kgliter Iodine Number, THE EFFECT OF PALM BIODIESEL FUEL ON THE

13 possible for blending with fossil diesel at higher ratio than currently suggested by the Wide World Fuel Chapter organization of 5. However, this fuel had relatively higher Cold Flow Plugging Point parameter CFPP 20 o C than that of FAME CFPP 12 o C, which prohibits its use in winter season and has problems in cold start up. Although this method may offer a great opportunity to substitute the diesel oil, large-scale demonstration of such a finding followed by full commercialization would take some time. On the other hand, transesterification of vegetable oil has reached full commercialization and it would be an ideal choice for diesel oil substitute. Transesterification [22], also called alcoholysis, is the displacement of alcohol from an ester by another alcohol in a process similar to hydrolysis, except alcohol is used instead of water. The result of fatty acid transesterification is Fatty Acid Methyl Esters FAME, generally known as biodiesel. Several vegetable oils methyl esters VOME characteristic is shown in Table 2 [17]. The resulting biodiesel is quite similar to conventional diesel fuel in its main characteristics. Biodiesel is compatible with conventional diesel and the two can be blended in any proportion. Therefore, transesterification with lower alcohols, however, has turned out to be an ideal modification, so that the term “biodiesel” is now only used to denote products obtained by this technology. Table 2. Vegetable Oil Methyl Esters VOME characteristics Methyl Ester Density at 15 o

C, kgliter

Kinematics Viscosity at 40 0C, cSt ∆Hc, MJliter Cetane number CFPP, o

C. Iodine Number,

g-I2100 g Coconut 0,869 2,7 30,80 63 8,0 10 Palm 0,874 4,40 32,40 63 16,0 52 Cooking Oil 0,880 4,20 32,80 49 -5 – +8 60 – 120 Jatropha Curcas 0,879 4,20 32,80 51 95 – 106 Canola 0,882 4,20 32,80 49 -12 114 Sunflower 0,885 4,00 32,80 47 -4 129 Soybean 0,885 4,05 33,50 46 -4 131 Source : Soerawidjaja, T., H., 2006 [17] 14 Biodiesel by definition is a compound of methyl ester derived from the esterification trans-esterification process of various types of vegetable oils or animal fats. The biodiesel definition has become important since many misleading definitions of biodiesel have been interpreted to define biodiesel as a substitute of diesel fuel from any vegetable oil without esterification or trans-esterification process. The production processes for biodiesel are well known. There are three basic methods of ester production from oilsfats: 1. Base catalyzed transesterification 2. Acid catalyzed esterification and 3. Enzymatic catalysis Each reaction has associated optimal operating parameters temperature, pressure and conversion, although many available literatures emphasized the base catalyzed route because it is claimed to be the most economical. The overall base catalyzed reaction is shown in Figure 4. Figure 4. Base catalyzed transesterification reaction The reaction progresses in three reversible steps: 1 the triglyceride reacts with the alcohol to form diglyceride and fatty acid ester, 2 the diglyceride reacts with the alcohol to form monoglyceride and fatty acid ester, and 3 the monoglyceride reacts with the alcohol to form glycerin and fatty acid ester. Glycerin Catalyst C-OOC-R 1 C-OOC-R 2 C-OOC-R 3 R 1 -COO-R’ R 2 -COO-R’ R 3 -COO-R’ 3R’OH C-OH C-OH C-OH Triglyceride Alcohol methanol Fatty Acid Ester With Example of R1, R2, R3 15 The type of alcohol used determines the type of esters formed. Although higher alcohols ethanol can be used in the transesterification, methanol is more advantageous. The reason is that the two main products of the reaction, Fatty Acid Methyl Ester FAME and glycerol, are hardly miscible and thus form separate phases – an upper ester phase and a lower glycerol phase. Moreover, the price of methanol is cheaper than ethanol, which makes it preferable for commercial biodiesel production. Figure 5 shows the typical biodiesel process flow diagram. Figure 5. Typical Biodiesel Process Flow Diagram As explained above, generally, there are three basic catalytic reaction methods of ester production from oilsfats. They are base catalyzed transesterification, acid catalyzed esterification and enzymatic catalysis. The first two types of catalytic reactions mentioned above have received the greatest attention, as for the enzyme-catalyzed system, it requires much longer reaction time than the other systems [23]. Therefore, to date, the enzyme-catalyzed