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Performance and emission of CI engine fuelled with camelina sativa oil
Energy Conversion and Management 65 (2013) 1–6
Contents lists available at SciVerse ScienceDirect
Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman
Performance and emission of CI engine fuelled with camelina sativa oil Stanisław W. Kruczyn´ski ⇑ Warsaw University of Technology, Faculty of Automotive and Construction Machinery Engineering, Narbutta St. 84, 02-524 Warszawa, Poland
a r t i c l e
i n f o
Article history: Received 4 February 2012 Received in revised form 30 June 2012 Accepted 30 June 2012 Available online 11 October 2012 Keywords: Camelina sativa Alternative fuels CI engine Engine speed curves Engine emissions
a b s t r a c t The paper describes the results of the tests of CI Perkins 1104C-44 engine fuelled with camelina sativa oil. The engine was not especially calibrated for fuelling with the vegetable fuel. During the test the engine performance and emissions were analysed. For comparison the same speed characteristic was examined for standard fuelling of the engine with diesel oil. In order to understand the engine performance and emission the mass fraction burnt and the rate of heat release was calculated and compared for the same energy provided to the engine cylinder with the injected fuels. The results show that there is possible to receive relatively good engine performance for fuelling the engine with camelina sativa oil but there is a need to change the calibration parameters of the engine fuel system when the engine is fuelled with this fuel. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Camelina sativa is a new crop with a variety of uses. It is relatively easy to grow with low input costs. It is a spring annual broadleaf oilseed herb of the Brassicaceae family that grows well in moderate climates. Its meal is valuable as animal feed, and its oil has important nutritional components (alpha linolenic acid and gamma-tocopherol). Camelina seed contains 30–40% oil that could be used as a fuel. There is a discussion on the use of camelina as biofuel because the linolenic acid and omega-3 fatty acid makes up about 35–39% of the total oil content. As yet, the production of camelina sativa is not significant (there are some exceptions like the state of Montana in the United States). It seems that the industrial potential of this plant, given the current fuel crisis, is rather significant. The potential contribution of biomass to the sustainable energy development is presented in [1]. The utilisation of biomass especially agricultural crops strongly depends on economy. About 7% of global vegetable oil supplies was used for biodiesel production in 2007. Extensive use of edible oils may cause other significant problems such as starvation in developing countries [2]. The economic performance of a biodiesel plant identified by many factors, such as plant capacity, process technology, raw material cost and chemical costs and government policy of biofuel concerns job creation, greater efficiency in the general business environment, and protection of the environment are described in [3]. Camelina sativa has several positive agronomic attributes: low agricultural inputs, cold-weather tolerance, short growing season ⇑ Tel.: +48 22 2348781; fax: +48 22 8490303. E-mail address: [email protected] 0196-8904/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.enconman.2012.06.022
(85–100 days), compatibility with existing farm equipment, and ability to grow well in semiarid regions and in low-fertility or saline soils [4]. It is possible to obtain as much as 1350 kg of the seeds from one hectare and to receive 400 kg of good quality oil that could also be used as a fuel [5]. Camelina sativa oil is a good base for the production of esters that fulfil high standards of second generation renewable fuels [5,6]. The camelina methyl ester has properties similar to the rapeseed methyl ester with the exception of its high iodine value [7] and is stable in airtight containers with periodic openings for at least 18 months, even without natural antioxidants [8]. Fuel-specific properties of camelina methyl esters are largely within specifications, though low-temperature behaviour could be a problem in some climates. This problem could be overcome by the use of suitable pour-point depressants or by blending with diesel oil. Another problem is the iodine number that exceeds the value of 120 required by the EU standards [9]. The oil can also be used to prepare the blends with standard diesel oil [10,11], which is important in the fuel market inevitably shifting towards sustainable energy sources [12]. Various methods for the production of biodiesel from vegetable oil, including direct use and blending are presented in [13]. There are some examples of direct use of neat camelina oil as a fuel for diesel engines [14]. In the Institute of Vehicles of the Faculty of Vehicles and Heavy Machines in Warsaw University of Technology the tests of possible application of camelina sativa oil as a fuel for CI engine were carried out. The aim of the tests was to check the performance and the emission of standard CI engine fuelled with neat camelina sativa oil and to compare the results with the results obtained for standard diesel oil for the same adjustment parameters of the injection of the fuels. The results also
