- Email: [email protected]
Performance characteristics of a diesel engine with deccan hemp oil
Fuel 85 (2006) 2187–2194 www.fuelfirst.com
Performance characteristics of a diesel engine with deccan hemp oil O.D. Hebbal b
a,*
, K.Vijayakumar Reddy b, K. Rajagopal
c
a Assistant Professor, Poojya Doddappa Appa College of Engineering, Gulbarga, India Controller of Examinations, Jawaharlal Nehru Technological University, Hyderabad, India c Vice chancellor, Jawaharlal Nehru Technological University, Hyderabad, India
Received 27 August 2005; received in revised form 14 March 2006; accepted 16 March 2006 Available online 18 April 2006
Abstract In this present investigation deccan hemp oil, a non-edible vegetable oil is selected for the test on a diesel engine and its suitability as an alternate fuel is examined. The viscosity of deccan hemp oil is reduced first by blending with diesel in 25/75%, 50/50%, 75/25%, 100/ 0% on volume basis, then analyzed and compared with diesel. Further blends are heated and effect of viscosity on temperature was studied. The performance and emission characteristics of blends are evaluated at variable loads of 0.37, 0.92, 1.48, 2.03, 2.58, 3.13 and 3.68 kW at a constant rated speed of 1500 rpm and results are compared with diesel. The thermal efficiency, brake specific fuel consumption (BSFC), and brake specific energy consumption (BSEC) are well comparable with diesel, and emissions are a little higher for 25% and 50% blends. At rated load, smoke, carbon monoxide (CO), and unburnt hydrocarbon (HC) emissions of 50% blend are higher compared with diesel by 51.74%, 71.42% and 33.3%, respectively. For ascertaining the validity of results obtained, pure deccan hemp oil results are compared with results of jatropha and pongamia oil for similar works available in the literature and were well comparable. From investigation it has been established that, up to 25% of blend of deccan hemp oil without heating and up to 50% blend with preheating can be substituted for diesel engine without any engine modification. 2006 Elsevier Ltd. All rights reserved. Keywords: Non-edible oil; Deccan hemp oil; Alternate fuel
1. Introduction Energy is considered as a critical factor for economic growth, social development and human welfare. With increasing trend of modernization and industrialization, the world energy demand is growing at a faster rate. Since their exploration, the petroleum fuels continued as major conventional energy source. On the other hand, they are limited in reserve. Both the factors have contributed to a sharp increase in petroleum prices. Also, petroleum fuels are currently the dominant global source of CO2 emissions and their combustion is posing stronger threat to clean environment. Sharp hike in petroleum prices and increase in environmental pollution jointly necessitated exploring *
Corresponding author. Address: Assistant Professor, Poojya Doddappa Appa College of Engineering, Gulbarga, India. E-mail address: siddu_pda@rediffmail.com (O.D. Hebbal). 0016-2361/$ - see front matter 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2006.03.011
some alternate to conventional petroleum fuels. Among the other possible options of the liquid fuels various kinds of vegetable oils have been considered as appropriate alternate due to prevalent fuel properties. A country like India, having huge agricultural potential vegetable oils proves a promising alternate for petroleum (diesel oil) fuel. The idea of using vegetable oils as fuel for diesel engines in not a new one. Rudolph Diesel used peanut oil to fuel his engine at the Paris Exposition of 1900. However, despite the technical feasibility, vegetable oil as fuel could not get acceptance, as they were more expensive than petroleum fuels. Later the various factors as stated earlier, created renewed interest of researchers in vegetable oil as substitute fuel for diesel engines. In recent years systematic effort have been made by several researchers [1–14] to use vegetable oils like sunflower, peanut, soybean, rapeseed, palm, olive, cottonseed, linseed, jatropha, coconut, pongamia, rubberseed, jojoba etc. as alternate fuel for diesel. Many of the
2188
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
vegetable oils are edible in nature, continuous use of them causes shortage for food supply and proves far expensive to be used as fuel at present. So far a very few of non-edible vegetable oils have been tried on diesel engine leaving a lot of scope in this area. From previous studies it is evident that vegetable oils offer acceptable engine performance and emissions for short-term operation [1]. While for long-term duration problems like filter clogging, carbon deposits on injector exterior, compression ring grooves, piston lands, etc. have been reported [2–7]. The high viscosity of vegetable oils is responsible for these problems. Therefore reduction in viscosity of vegetable oils is of the prime importance to make them suitable for diesel engines. There are several ways [15] available for this task, among them blending or dilution with other oils, preheating and transesterification are predominant. Testing of diesel engines with preheating [16–18], blending with diesel [6,11,19] and blending with preheating [20,21] improves the performance and reduces the emissions compared with neat vegetable oil. It also reduces the filter clogging and ensures smooth flow of oil. From above stated factors it is evident that identification and testing of new non-edible vegetable oils on diesel engine is of great importance. In present investigation deccan hemp oil, a non-edible vegetable oil is selected for the test and its suitability as an alternate fuel is examined. This is accomplished by blending of deccan hemp oil with diesel in 25/75%, 50/50%, 75/25%, 100/0% on volume basis, further these blends are heated to reduce viscosity equal to that of diesel at 30 C. Then the following investigations are carried out. • The effect of blending deccan hemp oil with diesel on viscosity. • The effect of temperature on the viscosity of various deccan hemp oil and diesel blends and the temperature at which the viscosity of blends equal to that of diesel at 30 C. • The performance and emission characteristics of diesel engine using various blends and compare the results with those of baseline diesel. • Further for ascertaining the validity of the results obtained, the performance and emission characteristics of neat deccan hemp oil is compared with the results available in literature for similar work.
Table 1 Comparison of properties of deccan hemp oil with diesel oil Property
Diesel oil
Deccan hemp oil
Density g/cc at 30 C Calorific value kJ/kg Viscosity cSt at 30 C Flash point C Fire point C
0.8–0.84 42000 5.0 57 65
0.913 38720 53.0 255 270
Table 2 Properties of deccan hemp oil–diesel blends Deccan hemp oil (%)
Diesel (%)
Density (g/cc), at 30 C
Viscosity (cSt), at 30 C
Viscosity reduction (%)
100 75 50 25 0
0 25 50 75 100
0.913 0.89 0.87 0.84 0.82
53.0 24.56 15.46 7.685 5.0
– 53.66 70.83 85.5 90.56
ing best in humid climate with a temperature range of 20–35 C, during growing season [22]. Whole seeds after milling and pressing yields 13% odorless clear yellow fatty oil. The important physical and chemical properties of deccan hemp oil are determined as per Indian Standards (IS) methods in fuels and lubricants laboratory. Determination of density, calorific value, viscosity, flash point and fire point are carried out using hydrometer, bomb calorimeter, Redwood viscometer and Able’s apparatus [23–26], respectively. It is observed that the properties like density, flash point, fire point and viscosity of deccan hemp oil is higher and the calorific value is lower as compared with diesel. Table 1 shows the comparison of properties of deccan hemp oil with diesel. 2.2. Effect of dilution on viscosity of deccan hemp oil and diesel blends Deccan hemp oil and diesel are blended in 0/100%, 25/ 75%, 50/50%, 75/25%, 100/0% on volume basis and mixture is stirred well to get a homogeneous stable mixture. Variation of density, viscosity and percentage reduction in viscosity of blends at 30 C are shown in Table 2. The density and viscosity of blends reduces with increase in percentage of diesel in blend. The blend containing 75% of diesel has density and viscosity close to that of diesel.