system has only been carried out on the laboratory scale. The base and acid catalyzed reaction method has a long story of development and now a high production cost and energy produced by this method is in the market in some countries. However, there are at least two problems associated with this process; the process is relatively time consuming and it requires purification of the product from catalyst and saponified products. Therefore, this conventional process still requires a high production cost and energy. To solve this problem, Saka and Kusdiana, 2001 [24] studied the high pressure – high temperature non-catalyzed transesterification of 16 vegetable oil in supercritical methanol. As a result, the reaction was successful to complete in a very short time within 2 - 4 minutes. The low pressure-high temperature non-catalytic transesterification of triglyceride from palm oil in a bubble column reactor at reaction temperatures of 250, 270, and 290 o C under atmospheric pressure have been studied by Joelianingsih et al. 2007 [25]. The result shows that methyl esterification of FFA and transesterification of TG can be conducted simultaneously in the bubble column reactor. The reaction rate of methyl esterification was faster than that of methyl trans-eseterification, but the ME content in the gaseous product was lower. More researchers have reported kinetics for both catalytic and non-catalytic transesterification reaction method. Four oil crops rapeseed, sunflower, soybean and palm dominate the feedstock sources used for worldwide biodiesel production. Table 3 shows that oilseed rape, sunflower, soy and oil palm also constitute the four major oil crops cultivated for human consumption and various industrial applications including the feedstock sources used for biodiesel production. Due to its properties, rapeseed oil still is the feedstock of choice in most European countries including the world’s largest biofuel producers, Germany and France. Sunflower seed oil as the second leading vegetable oil sources for biodiesel production in Europe, is cultivated in Southern European countries, such as Italy, Spain and Greece, because here the semi-arid climates prevent high oil yields for rapeseed. Soybean oil is the most popular biodiesel feedstock in the USA. Table 3. Current worldwide production of nine major vegetable oils [16] Vegetable Oils Estimated production in harvest year 2003-04 million metric tons Vegetable Oils Estimated production in harvest year 2003-04 million metric tons Soybean 31.83 Cottonseed 3.90 Palm 28.13 Palm Kernel 3.50 Rapeseed 12.57 Coconut 3.33 Sunflower 9.42 Olive 2.81 Peanut 4.81 Total 100.29 If biodiesel fuels are to be economically competitive with fossil diesel, even in the absence of tax concession programs, production cost has to be kept 17 low. This poses considerable difficulty with most other highly refined vegetable oils, which could also be utilized for food purposes. The main advantage of palm oil is the outstandingly high hectare yield and moderate world- market prices compared to other edible vegetable oils. Nevertheless, its high contents of saturated fatty acids, leading to unacceptably high values for cold filter plugging point +11 o C and cloud point +13 o C, prevent winter operation on neat palm oil methyl esters in temperate climates, therefore, the oil palm plays an important role for biofuel production in South Asia including Indonesia which has a tropical climate. The other alternative of biodiesel raw material, which is recently very popular and seems to be very promising as an energy plant is Jatropha Curcas L. The seeds of this plant cannot be used for nutritional purposes because they contain various poisonous compounds. The plant can be grown on very poor soils but it manages to produce a high average yield of seeds. The production of methyl esters from the jathropa oil via transesterification has been demonstrated. The ester fuel can be used directly in existing diesel engines without modification [26]. Recently, jatropha oil is also suggested by various researchers [27, 28], has great potential to be developed. However, such potentials should be explored further as there is no specific study on large-scale jatropha oil plantation in Indonesia. Various incentives to encourage farmers to plant Jatropha oil have to be explored so that the return from the plantation is much better than planting other commodities. Parameters quality of biodiesel such as cetane number, iodine number and cloud point are strictly depending on the fatty acid composition of raw materials. Each biodiesel product characteristic parameter can be categorized into two groups as follows: 1. The parameters that depend on the fatty acid composition of each raw material are cetane number, iodine number, cloud point, carbon residue, halphen test, density, and 90 vv recovered at distillation temperature. 