´ ski / Energy Conversion and Management 65 (2013) 1–6 S.W. Kruczyn
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give some information about phenomena that accompany the application of neat camelina sativa oil as a fuel. 2. Characteristic of the fuels The structure of neat camelina sativa oil slightly depends on the soil, climate as well as weather conditions. Even the date of planting by calendar influences the fatty acid profile of the oil as presented in [14]. Typical camelina sativa oils contains: oleic (14.1–19.5%), linoleic (18.8–24.0%), linolenic (27.0–34.7%), eicosenoic (12.0–14.9%), erucic (0.0–4.0%) and other (11.8–17.4%) fatty acids [15]. For the test of the engine performance and emissions the neat oil was used. It was examined and its features were compared to standard diesel oil. The comparison of major parameters of the fuels that were used in the experiment are shown in Table 1. There are many differences between features of diesel oil and camelina sativa oil. First of all camelina sativa oil has very high viscosity in comparison to standard diesel oil. In comparison to palm oil (41.69 mm2/s), canola oil (36.28 mm2/s) and soybean oil (31.49 mm2/s) the kinematic viscosity in 40 °C of camelina sativa oil is lower (28.94 mm2/s) but still very high (for diesel oil it is 2.92 mm2/s) [17]. Kinematic viscosity as well as higher surface tension could significantly influence the injection process as well as the process of mixture formation. The authors [18] point out that camelina sativa oil has a high level of linolenic acid, which makes this oil particularly susceptible to oxidation (Table 2). The content of linolenic acid is important for the combustion process particularly since it could affect the rate of heat release and should be analysed during the engine tests. The lower calorific value of camelina sativa oil is partially compensated by the higher density of the fuel. The thermal efficiency of the engine fuelled with the examined fuels depends on air/fuel mixture composition, especially on the air excess coefficient k. The injection dose of camelina sativa oil that is provided to the engine cylinder for the parameters of the injection system that are optimum for diesel oil can be different and provides some modifications to the mixture composition. 3. The engine and the test stand For the tests of performance and emissions of the engine fuelled with camelina sativa oil and standard diesel oil a Perkins 1104C-44 engine was used. The engine fulfils Tier 2 off-highway emissions legislation. The data and performance of the standard version of the Perkins 1104C-44 engine are shown in Table 3. The engine was installed on a test rig fitted with measurement equipment that enabled the measurement of the engine torque (SCHENCK eddy-current brake), engine speed, fuel consumption, the emissions of total hydrocarbons, nitric oxides, carbon monoxide (AVL CEB II analyser with heated exhaust line) and particulates (AVL 415). The high-speed measurement and data acquisition sys-
Table 2 Content of linolenic fatty acid in selected vegetable oils (%) [19]. Vegetable oil
Content of linolenic fatty acid (C18H30O2)
Camelina sativa oil Canola oil Rapeseed oil Sunflower oil High-oleic acid sunflower oil Soybean oil Olive oil Linseed oil Palm oil Castor oil Peanut oil Corn oil Coconut oil
31.2 8 7 0.1 6.0 6–11 0.5–1 51–54 1–2 0 0.5 1.1 0.0
Table 3 Perkins 1104C-44 – the data and rated performance of the standard version [20]. Number of cylinders Bore and stroke Displacement Aspiration Cycle Combustion system Fuel system Compression ratio Rated power output (kW) Rated maximum torque (Nm)
4 Straight 105 mm 127 mm 4.4 l Natural 4 Stroke Direct injection Distribution injection pump 19.3:1 64.0 at 2400 rpm 308 at 1200 rpm
tem (AVL Indi Smart) were used for the measurement of the engine cylinder pressure (see Fig. 1).
4. The experiment In order to obtain information about the engine performance and its emissions for fuelling with camelina sativa oil an engine speed curve was performed. The same curve was prepared for the engine that was fuelled with standard diesel oil. Both characteristics were performed to obtain the maximum engine torque for each engine speed without special adjustment of the engine. Injection timing was the same for both fuels and it was 12° BTDC,
Table 1 The comparison of properties of camelina sativa oil and diesel oil [16]. Parameter
Camelina sativa oil
Diesel oil
Density at 15 °C (kg/m3) Kinematic viscosity at 40 °C (mm2/s) Flash point (°C) Lower heating value (MJ/kg) Surface tension at 20 °C (mN/m) Ash (% mass) Sulphur content (mg/kg) Water content (mg/kg) Acid value (mg KOH/g) Iodine number (gI/100 g)
925.4 28.94 >220 38.2 32.9 0.003 14.1 720 1.46 157.2
838 2.92 102 42.3 24 0.01 9 43.8 – –
Fig. 1. The test rig: 1 – Perkins 1104-C44 engine, 2 – air intake, 3 – exhaust outlet, 4 – Schenck eddy-current brake; 5 – AVL GM 12 piezoelectric pressure sensor; 6 – crank position sensor, 7 – amplifier, 8 – AVL Indi Smart system, 9 – AVL 415 particulate matter concentration analyser, 10 – AVL CEB II Exhaust gas analyser, 11 – heated sample tube, 12 – calibration gases, and 13 – data acquisition system based on a PC [16].