2. Characterization of deccan hemp oil 2.1. Properties of deccan hemp oil
2.3. Effect of temperature on viscosity of deccan hemp oil and diesel blends
Deccan hemp oil is obtained from the dried seeds of the deccan hemp plant. It is an erect herbaceous annual with straight; slender glabrous or prickly stem plant. Its Botanical name is Hibiscus Cannabinus and English name is deccan hemp. The plant is cultivated mainly as fibre crop substitute to jute. This is essentially a tropical crop, thriv-
Fig. 1 shows the variation of viscosity of blends with temperature. The viscosity of blends decreases with increase in temperature. Blend containing 75% diesel have viscosity close to diesel at 30 C and does not require heating. However, blends containing 50%, 25% and 0% diesel requires heating up to 70, 80 and 95 C, respectively before
Kinematic Viscosity Centi Stokes
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
2189
60
9
50 40
4
6
3
Diesel
5
DH 25 30
DH 50 10
DH 75
20
DH 100
10 0
11
Air
9
8
7
Gas
12
0
20 40 60 80 Temperature Deg C
100
9 Water
Water 13
Fig. 1. Variations of viscosity of blends with temperature.
firing into combustion chamber to attain viscosity equivalent to that of diesel at 30 C.
2
1. Diesel engine 2. Dynamometer 3. Diesel tank 4. Vegetable oil tank 5. Heater 6. Measuring burette 7. Smoke meter 8. HC & CO analyzer 9. Digital thermocouples 10. Filter 11. Air tank 12. Orifice meter with manometer 13. Rotameter
3. Experimental test rig, instrumentation and programme
Fig. 2. Layout of experimental setup with instrumentation.
unburnt HC, CO and exhaust temperature. These performance and emission characteristics are compared with the results of baseline diesel. 4. Results and discussion 4.1. Performance characteristics The variation of brake thermal efficiency with brake power for diesel, deccan hemp oil and their blends are shown in Fig. 3. Brake thermal efficiency of 50% blend is very close to diesel for entire range of operation. Maximum brake thermal efficiency of 50% blend is 26.714% against, 26.673% of diesel oil, which is lower by 0.041%. We can say that brake thermal efficiency of 50% blend is well comparable with diesel. Brake thermal efficiency of other blends follows in the order of 25%, 75% blend and neat deccan hemp oil. The maximum brake thermal efficiency of 25% blend and neat deccan hemp oil are 26.281% and 25.063% against 26.67% of diesel [27].
Brake Thermal Efficiency %
The experiments are conducted on a 3.68 kW, AV1 Kirlosker make, naturally aspirated, direct injection (DI), single cylinder, water cooled diesel engine having 80 mm bore and 110 mm stroke. The Kirlosker, engine is one of the widely used engines in agricultural tractor, pump sets, farm machinery, transport-vehicles, small and medium scale commercial purposes. The engine can withstand the peak pressure encountered because of its high compression ratio. Further, the necessary modification on the cylinder head and piston crown can be easily carried out in this type of engine. Hence this engine is selected for the present research work. The engine is coupled to a SAJ Froude AG series eddy current dynamometer. It is a bi-directional water-cooled type. The torque is measured using a temperature compensation load cell and speed from a shaft mounted with sixty-tooth wheel and magnetic pick up. Smoke measurement is made using an OPAX2000 II/DX 200 P meter of Neptune Equipments and a non-dispersive infrared gas analyzer of SAJ Crypton is used to measure unburnt HC and CO emissions. Honey Well Chromel–Alumel thermocouples with digital display were used for various temperature measurements. The layout of experimental test rig and its instrumentation is shown in Fig. 2. Variable load tests are conducted for 0.37, 0.92, 1.48, 2.03, 2.58, 3.13 and 3.68 kW at a constant rated speed of 1500 rpm, with fuel injection pressure of 150 bar, and cooling water exit temperature of 60 C. The deccan hemp oil and its blends with diesel are heated externally to a required temperature as stated earlier before injecting into the test cylinder. The engine was sufficiently warmed up and stabilized before taking all readings. All observations recorded were replicated thrice to get a reasonable value. The performance characteristics of the engine is evaluated in terms of brake thermal efficiency, brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC), and emission characteristics in terms of smoke,
1
27 Diesel DH 25 DH 50
17
DH 75 DH 100
7
0
1
2
3
4
Brake Power kW Fig. 3. Variation of brake thermal efficiency with brake power.
2190
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
Fig. 4 shows the variation of brake specific fuel consumption (BSFC) with brake power for diesel, deccan hemp oil and its blends in the test engine. BSFC of 50% blend closely matches with diesel, followed by 25% blend. Minimum BSFC of 50% blend and 25% are 0.334 and 0.333 kg/kW h against 0.321 kg/kW h of diesel oil. BSFC of neat deccan hemp oil is 0.05 kg/kW h higher than that of diesel. The BSFC is not a very reliable parameter to compare the two fuels as the calorific value and the density of the blend follow a slightly different trend. Hence BSEC is a more reliable parameter for comparison. Fig. 5 shows the variation of brake specific energy consumption (BSEC) with brake power for deccan hemp oil and its blends in the test engine. BSEC of 50% blend is in well comparable with diesel followed by 25% blend. Minimum BSEC of 50% blend is 13475.87 kJ/kW h against 13496.77 kJ/kW h of diesel. BSEC of 25% blend is also comparable with 50% blend. BSEC increases with increase in percentage of deccan hemp oil in blends, for neat deccan hemp oil it is higher than diesel by 867.11 kJ/kW h. This drop in thermal efficiency and increase in BSFC and BSEC must be attributed to the poor combustion characteristic of deccan hemp oil due to poor volatility.