2. The parameters that correlate on the processing quality level are : kinematics viscosity, flash point , copper strip corrosion, acid number, ester content, free 18 glycerol, total glycerol, phosphorous content, sulfur content, ash content sulfated ash, and water and sediment content. Information on vegetable oil fuel and methyl ester characteristics of several potential oils is shown in Table 2. Table 4 shows the potential vegetable oil plants in Indonesia. Indonesia has abundant raw materials for biodiesel production, but currently palm still plays the most important role, while Jatropha Curcas L will be the other alternative, which is very promising for future energy plants. Table 4. Potential vegetable oil plants in Indonesia Name Latin name Oil Source Oil, -w dry E NE Jarak pagar Jatropha curcas Kernel 40 – 60 NE Sawit Elais guineensis Pulp + kernel 45-70 + 46-54 E Kapokrandu Ceiba pentandra Kernel 24 – 40 NE Kelapa Cocos nucifera Kernel 60 – 70 E Kecipir Psophocarpus tetrag. Seed 15 – 20 E Kelor Moringa oleifera Seed 30 – 49 E Kusambi Sleichera trijuga Kernel 55 – 70 NE Nimba Azadirachta indica Kernel 40 – 50 NE Saga utan Adenanthera pavonina Kernel 14 – 28 E Akar kepayang Hodgsonia macrocarpa Seed ≈ 65 E Gatep pait Samadera indica Seed ≈ 35 NE Kepoh Sterculia foetida Kernel 45 – 55 NE Ketiau Madhuca mottleyana Kernel 50 – 57 E Nyamplung Callophyllum inophyllum Kernel 40 – 73 NE Randu alas Bombax malabaricum Seed 18 – 26 NE Seminai Madhuca utilis Kernel 50 – 57 E Siur -siur Xanthophyllum lanceatum Seed 35 – 40 E Tengkawang. Terindak Isoptera borneensis Kernel 45 – 70 E Bidaro Ximenia Americana Kernel 49 – 61 NE Bintaro Cerbera manghasodollam Seed 43 – 64 NE Bulangan Gmelina asiatica Seed ? NE CerakinKroton Croton tiglium Kernel 50 – 60 NE Kampis Hernandia peltata Seed ? NE Kemiri cina Aleurites trisperma Kernel ? NE Nagasari gede Mesua ferrea Seed 35 – 50 NE Sirsak Annona muricata Kernel 20 – 30 NE Srikaya Annona squamosa Seed 15 – 20 NE Note : E ≡ Edible fatoil, NE ≡ Non-Edible fatoil [28]. The study is devoted to the performance and emission evaluation of automotive diesel engine as affected by utilization of palm biodiesel fuel The concentration of palm biodiesel used in the test was ranged from B0 pure diesel fuel, B10, B20, B30, B50 and B100 pure biodiesel. The engine performance 19 was evaluated by measuring torque, power, and specific fuel consumption, while the emission was evaluated through the content of its carbon monoxide CO, hydrocarbon HC, particulate matter PM, carbon dioxide CO 2 , and NO x pollutants. The result has been reported by Wirawan et al., 2008 [29]. Materials and Methods The Test Vehicle The performance and emission tests were conducted at the Thermodynamics and Propulsion Engine Research Center, a center within the Agency for the Assessment and Application of Technology, which focuses its work on diesel engine bench and non-stationary operation tests for performance and emissions of fuels, including biodiesel. The facility shown in Figure 6 consists of three rooms, namely the control and data management room, the vehicle test room and the emission analysis room. The control and data management room is used for controlling all testing activities including collecting testing data, ventilation system, Constant Volume Sampling CVS System, hydrocarbon and particulate sampling system and emission analysis facilities. Figure 6. The arrangement of emission test on chassis dynamometer The test vehicle was a 2004 built passenger car with direct injection, automatic transmission, and a 2,500 cc capacity diesel engine. The engine had a minor modification in its fuel delivery system for convenience of fuels changing between test runs. The chassis dynamometer CD, which is located in the vehicle test room, consists of a pair of 48 inch in diameter steel roll. The roll was 20 connected to a DC motor. The specification of CD is as follows: - Maximum speed : 200 kmh - Maximum power : 150 kW - Inertia measurement range : 454 – 2,722 kg - Room testing temperature : 5 – 40 o C The emission analysis system has five main