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Fig. 2. Maximum brake torque (a), power (b), specific fuel consumption (c), and engine overall efficiency (d) vs. engine speed for the fuelling of the Perkins 1104-C44 engine with camelina sativa oil and standard diesel oil for the same maximum setting of fuel control lever.
also the position of the control lever for maximum fuel dose was the same for both fuels. The injector opening pressure was 29 MPa. The temperature measured in the fuel tank was 21 °C (37–39 °C in the return pipe). The air excess coefficient was calculated based on the concentration of exhaust gas components measured with the use of AVL CEB II exhaust gas analyser. The Bretschneider’s formula was applied to calculate the k value. The calculation of engine thermal efficiency was one of the most important results of the test of the engine fuelled with both fuels. To compare the process of combustion of camelina sativa oil and diesel oil, particularly the mass fraction burned and the rate of heat release as well as the thermal efficiency an additional experiment was carried out. For the two engine speed values (1400 rpm and 2200 rpm) the same amount of energy per cycle included in camelina sativa oil dose and diesel oil dose was supplied to the engine cylinder.
5. The results of the experiment The results of the measurements and calculations yielded information about engine performance, particularly the engine overall efficiency and emissions. The engine speed characteristics show that it is possible to obtain higher torque for the engine fuelled with camelina sativa oil. However, the results of the measurements of fuel consumption show that the engine specific fuel consumption is much higher for this fuel. The engine overall efficiency is
much lower than for the engine fuelled with standard diesel oil. The difference is about 5% (Fig. 2). The engine emission and air excess coefficient as well as the percentage of monoxide in the exhaust gases for the two examined fuels that were measured for the speed characteristic are shown in Fig. 3. For lower engine speed the air excess coefficient was too low for fuelling with camelina sativa oil, hence, the emission of hydrocarbons, carbon monoxide and particulate matter is high. The drop of the air excess coefficient can be explained by the high density of camelina sativa oil as well as additional sealing of the distributor plunger mechanism in the injection pump caused by more viscous fuel [21]. Also, different proportion of carbon and hydrogen in camelina sativa oil than it is in the standard diesel oil contributes to this drop. NOx emission is higher for camelina sativa oil fuelling although the thermal efficiency seems to be much lower. It could be explained through the results of comparison of the calculation of the mass fraction burnt and the rate of heat release [22] as well as the emissions that were obtained for the two points of engine work when the amount of energy included in the injected fuel was the same for the engine fuelled with camelina sativa and diesel oil (Figs. 4 and 5). It was observed that for 1400 rpm the ignition delay was slightly shorter for camelina sativa oil/air mixture. During the premixed combustion phase it was observed that the maximum rate of heat release was higher for this fuel than for diesel oil. It is interesting because during the mixing controlled of the combustion phase, particularly for the later part of this phase, the rate of heat
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Fig. 3. Emission of (a) hydrocarbons, (b) carbon dioxide, (c) nitric oxides, (d) particulate matter with, (e) air excess coefficient, and (f) oxygen percentage in the exhaust gases for fuelling of the Perkins 1104-C44 engine with camelina sativa oil and standard diesel oil measured for speed characteristics of the engine.
release is slightly higher for diesel oil. The heat release calculation explains the difference of NOx emission that is higher for camelina sativa oil fuelling. 6. Conclusions The results of the examination of a CI engine fuelled with camelina sativa oil and standard diesel oil show that it is possible to fuel
the engine with this alternative fuel but the fuelling demands certain engine adjustments. The structure of camelina sativa oil, especially high content of linolenic acid that makes this oil particularly susceptible to oxidation, makes the combustion process different than the combustion of diesel oil. It is visible particularly for lower engine speeds where the injection should be slightly delayed in comparison with the injection timing of diesel oil. Also, the dose of camelina sativa oil should be limited in order to maintain the
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Fig. 4. The mass fraction burnt (a) and the rate of heat release (b) for fuelling of the Perkins 1104-C44 engine with camelina sativa oil (n = 1400 rpm, T = 236 Nm engine overall efficiency go = 0.27) and standard diesel oil (n = 1400 rpm, T = 308 Nm, engine overall efficiency go = 0.35) for the same energy provided to the engine cylinder per one cycle.
