ANALYSIS OF THE ECOLOGICAL PARAMETERS OF THE DIESEL ENGINE POWERED WITH BIODIESEL FUEL CONTAINING METHYL ESTERS FROM CAMELINA SATIVA OIL

!e article explores the possibilities of using fatty acid methyl esters derived from the oil of a new species of oily plant Camelina sativa not demanding on soil. !e performed research on the physical and chemical properties of pure methyl esters from Camelina sativa show that biofuels do not meet requirements for the biodiesel fuel standard (LST EN 14214:2009) of a high iodine value and high content of linoleic acid methyl ester, so they must be mixed with methyl esters produced from pork lard the content of which in the mixture must be not less than 32%. !is article presents the results of tests on combustion emission obtained when three-cylinder diesel engine VALMET 320 DMG was fuelled with a mixture containing 30% of this new kind of fuel with fossil diesel fuel comparing with emissions obtained when the engine was fuelled with a fuel mixture containing 30% of conventional biodiesel fuel (rapeseed oil methyl esters) with fossil diesel fuel. !e obtained results show that using both types of fuel, no signi#cant di$erences in CO and NOx concentrations were observed throughout the tested load range. When operating on fuels containing methyl esters from Camelina sativa, HC emissions decreased by 10 to 12% and the smokeness of exhaust gas by 12 to 25%.


Introduction
e European Commission encourages the use of biofuels in the transport sector. Directive 2003/30/EC (2003 states that the Member States of the EU should gradually increase the consumption of biofuels in transport and by 2010, in total, 5.75% of transport fuels should be replaced by biofuels.
Producing and using biofuels has opened a new area in Lithuania as well as researches in this area (Matijošius and Sokolovskij 2009;Pukalskas et al. 2009;Raslavičius and Bazaras 2009;Lebedevas and Lebedeva 2009;Pukalskas 2008a and2008b;Butkus et al. 2007;Lebedevas et al. 2007;Raslavičius and Markšaitis 2007;Lebedevas et al. 2006aLebedevas et al. , 2006b. However, despite the aspirations set out in the Directive, the development of using biofuels in the EU Member States is still insu cient. e actual average of EU biofuel consumption in the market is only about 3.21% (2009) and is below the target -5% (EU-27 Bio-Fuels Annual 2008). Meanwhile, the new EU documents ' An EU Strategy for Biofuels ' (2006) and 'Biofuels in the European Union. Vision to 2030 andBeyond' (2006) provide for an increase in biofuel consumption to 15% by 2020 and up to 25% by 2030. is will only be possible by increasing the production volumes and consumption of the rst generation biofuels and via the introduction of producing the second generation biofuels providing for intensive industrial development a er 2020.
In most cases, biodiesel fuel (75% of biofuels in the market) and bioethanol (20%) are used in the EU countries as the rst generation biofuels (EU-27 Bio-Fuels Annual 2008). However, the market of raw materials used in producing biodiesel fuel -rapeseed oil -is limited; therefore it is necessary to nd new suitable raw materials for producing biodiesel fuel. Certain new kinds of vegetable oil that should have lower prices than the traditional rapeseed oil would increase the pro tability of biodiesel fuel production and attractiveness to producers. In addition, it is necessary to nd oil plants not demanding on soil and cultivated on barren lands not suitable for rapeseed cultivation because the potential of the latter process currently both in Lithuania and EU countries is approaching the limit on a lack of suitable land and crop rotation requirements. One of these oil plants recently attracted the interest of scientists is Camelina sativa grown as undersowing cereals in order to protect them from weeds without the use of mineral fertilizers and pesticides. e oil content of Camelina sativa seed is high and reaches about 43% (Zubr 1997). However, the cultivation of this plant so far is for experimental purposes only and started in Lithuania relatively recently -in 2006. e properties of oil derived from this plant and the possibility of using it for producing fatty acid methyl esters are investigated. e preliminary results of foreign researchers show that due to the high content of polyunsaturated fatty acids, methyl esters from Camelina sativa oil could be used as biodiesel fuel only in a mixture with methyl esters from rapeseed oil (RME) (Mittelbach and Remschmidt 2004). Even better results might be obtained by inserting it into the mixtures of methyl esters from animal fat containing much saturated fatty acids.
In producing the new types of biodiesel fuel, it is necessary to evaluate not only its physical and chemical characteristics but also to carry out comparative performance tests on the engine assessing its motor and environmental performance in comparison with the properties of conventional biodiesel fuel. Literature and data about engine performance research on biodiesel fuel derived from Camelina sativa oil is relatively low and can be linked with recently launched experiments on cultivating and using this plant. erefore, the aim of our work was to carry out comparative performance tests on the engine assessing the motor and ecological characteristics of fuels containing fatty acid methyl esters from Camelina sativa oil.

