Keywords: Jatropha oil, Taguchi Method, S/N Ratio, emmision.

Transcription

1 Feasibility Study of different Blends of Biodiesel in Diesel Engine and Optimization of Engine parameters using Taguchi Method - A Case Study for implementation of Biodiesel in Oil India Limited. (By: D K Singha, N J Neog, N Das & A Gogoi, ) Field Engg Deptt, Oil India Limited, Duliajan. Abstract Diesel engines are the most popular and efficient prime movers used in today s industries. It becomes imperative from the point of view of using green energy in diesel engines to reduce the dependency on fossil fuels and also protecting the global environment. So, it is necessary to develop and use alternative fuels with properties comparable to conventional diesel oil. In this paper the author performs a feasibility study on the performance of Single Cylinder diesel engine (Kirloskar, TA-) fueled with blends of Jatropha oil and Diesel at different proportions. The engine parameters such as Brake Power, Engine speed, Brake specific fuel consumption (BSFC), Brake thermal efficiency (BTE), NOx emission, CO emission and Hydrocarbon (HC) emission is taken as output responses. In this study for optimizing the engine parameters Design of Experiment (Taguchi Method) is used. It is found that the Specific fuel consumption is lower than diesel for various blends of Jatropha Oil. The CO emission and HC emission decreases with increase in jatropha oil blends. However, a slight increase in NOx is observed with increase in percentage of jatropha oil blends. Keywords: Jatropha oil, Taguchi Method, S/N Ratio, emmision. Introduction: Various types of renewable energies like solar, wind, hydro, bio-fuel etc are getting popular world wide. As conventional fuels are depleting day by day and the increasing industrialization and motorization in the world has led to a steep rise on the demand of petroleum based fuels. This has led to the need of an alternative fuels for the existing engines. The basic quality of alternative fuel is renewable, eco-friendly and can be used in existing engines without modification. Alternative fuel like biodiesel can be used in standard diesel engines and is thus distinct from the vegetable and waste oils used to fuel modified diesel engines. Unlike the rest of the world, India s demand for diesel fuels is roughly six times that of gasoline, hence seeking alternative to mineral diesel is a natural choice (Barnwal et al., 005). Usage of biodiesel will allow a balance to be sought between agriculture, economic development and the environment (Altõn, 998). Jatropha curcas is non-edible oil being singled out for large-scale for plantation on wastelands and it can be used as a biodiesel. The production of Jatropha seeds is about 0.8 kg per square meter per year. The oil content of Jatropha seed ranges from 0% to 0% by weight. Fresh Jatropha oil is slow drying, odorless and colorless oil, but it turns yellow after aging (Sarin et al., 007). Forson et al. (00) used Jatropha oil and diesel blends in CI engines and found its performance and emissions characteristics similar to that of mineral diesel at low concentration of Jatropha oil in blends. Pramanik (00) tried to reduce viscosity of Jatropha oil by heating it and also blending it with mineral diesel. Studies on using biodiesel as fuel in diesel engines have shown greater reduction in emissions of hydrocarbons, smoke, particulate matter, oxides of sulphur and carbon and polyaromatics as compared to diesel (Graboski & McCormick, 997, Wang et al., 000, Agarwal & Das, 00, Kalligeros et al., 00,Ramadass et al., 005; Hanumantha Rao et al., 009;Hariharan et al., 009). The present study is aimed at exploring technical feasibility of blends of Jatropha Biodiesel in diesel engine without any modification of the engine. Fig shows the world wide production trend of Biodiesel.

2 Fig World wide production Biodiesel Feedstock for Biodiesel in India Under Indian condition only such oil bearing plant sources can be considered for biodiesel production which is not edible, available in appreciable quantity and which can be grown on largescale on wastelands. Why Jatropha is used as biodiesel in India According to the Economic Survey (995-96), Govt of India, of the cultivable land area about million hectares are classified as waste or degraded land Jatropha (Jatropha curcas, Ratanjyot, wild castor) thrives on any type of soil. Its important characteristics like: Needs minimum inputs or management Has no insect, pests attack & not browsed by cattle or sheep Can survive long periods of drought Propagation is easy Yield from the rd year onwards and continues up to 5-0 years 5% oil from seeds by expelling; 0% by solvent extraction The meal after extraction excellent organic manure (8% protein, N:P:K ratio.7:.:) Objective In Oil India Limited diesel engines used as an important primemover for gen-set and pump-set applications for captive power generation and CODP s for its wide spread operational areas. More than 80 engines small and big run on diesel fuel. Out of which approximately 5 engines are used for pumpset application for CODP, water injection and potable water supply for domestic and nearby field installations. The annual diesel consumption is very high. It is estimated that % reduction in annual consumption in diesel in India may lead to 5000 Crore reduction in import bill. Therefore, to reduce the dependency on fossil fuels and also protecting the global environment it is necessary to introduce alternative fuels with properties comparable to conventional diesel oil.