Fig. 5. The mass fraction burnt (a) and the rate of heat release (b) for fuelling of the Perkins 1104-C44 engine with camelina sativa oil (n = 2200 rpm, T = 210 Nm, engine overall efficiency go = 0.26) and standard diesel oil (n = 2200 rpm, T = 271 Nm, engine overall efficiency go = 0.33) for the same energy provided to the cylinder per one cycle.
air excess coefficient higher than 1.25. It is easy to exceed this limit because of a high density of camelina sativa oil. Without proper control of the fuel system adapting to the properties of camelina sativa oil, the engine consumes much more fuel and the engine overall efficiency drops significantly in comparison with the fuelling with standard diesel oil. Also, the engine emissions can be improved in this way. Thanks to its properties neat camelina sativa oil could be alternative fuel for the selected engine applications such as stationary engines or agricultural machines but it demands some changes in engine control and change of the engine maintenance procedure because of a higher risk of damage to the fuel system. References [1] Demirbas MF, Balat M, Balat H. Potential contribution of biomass to the sustainable energy development. Energy Convers Manage 2009;50(7):1746–60. [2] Balat M. Potential alternatives to edible oils for biodiesel production – a review of current work. Energy Convers Manage 2011;52(2):1479–92. [3] Demirbas A. Biofuels securing the planet’s future energy needs. Energy Convers Manage 2009;50(9):2239–49.
[4] Moser BR, Vaughn SF. Evaluation of alkyl esters from Camelina sativa oil as biodiesel and as blend components in ultra low-sulphur diesel fuel. Bioresour Technol 2010;101:646–53. [5] Moser BR, Vaughn SF. Evaluation of alkyl esters from camelina sativa oil as biodiesel and as blend components in ultra low-sulphur diesel fuel. Bioresour Technol 2010;101(2):646–53. Elsevier. [6] Demirbas A. Progress and recent trends in biodiesel fuels energy conversion and management 50. Elsevier; 2009. p. 14–30. [7] Rice B, Fröhlich A, Leonard R. Bio-diesel production from camelina sativa oil, waste cooking oil and tallow. Dublin: Teagasc; 1998. [8] Fröhlich A. Storage stabilities of fuel grade camelina, sunflower rapeseed methyl esters. Dublin: Teagasc; 1999. [9] Budin JT, Breene WM, Putnam DH. Some compositional properties of camelina (Camelina sativa L. Crantz) seeds and oils. J Am Oil Chem Soc 1995;72(3):309–15. [10] Kruczyn´ski SW, Ambrozik A, Danilczyk W. Assesment of operating characteristics of fuels for diesel engines. TEKA Komisji Motoryzacji i Energetyki Rolnictwa, PAN, Lublin; 2006 [/in Polish/]. [11] Singh SP, Singh D. Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: a review. Renew Sustain Energy Rev 2010;14:200–16. [12] Yusuf NNAN, Kamarudin SK, Yaakub Z. Overview on the current trends in biodiesel production. Energy Convers Manage 2011;52(7):2741–51. [13] Bernardo A, Howard-Hildige R, O’Connell A, Nichol R, Ryan J, Rice B, et al. Camelina oil as a fuel for diesel transport engines. Ind Crops Prod 2003;17:191–7.
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[14] Pavlista AD, Isbell TA, Baltensperger DD, Hergert GW. Planting date and development of spring-seeded irrigated canola, brown mustard and camelina. Ind Crops Prod 2011;33:451–6. [15] Franco Z, Nguyen QD. Rheological properties of vegetable oil-diesel fuel blends. In: The XV International Congress on Rheology, 3–8 August 2008, AIP Conf Proc 1027. p. 1450–52. [16] Kołodziejczyk K, Frydrych J, Kruczyn´ski SW, Orlin´ski P, Jakubczyk D. Quality characteristic of camelina sativa oil used as a biofuel component for CI engines. Zeszyty Naukowe Instytutu Pojazdów, Politechnika Warszawska 2011;1(82) [/ in Polish/]. [17] Pilgeram AL, Sands DC, Boss D, Dale N, Wichman D, Lamb P, et al. A Montana omega-3 and fuel crop. In: Janick J, Whipkey A, editors. Issues in new crops and new uses. Alexandria: ASHS Press; 2007. p. 129–31.