Object of Research
e object of research was 3-cylinder diesel engine VAL-MET 320 DMG manufactured by AGCO SISU POWER which is a part of vessel diesel generator STAMFORD UC.M224C2 alternating the current of 28 kW. e main parameters of the diesel engine are given in Table 1.
Diesel engine design provides for its operation using fatty acid methyl esters (FAME) produced from rapeseed oil or cabbage oil.
During testing, the engine load has been ensured by gradually increasing electricity consumption produced by the diesel generator in the ship. With the diesel engine operating with all types of fuel, its load was increased from the modes close to idle to nominal modes (P enom ): 5-10% P enom , ~25% P enom , ~ 55% P enom , 65-70% P enom and 80-85% P enom at nominal rotation speed, n = 1500 min -1 . In order to ensure the repeatability of results and the stability control of engine technical condition at the beginning and end of the tests, they were carried out using fossil diesel fuel.

Fuel Used for Researches
Camelina sativa oil was obtained by mechanical pressing using Skeepsta Maskin Type 40A press (Sweden). Oil transesteri cation with methanol was carried out using laboratory equipment and applying a conventional method of rapeseed oil transesteri cation. Analytically pure methanol (Aldrich Chemical Company, Inc.) was used for transesteri cation and analytically pure KOH (Aldrich Chemical Company, Inc.) was used as a catalyst. Transesteri cation was carried out at two stages during the rst of which, 11% of methanol was inserted into oil using 0.9% KOH content while during the second stage 6% of methanol and 0.4 KOH were used. A er passing through each stage, glycerol fraction was separated and the esters obtained a er the second stage had been over were washed using 10% of ester content with a 5% of phosphoric acid solution (Aldrich Chemical Company, Inc.). Following the process of washing with phosphoric acid, solution esters were washed twice using 10% of water. e traces of water from the esters were evaporated in a vacuum.
Pork lard methyl esters were produced from pork lard purchased from the market (Poland). A er the evaporation of moisture, transesteri cation and the ester cleaning procedure of lard were carried out in the same way as the process of producing fatty acid methyl esters from Camelina sativa oil.
While preparing fuel for engine testing, in addition to the experimentally derived fatty acid methyl esters (FAME), fossil diesel fuel (D) purchased from the trade network and conforming to the requirements of LST EN 590 was used. According to the standard, it contained 5% (vol.) of rapeseed oil methyl esters (RME). Given the fact that pure biodiesel fuel still has no perspectives to be used as fuel in Lithuania for our tests, we took 30% Nominal power (P enom ), kW 30 Nominal rpm (n nom ), min -1 1500 (vol.) of biological origin fuel mixtures with fossil diesel fuel. is concentration was chosen taking into account a fact that foreign authors carried out tests on diesel engines (Lebedevas et al. 2006a(Lebedevas et al. , 2007 and found out that 30% of FAME mixture with D was of optimal concentration, in a view of improving diesel fuel economy and ecological indicators. e quality indicators of fatty acid methyl esters and their mixtures were evaluated applying the procedures speci ed in the standard LST EN 14214:2009. e physical and chemical parameters of the tested fuels (methyl ester mixtures with fossil diesel fuel) were determined applying standard methods: •

Engine
Testing e temperature mode of the diesel engine during the test was controlled using stationary devices for diesel generator on the control panel.
e power consumed by the generator was identied according to electrical current and voltage indications and was measured with portable device MINI AC/ DC CLAMP METER: current in the range of up to 40 A had the resolution of 0.01 A with the accuracy of ± 2.5%; in measuring the voltage range of up to 400 V, resolution was 0.1 V and accuracy made ± 1%. On this basis, the accuracy of sensing power consumption was ± 3.5% and was rated as satisfactory for research operation. e parameters of measurement devices for the harmful components of engine exhaust gas are given in Table 2.

Physical and Chemical Parameters of Fuel
e performed analysis on the quality of methyl esters from Camelina sativa oil (KSME) demonstrated that such methyl esters did not meet requirements for the standard LST EN 14214:2009 of the quality indicators of biodiesel fuel. ese fuels have too high iodine value -143 g I 2 /100 g while the standard speci es a maximum of 120 g I 2 /100 g. Because of the large content of polyunsaturated fatty acids in Camelina sativa oil, the resulting methyl esters have too high linolenic acid methyl esters content making 44.8%, whereas the maximum limit under the standard is 12%. For these reasons, pure KSME could not be used as fuel. On the contrary, pork lard has low unsaturated fatty acid content, and therefore the iodine value of pork lard methyl esters (KME) is low and makes 64.9 g I 2 /100 g. ey don't contain linoleic acid methyl esters at all. e assumption was made that when mixing KSME and KME considering an appropriate ratio, biofuel meeting the requirements of standard LST EN 14214:2009 could be obtained. A er testing, it was found that such mixtures had to contain 68% (vol.) of Camelina sativa oil and 32% (vol.) of pork lard methyl esters. e quality indicators of such mixture and their compliance with the requirements of the standard are given in Table 3. e data show that the mixture of KSME and KME meets quality requirements for biodiesel fuel, so in this composition it was used for producing fuel to test the engine. As mentioned above, this fuel included 30% (vol.) of the fuel of biological origin which accounted for 5% of methyl esters from rapeseed oil (RME) mandatory included into mineral diesel fuel (D) in the marketing network. e composition of fuel used for comparative tests on the engine was as follows: fuel No. 1 -70% D, 30% RME; fuel No. 2 -70% D, 17% KSME, 8% KME, 5% RME.
Quality indicators of such mixtures are presented in Table 4. e presented data indicate that the mixtures containing KSME have characteristics slightly di erent from those containing RME and according to the main regulated characteristics of fuel for diesel engines, are in full compliance with the standard of biofuels. ey have slightly higher viscosity and density and a lower Cetane number. Compared with pure D, it can be noted that the mixtures of biofuels also have higher density, viscosity, Cetane number and ash point.