divisions, namely the CVS System, the handling unit, the bag, the particulate and the hydrocarbon sampling system and the emission analyzer. The function of handling system is to control the exhaust gas circulation. The emission from CVS was collected in the bag. The particulate and hydrocarbon sampling systems are only used for a diesel vehicle test. The emission analysis system consists of a gas analyzer, which functions to analyze the exhaust gas emission both from the bag or transient condition and from weighing the particulate. The specification of analyzers that were used in the test is shown below. • Total Hydrocarbon Analyzer Detector: heated flame ionization Accuracy and repeatability: +- 1 Measurement range: 0-4, 0-10, 0-100, 0-400, 0-1000, 0-4000, 0-10000 ppm Response time: 2 s at 2 Lmin flow rate Ambient temperature: 5-40 C Relative humidity: maximum 95 • NO X analyzer Detector: Chemiluminescent Accuracy and repeatability: +- 1 Measurement range: 0-4, 0-10, 0-100, 0-400, 0-1000, 0-4000, 0-10000 ppm Respond time: 1.5 s at 2 Lmin flow rate Ambient temperature: 5-40 C Relative humidity: maximum 95 • CO analyzer Detector: non-dispersive infrared Accuracy and repeatability: +- 1 Measurement range: 0-100, 500,1000 ppm, 1, 5, 10 21 Respond time: 15 s at 1 L min flow rate Ambient temperature: 5-30 C • Particulate weighing Maximum load: 5000 mg Readability: 0.001 mg Time for stabilization: 10 s Filter used: PALLFLEX-70mm The Test Fuel Palm biodiesel used in the experiment was obtained from a 1.5 tonday capacity biodiesel plant located at the Science and Technology Research Center PUSPIPTEK in Serpong, which has been constructed and operated by the Institute for Engineering and Technology System Design, The Agency for the Assessment and Application of Technology EC – BPPT since 2003. The process flow diagram and the facility can be seen on Figures 7 and 8 respectively. Figure 7. Biodiesel test sample Process Flow Diagram Preparation Washing Distillation Purification Methanol Drying By Product Trans-esterification C C P P O O ADO Methanol Alkaline Catalyst Biodiesel Blending Fuel test samples Glycerol B0, B10, B20, B30, B50, B100 22 Figure 8. Biodiesel plant 1.5 tonday capacity at PUSPIPTEK, Serpong The tests were performed using palm biodiesel with various composition blend, ranged from B0 pure diesel fuel, B10, B20, B30, B50, and B100 pure biodiesel. In order to consider the possibility of inconsistency in the quality of diesel fuel come from the processing refinery and diesel fuel sold in public pump stations, two kind of pure diesel fuel was used to prepare B10, B20, B30 and B50 fuel samples. The first is pure diesel fuel sample B01 from PERTAMINA’s Balongan refinery and the second is pure diesel fuel sample B02 from the public fuel pump stations. The characteristics of the tested fuel are shown in Table 5. Table 5. Characteristics of pure petro-diesel and biodiesel used in the research No Parameter Unit B01 B02 B100 SNI 1 Density40°C kgm 3 0.836 0.836 0.859 0.850 – 0.890 2 Kinematics viscosity 40 °C Mm 2 s cSt 5.436 4.425 4.666 2.3 – 6.0 3 Cetane number 54.5 NM 61.8 min. 51 4 Flash point °C 101 NM 185 min. 100 5 Cloud point °C 18 18 16 max. 18 6 Water and sediment -vol. 0.05 0.02 0.02 max. 0.05 7 Sulphur content ppm-m mgkg 335 1497 3 max. 100 8 Acid number mg-KOHg 0.18 0.28 0.504 max. 0.8 Note : NM : Not Measured can be separately tested as long as sediment content not exceed 0.01-vol 23 All parameters of the biodiesel used in the research complied with Indonesian Biodiesel Standard SNI 04-7182-2006. As expected, the biodiesel had considerably lower sulfur content than diesel fuel and complied with the result of the specific gravity of biodiesel fuels studied by Yuan et. al. 2004 [30], the density of our test fuel is increase proportionally with the higher content of biodiesel. As shown in Table 5, pure diesel fuel from PERTAMINA B01 has lower sulfur content compared to pure diesel fuel from public fuel pump stations B02. All parameters are still in the standard range, but it is found that B01 has higher viscosity and water and sediment content compared to both of B02 and pure biodiesel fuel B100. In general, diesel fuel viscosity is usually lower than pure biodiesel viscosity [31] as shown in the case of B02. The higher viscosity and water and sediment value of B0 1 might be caused by the inconsistency of refinery process level and crude oil quality used as a raw material. A higher value of viscosity will increases the problem in