifications are given in Table 2. The engine used for the engine tests was braked according to Renault standard test method, 34–00–020, and the tests were performed under the Renault test standard 34–00–019. The tests were conducted 3 times, and the averages of these 3 consecutive test results are presented in the figures. In order to examine the durability of the engine, constant engine speeds versus loads tests were performed when the acceleration pedal was at full throttle. As a result of application of No. 2 Diesel fuel to the engine and then applying biodiesel, a comparison of the emission values of the two different kinds of fuel was obtained. During the engine performance tests, the engine temperature was kept under control, and the values were recorded after reaching the ideal engine temperature. 2.3. Duration test
The test was conducted through a 7500 km test drive with a vehicle utilizing on biodiesel. Vehicle engine parts were examined, and the combustion chamber was controlled with an endoscopy Table 2 Technical properties of F9Q732 type Renault Me´gane Diesel engine Technical properties
F9Q732-Diesel
Fuel injection system Cylinder diameter · Stroke (mm) Cubic capacity (cm 3) Compression ration Maximum power (4000 minÀ1) (kW) Maximum torque (1500 minÀ1) (Nm)
Common rail electronic 80 · 93 1870 18.3:1 75 200
1284
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
instrument at the beginning, the middle and the end of the test. As a result, the effect of biodiesel utilization was observed by comparison of the results obtained from these investigations. The duration test program is given below; 03.12.2001: Beginning of the duration test. 17.12.2001–24.12.2001: Trial drive in cold weather. 10.01.2002: Catalyst replacement. 29.01.2002: Injector replacement. 05.03.2002: End of the duration test (7500 km). At the beginning of the test, No. 2 Diesel fuel was used to obtain comparative results with biodiesel. The formed soot inside the cylinders was examined with an endoscopy instrument by pro jecting the bottom and sides of the cylinders. The soots on cylinder pumps, jackets, ignition spark plugs and cylinder heads were also investigated. 2.4. Vehicle performance and speed test
Vehicle road tests were begun on the 3rd of December 2001 and ended on the 5th of March 2002. The Renault Me´gane was the test automobile for the vehicle road tests. The vehicle performance test was conducted according to Renault test standard, 37–00–001. The results of the Renault standard test procedure are given in Table 3. The vehicle performance tests were divided into two parts because of the fuel problems due to winter weather conditions. The effects of Table 3 Vehicle performance test results F9Q732 Diesel fuel
F9Q732 No. 2 Diesel fuel
Temperature °C Power kW Torque Nm
16 75/4000 200
13 75/4000 200
Acceleration (sn) 0–100 km/h 400 m 1000 m
13, 17 18, 80 34, 66
12, 72 18, 65 34, 26
Last speed (km/h) 5. gear
175.60
183.00
4. gear
8.25 9.34 12.75 11.99
7.93 8.07 11.34 10.50
5. gear
12.5 12.98 18.52 18.93
12.46 11.31 16.03 14.28
Flexibility (sn) DL 50–80 km/h DL 80–110 km/h DL 80–120 km/h DL 110–140 km/h DL DL DL DL
50–80 km/h 80–110 km/h 80–120 km/h 110–140 km/h
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1285
biodiesel application on the engine were measured by dividing the 7500 km into two periods. The tests were conducted 3 times, and the averages of these 3 consecutive test results are presented in Table 3. The records were taken at the end of each period and the difference between the two data sets was considered to be the effect of biodiesel on the engine.
3. Results and discussion
According to Table 1, the used cooking oil originated biodiesel that was utilized in the engine and road performance tests meet the ASTM biodiesel Standard. When the fuel properties of biodiesel and No. 2 Diesel fuel in Table 1 are compared, it can be observed that the biodiesel properties are close to those of No. 2 Diesel fuel. From Table 1, it can be seen that biodiesel has a higher flash point and pour point than those of No. 2 Diesel fuel. As can be seen from Table 1, the pour point of biodiesel was measured to be À4 °C without any Diesel fuel additive. To have better results in winter conditions, the Skot Diesel Treatment Fuel System Cleaner was used to decrease the biodiesel (BDP) pour point from À4 to À10 °C. In Table 3, the result of Renault standard test method, 37–00–001 is listed. Table 3 shows a slight drop in engine performance, which can be the result of low specific heating value, viscosity and pour point of the biodiesel, as can be seen from the brake power output and torque graphs, too. This drop in engine performance coincides with the subjective opinions of test drivers. Torque versus engine speed graphs with biodiesel and No. 2 Diesel fuel are given in Fig. 1, brake power output versus engine speed graphs are given in Fig. 2 and the fuel consumption values are given in Fig. 3. The torque and brake power output obtained during the used cooking oil originated biodiesel applications are 3–5% less then those of No. 2 Diesel fuel. The lower specific heating value of biodiesel is the reason for this difference. As can be observed in Fig. 3, despite these differences, the fuel consumptions are very similar for the two fuels because of the high oxygen content of biodiesel. The engine exhaust gas temperature versus engine speed and injection pressures (in slopes) versus engine speed are given in Fig. 4 and Fig. 5, respectively, and the exhaust pressures versus engine speed are presented in Fig. 6. The engine exhaust gas temperatures, at each engine speed for biodiesel were less than those of No. 2 Diesel fuel. The difference appears to be minimum at 250
) 200 m N ( 150 e u q r o 100 T 50
Diesel
Biodiesel
0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 1. Torque vs. engine speed for the test fuels.