4.2. Emission characteristics Fig. 6 shows the variation of smoke emission with brake power for deccan hemp oil and its blends in the test engine. Smoke emission of 50% blend is lower compared with other blends followed by 25% blend. However smoke emission of 50% blend is higher than that of diesel. Smoke emission at maximum load for 50% and 25% blends are 6.1 and 6.45 Bosch units against, 4.020 Bosch units of diesel. For neat deccan hemp oil smoke emission is on higher side for entire range of operation and maximum emission of 7.1 Bosch units occurs at maximum load [27]. Fig. 7 shows the variation of carbon monoxide emission with brake power for deccan hemp oil and its blends in the test engine. CO emission of all blends is higher than that of diesel. Among the blends, 50% blend has a lower CO emission followed by 25% blend. CO emission of 50% and 25% blends at maximum load is 1.2% and 1.306% volume against 0.700% volume of diesel. CO emission of neat deccan hemp oil is higher than all other blends for entire operating range and maximum of 1.7% volume occurs at rated load. Fig. 8 shows the variation of unburnt HC emission with brake power for deccan hemp oil and its blends in the test
1.3 8 Diesel DH 25
0.9
DH 50 0.7
DH 75 DH 100
0.5
7 Smoke No. Bosch
BSFC kg/kW-h
1.1
6
Diesel
5
DH 25
4
DH 50
3
DH 75 DH 100
2 1
0.3 0
1 2 3 Brake Power kW
4
0 0
1 2 3 Brake Power kW
4
Fig. 4. Variation of BSFC with brake power. Fig. 6. Variation of smoke emission with brake power.
47000 2
37000
Diesel
32000
DH 25 DH 50
27000
DH 75 DH 100
22000 17000 12000
0
1 2 3 Brake Power kW
4
Fig. 5. Variation of BSEC with brake power.
Carbon Monoxide % Vol
BSEC kJ/kW-h
42000
1.6 Diesel 1.2
DH 25 DH 50
0.8
DH 75 DH 100
0.4 0
0
1 2 3 Brake Power kW
4
Fig. 7. Variation of carbon monoxide with brake power.
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
2191
4.3. Comparison of deccan hemp oil performance with jatropha and pongamia oil
300
Unburnt HC PPM
250 Diesel
200
DH 25 150
DH 50 DH 75
100
DH 100
50 0
0
1 2 3 Brake Power kW
4
Fig. 8. Variation of unburnt HC with brake power.
engine. Unburnt HC emission of all blends except 75% blend are lower than that of diesel for low and part load operation. However at maximum load unburnt HC is more for 50% blend and neat deccan hemp oil. Maximum unburnt HC of neat deccan hemp oil is 230 ppm compared with 180 ppm of diesel. Fig. 9 shows the variation of exhaust temperature with brake power for deccan hemp oil and its blend in the test engine. Exhaust temperature of 50% blends is lower compared with diesel. This is an indication of lower exhaust loss and could be the possible reason for higher performance. Exhaust temperature of all other blends are higher than diesel and there is not much variation among blends. From the above observation it is clear that engine operates at lower performance and higher smoke, CO and unburnt HC emissions compared with diesel. This could be due to low volatility, which effects the spray formation in combustion chamber and thus leads to slow combustion. From above discussion it is clear that, blends with 25% and 50% deccan hemp oil has acceptable performance with higher emissions. Twenty five percent blend without heating and 50% blend with heating can be used as an alternate fuel.
To ascertain the validity of results obtained, deccan hemp oil performance is compared with results obtained by similar experimental work of Vijayakumar Reddy [10] and Pramanik [20]. Both of them in their experimental work reduced the viscosity of vegetable oil by dilution with diesel and further, blends are heated to reduce the viscosity equivalent to that of diesel at room temperature. They have also used the similar 3.68 kW, 1500 rpm, naturally aspirated, Kirlosker make diesel engine, which further simplifies the process of comparison. Vijayakumar Reddy conducted the variable load performance test with jatropha and pongamia oil at fuel injection pressure of 150 bar, and constant cooling water outlet temperature of 70 C. Then the performance of engine is evaluated in terms of brake thermal efficiency, smoke, unburnt HC, CO emissions and exhaust temperature. Pramanik, also conducted the variable load test at fuel injection pressure of 210 bar and constant cooling water outlet temperature of 55 C. Performance of engine is evaluated only in terms of brake thermal efficiency, BSFC and exhaust temperature. Though the performance results are available for blends, for convenience only results of neat vegetable oils are used for comparison. The results are plotted with trend lines for easy understanding. For the purpose of comparison jatropha oil used by Vijayakumar Reddy is labeled as jatropha oil No. 1 (1JT100) and of Pramanik as jatropha oil No. 2 (2JT100). Figs. 10–12 shows the variation of brake thermal efficiency, BSFC and exhaust temperature of neat deccan hemp (DH100), 1JT100, 2JT100 and neat pongamia oil (PO100) with brake power. Brake thermal efficiency of deccan hemp oil is higher than that of other oils for entire range of operation. The maximum thermal efficiency of deccan hemp, 1JT100, and PO100 are 25.063%, 24.54%
Exhaust Temperature Deg. C
545 495 445
Diesel
395
DH 25
345
DH 50
295
DH 75 DH 100
245
Brake Thermal Efficiency %
30 25 DH 100 20
1JT 100
15
PO 100 2JT 100
10 5
195 145
0 0
1 2 3 Brake Power kW
4
Fig. 9. Variation of exhaust temperature with brake power.
0
1
2
3
4
Brake Power kW Fig. 10. Variation of brake thermal efficiency with brake power.
2192
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
1.4
8
1.2
7
BSFC kg/kW-h
DH 100 2JT 100
0.8 0.6 0.4
Smoke No. Bosch
6
1
0.2 0
5 DH 100 1JT 100 PO 100
4 3 2 1
0
1 2 3 Brake Power kW
0
4
Fig. 11. Variation of BSFC with brake power.
0
1 2 3 Brake Power kW
4
Fig. 13. Variation of smoke emission with brake power.
600 500 DH 100 400
200
1JT 100 PO 100
300
2JT 100
200
Unburnt HC ppm
Exhaust Temperature deg. C
250
150 DH 100 1JT 100 PO 100
100
100 50 0
0
1
2
3
4
0
Brake Power kW
0
1
2
3
4
Brake Power kW
Fig. 12. Variation of exhaust temperature with brake power.
Fig. 14. Variation of unburnt HC with brake power.
2 1.8 Carbon Monoxide % Vol.
and 24.3% respectively and are well comparable at maximum load. Brake thermal efficiency is lower and BSFC is higher for entire range of operation for 2JT100 oil compared with deccan hemp oil. This drop in performance must be attributed to the higher exhaust temperature which increases losses and also low cylinder liner temperature which increases emissions due to incomplete combustion. Figs. 13–15 shows the variation of smoke, unburnt HC and CO emissions of DH 100, 1JT100 and PO100 with brake power. Emission of smoke and unburnt HC at low load and part load for deccan hemp oil is lower than 1JT100 and PO100. This could be the reason for higher efficiency of deccan hemp oil for these loads. The typical smoke and CO values are 0.52 Bosch No. and 20 ppm. However, smoke emission at full load and CO emission for entire range are little higher than 1JT100 and PO100. The higher cooling water outlet temperature maintains the cylinder liner at higher temperature, which attributes for lower emissions.
1.6 1.4 1.2 DH 100 1JT 100 PO 100
1 0.8 0.6 0.4 0.2 0
0
1 2 3 Brake Power kW
4
Fig. 15. Variation of CO emission with brake power.