[18] Fröhlich A, Rice B. Evaluation of camelina sativa oil as a feedstock for biodiesel production. Ind Crops Prod 2005;21(1):25–31. [19] Ambrozik A, Kruczyn´ski P, Orlin´ski P. The influence of CI engine fuelling with alternative fuels on selected combustion parameters and emission. Zeszyty Naukowe Instytutu Pojazdów, Politechnika Warszawska 2010;2(78) [/in Polish/]. [20] Perkins 1100 Series 1104C-44. Perkins Engines Company Limited. [21] Koniuszy A, Nadolny R. Influence of RME fuels on choosen variables of diesel engine supply process. TEKA Komisji Motoryzacji i Energetyki Rolnictwa 2004 [/in Polish/]. [22] Heywood JB. Internal combustion engine fundamentals. New York: McGrawHill; 1988.
Contents lists available at SciVerse ScienceDirect
Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman
Performance and emission of CI engine fuelled with camelina sativa oil Stanisław W. Kruczyn´ski ⇑ Warsaw University of Technology, Faculty of Automotive and Construction Machinery Engineering, Narbutta St. 84, 02-524 Warszawa, Poland
a r t i c l e
i n f o
Article history: Received 4 February 2012 Received in revised form 30 June 2012 Accepted 30 June 2012 Available online 11 October 2012 Keywords: Camelina sativa Alternative fuels CI engine Engine speed curves Engine emissions
a b s t r a c t The paper describes the results of the tests of CI Perkins 1104C-44 engine fuelled with camelina sativa oil. The engine was not especially calibrated for fuelling with the vegetable fuel. During the test the engine performance and emissions were analysed. For comparison the same speed characteristic was examined for standard fuelling of the engine with diesel oil. In order to understand the engine performance and emission the mass fraction burnt and the rate of heat release was calculated and compared for the same energy provided to the engine cylinder with the injected fuels. The results show that there is possible to receive relatively good engine performance for fuelling the engine with camelina sativa oil but there is a need to change the calibration parameters of the engine fuel system when the engine is fuelled with this fuel. Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction Camelina sativa is a new crop with a variety of uses. It is relatively easy to grow with low input costs. It is a spring annual broadleaf oilseed herb of the Brassicaceae family that grows well in moderate climates. Its meal is valuable as animal feed, and its oil has important nutritional components (alpha linolenic acid and gamma-tocopherol). Camelina seed contains 30–40% oil that could be used as a fuel. There is a discussion on the use of camelina as biofuel because the linolenic acid and omega-3 fatty acid makes up about 35–39% of the total oil content. As yet, the production of camelina sativa is not significant (there are some exceptions like the state of Montana in the United States). It seems that the industrial potential of this plant, given the current fuel crisis, is rather significant. The potential contribution of biomass to the sustainable energy development is presented in [1]. The utilisation of biomass especially agricultural crops strongly depends on economy. About 7% of global vegetable oil supplies was used for biodiesel production in 2007. Extensive use of edible oils may cause other significant problems such as starvation in developing countries [2]. The economic performance of a biodiesel plant identified by many factors, such as plant capacity, process technology, raw material cost and chemical costs and government policy of biofuel concerns job creation, greater efficiency in the general business environment, and protection of the environment are described in [3]. Camelina sativa has several positive agronomic attributes: low agricultural inputs, cold-weather tolerance, short growing season ⇑ Tel.: +48 22 2348781; fax: +48 22 8490303. E-mail address: [email protected] 0196-8904/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.enconman.2012.06.022
(85–100 days), compatibility with existing farm equipment, and ability to grow well in semiarid regions and in low-fertility or saline soils [4]. It is possible to obtain as much as 1350 kg of the seeds from one hectare and to receive 400 kg of good quality oil that could also be used as a fuel [5]. Camelina sativa oil is a good base for the production of esters that fulfil high standards of second generation renewable fuels [5,6]. The camelina methyl ester has properties similar to the rapeseed methyl ester with the exception of its high iodine value [7] and is stable in airtight containers with periodic openings for at least 18 months, even without natural antioxidants [8]. Fuel-specific properties of camelina methyl esters are largely within specifications, though low-temperature behaviour could be a problem in some climates. This problem could be overcome by the