1286
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291 80 70 60 ) W 50 k ( r 40 e w 30 o P 20
Diesel
Biodiesel
10 0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 2. Brake power output vs. engine speed for the test fuels.
) e k o r t S / g m ( n o i t p m u s n o C l e u F
55 50 45 40 35
Diesel
Biodiesel
30 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 3. Fuel consumption vs. engine speed for the test fuels.
) C 700 ( e r 600 u t a r 500 e p 400 m e T 300 t s u 200 a Diesel Biodiesel h 100 x E 0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
0
Fig. 4. Engine exhaust gas temperatures vs. engine speed for the test fuels.
2000 rpm engine speed. The low value of engine exhaust gas temperature indicates that the used cooking oil originated biodiesel burned well in the cylinders when compared to No. 2 Diesel fuel. This result is relevant when the higher O2 content of the used cooking oil is considered. Also, in
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291 ) r a B ( e r u s s e r P n o i t c e j n I
1287
1400 1200 1000 800 600 400
Diesel
Biodiesel
200 0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 5. Injection pressure vs. engine speed for the test fuels.
) r a B ( e r u s s e r P t s u a h x E
300
Diesel
Biodiesel
250 200 150 100 50 0 1000 1500 2000 2525 3000 3500 4000 4500 Engine Speed- rpm
Fig. 6. Exhaust pressure vs. engine speed for the test fuels.
the early study on this subject, the observed decrease in smoke values up to 60% support this result [7]. The injection pressures of both fuels are similar due to the common rail system. The higher viscosity of biodiesel does not seem to be a disadvantage for this system. The high value of the exhaust pressures for No. 2 Diesel fuel at each engine speed support the results for the engine exhaust gas temperatures. As a result of the vehicle road tests, the effects of the two fuels on the injectors are presented separately. The distance of 7500 km was divided in to two periods due to the winter conditions. The effect of No. 2 Diesel fuel on the injectors can be observed in Fig. 7, whereas the effect of the used cooking oil originated biodiesel fuel at the end of the first period is shown in Fig. 8 and that for the biodiesel at the end of the second period is given in Fig. 9. As a result of the No. 2 Diesel fuel application, the engine injectors were normally carbonized (Fig. 7). After the first period, as a result of the winter conditions and insufficient combustion, carbonization in the injectors was observed due to biodiesel usage (Fig. 8). As a result of the second period, since the viscosity of the biodiesel was decreased, the injectors were observed to be cleaner (Fig. 9). The changes in the catalytic converter after the first and the second periods of the used cooking oil originated biodiesel utilization are given in Figs. 10 and 11, respectively. Also, no carbonization was observed on the surfaces of the cylinders and piston heads. The catalytic converter was
1288
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
Fig. 7. The view of injectors after No. 2 Diesel fuel application.
Fig. 8. The view of injectors after biodiesel application at the first period.
Fig. 9. The view of injectors after biodiesel (BDV) application at the second period.
plugged because of the viscosity in the first period (Fig. 10). After the first period, an additional washing step was added to the biodiesel production procedure to reduce the glycerin content of the used cooking oil originated biodiesel, and the test was continued with low glycerin content
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1289
Fig. 10. The view of catalyser after biodiesel application at the first period.
Fig. 11. The view of catalyser after biodiesel (BDV) application at the second period.
biodiesel in the second period. Also, the commercial viscosity improver for No. 2 Diesel fuel additive was added to the used cooking oil originated biodiesel (BDV). As a result of these modifications, in the second period, no problem was observed on the catalytic converter and injectors.
4. Conclusion
The engine performance test and road test performance results of used cooking oil originated biodiesel were evaluated in a Renault Me´gane automobile with a four stroke, four cylinder, F9Q732 code and 75 kW Renault Me´gane Diesel engine in winter conditions for 7500 km road tests and the measured results were compared to No. 2 Diesel fuel. The following results are obtained from the experimental results. •
The engine performance of biodiesel is directly related to the quality and fuel properties of the biodiesel. Utilization of fuel additives is one of the important and advantageous ways to improve fuel quality. Viscosity improver and pour point additives, which are commercially
1290
• •
• •
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
available, were used to improve the fuel property of the used cooking oil originated biodiesel, and the effects of these 2 additives were observed. The results showed that addition of these additives showed a significant effect on the fuel property of the used cooking oil originated biodiesel. The biodiesel application has caused a decrease in brake power output and torque when compared to No. 2 Diesel fuel. The engine exhaust gas temperature at each engine speed with biodiesel was less than that of No. 2 Diesel fuel, which showed that the biodiesel was burned better in the cylinders than No. 2 Diesel fuel. The injection pressures of both fuels were similar. The higher values of the exhaust pressures for No. 2 Diesel fuel at each engine speed made the engine exhaust gas temperature results relevant. As a result of the No. 2 Diesel fuel application, the engine injectors were normally carbonized. After the first period, as a result of the winter conditions and insufficient combustion, carbonization in the injectors was observed for the biodiesel application. As a result of the second period, since the viscosity of the biodiesel was decreased, the injectors were observed to be cleaner. Also, no carbonization was observed on the surfaces of the cylinders and piston heads. The catalytic converter was plugged because of the viscosity in the first period. In the second period, no problem was observed on the catalytic converter.
Based on the experimental results of this study, used cooking oil originated biodiesel can be recommended as a No. 2 Diesel fuel alternative for winter conditions.
