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Item Technical aspects of biodiesel and its oxidation stability(2009) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.Biodiesel is a clean burning alternative renewable fuel made from natural renewable sources. It is defined as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, which conform to ASTM specifications for use in diesel engines. Biodiesel present a very promising alternative fuel to diesel oil and properties of this oil offer the advantage of immediate substitution in existing diesel engines with little or no modifications at all. But one of the major technical problems associated with the biodiesel is its susceptibility to oxidation, which can cause the fuel to become acidic and to form insoluble gums and sediments that can plug fuel filters. This is due to the unsaturated fatty acid chains and the presence of the double bond in the molecule, which produce a high level of reactivity with the oxygen, especially when it placed in contact with air. The oxidation of fatty acid chains is a complex process that proceeds by a variety of mechanisms. The various other factors influence the oxidation process of biodiesel includes light, temperature, extraneous materials, peroxides, size of the surface area between biodiesel and air. One of the methods of improving biodiesel oxidative stability includes the deliberate addition of antioxidants or modification of the fatty ester profile. This article discusses the technical aspects of biodiesel and its oxidation stability.Item Comparison of performance of biodiesels of mahua oil and gingili oil in dual fuel engine(Serbian Society of Heat Transfer Engineers, 2008) Nadar, K.N.; Reddy, R.P.; Anjuri, E.R.In this work, an experimental work was carried out to compare the performance of biodiesels made from non edible mahua oil and edible gingili oil in dual fuel engine. A single cylinder diesel engine was modified to work in dual fuel mode and liquefied petroleum gas was used as primary fuel. Biodiesel was prepared by transesterification process and mahua oil methyl ester (MOME) and gingili oil methyl ester (GOME) were used as pilot fuels. The viscosity of MOME is slightly higher than GOME. The dualfuel engine runs smoothly with MOME and GOME. The test results show that the performance of the MOME is close to GOME, at the pilot fuel quantity of 0.45 kg/h and at the advanced injection timing of 30 deg bTDC. Also it is observed that the smoke, carbon monoxide and unburnt hydro carbon emissions of GOME lower than the MOME. But the GOME results in slightly higher NOx emissions. From the experimental results it is concluded that the biodiesel made from mahua oil can be used as a substitute for diesel in dual fuel engine.Item Methyl esters of Mahua oil as an ecofriendly fuel in heavy duty vehicles(Chemical Publishing Co., 2008) Kapilan, N.; Krishna; Reddy, R.P.In this investigation, Mahua oil methyl ester (MOME) was prepared by transesterfication using potassium hydroxide. According to the ASTM procedure, several tests were conducted to characterize mahua oil in relation to diesel oil. Various physical, chemical and thermal properties such as viscosity, flash point, fire point and calorific value were evaluated. From the analysis, it was observed that the properties of mahua oil methyl ester are close to diesel oil. To evaluate the mahua oil methyl ester as a fuel for diesel engine and dual engine, it was used as a fuel in a single cylinder, four stroke, direct injection, constant speed, compression ignition diesel engine and dual fuel engine. From the experimental results, it was observed that the mahua oil methyl ester result in performance and emissions close to diesel operation.Item Combustion and emission characteristics of a dual fuel engine operated with mahua oil and liquefied petroleum gas(Serbian Society of Heat Transfer Engineers, 2008) Nadar, K.N.; Reddy, R.P.For the present work, a single cylinder diesel engine was modified to work in dual fuel mode. To study the feasibility of using methyl ester of mahua oil as pilot fuel, it was used as pilot fuel and liquefied petroleum gas was used as primary fuel. In dual fuel mode, pilot fuel quantity and injector opening pressure are the few variables, which affect the performance and emission of dual fuel engine. Hence, in the present work pilot fuel quantity and injector opening pressure were varied. From the test results, it was observed that the pilot fuel quantity of 5 mg per cycle and injector opening pressure of 200 bar results in higher brake thermal efficiency. Also the exhaust emissions such as smoke, unburnt hydrocarbon and carbon monoxide are lower than other pressures and pilot fuel quantities. The higher injection pressure and proper pilot fuel quantity might have resulted in better atomization, penetration of methyl ester of mahua oil and better combustion of fuel.Item Evaluation of methyl esters of mahua oil (mahua indica) as diesel fuel(2008) Kapilan, N.; Reddy, R.P.There is increasing interest in India for suitable alternative fuels that are environment friendly. This search has led to mahua oil (MO) as one alternative for diesel fuel in India. Mahua oil methyl esters (MOME) were prepared by transesterification using potassium hydroxide (KOH) as catalyst and nuclear magnetic resonance (NMR) testing was done to determine the conversion of vegetable oil to biodiesel (MOME). The properties of MOME were close to those of diesel oil. Engine testing was conducted using a single-cylinder 4-stroke direct-injection, constant-speed compression-ignition diesel engine using MO, MOME and B20 as fuels. The engine ran smoothly with MOME and B20, but heavy smoke emissions were observed when MO was used as fuel. © 2007 AOCS.Item Experimental investigation of esters of mahua oil as an alternative fuel for dual fuel engine(2008) Reddy, P.B.; Kapilan, N.; Reddy, R.P.In