use of suitable pour-point depressants or by blending with diesel oil. Another problem is the iodine number that exceeds the value of 120 required by the EU standards [9]. The oil can also be used to prepare the blends with standard diesel oil [10,11], which is important in the fuel market inevitably shifting towards sustainable energy sources [12]. Various methods for the production of biodiesel from vegetable oil, including direct use and blending are presented in [13]. There are some examples of direct use of neat camelina oil as a fuel for diesel engines [14]. In the Institute of Vehicles of the Faculty of Vehicles and Heavy Machines in Warsaw University of Technology the tests of possible application of camelina sativa oil as a fuel for CI engine were carried out. The aim of the tests was to check the performance and the emission of standard CI engine fuelled with neat camelina sativa oil and to compare the results with the results obtained for standard diesel oil for the same adjustment parameters of the injection of the fuels. The results also
´ ski / Energy Conversion and Management 65 (2013) 1–6 S.W. Kruczyn
2
give some information about phenomena that accompany the application of neat camelina sativa oil as a fuel. 2. Characteristic of the fuels The structure of neat camelina sativa oil slightly depends on the soil, climate as well as weather conditions. Even the date of planting by calendar influences the fatty acid profile of the oil as presented in [14]. Typical camelina sativa oils contains: oleic (14.1–19.5%), linoleic (18.8–24.0%), linolenic (27.0–34.7%), eicosenoic (12.0–14.9%), erucic (0.0–4.0%) and other (11.8–17.4%) fatty acids [15]. For the test of the engine performance and emissions the neat oil was used. It was examined and its features were compared to standard diesel oil. The comparison of major parameters of the fuels that were used in the experiment are shown in Table 1. There are many differences between features of diesel oil and camelina sativa oil. First of all camelina sativa oil has very high viscosity in comparison to standard diesel oil. In comparison to palm oil (41.69 mm2/s), canola oil (36.28 mm2/s) and soybean oil (31.49 mm2/s) the kinematic viscosity in 40 °C of camelina sativa oil is lower (28.94 mm2/s) but still very high (for diesel oil it is 2.92 mm2/s) [17]. Kinematic viscosity as well as higher surface tension could significantly influence the injection process as well as the process of mixture formation. The authors [18] point out that camelina sativa oil has a high level of linolenic acid, which makes this oil particularly susceptible to oxidation (Table 2). The content of linolenic acid is important for the combustion process particularly since it could affect the rate of heat release and should be analysed during the engine tests. The lower calorific value of camelina sativa oil is partially compensated by the higher density of the fuel. The thermal efficiency of the engine fuelled with the examined fuels depends on air/fuel mixture composition, especially on the air excess coefficient k. The injection dose of camelina sativa oil that is provided to the engine cylinder for the parameters of the injection system that are optimum for diesel oil can be different and provides some modifications to the mixture composition. 3. The engine and the test stand For the tests of performance and emissions of the engine fuelled with camelina sativa oil and standard diesel oil a Perkins 1104C-44 engine was used. The engine fulfils Tier 2 off-highway emissions legislation. The data and performance of the standard version of the Perkins 1104C-44 engine are shown in Table 3. The engine was installed on a test rig fitted with measurement equipment that enabled the measurement of the engine torque (SCHENCK eddy-current brake), engine speed, fuel consumption, the emissions of total hydrocarbons, nitric oxides, carbon monoxide (AVL CEB II analyser with heated exhaust line) and particulates (AVL 415). The high-speed measurement and data acquisition sys-
Table 2 Content of linolenic fatty acid in selected vegetable oils (%) [19]. Vegetable oil
Content of linolenic fatty acid (C18H30O2)
Camelina sativa oil Canola oil Rapeseed oil Sunflower oil High-oleic acid sunflower oil Soybean oil Olive oil Linseed oil Palm oil Castor oil Peanut oil Corn oil Coconut oil
31.2 8 7 0.1 6.0 6–11 0.5–1 51–54 1–2 0 0.5 1.1 0.0
Table 3 Perkins 1104C-44 – the data and rated performance of the standard version [20]. Number of cylinders Bore and stroke Displacement Aspiration Cycle Combustion system Fuel system Compression ratio Rated power output (kW) Rated maximum torque (Nm)
4 Straight 105 mm 127 mm 4.4 l Natural 4 Stroke Direct injection Distribution injection pump 19.3:1 64.0 at 2400 rpm 308 at 1200 rpm
tem (AVL Indi Smart) were used for the measurement of the engine cylinder pressure (see Fig. 1).