Acknowledgement
The authors would like to thank the Renault Factory, Bursa for their support.
References [1] C¸ etinkaya M, Karaosmanog˘lu F. Today s Position of biodiesel in Turkey and EU. Presented at 94th AOCS Annual Meeting and Expo. 4–7 May 2003. Kansas City/Missouri, USA. [2] Clarke LJ, Crawshaw EH, Lilley LC, Fatty Acid Methyl Esters (FAMEs) as Diesel blend component. Presented at 9th Annual Fuels and Lubes Asia Conference and Exhibition. January 2003. Singapore, PR China. [3] Ulusoy Y, Alibas K. Technological and economical investigation of usage of biodiesel as an alternative fuel. J Fac Agric, Uludag University 2002;16(1). [4] Karaosmanog˘lu F. Vegetable oil fuels: A review. Energy Sources 1999;21:221–31. [5] Geyer SM, Jacobus MJ, Lestz SS. Comparison of Diesel engine performance and emissions from neat and transesterified vegetable oils. Tran ASAE 1984:221–31. [6] Scha¨fer A. Vegetable oil originated alternative Diesel engine fuel. Raps Sonderausgabe 1988:145–8 [in German]. [7] Ko¨rbitz W. Rapeseed oil originated biodiesel: Production starts in Austria. Raps 1990(4):192–5 [in German]. ¨ L. Safflower seed oil of Turkish origin as a [8] Is ıg˘ıgu¨r A, Karaosmanog˘lu F, Aksoy HA, Hamdullahpur F, Gu¨lder O Diesel fuel alternative. Appl Biochem Biotechnol 1993;40-41:89–103. ¨ L. Performance and emission charac[9] Is ıg˘ıgu¨r A, Karaosmanog˘lu F, Aksoy HA, Hamdullahpur F, Gu¨lder O teristics of a Diesel engine operating on safflower seed oil methyl ester. Appl Biochem Biotechnol 1994;45– 46:93–102. Õ
ß
ß
ß
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1291
[10] Gomez Gonzales ME, Howard-Hildige R, Leahy JJ, O Reilly TO, Supple B, Malone M. Emission and performance characteristics of a 2 litre Toyota van operating on esterified waste cooking oil and mineral Diesel fuel. Environmental Monitoring and Assessment 2000;65:13–20. [11] Al-Widyam MI, Tashtoush G, Abu-Quadais M. Utilization of ethyl ester of waste vegetable oils as fuel in Diesel engine. Fuel Process Technol 2002;76:91–103. [12] Dorado MP, Ballesteros E, Arnal JM, Gomez J, Gimenez Lopez FJ. Exhaust emissions from a Diesel engine fueled with transesterified waste olive oil. Fuel 2003;82(11):1311–5. [13] Dorado MP, Arnal JM, Gomez J, Gil A, Lopez FJ. The effect of a waste vegetable oil blend with Diesel fuel on engine performance. Trans ASAE 2002;45(3):519–23. [14] C¸ anakc¸i M, Van Gerpen J. The performance and emissions of a Diesel engine fueled with biodiesel from yellow grease and soybean oil. Presented in the Proceedings of 2001 ASAE International Meeting 2001. California, USA. [15] Leung DYC. Development of a clean biodiesel fuel in Hong Kong used cooking oil. Water, Air Soil Pollut 2001;130:277–82. [16] Zaher AF, Megahed OA, El Kinawy OS. Utilization of used frying oil as Diesel engine fuel. Energy Sources 2003;25(8):819–26. [17] Guo Y, Leung YC, Koo CP. A clean biodiesel fuel produced from recycled oils and grease trap oils. Better Air Quality in Asian and Pasific Rim Cities (BAQ 2002) 16–18 December, 2002. Hong Kong. [18] Ulusoy Y, Tekin Y, C ¸ etinkaya M, Karaosmanoglu F. The engine tests of biodiesel from used frying oil. Energy Sources 2004;26:927–32. Õ
Engine and winter road test performances of used cooking oil originated biodiesel Merve Mer ve C ¸ etinka eti nkaya ya a, Yahya Ulusoy b, Yu¨ cel Tekın b, Fılız Karaosmanog˘ lu
a
a,*
Department of Chemical Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey b Vocational School of Technical Sciences, Agricultural Equipments and Machinery Program, ˘ University, 16059 Go¨ ru Uludag ¨ ru¨ kle, ¨ kle, Bursa, Turkey Received 15 October 2003; received in revised form 3 March 2004; accepted 13 June 2004 Available online 11 September 2004
Abstract
Biodiesel Biodiesel is a renewable renewable and environmen environmentally tally friendly friendly alternative alternative fuel that can be used in Diesel engines with little or no modification. Low cost feedstocks, such as waste oils, used cooking oil and animal fats, are important for low cost biodiesel production. The objective of this study was to investigate the engine performance and the road performance of biodiesel fuel originated from used cooking oil in a Renault Me´ Me´ gane automobile and four stroke, four cylinder, F9Q732 code and 75 kW Renault Me´ Me´ gane Diesel engine in winter conditions for 7500 km road tests in urban and long distance traffic. The results were compared to those of No. 2 Diesel fuel. The results indicated that the torque and brake power output obtained during the used cooking oil originated biodiesel application were 3–5% less then those of No. 2 Diesel fuel. The engine exhaust gas temperature at each engine speed of biodiesel was less than that of No. 2 Diesel fuel. The injection pressures of both fuels were similar. Higher values of exhaust pressures were found for No. 2 Diesel fuel at each engine speed. As a result of the No. 2 Diesel fuel application, the engine injectors were normally carbonized. After the first period, as a result of winter conditions and insufficient combustion, carbonization of the injectors was observed with biodiesel usage. As a result of the second period, since the viscosity of the biodiesel was decreased, the injectors were observed to be cleaner. Also, no carbonization was observed on the surface of the cylinders and piston heads. The catalytic converter was plugged because
*
Corresponding author. Tel.: +90 212 285 6837; fax: +90 212 285 2925. E-mail address: fi[email protected] (F. Karaosmanog˘ lu).