Comparative Analysis of Environmental Indicators for the Diesel Engine
Carbon monoxide. e nature of CO emissions changes when changing the engine load is equal for all tested fuels: minimum emission values are ~150 ppm, reached at 60-70% P enom ; at a lesser and higher load from 60-70% P enom , CO emission increases (see Fig. 1). e authors obtained a similar dependence of CO emission on P e was during 1A41 and 2FL511 diesel engine tests on RME (Lebedevas et al. 2006b). Di erently from those mentioned in the previous studies, a markedly less intensive growth of CO is close to the nominal one within the load modes. is could be explained by the improved operational process of engine 320 compared with the previously tested engines, especially with the obsolete model 1A41.
e level of CO emission in low and medium load modes are the same when using D and its mixtures containing only RME (D70/RME30) and the mixtures containing KSME (D70/RME5/KSME17/KME8). For the load exceeding 60 to 70% P enom , the consumption of biofuel with the types of methyl esters (B30) allows to reduce the emissions of CO by ~20 to 25% compared with fossil diesel fuel (D). Maximum CO emission was ~250 ppm recorded under low load conditions. Nitrogen oxides. When increasing the load of the diesel engine, NO x emissions are monotonously growing from 170 ppm to ~1800 ppm under nominal load conditions. A physical mechanism of NO x and CO formation in the engine cylinder is di erent (Kruggel 1989;Звонов 1981). erefore, in most cases, the conversion of the diesel engine to work using di erent types of fuel is related to contrary changes in CO and NO x emissions (Lebedevas et al. 2006b;Chen et al. 2008;Al-Hasan and Al-Momany 2008;He et al. 2003). Similar results are obtained in the current tests. Unlike CO emission, the NO x emission of the diesel engine operating on both fuel containing 30% of RME, pure RME and fuel containing KSME increases by 7 to 8% in the nominal power modes, compared with pure fossil diesel fuel (see Fig. 2). With the diesel engine operating on D70/RME30 and D70/RME5/KSME17/KME8 fuels, nearly the same NO x emission was obtained within the entire range of load.
Hydrocarbons HC. e general positive characteristics of HC emission of all tested fuels features a strong increase in idle up to 30% P enom modes, and further stabilization of their values under medium and nominal load conditions (see Fig. 3). HC emissions do not di er when the diesel engine operates on fossil diesel fuel and 30% RME mixtures with D. e use of a new kind of diesel fuel D70/RME5/KSME17/KME8 based on Camelina sativa oil reduces HC emissions by ~25 to 30 ppm or by 10 to 12% within the main load range. is is one of the recorded advantages of the motor features of the new fuels.
Smokeness. e second advantage of fuel containing Camelina sativa oil methyl esters is reducing the smokeness of exhaust gas (SM) where the diesel engine operates on D70/RME5/KSME17/KME8. e reduction of SM content was recorded across the entire range of P e and was equal to 12-25% (K factor values decrease to 0.025-0.05 units at its maximum level of ~0.35 units) compared with D and D70/RME30 (see Fig. 4).

Conclusions
1. Methyl esters produced from pure Camelina sativa oil do not meet quality requirements applied for biodiesel fuel due to a high iodine value and the high content of linoleic acid methyl esters, and therefore cannot be directly used as fuel for diesel engines. 2. In order to use methyl esters from Camelina sativa oil in the diesel engine, they must be mixed with methyl esters from pork lard. A mixture containing methyl esters from Camelina sativa oil and pork lard complies with the requirements of LST EN 14214 at the ratio of 68:32 regarding the iodine value and the content of linolenic acid methyl esters. 3. e tests on operating diesel engine 320 manufactured by the company AGCO SISU POWER and used in the vessel, demonstrate favourable motor characteristics of the new type of biofuel containing methyl esters from Camelina sativa oil (KSME) in the mixture with methyl esters from pork lard (KME) at the determined optimum ratio of 68:32: • when compared with fuel containing 30% of RME in the mixture with fossil diesel fuel, the use of KSME-based biofuel (D70/RME5/KSME17/KME8) features the same CO and NO x emissions within the entire investigated range of loads from idle travel and makes up to 80% P enom , in comparison with fossil diesel fuel at the load greater than 60% of the nominal where CO emissions decrease from 20 to 25% and NO x increase from 7 to 8%; • the use of fuels D70/RME5/KSME17/KME8 reduced HC emissions by ~10 to 12% within the main load range and the smokeness of exhaust gas by 12 to 25% compared with D and D70/RME30. 4. Diesel fuel cost-saving and traction characteristics of the engines operating on KSME and based on the new types of biofuels will be tested on the motor test stand.