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
From above discussion it is clear that performance and emission characteristics of deccan hemp oil is better than that of other oils considered.
2193
Hence, from above conclusions it may be stated that, blends up to 25% with out preheating and up to 50% with preheating can be substituted as fuel for diesel engine without any modifications in the diesel engine.
4.4. Other observations Deccan hemp oil exhibited greater nozzle deposits than diesel. These deposits were on exterior of nozzle and removal required light scraping. For smooth operation of engine nozzle cleaning was done for every 8 h of operation. Another observation is that, combustion noise was lower for deccan hemp oil, this could be due to lower pressure rise during combustion. 5. Conclusion Experimental investigations are carried out on a single cylinder DI diesel engine to examine the suitability of deccan hemp oil as an alternate fuel. At the beginning effect of dilution with diesel and heating of blends on viscosity are studied. Then the performance and emission characteristics of blends are evaluated and compared with diesel and optimum blend is determined. Further for confirming its validity the results are compared with the results of jatropha and pongamia oil available in literature for similar work. From the above investigations, the following conclusions are drawn. • The properties viz; density, viscosity, flash point and fire point of deccan hemp oil is higher and calorific value is 0.92 times that of diesel. • Dilution of deccan hemp oil reduces the viscosity considerably. The blend containing 75% of diesel has viscosity 7.658 cSt, which is very close to viscosity of diesel at 30 C and does not require any heating prior to injection into combustion chamber. Blends containing 50%, 25% and 0% diesel require preheating up to 70, 80 and 95 C, respectively. • Performance and emission characteristics of 50% blend are better than the other blends, followed by 25% blend. The maximum efficiency of 50% blend is well comparable with diesel. However smoke, unburnt HC, and CO emissions are respectively 51.74%, 71.42% and 33.3% higher as compared with diesel. The performance characteristics of 25% blend is well comparable with 50% blend. • The maximum brake thermal efficiency, minimum BSFC and BSEC of neat deccan hemp oil are respectively 1.61% lower, 0.05 kg/kW h higher and 867.11 kJ/kW h higher compared with diesel. • Smoke, unburnt HC and CO emissions at maximum load for neat deccan hemp compared with diesel are higher by 3.08 Bosch No., 1.0 vol.%, and 50 ppm, respectively. • Performance of deccan hemp oil is validated as results are in well comparison with results of jatropha and pongamia oils.
References [1] Barsic NJ, Humke AL. Performance and emissions characteristics of a naturally aspirated diesel engine with vegetable oil fuels. SAE paper No. 810262. [2] Humke AL , Barsic NJ. Performance and emissions characteristics of a naturally aspirated diesel engine with vegetable oil fuels- part (2): SAE paper No. 810955. [3] Vellguth G. Performance of vegetable oils and their monoesters as fuels for diesel engines. SAE paper No. 831358. [4] Henham AWE. Experience with alternate fuels for small stationary diesel engines: fuels for automotive and industrial diesel engines. I Mech E 1990:117–22. [5] Hemmerlien N, Korte V, Richter H. Performance, exhaust emissions and durability of modern diesel engines running on rapeseed oil. SAE Paper No. 910848. [6] Rao PS, Gopalakrishan KV. Use of non-edible vegetable oils as diesel engine fuels. J Inst Eng India 1989;70(4). [7] Michael SG, Robert LM. Combustion of fat and vegetable oil derived fuels in diesel engines. Prog Energy Combust Sci 1998;24:125–64. [8] Rakopoulos CD. Olive oil as a fuel supplement in DI and IDI diesel engines. Energy 1992;17(8):787–90. [9] Radu R, Mirca Z. The use of sunflower oil in diesel engines. SAE paper No. 972979. [10] Reddy KV. Experimental investigations on the use of vegetable oil fuels in a four-stroke single cylinder diesel engines: PhD Thesis, JNTU college of Engineering Anantapur, Andhra Pradesh, India, 2000. [11] Herchel TCM, Seiichi S, Takao K, Hisao N. Performance and emission characteristics of a diesel engine fueled with coconut oil– diesel fuel blend. Biomass Bioenergy 2001;20:63–9. [12] Altin R, Cetinkaya S, Yucesu HS. The potentials of using vegetable oil fuels as fuel for diesel engines. Energy Convers Manage 2001;42:529–38. [13] Agarwal AK, Das LM. Bio diesel development and characterization for use as fuel in compression ignition engines. Trans ASME 2001;123:440–7. [14] de Almeida SCA, Belchior CR, Nascimento MVG, Vieira LSR, Fleury G. Performance of a diesel generator fuelled with palm oil. Fuel 2002;81:2097–102. [15] Ramadhas AS, Jayaraj S, Muraleedharan C. Use of vegetable oils as IC engine fuels—a review. Renew Energy 2004;29:727–42. [16] Bari S, Lim TH, Yu CW. Effects of preheating of crude palm oil (CPO) on injection system, performance and emission of a diesel engine. Renew Energy 2002;27:339–51. [17] Kalam MA, Masjuki HH. Emission and deposit characteristics of a small diesel engine when operated on preheated crude palm oil. Biomass Bioenergy 2004;27:289–97. [18] Nwafor OMI. Emission characteristics of a diesel engine running on vegetable oil with elevated fuel inlet temperature. Biomass Bioenergy 2004;29:727–42. [19] Huzayyin AS, Bawady AH, Rady MA, Dawood A. Experimental evaluation of diesel engine performance and emission using blends of jojoba oil and diesel fuel. Energy Convers Manage 2004;45: 2093–112. [20] Pramanik K. Properties and use of jatropha curcas oil and diesel fuel blends in compression ignition engines. Renew Energy 2003;28:239–48. [21] Ramadhas AS, Jayaraj S, Muraleedharan C. Characterization and effect of using rubber seed oil as fuel in compression ignition engines. Renew Energy 2005;30:795–803.
2194
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
[22] Wealth of India: publications information directorate, CSIR, New Delhi, 1966;vol. V:77–84. [23] IS: 1448 [P:16]; Methods of test for petroleum and its products; density of crude petroleum and liquid petroleum products by hydrometer method, Bureau of Indian Standards, New Delhi, 1990. [24] IS: 1448 [P:6]; Methods of test for petroleum and its products; heat of combustion of liquid hydrocarbon fuels by bomb calorimeter method, Bureau of Indian Standards, New Delhi, 1984. [25] IS: 1448 [P:25]; Methods of test for petroleum and its products; determination of kinematics and dynamic viscosity, Bureau of Indian Standards, New Delhi, 1976.
[26] IS: 1448 [P:20]; Methods of test for petroleum and its products; determination of flash point by Able’s apparatus, Bureau of Indian Standards, New Delhi, 1998. [27] Hebbal OD, Reddy KV, Rajagopal K. Deccan hemp oil as an alternative fuel for diesel engines. Energy and Fuel Users Journal 2005;55(3):1–5.