0196-8904/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.enconman.2004.06.022
1280
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
of the viscosity in the first period. At the second period, no problem was observed with the catalytic converter. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Biodiesel; Used cooking oil; Used cooking oil methyl ester; Diesel engine; Engine performance test; Road test; Durability test
1. Introduction
Biodiesel is an environmentally friendly alternative for petroleum based Diesel fuel. It has proven itself as a technically sufficient alternative Diesel fuel in the fuel market since the beginning of the 1990s [1]. Its reducing characteristic for greenhouse gas emissions, its help on reducing a country s reliance on crude oil imports, its supportive characteristic on agriculture by providing a new market for domestic crops, its effective lubricating property that eliminates the need of any lubricating additive and its wide acceptance by vehicle manufacturers can be listed as the most important advantages of the fuel [2]. Many studies have shown that the properties of biodiesel are very close to those of No. 2 Diesel fuel. Therefore, biodiesel can be used in Diesel engines with little or no modification [3,4]. The first application of vegetable based oils for engine performance was in World War II. Although vegetable oil applications have been available since the 1950s, it was necessary to research on engine design and fuel technology. Geyer et al. [5] used a mixture of No. 2 Diesel fuel and cotton oil, sunflower oil and their methyl esters in a one cylinder Diesel engine and compared engine performances and emission values. According to the results, it was reported that the thermal efficiencies of vegetable based fuels were equal to or much higher than those of No. 2 Diesel fuel. The temperatures of the exhaust gases and emission values were equal to or much higher also [5]. Schafer researched the application of vegetable based oils in Diesel engines as an alternative fuel [6]. For this aim, during the research in Daimler Benz AG, it was observed that carbonization and stratification in the combustion chamber and the fuel consumption were similar to those of No. 2 Diesel fuel, and the values were more suitable. The amount of wear occurring due to the engine working for long hours was observed to be similar to that with conventional Diesel fuels [6]. In his study, Ko¨rbitz [7], worked on the use of vegetable based fuels that were cultivated in Austria for the purpose of biodiesel production. As a result, biodiesel was found to be more benign ecologically and the emissions were similar to Diesel fuel emissions and some had better results. Besides special vehicles, trucks (lorry) and government vehicles have been tested, and no problem resulting from biodiesel use was observed [7]. Is ıg˘ıgu¨r et al. [8] investigated the ASTM fuel properties of different ratio blends of safflower seed oil methyl ester and No. 2 Diesel fuel. As a result of the study, the 20% blend had fuel properties close to the limits of specified No. 2 Diesel fuel, and the engine and emission performance of the 20% blend were found to be similar to those of No. 2 Diesel fuel [8]. Is ıg˘ıgu¨r et al. [9] studied the performance and emission characteristics of safflower seed oil methyl ester, and it was reported that the safflower seed oil methyl ester revealed similar engine performance characteristics to those of the reference No. 2 Diesel fuel. Lower CO and HC emissions were obtained when the methyl ester was used, and a negligible amount of sulfur content was another advantage of the methyl ester application [9]. Gomez et al. [10] investigated the Õ
ß
ß
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1281
exhaust emission and performance characteristics of a Toyota van powered by a 2 l indirect injection (IDI), naturally aspirated Diesel engine operating on vegetable based waste cooking oil methyl ester. The waste cooking oil methyl ester developed a significantly lower smoke opacity level and reduced CO, CO2 and SO2 values, whereas the O2, NO2 and NO levels were higher when compared to those of No. 2 Diesel fuel. The power values were comparable for the two fuels [10]. Al-Widyan et al. [11] investigated the performance of an ethyl ester of waste vegetable oil in a Diesel engine. The fuels tested were different ester/Diesel blends, including 100% ester, with No. 2 Diesel fuel. Variable speed tests were run on all fuels on a standard test rig of a single cylinder, direct injection Diesel engine. As a result, it was reported that the blends burned more efficiently with less specific fuel consumption and, therefore, resulted in higher engine thermal efficiency. The blends produced less CO and unburned HC than Diesel fuel [11]. The exhaust emissions of a Diesel direct injection Perkins engine fueled with waste olive oil methyl ester were studied by Dorado et al. [12] at several steady state operating conditions. Emissions were characterized for biodiesel from used olive oil and No. 2 Diesel fuel. The use of biodiesel resulted in lower emissions of CO, CO2, NO and SO2 with an increase in the emissions of NO2. Biodiesel also presented a slight increase in brake specific fuel consumption. Combustion efficiency remained