4. The experiment In order to obtain information about the engine performance and its emissions for fuelling with camelina sativa oil an engine speed curve was performed. The same curve was prepared for the engine that was fuelled with standard diesel oil. Both characteristics were performed to obtain the maximum engine torque for each engine speed without special adjustment of the engine. Injection timing was the same for both fuels and it was 12° BTDC,
Table 1 The comparison of properties of camelina sativa oil and diesel oil [16]. Parameter
Camelina sativa oil
Diesel oil
Density at 15 °C (kg/m3) Kinematic viscosity at 40 °C (mm2/s) Flash point (°C) Lower heating value (MJ/kg) Surface tension at 20 °C (mN/m) Ash (% mass) Sulphur content (mg/kg) Water content (mg/kg) Acid value (mg KOH/g) Iodine number (gI/100 g)
925.4 28.94 >220 38.2 32.9 0.003 14.1 720 1.46 157.2
838 2.92 102 42.3 24 0.01 9 43.8 – –
Fig. 1. The test rig: 1 – Perkins 1104-C44 engine, 2 – air intake, 3 – exhaust outlet, 4 – Schenck eddy-current brake; 5 – AVL GM 12 piezoelectric pressure sensor; 6 – crank position sensor, 7 – amplifier, 8 – AVL Indi Smart system, 9 – AVL 415 particulate matter concentration analyser, 10 – AVL CEB II Exhaust gas analyser, 11 – heated sample tube, 12 – calibration gases, and 13 – data acquisition system based on a PC [16].
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Fig. 2. Maximum brake torque (a), power (b), specific fuel consumption (c), and engine overall efficiency (d) vs. engine speed for the fuelling of the Perkins 1104-C44 engine with camelina sativa oil and standard diesel oil for the same maximum setting of fuel control lever.
also the position of the control lever for maximum fuel dose was the same for both fuels. The injector opening pressure was 29 MPa. The temperature measured in the fuel tank was 21 °C (37–39 °C in the return pipe). The air excess coefficient was calculated based on the concentration of exhaust gas components measured with the use of AVL CEB II exhaust gas analyser. The Bretschneider’s formula was applied to calculate the k value. The calculation of engine thermal efficiency was one of the most important results of the test of the engine fuelled with both fuels. To compare the process of combustion of camelina sativa oil and diesel oil, particularly the mass fraction burned and the rate of heat release as well as the thermal efficiency an additional experiment was carried out. For the two engine speed values (1400 rpm and 2200 rpm) the same amount of energy per cycle included in camelina sativa oil dose and diesel oil dose was supplied to the engine cylinder.
5. The results of the experiment The results of the measurements and calculations yielded information about engine performance, particularly the engine overall efficiency and emissions. The engine speed characteristics show that it is possible to obtain higher torque for the engine fuelled with camelina sativa oil. However, the results of the measurements of fuel consumption show that the engine specific fuel consumption is much higher for this fuel. The engine overall efficiency is
much lower than for the engine fuelled with standard diesel oil. The difference is about 5% (Fig. 2). The engine emission and air excess coefficient as well as the percentage of monoxide in the exhaust gases for the two examined fuels that were measured for the speed characteristic are shown in Fig. 3. For lower engine speed the air excess coefficient was too low for fuelling with camelina sativa oil, hence, the emission of hydrocarbons, carbon monoxide and particulate matter is high. The drop of the air excess coefficient can be explained by the high density of camelina sativa oil as well as additional sealing of the distributor plunger mechanism in the injection pump caused by more viscous fuel [21]. Also, different proportion of carbon and hydrogen in camelina sativa oil than it is in the standard diesel oil contributes to this drop. NOx emission is higher for camelina sativa oil fuelling although the thermal efficiency seems to be much lower. It could be explained through the results of comparison of the calculation of the mass fraction burnt and the rate of heat release [22] as well as the emissions that were obtained for the two points of engine work when the amount of energy included in the injected fuel was the same for the engine fuelled with camelina sativa and diesel oil (Figs. 4 and 5). It was observed that for 1400 rpm the ignition delay was slightly shorter for camelina sativa oil/air mixture. During the premixed combustion phase it was observed that the maximum rate of heat release was higher for this fuel than for diesel oil. It is interesting because during the mixing controlled of the combustion phase, particularly for the later part of this phase, the rate of heat
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Fig. 3. Emission of (a) hydrocarbons, (b) carbon dioxide, (c) nitric oxides, (d) particulate matter with, (e) air excess coefficient, and (f) oxygen percentage in the exhaust gases for fuelling of the Perkins 1104-C44 engine with camelina sativa oil and standard diesel oil measured for speed characteristics of the engine.
release is slightly higher for diesel oil. The heat release calculation explains the difference of NOx emission that is higher for camelina sativa oil fuelling. 6. Conclusions The results of the examination of a CI engine fuelled with camelina sativa oil and standard diesel oil show that it is possible to fuel
the engine with this alternative fuel but the fuelling demands certain engine adjustments. The structure of camelina sativa oil, especially high content of linolenic acid that makes this oil particularly susceptible to oxidation, makes the combustion process different than the combustion of diesel oil. It is visible particularly for lower engine speeds where the injection should be slightly delayed in comparison with the injection timing of diesel oil. Also, the dose of camelina sativa oil should be limited in order to maintain the
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Fig. 4. The mass fraction burnt (a) and the rate of heat release (b) for fuelling of the Perkins 1104-C44 engine with camelina sativa oil (n = 1400 rpm, T = 236 Nm engine overall efficiency go = 0.27) and standard diesel oil (n = 1400 rpm, T = 308 Nm, engine overall efficiency go = 0.35) for the same energy provided to the engine cylinder per one cycle.