Performance characteristics of a diesel engine with deccan hemp oil O.D. Hebbal b
a,*
, K.Vijayakumar Reddy b, K. Rajagopal
c
a Assistant Professor, Poojya Doddappa Appa College of Engineering, Gulbarga, India Controller of Examinations, Jawaharlal Nehru Technological University, Hyderabad, India c Vice chancellor, Jawaharlal Nehru Technological University, Hyderabad, India
Received 27 August 2005; received in revised form 14 March 2006; accepted 16 March 2006 Available online 18 April 2006
Abstract In this present investigation deccan hemp oil, a non-edible vegetable oil is selected for the test on a diesel engine and its suitability as an alternate fuel is examined. The viscosity of deccan hemp oil is reduced first by blending with diesel in 25/75%, 50/50%, 75/25%, 100/ 0% on volume basis, then analyzed and compared with diesel. Further blends are heated and effect of viscosity on temperature was studied. The performance and emission characteristics of blends are evaluated at variable loads of 0.37, 0.92, 1.48, 2.03, 2.58, 3.13 and 3.68 kW at a constant rated speed of 1500 rpm and results are compared with diesel. The thermal efficiency, brake specific fuel consumption (BSFC), and brake specific energy consumption (BSEC) are well comparable with diesel, and emissions are a little higher for 25% and 50% blends. At rated load, smoke, carbon monoxide (CO), and unburnt hydrocarbon (HC) emissions of 50% blend are higher compared with diesel by 51.74%, 71.42% and 33.3%, respectively. For ascertaining the validity of results obtained, pure deccan hemp oil results are compared with results of jatropha and pongamia oil for similar works available in the literature and were well comparable. From investigation it has been established that, up to 25% of blend of deccan hemp oil without heating and up to 50% blend with preheating can be substituted for diesel engine without any engine modification. 2006 Elsevier Ltd. All rights reserved. Keywords: Non-edible oil; Deccan hemp oil; Alternate fuel
1. Introduction Energy is considered as a critical factor for economic growth, social development and human welfare. With increasing trend of modernization and industrialization, the world energy demand is growing at a faster rate. Since their exploration, the petroleum fuels continued as major conventional energy source. On the other hand, they are limited in reserve. Both the factors have contributed to a sharp increase in petroleum prices. Also, petroleum fuels are currently the dominant global source of CO2 emissions and their combustion is posing stronger threat to clean environment. Sharp hike in petroleum prices and increase in environmental pollution jointly necessitated exploring *
Corresponding author. Address: Assistant Professor, Poojya Doddappa Appa College of Engineering, Gulbarga, India. E-mail address: siddu_pda@rediffmail.com (O.D. Hebbal). 0016-2361/$ - see front matter 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2006.03.011
some alternate to conventional petroleum fuels. Among the other possible options of the liquid fuels various kinds of vegetable oils have been considered as appropriate alternate due to prevalent fuel properties. A country like India, having huge agricultural potential vegetable oils proves a promising alternate for petroleum (diesel oil) fuel. The idea of using vegetable oils as fuel for diesel engines in not a new one. Rudolph Diesel used peanut oil to fuel his engine at the Paris Exposition of 1900. However, despite the technical feasibility, vegetable oil as fuel could not get acceptance, as they were more expensive than petroleum fuels. Later the various factors as stated earlier, created renewed interest of researchers in vegetable oil as substitute fuel for diesel engines. In recent years systematic effort have been made by several researchers [1–14] to use vegetable oils like sunflower, peanut, soybean, rapeseed, palm, olive, cottonseed, linseed, jatropha, coconut, pongamia, rubberseed, jojoba etc. as alternate fuel for diesel. Many of the
2188
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
vegetable oils are edible in nature, continuous use of them causes shortage for food supply and proves far expensive to be used as fuel at present. So far a very few of non-edible vegetable oils have been tried on diesel engine leaving a lot of scope in this area. From previous studies it is evident that vegetable oils offer acceptable engine performance and emissions for short-term operation [1]. While for long-term duration problems like filter clogging, carbon deposits on injector exterior, compression ring grooves, piston lands, etc. have been reported [2–7]. The high viscosity of vegetable oils is responsible for these problems. Therefore reduction in viscosity of vegetable oils is of the prime importance to make them suitable for diesel engines. There are several ways [15] available for this task, among them blending or dilution with other oils, preheating and transesterification are predominant. Testing of diesel engines with preheating [16–18], blending with diesel [6,11,19] and blending with preheating [20,21] improves the performance and reduces the emissions compared with neat vegetable oil. It also reduces the filter clogging and ensures smooth flow of oil. From above stated factors it is evident that identification and testing of new non-edible vegetable oils on diesel engine is of great importance. In present investigation deccan hemp oil, a non-edible vegetable oil is selected for the test and its suitability as an alternate fuel is examined. This is accomplished by blending of deccan hemp oil with diesel in 25/75%, 50/50%, 75/25%, 100/0% on volume basis, further these blends are heated to reduce viscosity equal to that of diesel at 30 C. Then the following investigations are carried out. • The effect of blending deccan hemp oil with diesel on viscosity. • The effect of temperature on the viscosity of various deccan hemp oil and diesel blends and the temperature at which the viscosity of blends equal to that of diesel at 30 C. • The performance and emission characteristics of diesel engine using various blends and compare the results with those of baseline diesel. • Further for ascertaining the validity of the results obtained, the performance and emission characteristics of neat deccan hemp oil is compared with the results available in literature for similar work.
Table 1 Comparison of properties of deccan hemp oil with diesel oil Property
Diesel oil
Deccan hemp oil
Density g/cc at 30 C Calorific value kJ/kg Viscosity cSt at 30 C Flash point C Fire point C
0.8–0.84 42000 5.0 57 65
0.913 38720 53.0 255 270
Table 2 Properties of deccan hemp oil–diesel blends Deccan hemp oil (%)
Diesel (%)
Density (g/cc), at 30 C
Viscosity (cSt), at 30 C
Viscosity reduction (%)
100 75 50 25 0
0 25 50 75 100
0.913 0.89 0.87 0.84 0.82
53.0 24.56 15.46 7.685 5.0
– 53.66 70.83 85.5 90.56
ing best in humid climate with a temperature range of 20–35 C, during growing season [22]. Whole seeds after milling and pressing yields 13% odorless clear yellow fatty oil. The important physical and chemical properties of deccan hemp oil are determined as per Indian Standards (IS) methods in fuels and lubricants laboratory. Determination of density, calorific value, viscosity, flash point and fire point are carried out using hydrometer, bomb calorimeter, Redwood viscometer and Able’s apparatus [23–26], respectively. It is observed that the properties like density, flash point, fire point and viscosity of deccan hemp oil is higher and the calorific value is lower as compared with diesel. Table 1 shows the comparison of properties of deccan hemp oil with diesel. 2.2. Effect of dilution on viscosity of deccan hemp oil and diesel blends Deccan hemp oil and diesel are blended in 0/100%, 25/ 75%, 50/50%, 75/25%, 100/0% on volume basis and mixture is stirred well to get a homogeneous stable mixture. Variation of density, viscosity and percentage reduction in viscosity of blends at 30 C are shown in Table 2. The density and viscosity of blends reduces with increase in percentage of diesel in blend. The blend containing 75% of diesel has density and viscosity close to that of diesel.