constant using either biodiesel or No. 2 Diesel fuel [12]. Dorado et al. [13] also worked to determine the feasibility of running a 10% waste vegetable oil–90% Diesel fuel blend during a 500 h period in a three-cylinder, direct injection, 2500 cm3 Diter Diesel engine. Approximately 12% power loss, a slight fuel consumption increase and normal smoke emissions were observed. The Diter Diesel engine, without any modifications, ran successfully on a blend of 10% waste oil–90% Diesel fuel without externally apparent damage to the engine parts. As a result of the studies, it was concluded that the long term use of waste oil blended with Diesel fuel may need further testing before use as a viable energy solution [13]. C ¸ anakc¸i and Gerpen [14] investigated the performance and emissions of a John Deere 4276T model Diesel engine with biodiesel from yellow grease and soybean oil. Two different biodiesels from yellow grease and soybean oil were prepared, and their 20% blends with No. 2 Diesel fuel were studied at steady state engine operating conditions in a four cylinder turbocharged Diesel engine. Significant reductions in particulates, CO and unburned HCs were observed, whereas an increse of 11% and 13% in oxides of nitrogen were found for the yellow grease methyl ester and soybean oil methyl ester, respectively [14]. Leung [15] has studied the properties of biodiesel produced from used waste cooking oil and animal fats from restaurants as feedstock. Tests of the fuel with three different proportions, 0%, 10% and 15%, of Diesel have been conducted on various Diesel engines. A 7% reduction in smoke opacity at a blending ratio of 15% was observed without affecting the engine power, torque and fuel consumption. A reduction of air pollutants from 1.5% to 44% was observed for most of the pollutants other than NO, which had a slight reduction at the idle condition but increased by about 16% at 2500 rpm. The third test was conducted on a Diesel generator (Robin GS 3300RD) that consisted of a generator and a four stroke single cylinder Diesel engine with rated power 3.4 kW. CO levels decreased with increasing biodiesel percentages for both idle and loaded conditions. The NOX level showed a decreasing trend for the idling case, whereas at loaded conditions, the level fluctuated within a narrow range. The fuel consumption showed a slight increase with increasing biodiesel percentage for idle and loaded conditions [15]. Guo et al. [17] studied three different feed stocks for biodiesel production. The aim of their study was to investigate the optimum conditions for biodiesel production and to study the fuel properties and engine performance of the produced biodiesel samples in a light Diesel van on a chassis
1282
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
dynamometer. Experiments showed that utilization of the produced biodiesel could reduce smoke and HC emissions, while the NOX emissions changed slightly. An unnoticeable drop in the maximum engine power output was observed even at 100% biodiesel [17]. The work of Zaher et al. [16] was done on the utilization of used frying oil as an alternative fuel for Diesel engines. Used frying oil was modified with thermal cracking in the presence of 2% CaO to reduce its viscosity. The fuel properties of the modified oil were determined, and the performance of the oil as 50% blend with No. 2 Diesel fuel was evaluated. The product obtained after thermal cracking showed similar properties to those of No. 2 Diesel fuel. The output power, brake thermal efficiency and brake specific fuel consumption of the Diesel engine were changed markedly by blending the cracked product and No. 2 Diesel fuel [16]. Ulusoy et al. [18] investigated the effects of used frying oil originated biodiesel on engine performance and emissions in a Fiat Doblo 1.9 DS, four cylinder, four stroke, 46 kW power capacity Diesel engine. Comparative measurements with No. 2 Diesel fuel were done on both engine power and emission characteristics for each of the fuels used. Biodiesel, when compared to No. 2 Diesel fuel, showed a reduction in wheel force of over 3.35% and it also reduced the wheel power by over 2.03%. In the acceleration tests, 40–100 km/h and 60–100 km/h acceleration periods were measured, and a reduction of 7.32% and 8.78% were observed, respectively. According to the emission tests, as a result of biodiesel consumption, a reduction of 8.59% in CO emission and an increase of 2.62% in CO2 emission were observed. Also, as a result of biodiesel consumption, the NOX emissions increased by 5.03%. HC emissions and particulate emissions have a significant effect on air pollution. As a result of biodiesel use, the HC and particulate emissions decreased by 30.66% and 63.33%, respectively. When the fuel consumption amounts are compared, it was observed that the biodiesel consumption was 2.43% less than that of No. 2 Diesel fuel [18]. In this study, used cooking oil, as a low cost feedstock, was used for biodiesel production, and the engine performance and road performance of biodiesel were investigated in a Renault Me´gane automobile and four stroke, four cylinder, F9Q732 code and 75 kW Renault Me´gane Diesel engine in winter conditions for 7500 km road tests. The measured results were compared to those of No. 2 Diesel fuel.