Fig. 5. The mass fraction burnt (a) and the rate of heat release (b) for fuelling of the Perkins 1104-C44 engine with camelina sativa oil (n = 2200 rpm, T = 210 Nm, engine overall efficiency go = 0.26) and standard diesel oil (n = 2200 rpm, T = 271 Nm, engine overall efficiency go = 0.33) for the same energy provided to the cylinder per one cycle.
air excess coefficient higher than 1.25. It is easy to exceed this limit because of a high density of camelina sativa oil. Without proper control of the fuel system adapting to the properties of camelina sativa oil, the engine consumes much more fuel and the engine overall efficiency drops significantly in comparison with the fuelling with standard diesel oil. Also, the engine emissions can be improved in this way. Thanks to its properties neat camelina sativa oil could be alternative fuel for the selected engine applications such as stationary engines or agricultural machines but it demands some changes in engine control and change of the engine maintenance procedure because of a higher risk of damage to the fuel system. References [1] Demirbas MF, Balat M, Balat H. Potential contribution of biomass to the sustainable energy development. Energy Convers Manage 2009;50(7):1746–60. [2] Balat M. Potential alternatives to edible oils for biodiesel production – a review of current work. Energy Convers Manage 2011;52(2):1479–92. [3] Demirbas A. Biofuels securing the planet’s future energy needs. Energy Convers Manage 2009;50(9):2239–49.
[4] Moser BR, Vaughn SF. Evaluation of alkyl esters from Camelina sativa oil as biodiesel and as blend components in ultra low-sulphur diesel fuel. Bioresour Technol 2010;101:646–53. [5] Moser BR, Vaughn SF. Evaluation of alkyl esters from camelina sativa oil as biodiesel and as blend components in ultra low-sulphur diesel fuel. Bioresour Technol 2010;101(2):646–53. Elsevier. [6] Demirbas A. Progress and recent trends in biodiesel fuels energy conversion and management 50. Elsevier; 2009. p. 14–30. [7] Rice B, Fröhlich A, Leonard R. Bio-diesel production from camelina sativa oil, waste cooking oil and tallow. Dublin: Teagasc; 1998. [8] Fröhlich A. Storage stabilities of fuel grade camelina, sunflower rapeseed methyl esters. Dublin: Teagasc; 1999. [9] Budin JT, Breene WM, Putnam DH. Some compositional properties of camelina (Camelina sativa L. Crantz) seeds and oils. J Am Oil Chem Soc 1995;72(3):309–15. [10] Kruczyn´ski SW, Ambrozik A, Danilczyk W. Assesment of operating characteristics of fuels for diesel engines. TEKA Komisji Motoryzacji i Energetyki Rolnictwa, PAN, Lublin; 2006 [/in Polish/]. [11] Singh SP, Singh D. Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel: a review. Renew Sustain Energy Rev 2010;14:200–16. [12] Yusuf NNAN, Kamarudin SK, Yaakub Z. Overview on the current trends in biodiesel production. Energy Convers Manage 2011;52(7):2741–51. [13] Bernardo A, Howard-Hildige R, O’Connell A, Nichol R, Ryan J, Rice B, et al. Camelina oil as a fuel for diesel transport engines. Ind Crops Prod 2003;17:191–7.
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[18] Fröhlich A, Rice B. Evaluation of camelina sativa oil as a feedstock for biodiesel production. Ind Crops Prod 2005;21(1):25–31. [19] Ambrozik A, Kruczyn´ski P, Orlin´ski P. The influence of CI engine fuelling with alternative fuels on selected combustion parameters and emission. Zeszyty Naukowe Instytutu Pojazdów, Politechnika Warszawska 2010;2(78) [/in Polish/]. [20] Perkins 1100 Series 1104C-44. Perkins Engines Company Limited. [21] Koniuszy A, Nadolny R. Influence of RME fuels on choosen variables of diesel engine supply process. TEKA Komisji Motoryzacji i Energetyki Rolnictwa 2004 [/in Polish/]. [22] Heywood JB. Internal combustion engine fundamentals. New York: McGrawHill; 1988.