the atomization and combustion process, which can potentially form engine deposits [19]. Water and sediment can shorten filter life or plug fuel filters, which can lead to engine fuel starvation. In addition, water can promote fuel corrosion and microbial growth [32]. All samples were tested by ECE R83 EURO 2 for an emission test cycle method as shown in Figure 9. Fuel consumption was measured by the ECE No. 84 test method and vehicle performance was tested by the 801269 EEC test method. Figure 9. Emission test cycle based on ECE 83-04 M S Urban Drive Cycle LP 20 40 60 80 100 120 195 195 195 195 400 Time s Cycle 1 Cycle 2 Speed kmh 40 1220 - Extra Urban Drive Cycle 40 A S LP : Low-powered MS : Sampling Start AS : Sampling End 24 Result and Discussion Engine Performance Figures 10 and 11 shows the curves of engine performances torque and power against engine speed as a function of biodiesel – diesel fuel blending composition. As shown in figure 10, the peak power was reached at the same speed of 70 kmh. The highest peak power of 67 kW was reached by the pure diesel fuel which is commercially sold at public fuel pump stations B02, followed by the high quality low sulfur pure diesel fuel B01 of around 62 kW, while the lowest peak power of 56 kW was shown by pure biodiesel B100. This result is acceptable, because the calorific value of pure biodiesel is about 10 lower than that of pure diesel fuel. lower than that of pure diesel fuel. Figure 10. Power vs. engine speed 10 20 30 40 50 60 70 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Speed kmh Po w e r k W Power B01 Power B10 Power B20 Power B30 Power B50 Power B100 Power B02 25 10 1010 2010 3010 4010 5010 6010 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 Speed kmh T o rq u e N Torque B01 Torque B10 Torque B20 Torque B30 Torque B50 Torque B100 Torsi B02 Figure 11. Torque vs engine speed The figure also shows that the B10, B20, B30 and B50 biodiesel blend gave higher power than the B01. This results contradicted the ones obtained by Wirawan, et al. 2005 [33] that showed power and torque for biodiesel blends were higher than pure biodiesel B100 but lower than pure diesel fuel B0. Therefore, it is clear that the higher power of the blending fuel in comparison with the power of pure diesel fuel in this study could be affected by the lower viscosity value of tested pure biodiesel B100 than viscosity value of tested pure diesel fuel B01. Fuel viscosity has impacts on injection and combustion. If the fuel viscosity is high, the injection pump will be unable to supply sufficient fuel to fill the pumping chamber, which will cause a power loss for the engine [19]. Figure 11 shows that the torque decreased when the test vehicle speed increased. Maximum torques exerted by all test fuels was reached at a speed of around 30 to 40 km. The highest maximum torque was reached by B02 followed by B01 and the lowest torque was shown by B100, which is consistent with the peak power. 26 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 CO gkm HC gkm NOx gkm Particle gkm CO2 gkm Fuel Consumption L10 km B01 B02 B100 Effect of Biodiesel on Emission and Fuel Consumption Figure 12 shows the effect of the biodiesel blend on emission of carbon monoxide CO, hydrocarbon HC, nitrogen oxide NO x and particulate from three test fuels B01, B02 and B100. Figure 12. Emission profile A fuel consumption of B100 0.69 L10 km was higher than a fuel consumption of B02 0.65 L10 km, but lower than B01 1.03 L10 km. Although the CO and HC emission of B02 was higher than B100, B02 released lower CO2 emission than B100, which gives significant effect to the reduction of the fuel consumption. Figure 13 shows that the reduction of fuel consumption as a function of the biodiesel blend composition of B10, B20, B30, B50 and B100 were 6, 9, 16, 22 and 33 respectively. Those results were clearly shows a close relationship between fuel viscosity and atomization. Higher viscosity of the fuel tends to reduce the quality of fuel atomization, which could potentially give impacts to the higher emission and fuel consumption. CO2 kgkm 27 Figure 13. Fuel consumption vs biodiesel blending composition The effect of biodiesel on the reduction of the exhaust gas emission is shown in Figure 14. The figure demonstrates that the exhaust gas emission decreased linearly with the increasing concentration of the biodiesel blend. The reduction in particle and HC emission was swifter than other emissions. Particle emission was found to reduce