2. Characterization of deccan hemp oil 2.1. Properties of deccan hemp oil
2.3. Effect of temperature on viscosity of deccan hemp oil and diesel blends
Deccan hemp oil is obtained from the dried seeds of the deccan hemp plant. It is an erect herbaceous annual with straight; slender glabrous or prickly stem plant. Its Botanical name is Hibiscus Cannabinus and English name is deccan hemp. The plant is cultivated mainly as fibre crop substitute to jute. This is essentially a tropical crop, thriv-
Fig. 1 shows the variation of viscosity of blends with temperature. The viscosity of blends decreases with increase in temperature. Blend containing 75% diesel have viscosity close to diesel at 30 C and does not require heating. However, blends containing 50%, 25% and 0% diesel requires heating up to 70, 80 and 95 C, respectively before
Kinematic Viscosity Centi Stokes
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
2189
60
9
50 40
4
6
3
Diesel
5
DH 25 30
DH 50 10
DH 75
20
DH 100
10 0
11
Air
9
8
7
Gas
12
0
20 40 60 80 Temperature Deg C
100
9 Water
Water 13
Fig. 1. Variations of viscosity of blends with temperature.
firing into combustion chamber to attain viscosity equivalent to that of diesel at 30 C.
2
1. Diesel engine 2. Dynamometer 3. Diesel tank 4. Vegetable oil tank 5. Heater 6. Measuring burette 7. Smoke meter 8. HC & CO analyzer 9. Digital thermocouples 10. Filter 11. Air tank 12. Orifice meter with manometer 13. Rotameter
3. Experimental test rig, instrumentation and programme
Fig. 2. Layout of experimental setup with instrumentation.
unburnt HC, CO and exhaust temperature. These performance and emission characteristics are compared with the results of baseline diesel. 4. Results and discussion 4.1. Performance characteristics The variation of brake thermal efficiency with brake power for diesel, deccan hemp oil and their blends are shown in Fig. 3. Brake thermal efficiency of 50% blend is very close to diesel for entire range of operation. Maximum brake thermal efficiency of 50% blend is 26.714% against, 26.673% of diesel oil, which is lower by 0.041%. We can say that brake thermal efficiency of 50% blend is well comparable with diesel. Brake thermal efficiency of other blends follows in the order of 25%, 75% blend and neat deccan hemp oil. The maximum brake thermal efficiency of 25% blend and neat deccan hemp oil are 26.281% and 25.063% against 26.67% of diesel [27].
Brake Thermal Efficiency %
The experiments are conducted on a 3.68 kW, AV1 Kirlosker make, naturally aspirated, direct injection (DI), single cylinder, water cooled diesel engine having 80 mm bore and 110 mm stroke. The Kirlosker, engine is one of the widely used engines in agricultural tractor, pump sets, farm machinery, transport-vehicles, small and medium scale commercial purposes. The engine can withstand the peak pressure encountered because of its high compression ratio. Further, the necessary modification on the cylinder head and piston crown can be easily carried out in this type of engine. Hence this engine is selected for the present research work. The engine is coupled to a SAJ Froude AG series eddy current dynamometer. It is a bi-directional water-cooled type. The torque is measured using a temperature compensation load cell and speed from a shaft mounted with sixty-tooth wheel and magnetic pick up. Smoke measurement is made using an OPAX2000 II/DX 200 P meter of Neptune Equipments and a non-dispersive infrared gas analyzer of SAJ Crypton is used to measure unburnt HC and CO emissions. Honey Well Chromel–Alumel thermocouples with digital display were used for various temperature measurements. The layout of experimental test rig and its instrumentation is shown in Fig. 2. Variable load tests are conducted for 0.37, 0.92, 1.48, 2.03, 2.58, 3.13 and 3.68 kW at a constant rated speed of 1500 rpm, with fuel injection pressure of 150 bar, and cooling water exit temperature of 60 C. The deccan hemp oil and its blends with diesel are heated externally to a required temperature as stated earlier before injecting into the test cylinder. The engine was sufficiently warmed up and stabilized before taking all readings. All observations recorded were replicated thrice to get a reasonable value. The performance characteristics of the engine is evaluated in terms of brake thermal efficiency, brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC), and emission characteristics in terms of smoke,
1
27 Diesel DH 25 DH 50
17
DH 75 DH 100
7
0
1
2
3
4
Brake Power kW Fig. 3. Variation of brake thermal efficiency with brake power.
2190
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
Fig. 4 shows the variation of brake specific fuel consumption (BSFC) with brake power for diesel, deccan hemp oil and its blends in the test engine. BSFC of 50% blend closely matches with diesel, followed by 25% blend. Minimum BSFC of 50% blend and 25% are 0.334 and 0.333 kg/kW h against 0.321 kg/kW h of diesel oil. BSFC of neat deccan hemp oil is 0.05 kg/kW h higher than that of diesel. The BSFC is not a very reliable parameter to compare the two fuels as the calorific value and the density of the blend follow a slightly different trend. Hence BSEC is a more reliable parameter for comparison. Fig. 5 shows the variation of brake specific energy consumption (BSEC) with brake power for deccan hemp oil and its blends in the test engine. BSEC of 50% blend is in well comparable with diesel followed by 25% blend. Minimum BSEC of 50% blend is 13475.87 kJ/kW h against 13496.77 kJ/kW h of diesel. BSEC of 25% blend is also comparable with 50% blend. BSEC increases with increase in percentage of deccan hemp oil in blends, for neat deccan hemp oil it is higher than diesel by 867.11 kJ/kW h. This drop in thermal efficiency and increase in BSFC and BSEC must be attributed to the poor combustion characteristic of deccan hemp oil due to poor volatility.