the present work, an attempt was made to use methyl ester of mahua oil (MEMO) as substitute for dieselin dual fuel engine. A four stroke single cylinder engine was modified to work in dual fuel mode. From the test results, it was observed that the MEMO could be used as pilot fuel in dual fuel engine. At lower loads, diesel gave higher brake thermal efficiency. But at higher loads, biodiesel resulted in brake thermal efficiency comparable with diesel and lower smoke and oxides of nitrogen emissions. From the test results, it was concluded that MEMO could be used as a substitute for diesel in dual fuel engine.Item 6 CTA 8.3 G1-1 Cummins engine performance & exhaust emission tests using methyl ester Mahua oil and diesel fuel blends(2008) Godiganur, S.; Reddy, R.P.; Murthy, C.H.S.A Cummins 6 CTA 8.3G1-1 turbocharged DI diesel engine was fueled with blends of esters of Mahua oil and the performance and emissions were compared with diesel. The neat biodiesel, 10%, 20%, 40%, 60%, 80%, and base fuel were tested at constant load (28% of rated load) and at constant speed of 1500 rpm. This experiment is conducted on D.G Set, used to supply power to mining equipments in MSPL Iron Ore Company Hospet. Dist. Bellary. The objective of this study was to evaluate the impact of various blends of biodiesel on engine performance and emissions. Neat Mahua oil poses some problems when subjected to prolonged usage in CI engine. These problems can be reduced to minimum by subjecting the Mahua oil to the process of transesterification. Various properties of the biodiesel thus developed are evaluated and compared in relation to that of conventional diesel oil. Copyright © Enviromedia.Item Evaluation of properties and storage stability of Madhuca indica biodiesel(Japan Oil Chemists Society yukagaku@jocs-office.or.jp, 2009) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.Mahua Oil (MO) is an underutilized non-edible vegetable oil, which is available in large quantities in India. In the present work, biodiesel was derived from the MO by the transesterification process. The fuel properties of the MO biodiesel were found to be within the limits of biodiesel specifications of many countries. The chemical nature of biodiesel makes it more susceptible to oxidation during long-term storage which leads to degradation of fuel properties that can compromise fuel quality. The effect of long storage condition on the stability of the MO biodiesel was studied in the present work. The biodiesel samples were stored in plastic containers at room temperature. The study was conducted for a period of 12 months and the test sample was kept in the darkness. From the experimental results, it was observed that the acid value and viscosity increases with the storage time, but the iodine value decreased with increasing storage time. This is due to the presence of the double bond in the molecule of the biodiesel which produce a high level of reactivity. This high level reactivity produces formation of hydroperoxides, soluble polymers and other secondary products. From the experimental results, a slight difference in the acid value, iodine value and viscosity of the MO biodiesel stored for a period of 30 days was observed. But after this period, the differences were significant. © 2009 by Japan Oil Chemists' Society.Item Studies on exhaust emissions of mahua oil operated compression ignition engine(2009) Kapilan, N.; Reddy, R.P.The world is confronted with fossil fuel depletion and environmental degradation. The energy demand and pollution problems lead to research for an alternative renewable energy sources. Vegetable oils and biodiesel present a very promising alternative fuel to diesel. In this work, an experimental work was carried out to study the feasibility of using raw mahua oil (MO) as a substitute for diesel in dual fuel engine. A single cylinder diesel engine was modified to work in dual fuel mode and liquefied petroleum gas (LPG) was used as primary fuel and mahua oil was used as pilot fuel. The results show that the performance of the dual fuel engine at the injector opening pressure of 220 bar and the advanced injection timing of 30°bTDC results in performance close to diesel base line (DBL) operation and lower smoke and oxides of nitrogen emission.Item 6BTA 5.9 G2-1 Cummins engine performance and emission tests using methyl ester mahua (Madhuca indica) oil/diesel blends(2009) Godiganur, S.; Suryanarayana Murthy, C.H.; Reddy, R.P.Neat mahua oil poses some problems when subjected to prolonged usage in CI engine. The transesterification of mahua oil can reduce these problems. The use of biodiesel fuel as substitute for conventional petroleum fuel in heavy-duty diesel engine is receiving an increasing amount of attention. This interest is based on the properties of bio-diesel including the fact that it is produced from a renewable resource, its biodegradability and potential to exhaust emissions. A Cummins 6BTA 5.9 G2- 1, 158 HP rated power, turbocharged, DI, water cooled diesel engine was run on diesel, methyl ester of mahua oil and its blends at constant speed of 1500 rpm under variable load conditions. The volumetric blending ratios of biodiesel with conventional diesel fuel were set at 0, 20, 40, 60, and 100. Engine performance (brake specific fuel consumption, brake specific energy consumption, thermal efficiency and exhaust gas temperature) and emissions (CO, HC and NOx) were measured to evaluate and compute the behavior of the diesel engine running on biodiesel. The results indicate that with the increase of biodiesel in the blends CO, HC reduces significantly, fuel consumption and NOx emission of biodiesel increases slightly compared with diesel. Brake specific energy consumption decreases and thermal efficiency of engine slightly increases when operating on 20% biodiesel than that operating on diesel. © 2008 Elsevier Ltd. All rights reserved.