2. Experimental section
2.1. Materials and methods
Biodiesel production was conducted in a pilot scale reactor in the Vocational School of Technical Sciences, Agricultural Equipments and Machinery Laboratory, Uludag University in Bursa, Turkey, according to the methods chosen from the literature [18]. The fuel properties of biodiesel and No. 2 Diesel fuel, were determined according to the ASTM standard methods in the TUBITAK-MAM Laboratories, and they are given in Table 1. The biodiesel types utilized during the experiments can be defined as follows: used cooking oil originated biodiesel (BD), BD with viscosity improver additive (BDV) and BD with pour point improver additive (BDP). These additives were applied to the original used cooking oil originated biodiesel (BD) due to the cold winter conditions in Turkey and the authors aimed to measure the effects of these additives on the biodiesel engine performance and duration and vehicle performances. The viscosity improver additive, which was obtained from Adco Petroleum Product Additives Company, Turkey, and the
1283
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291 Table 1 Fuel properties of No. 2 Diesel fuel, BD, BDV, BDP and biodiesel ASTM standards Properties
Test method
No. 2 Diesel fuel
Used cooking oil originated biodiesel (BD)
BD with viscosity improver (BDV)
BD with pour point improver (BDP)
Biodiesel fuel standard ASTM D6751-02
Flash Point, °C Kinematic viscosity, cSt (40 °C) Pour point, °C Cetane number
D 93 D 445
58 2.5
148 5.18
148 4.92
148 5.18
130 min 1.9–6.0
D 2500 D 613
À33
À4
À4
À10
55
48
49
48
Report 47 min
Skot Diesel Treatment Fuel System Cleaner, a commercially available pour point additive, were applied to decrease the biodiesel viscosity and pour point for the engine performance and duration and vehicle performance and speed tests. 2.2. Engine performance test
Studies on the vehicle and engine were performed in the Renault Factory, Bursa. In this study, the Renault Test Laboratories were used for identification of the engine durability. For the performance tests, the Renault Me´gane F9Q732 type Diesel engine was used. The engine technical specifications are given in Table 2. The engine used for the engine tests was braked according to Renault standard test method, 34–00–020, and the tests were performed under the Renault test standard 34–00–019. The tests were conducted 3 times, and the averages of these 3 consecutive test results are presented in the figures. In order to examine the durability of the engine, constant engine speeds versus loads tests were performed when the acceleration pedal was at full throttle. As a result of application of No. 2 Diesel fuel to the engine and then applying biodiesel, a comparison of the emission values of the two different kinds of fuel was obtained. During the engine performance tests, the engine temperature was kept under control, and the values were recorded after reaching the ideal engine temperature. 2.3. Duration test
The test was conducted through a 7500 km test drive with a vehicle utilizing on biodiesel. Vehicle engine parts were examined, and the combustion chamber was controlled with an endoscopy Table 2 Technical properties of F9Q732 type Renault Me´gane Diesel engine Technical properties
F9Q732-Diesel
Fuel injection system Cylinder diameter · Stroke (mm) Cubic capacity (cm 3) Compression ration Maximum power (4000 minÀ1) (kW) Maximum torque (1500 minÀ1) (Nm)
Common rail electronic 80 · 93 1870 18.3:1 75 200
1284
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
instrument at the beginning, the middle and the end of the test. As a result, the effect of biodiesel utilization was observed by comparison of the results obtained from these investigations. The duration test program is given below; 03.12.2001: Beginning of the duration test. 17.12.2001–24.12.2001: Trial drive in cold weather. 10.01.2002: Catalyst replacement. 29.01.2002: Injector replacement. 05.03.2002: End of the duration test (7500 km). At the beginning of the test, No. 2 Diesel fuel was used to obtain comparative results with biodiesel. The formed soot inside the cylinders was examined with an endoscopy instrument by pro jecting the bottom and sides of the cylinders. The soots on cylinder pumps, jackets, ignition spark plugs and cylinder heads were also investigated. 2.4. Vehicle performance and speed test
Vehicle road tests were begun on the 3rd of December 2001 and ended on the 5th of March 2002. The Renault Me´gane was the test automobile for the vehicle road tests. The vehicle performance test was conducted according to Renault test standard, 37–00–001. The results of the Renault standard test procedure are given in Table 3. The vehicle performance tests were divided into two parts because of the fuel problems due to winter weather conditions. The effects of Table 3 Vehicle performance test results F9Q732 Diesel fuel
F9Q732 No. 2 Diesel fuel
Temperature °C Power kW Torque Nm
16 75/4000 200
13 75/4000 200
Acceleration (sn) 0–100 km/h 400 m 1000 m
13, 17 18, 80 34, 66
12, 72 18, 65 34, 26
Last speed (km/h) 5. gear
175.60
183.00
4. gear
8.25 9.34 12.75 11.99
7.93 8.07 11.34 10.50
5. gear
12.5 12.98 18.52 18.93
12.46 11.31 16.03 14.28
Flexibility (sn) DL 50–80 km/h DL 80–110 km/h DL 80–120 km/h DL 110–140 km/h DL DL DL DL
50–80 km/h 80–110 km/h 80–120 km/h 110–140 km/h
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1285
biodiesel application on the engine were measured by dividing the 7500 km into two periods. The tests were conducted 3 times, and the averages of these 3 consecutive test results are presented in Table 3. The records were taken at the end of each period and the difference between the two data sets was considered to be the effect of biodiesel on the engine.