4.2. Emission characteristics Fig. 6 shows the variation of smoke emission with brake power for deccan hemp oil and its blends in the test engine. Smoke emission of 50% blend is lower compared with other blends followed by 25% blend. However smoke emission of 50% blend is higher than that of diesel. Smoke emission at maximum load for 50% and 25% blends are 6.1 and 6.45 Bosch units against, 4.020 Bosch units of diesel. For neat deccan hemp oil smoke emission is on higher side for entire range of operation and maximum emission of 7.1 Bosch units occurs at maximum load [27]. Fig. 7 shows the variation of carbon monoxide emission with brake power for deccan hemp oil and its blends in the test engine. CO emission of all blends is higher than that of diesel. Among the blends, 50% blend has a lower CO emission followed by 25% blend. CO emission of 50% and 25% blends at maximum load is 1.2% and 1.306% volume against 0.700% volume of diesel. CO emission of neat deccan hemp oil is higher than all other blends for entire operating range and maximum of 1.7% volume occurs at rated load. Fig. 8 shows the variation of unburnt HC emission with brake power for deccan hemp oil and its blends in the test
1.3 8 Diesel DH 25
0.9
DH 50 0.7
DH 75 DH 100
0.5
7 Smoke No. Bosch
BSFC kg/kW-h
1.1
6
Diesel
5
DH 25
4
DH 50
3
DH 75 DH 100
2 1
0.3 0
1 2 3 Brake Power kW
4
0 0
1 2 3 Brake Power kW
4
Fig. 4. Variation of BSFC with brake power. Fig. 6. Variation of smoke emission with brake power.
47000 2
37000
Diesel
32000
DH 25 DH 50
27000
DH 75 DH 100
22000 17000 12000
0
1 2 3 Brake Power kW
4
Fig. 5. Variation of BSEC with brake power.
Carbon Monoxide % Vol
BSEC kJ/kW-h
42000
1.6 Diesel 1.2
DH 25 DH 50
0.8
DH 75 DH 100
0.4 0
0
1 2 3 Brake Power kW
4
Fig. 7. Variation of carbon monoxide with brake power.
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
2191
4.3. Comparison of deccan hemp oil performance with jatropha and pongamia oil
300
Unburnt HC PPM
250 Diesel
200
DH 25 150
DH 50 DH 75
100
DH 100
50 0
0
1 2 3 Brake Power kW
4
Fig. 8. Variation of unburnt HC with brake power.
engine. Unburnt HC emission of all blends except 75% blend are lower than that of diesel for low and part load operation. However at maximum load unburnt HC is more for 50% blend and neat deccan hemp oil. Maximum unburnt HC of neat deccan hemp oil is 230 ppm compared with 180 ppm of diesel. Fig. 9 shows the variation of exhaust temperature with brake power for deccan hemp oil and its blend in the test engine. Exhaust temperature of 50% blends is lower compared with diesel. This is an indication of lower exhaust loss and could be the possible reason for higher performance. Exhaust temperature of all other blends are higher than diesel and there is not much variation among blends. From the above observation it is clear that engine operates at lower performance and higher smoke, CO and unburnt HC emissions compared with diesel. This could be due to low volatility, which effects the spray formation in combustion chamber and thus leads to slow combustion. From above discussion it is clear that, blends with 25% and 50% deccan hemp oil has acceptable performance with higher emissions. Twenty five percent blend without heating and 50% blend with heating can be used as an alternate fuel.
To ascertain the validity of results obtained, deccan hemp oil performance is compared with results obtained by similar experimental work of Vijayakumar Reddy [10] and Pramanik [20]. Both of them in their experimental work reduced the viscosity of vegetable oil by dilution with diesel and further, blends are heated to reduce the viscosity equivalent to that of diesel at room temperature. They have also used the similar 3.68 kW, 1500 rpm, naturally aspirated, Kirlosker make diesel engine, which further simplifies the process of comparison. Vijayakumar Reddy conducted the variable load performance test with jatropha and pongamia oil at fuel injection pressure of 150 bar, and constant cooling water outlet temperature of 70 C. Then the performance of engine is evaluated in terms of brake thermal efficiency, smoke, unburnt HC, CO emissions and exhaust temperature. Pramanik, also conducted the variable load test at fuel injection pressure of 210 bar and constant cooling water outlet temperature of 55 C. Performance of engine is evaluated only in terms of brake thermal efficiency, BSFC and exhaust temperature. Though the performance results are available for blends, for convenience only results of neat vegetable oils are used for comparison. The results are plotted with trend lines for easy understanding. For the purpose of comparison jatropha oil used by Vijayakumar Reddy is labeled as jatropha oil No. 1 (1JT100) and of Pramanik as jatropha oil No. 2 (2JT100). Figs. 10–12 shows the variation of brake thermal efficiency, BSFC and exhaust temperature of neat deccan hemp (DH100), 1JT100, 2JT100 and neat pongamia oil (PO100) with brake power. Brake thermal efficiency of deccan hemp oil is higher than that of other oils for entire range of operation. The maximum thermal efficiency of deccan hemp, 1JT100, and PO100 are 25.063%, 24.54%
Exhaust Temperature Deg. C
545 495 445
Diesel
395
DH 25
345
DH 50
295
DH 75 DH 100
245
Brake Thermal Efficiency %
30 25 DH 100 20
1JT 100
15
PO 100 2JT 100
10 5
195 145
0 0
1 2 3 Brake Power kW
4
Fig. 9. Variation of exhaust temperature with brake power.
0
1
2
3
4
Brake Power kW Fig. 10. Variation of brake thermal efficiency with brake power.
2192
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
1.4
8
1.2
7
BSFC kg/kW-h
DH 100 2JT 100
0.8 0.6 0.4
Smoke No. Bosch
6
1
0.2 0
5 DH 100 1JT 100 PO 100
4 3 2 1
0
1 2 3 Brake Power kW
0
4
Fig. 11. Variation of BSFC with brake power.
0
1 2 3 Brake Power kW
4
Fig. 13. Variation of smoke emission with brake power.
600 500 DH 100 400
200
1JT 100 PO 100
300
2JT 100
200
Unburnt HC ppm
Exhaust Temperature deg. C
250
150 DH 100 1JT 100 PO 100
100
100 50 0
0
1
2
3
4
0
Brake Power kW
0
1
2
3
4
Brake Power kW
Fig. 12. Variation of exhaust temperature with brake power.
Fig. 14. Variation of unburnt HC with brake power.
2 1.8 Carbon Monoxide % Vol.
and 24.3% respectively and are well comparable at maximum load. Brake thermal efficiency is lower and BSFC is higher for entire range of operation for 2JT100 oil compared with deccan hemp oil. This drop in performance must be attributed to the higher exhaust temperature which increases losses and also low cylinder liner temperature which increases emissions due to incomplete combustion. Figs. 13–15 shows the variation of smoke, unburnt HC and CO emissions of DH 100, 1JT100 and PO100 with brake power. Emission of smoke and unburnt HC at low load and part load for deccan hemp oil is lower than 1JT100 and PO100. This could be the reason for higher efficiency of deccan hemp oil for these loads. The typical smoke and CO values are 0.52 Bosch No. and 20 ppm. However, smoke emission at full load and CO emission for entire range are little higher than 1JT100 and PO100. The higher cooling water outlet temperature maintains the cylinder liner at higher temperature, which attributes for lower emissions.
1.6 1.4 1.2 DH 100 1JT 100 PO 100
1 0.8 0.6 0.4 0.2 0
0
1 2 3 Brake Power kW
4
Fig. 15. Variation of CO emission with brake power.