sharply on 10 blend of the biodiesel B10, while the reduction of HC emission started to reduce sharply on 20 biodiesel blend B20. Biodiesel Composition 20 40 60 80 100 120 B0 B10 B20 B30 B40 B50 B60 B70 B80 B90 B100 E xh au st G as E m is si o n NOX SO2 PM CO HC Figure 14. The effect of biodiesel on exhaust gas emission 4 5 6 7 8 9 10 11 12 B0 B10 B20 B30 B50 B100 F u e l C o n s u m p ti o n L 1 k m 5 10 15 20 25 30 35 F u el C o n su mp ti o n D ecr eases, Fuel Consumption Measurement, L100 km Fuel Consumption Decreases, 28 The distinct influence of sulfur content in diesel fuel on particulate emissions has been investigated by Merkisz, et al., 2002 [34]. As expected, their result showed that the highest PM emission was obtained at the highest sulfur content in diesel fuel. The reduction of PM emission depended on the value of the sulfur content in the fuel. For fuels with lower sulfur 350 and 50 ppm content, they emitted almost the same PM emission level, but for fuel with higher sulfur 2000 ppm content about 20 higher PM emission than lower sulfur diesel fuel. B02 has higher sulfur content 1,479 ppm than B01 335 ppm, but as showed on Figure 12, PM emission of B02 was lower than B01. This slightly contradictive result demonstrated that the lower viscosity value of B02 4.425 cSt than the viscosity value of B01 5.436 cSt is more effective to the reduction of PM emission compare to the effect of lower sulfur content value. CO and NO x emissions were also reduced although not as sharp as the reduction of particle and HC emission. Lower NO x emission at higher biodiesel blend concentration is contradictive with those generally found in previous non- palm biodiesel studies. The formation of NO x depends on the combustion temperature and oxygen content in the mixing combustion product. Biodiesel blend fuel has a faster ignition ability, increase the combustion room temperature and pressure, which would finally stimulate the NO x formation. Nearly all cited studies report that biodiesel-fuelled engine has a slight increase in NO x emission [16]. Chemical and physical properties of the fuel, such as cetane number, also determine the NO x emission content. There is a strong link between increasing cetane numbers and reducing NO x emissions, but the response varies from engine to engine [35, 36]. Generally, the formation of NO x emission is very complex, which depends on fuel, engine technology, and test cycle factors. The use of the palm biodiesel, application of EURO II cycle test method, and utilization of the modern common rail engine technology, could yield in the decrease in NO x emission. Table 6 shows that the emission of CO and particle for blend biodiesel has met the Euro II regulation. However, it is found that NO x + HC emission is still higher than maximum Euro II value. This is because NO x emitted from B01 and 29 B02 were too high compared to the Euro II regulation. Meanwhile, pure biodiesel B100 has met the Euro II emission standard for all CO, particle as well as for NO x + HC emissions. The increase in the NO x emission can be mitigated by tuning the ignition time to prevent temperature and pressure increase in temperature and pressure [19]. Table 6. Emission of biodiesel blend as compared to Euro II regulation Emission gkm Fuel Type Maximum Euro II B01 B02 B10 B20 B30 B50 B100 HC 0.121 0.045 0.106 0.063 0.051 0.043 0.031 NO x 1.167 1.062 1.107 1.138 1.079 1.031 0.860 NO x + HC 1.288 1.107 1.213 1.201 1.13 1.074 0.891 0.9 gkm CO 0.876 0.754 0.831 0.790 0.707 0.656 0.622 1.0 gkm Particle 0.176 0.077 0.108 0.095 0.090 0.072 0.057 0.1 gkm Conclusion Investigation on benched engine test has been carried out to obtain comparative measurement of engine performance torque, power, specific fuel consumption and emission of pollutants, and to evaluate the behavior of a diesel engine running on palm biodiesel blend. The emission of CO, HC and particle decreased considerably with the increase of biodiesel blend. The reduction in particle emission was very sharp at 10 blend B10, while the sharp reduction in HC emission started at 20 blend B20. The results also showed lower NO x emission as well as higher torque and power for biodiesel blend compared to that of pure petro-diesel fuel. These results could be as a consequence of the properties of the tested palm biodiesel, which has higher cetane number and lower viscosity compared to the tested diesel fuel sample from PERTAMINA B01.

CHAPTER III THE EFFECT OF BIODIESEL UTILIZATION ON