3. Results and discussion
According to Table 1, the used cooking oil originated biodiesel that was utilized in the engine and road performance tests meet the ASTM biodiesel Standard. When the fuel properties of biodiesel and No. 2 Diesel fuel in Table 1 are compared, it can be observed that the biodiesel properties are close to those of No. 2 Diesel fuel. From Table 1, it can be seen that biodiesel has a higher flash point and pour point than those of No. 2 Diesel fuel. As can be seen from Table 1, the pour point of biodiesel was measured to be À4 °C without any Diesel fuel additive. To have better results in winter conditions, the Skot Diesel Treatment Fuel System Cleaner was used to decrease the biodiesel (BDP) pour point from À4 to À10 °C. In Table 3, the result of Renault standard test method, 37–00–001 is listed. Table 3 shows a slight drop in engine performance, which can be the result of low specific heating value, viscosity and pour point of the biodiesel, as can be seen from the brake power output and torque graphs, too. This drop in engine performance coincides with the subjective opinions of test drivers. Torque versus engine speed graphs with biodiesel and No. 2 Diesel fuel are given in Fig. 1, brake power output versus engine speed graphs are given in Fig. 2 and the fuel consumption values are given in Fig. 3. The torque and brake power output obtained during the used cooking oil originated biodiesel applications are 3–5% less then those of No. 2 Diesel fuel. The lower specific heating value of biodiesel is the reason for this difference. As can be observed in Fig. 3, despite these differences, the fuel consumptions are very similar for the two fuels because of the high oxygen content of biodiesel. The engine exhaust gas temperature versus engine speed and injection pressures (in slopes) versus engine speed are given in Fig. 4 and Fig. 5, respectively, and the exhaust pressures versus engine speed are presented in Fig. 6. The engine exhaust gas temperatures, at each engine speed for biodiesel were less than those of No. 2 Diesel fuel. The difference appears to be minimum at 250
) 200 m N ( 150 e u q r o 100 T 50
Diesel
Biodiesel
0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 1. Torque vs. engine speed for the test fuels.
1286
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291 80 70 60 ) W 50 k ( r 40 e w 30 o P 20
Diesel
Biodiesel
10 0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 2. Brake power output vs. engine speed for the test fuels.
) e k o r t S / g m ( n o i t p m u s n o C l e u F
55 50 45 40 35
Diesel
Biodiesel
30 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 3. Fuel consumption vs. engine speed for the test fuels.
) C 700 ( e r 600 u t a r 500 e p 400 m e T 300 t s u 200 a Diesel Biodiesel h 100 x E 0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
0
Fig. 4. Engine exhaust gas temperatures vs. engine speed for the test fuels.
2000 rpm engine speed. The low value of engine exhaust gas temperature indicates that the used cooking oil originated biodiesel burned well in the cylinders when compared to No. 2 Diesel fuel. This result is relevant when the higher O2 content of the used cooking oil is considered. Also, in
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291 ) r a B ( e r u s s e r P n o i t c e j n I
1287
1400 1200 1000 800 600 400
Diesel
Biodiesel
200 0 1000 1500 2000 2500 3000 3500 4000 4500 Engine Speed-rpm
Fig. 5. Injection pressure vs. engine speed for the test fuels.
) r a B ( e r u s s e r P t s u a h x E
300
Diesel
Biodiesel
250 200 150 100 50 0 1000 1500 2000 2525 3000 3500 4000 4500 Engine Speed- rpm
Fig. 6. Exhaust pressure vs. engine speed for the test fuels.
the early study on this subject, the observed decrease in smoke values up to 60% support this result [7]. The injection pressures of both fuels are similar due to the common rail system. The higher viscosity of biodiesel does not seem to be a disadvantage for this system. The high value of the exhaust pressures for No. 2 Diesel fuel at each engine speed support the results for the engine exhaust gas temperatures. As a result of the vehicle road tests, the effects of the two fuels on the injectors are presented separately. The distance of 7500 km was divided in to two periods due to the winter conditions. The effect of No. 2 Diesel fuel on the injectors can be observed in Fig. 7, whereas the effect of the used cooking oil originated biodiesel fuel at the end of the first period is shown in Fig. 8 and that for the biodiesel at the end of the second period is given in Fig. 9. As a result of the No. 2 Diesel fuel application, the engine injectors were normally carbonized (Fig. 7). After the first period, as a result of the winter conditions and insufficient combustion, carbonization in the injectors was observed due to biodiesel usage (Fig. 8). As a result of the second period, since the viscosity of the biodiesel was decreased, the injectors were observed to be cleaner (Fig. 9). The changes in the catalytic converter after the first and the second periods of the used cooking oil originated biodiesel utilization are given in Figs. 10 and 11, respectively. Also, no carbonization was observed on the surfaces of the cylinders and piston heads. The catalytic converter was
1288
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
Fig. 7. The view of injectors after No. 2 Diesel fuel application.
Fig. 8. The view of injectors after biodiesel application at the first period.
Fig. 9. The view of injectors after biodiesel (BDV) application at the second period.
plugged because of the viscosity in the first period (Fig. 10). After the first period, an additional washing step was added to the biodiesel production procedure to reduce the glycerin content of the used cooking oil originated biodiesel, and the test was continued with low glycerin content
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1289
Fig. 10. The view of catalyser after biodiesel application at the first period.
Fig. 11. The view of catalyser after biodiesel (BDV) application at the second period.
biodiesel in the second period. Also, the commercial viscosity improver for No. 2 Diesel fuel additive was added to the used cooking oil originated biodiesel (BDV). As a result of these modifications, in the second period, no problem was observed on the catalytic converter and injectors.