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
From above discussion it is clear that performance and emission characteristics of deccan hemp oil is better than that of other oils considered.
2193
Hence, from above conclusions it may be stated that, blends up to 25% with out preheating and up to 50% with preheating can be substituted as fuel for diesel engine without any modifications in the diesel engine.
4.4. Other observations Deccan hemp oil exhibited greater nozzle deposits than diesel. These deposits were on exterior of nozzle and removal required light scraping. For smooth operation of engine nozzle cleaning was done for every 8 h of operation. Another observation is that, combustion noise was lower for deccan hemp oil, this could be due to lower pressure rise during combustion. 5. Conclusion Experimental investigations are carried out on a single cylinder DI diesel engine to examine the suitability of deccan hemp oil as an alternate fuel. At the beginning effect of dilution with diesel and heating of blends on viscosity are studied. Then the performance and emission characteristics of blends are evaluated and compared with diesel and optimum blend is determined. Further for confirming its validity the results are compared with the results of jatropha and pongamia oil available in literature for similar work. From the above investigations, the following conclusions are drawn. • The properties viz; density, viscosity, flash point and fire point of deccan hemp oil is higher and calorific value is 0.92 times that of diesel. • Dilution of deccan hemp oil reduces the viscosity considerably. The blend containing 75% of diesel has viscosity 7.658 cSt, which is very close to viscosity of diesel at 30 C and does not require any heating prior to injection into combustion chamber. Blends containing 50%, 25% and 0% diesel require preheating up to 70, 80 and 95 C, respectively. • Performance and emission characteristics of 50% blend are better than the other blends, followed by 25% blend. The maximum efficiency of 50% blend is well comparable with diesel. However smoke, unburnt HC, and CO emissions are respectively 51.74%, 71.42% and 33.3% higher as compared with diesel. The performance characteristics of 25% blend is well comparable with 50% blend. • The maximum brake thermal efficiency, minimum BSFC and BSEC of neat deccan hemp oil are respectively 1.61% lower, 0.05 kg/kW h higher and 867.11 kJ/kW h higher compared with diesel. • Smoke, unburnt HC and CO emissions at maximum load for neat deccan hemp compared with diesel are higher by 3.08 Bosch No., 1.0 vol.%, and 50 ppm, respectively. • Performance of deccan hemp oil is validated as results are in well comparison with results of jatropha and pongamia oils.
References [1] Barsic NJ, Humke AL. Performance and emissions characteristics of a naturally aspirated diesel engine with vegetable oil fuels. SAE paper No. 810262. [2] Humke AL , Barsic NJ. Performance and emissions characteristics of a naturally aspirated diesel engine with vegetable oil fuels- part (2): SAE paper No. 810955. [3] Vellguth G. Performance of vegetable oils and their monoesters as fuels for diesel engines. SAE paper No. 831358. [4] Henham AWE. Experience with alternate fuels for small stationary diesel engines: fuels for automotive and industrial diesel engines. I Mech E 1990:117–22. [5] Hemmerlien N, Korte V, Richter H. Performance, exhaust emissions and durability of modern diesel engines running on rapeseed oil. SAE Paper No. 910848. [6] Rao PS, Gopalakrishan KV. Use of non-edible vegetable oils as diesel engine fuels. J Inst Eng India 1989;70(4). [7] Michael SG, Robert LM. Combustion of fat and vegetable oil derived fuels in diesel engines. Prog Energy Combust Sci 1998;24:125–64. [8] Rakopoulos CD. Olive oil as a fuel supplement in DI and IDI diesel engines. Energy 1992;17(8):787–90. [9] Radu R, Mirca Z. The use of sunflower oil in diesel engines. SAE paper No. 972979. [10] Reddy KV. Experimental investigations on the use of vegetable oil fuels in a four-stroke single cylinder diesel engines: PhD Thesis, JNTU college of Engineering Anantapur, Andhra Pradesh, India, 2000. [11] Herchel TCM, Seiichi S, Takao K, Hisao N. Performance and emission characteristics of a diesel engine fueled with coconut oil– diesel fuel blend. Biomass Bioenergy 2001;20:63–9. [12] Altin R, Cetinkaya S, Yucesu HS. The potentials of using vegetable oil fuels as fuel for diesel engines. Energy Convers Manage 2001;42:529–38. [13] Agarwal AK, Das LM. Bio diesel development and characterization for use as fuel in compression ignition engines. Trans ASME 2001;123:440–7. [14] de Almeida SCA, Belchior CR, Nascimento MVG, Vieira LSR, Fleury G. Performance of a diesel generator fuelled with palm oil. Fuel 2002;81:2097–102. [15] Ramadhas AS, Jayaraj S, Muraleedharan C. Use of vegetable oils as IC engine fuels—a review. Renew Energy 2004;29:727–42. [16] Bari S, Lim TH, Yu CW. Effects of preheating of crude palm oil (CPO) on injection system, performance and emission of a diesel engine. Renew Energy 2002;27:339–51. [17] Kalam MA, Masjuki HH. Emission and deposit characteristics of a small diesel engine when operated on preheated crude palm oil. Biomass Bioenergy 2004;27:289–97. [18] Nwafor OMI. Emission characteristics of a diesel engine running on vegetable oil with elevated fuel inlet temperature. Biomass Bioenergy 2004;29:727–42. [19] Huzayyin AS, Bawady AH, Rady MA, Dawood A. Experimental evaluation of diesel engine performance and emission using blends of jojoba oil and diesel fuel. Energy Convers Manage 2004;45: 2093–112. [20] Pramanik K. Properties and use of jatropha curcas oil and diesel fuel blends in compression ignition engines. Renew Energy 2003;28:239–48. [21] Ramadhas AS, Jayaraj S, Muraleedharan C. Characterization and effect of using rubber seed oil as fuel in compression ignition engines. Renew Energy 2005;30:795–803.
2194
O.D. Hebbal et al. / Fuel 85 (2006) 2187–2194
[22] Wealth of India: publications information directorate, CSIR, New Delhi, 1966;vol. V:77–84. [23] IS: 1448 [P:16]; Methods of test for petroleum and its products; density of crude petroleum and liquid petroleum products by hydrometer method, Bureau of Indian Standards, New Delhi, 1990. [24] IS: 1448 [P:6]; Methods of test for petroleum and its products; heat of combustion of liquid hydrocarbon fuels by bomb calorimeter method, Bureau of Indian Standards, New Delhi, 1984. [25] IS: 1448 [P:25]; Methods of test for petroleum and its products; determination of kinematics and dynamic viscosity, Bureau of Indian Standards, New Delhi, 1976.
[26] IS: 1448 [P:20]; Methods of test for petroleum and its products; determination of flash point by Able’s apparatus, Bureau of Indian Standards, New Delhi, 1998. [27] Hebbal OD, Reddy KV, Rajagopal K. Deccan hemp oil as an alternative fuel for diesel engines. Energy and Fuel Users Journal 2005;55(3):1–5.