4. Conclusion
The engine performance test and road test performance results of used cooking oil originated biodiesel were evaluated in a Renault Me´gane automobile with a four stroke, four cylinder, F9Q732 code and 75 kW Renault Me´gane Diesel engine in winter conditions for 7500 km road tests and the measured results were compared to No. 2 Diesel fuel. The following results are obtained from the experimental results. •
The engine performance of biodiesel is directly related to the quality and fuel properties of the biodiesel. Utilization of fuel additives is one of the important and advantageous ways to improve fuel quality. Viscosity improver and pour point additives, which are commercially
1290
• •
• •
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
available, were used to improve the fuel property of the used cooking oil originated biodiesel, and the effects of these 2 additives were observed. The results showed that addition of these additives showed a significant effect on the fuel property of the used cooking oil originated biodiesel. The biodiesel application has caused a decrease in brake power output and torque when compared to No. 2 Diesel fuel. The engine exhaust gas temperature at each engine speed with biodiesel was less than that of No. 2 Diesel fuel, which showed that the biodiesel was burned better in the cylinders than No. 2 Diesel fuel. The injection pressures of both fuels were similar. The higher values of the exhaust pressures for No. 2 Diesel fuel at each engine speed made the engine exhaust gas temperature results relevant. As a result of the No. 2 Diesel fuel application, the engine injectors were normally carbonized. After the first period, as a result of the winter conditions and insufficient combustion, carbonization in the injectors was observed for the biodiesel application. As a result of the second period, since the viscosity of the biodiesel was decreased, the injectors were observed to be cleaner. Also, no carbonization was observed on the surfaces of the cylinders and piston heads. The catalytic converter was plugged because of the viscosity in the first period. In the second period, no problem was observed on the catalytic converter.
Based on the experimental results of this study, used cooking oil originated biodiesel can be recommended as a No. 2 Diesel fuel alternative for winter conditions.
Acknowledgement
The authors would like to thank the Renault Factory, Bursa for their support.
References [1] C¸ etinkaya M, Karaosmanog˘lu F. Today s Position of biodiesel in Turkey and EU. Presented at 94th AOCS Annual Meeting and Expo. 4–7 May 2003. Kansas City/Missouri, USA. [2] Clarke LJ, Crawshaw EH, Lilley LC, Fatty Acid Methyl Esters (FAMEs) as Diesel blend component. Presented at 9th Annual Fuels and Lubes Asia Conference and Exhibition. January 2003. Singapore, PR China. [3] Ulusoy Y, Alibas K. Technological and economical investigation of usage of biodiesel as an alternative fuel. J Fac Agric, Uludag University 2002;16(1). [4] Karaosmanog˘lu F. Vegetable oil fuels: A review. Energy Sources 1999;21:221–31. [5] Geyer SM, Jacobus MJ, Lestz SS. Comparison of Diesel engine performance and emissions from neat and transesterified vegetable oils. Tran ASAE 1984:221–31. [6] Scha¨fer A. Vegetable oil originated alternative Diesel engine fuel. Raps Sonderausgabe 1988:145–8 [in German]. [7] Ko¨rbitz W. Rapeseed oil originated biodiesel: Production starts in Austria. Raps 1990(4):192–5 [in German]. ¨ L. Safflower seed oil of Turkish origin as a [8] Is ıg˘ıgu¨r A, Karaosmanog˘lu F, Aksoy HA, Hamdullahpur F, Gu¨lder O Diesel fuel alternative. Appl Biochem Biotechnol 1993;40-41:89–103. ¨ L. Performance and emission charac[9] Is ıg˘ıgu¨r A, Karaosmanog˘lu F, Aksoy HA, Hamdullahpur F, Gu¨lder O teristics of a Diesel engine operating on safflower seed oil methyl ester. Appl Biochem Biotechnol 1994;45– 46:93–102. Õ
ß
ß
ß
M. C ¸ etinkaya et al. / Energy Conversion and Management 46 (2005) 1279–1291
1291
[10] Gomez Gonzales ME, Howard-Hildige R, Leahy JJ, O Reilly TO, Supple B, Malone M. Emission and performance characteristics of a 2 litre Toyota van operating on esterified waste cooking oil and mineral Diesel fuel. Environmental Monitoring and Assessment 2000;65:13–20. [11] Al-Widyam MI, Tashtoush G, Abu-Quadais M. Utilization of ethyl ester of waste vegetable oils as fuel in Diesel engine. Fuel Process Technol 2002;76:91–103. [12] Dorado MP, Ballesteros E, Arnal JM, Gomez J, Gimenez Lopez FJ. Exhaust emissions from a Diesel engine fueled with transesterified waste olive oil. Fuel 2003;82(11):1311–5. [13] Dorado MP, Arnal JM, Gomez J, Gil A, Lopez FJ. The effect of a waste vegetable oil blend with Diesel fuel on engine performance. Trans ASAE 2002;45(3):519–23. [14] C¸ anakc¸i M, Van Gerpen J. The performance and emissions of a Diesel engine fueled with biodiesel from yellow grease and soybean oil. Presented in the Proceedings of 2001 ASAE International Meeting 2001. California, USA. [15] Leung DYC. Development of a clean biodiesel fuel in Hong Kong used cooking oil. Water, Air Soil Pollut 2001;130:277–82. [16] Zaher AF, Megahed OA, El Kinawy OS. Utilization of used frying oil as Diesel engine fuel. Energy Sources 2003;25(8):819–26. [17] Guo Y, Leung YC, Koo CP. A clean biodiesel fuel produced from recycled oils and grease trap oils. Better Air Quality in Asian and Pasific Rim Cities (BAQ 2002) 16–18 December, 2002. Hong Kong. [18] Ulusoy Y, Tekin Y, C ¸ etinkaya M, Karaosmanoglu F. The engine tests of biodiesel from used frying oil. Energy Sources 2004;26:927–32. Õ