3 Literature Review Extensive research in the field of alternative fuels specifically biodiesel has led to a better understanding of the possibilities of using it in diesel engines. According to K Pramanik [] acceptable brake thermal efficiencies and SFCs were achieved with blends containing up to 50% Jatropha oil. Blends with a lower percentage of vegetable oils showed slightly higher gas temperature when compared to an engine running with diesel but they were much lower than the jatropha curcas oil in all cases. Blends with a lower percentage of vegetable oils showed slightly higher gas temperature. From the engine, test results it was recommended that up to 50 percent jatropha oil can be substituted for diesel for use in a CI engines. Chaturvedi S [] found that Blends containing 0 to 0 percent jatropha oil had their kinematic viscosity and relative density comparable with diesel but ash content, total acidity and carbon residue content more than those of diesel. Moreover, M. Pugazhvadivu et al [] determine the engine performance and emission characteristics. The engine NO X emission was noted to be higher than the diesel fuel operation with all blends. The addition of diethyl ether to the blends reduced the NO X emission at low and medium loads. Hanumantha Rao et al [] B5 have closer performance to diesel and B00 had lower brake thermal efficiency mainly due to its high viscosity compared to diesel. For Jatropha biodiesel and its blended fuels, the exhaust gas temperature increased with increase in power and amount of biodiesel. Niraj Kumar et al [5] studied the environmental benefits of biodiesel in terms of reductions in the emission of greenhouse gases, and reduction of other pollutants e.g. acid rain, photochemical smog etc. The major pollutants from diesel engine are smoke, particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx) and unburnt hydrocarbon (UBHC) Raja et al [6]. Studies have shown that the high viscosity of vegetable oils and the low volatility affect the atomization and spray pattern of fuel, leading to incomplete combustion and severe carbon deposits, injector choking and piston ring sticking. Various methods like blending with diesel, emulsification, pyrolysis and transesterification are used to reduce the viscosity. Among these, the transesterification is the commonly used commercial process to produce clean and environmental friendly fuel.. Experimental set-up A series of experiments were conducted to study the effects of various operating parameters on the engine output. Studies have been undertaken to investigate the effects of important parameters viz. Fuel type (diesel and various blends), Brake load on Brake power kw, Engine speed RPM, CO emission, percentage HC emission, Brake specific fuel consumption Kg-kW/h, Brake thermal efficiency percentage and NOx emission, ppm The test was conducted on Kirloskar TA-, single cylinder engine. Selection of operating parameters Each parameters having diferent effect on the engine performance. So, it is necessary to identify which parameters have considerable effect on the engine output. Therefore, this is the aim of the study to identify and to achieve optimal setting for various responses characteristic and the important parameters among the various parameters using design of experiment. Selection of Basic Level The various parameters along with their range is shown in Table. Factor levels correspond to the best condition is determined from analysis of the prior information and literature. Sl No Factors Parameter Level Level Level Level Desig Fuel Type F Diesel (F) 5 % Jatropha Ethyl Ester + 95% Diesel (F) Brake load (% of rated load) 0% Jatropha Ethyl Ester + 90% Diesel (F) 0% Jatropha Ethyl Ester + 80% Diesel (F) L 0% (L) 0% (L) 60% (L) 00% (L) Table : Parameters & Levels

4 Engine specification: Make Kirloskar Model TA Rated Brake Power (BHP) 5 Number of Cylinder Rated Speed 500 Bore X Stroke (mm) 87.5 x 0 Compression Ratio 6.5: Cooling System Air Cooled Lubrication System Forced Lubrication Table : Engine Specification Fig Experimental set-up Taguchi method Engineers and scientists are most often faced with two product or process development situations. One process development situation is to find a parameter that will improve some performance to an acceptable or optimum value. A second situation is to find a less expensive, alternative design, material or method, which will provide equivalent performances. For this, A Person typically conducts experiment observes some performance of the product and make a decision to use or not to use the design. Experimental design is considered to be a very useful strategy for accomplishing these tasks. To design an experiment is to select the most suitable OA and to assign the parameters and interactions of interest to the appropriate columns. In the Taguchi method the results of the experiments are analyzed to achieve one or more of the following objectives.. To establish the best or the optimum condition for a product or process.. To estimate the contribution of individual parameters and interactions.. To estimate the response under the optimum condition. The optimum condition is identified by studying the main effects of each of the parameters. The main effect indicates the general trend of influence of each parameter. The analysis of variance (ANOVA) is the statistical procedure to analyze data. It is applied to the results of the experiments in determining the percent contribution of each parameter against a stated level of confidence. Study of ANOVA table for a given analysis helps us to determine which of the parameters need control and which do not. The S/N ratio is a concurrent quality metric linked to the loss function. By maximizing the S/N ratio, the loss associated can be minimized. The S/N ratio is treated as a response (transform of raw data) of the experiment.

5 Signal-to-Noise (S/N) Ratio The loss function discussed above is an effective figure of merit for making engineering design decisions. However, to establish an appropriate loss function with its k value to use as a figure of merit is not always cost effective and easy. Therefore, Taguchi created a transform for the loss function which is named as the signal-tonoise (S/N) ratio. The S/N Ratio is a concurrent statistic. A concurrent statistic is able to look at two characteristic of a distribution and roll these characteristic into a single number or figure of merit. The S/N ratio combines both the parameters (the mean level of the quality characteristic and variance around this mean) into a single metric. A high value of S/N implies that the signal is much higher than the random effects of noise factors. Process operation consistent with highest S/N, always yields optimum quality with minimum variation. OA Selection and Assignment of Factors For selecting a particular OA for an experiment two items must be first established. These are: i) The number of parameters and interactions of interest. ii) Number of levels for the parameters of interest. The OA selected must satisfy the following inequality: Total DOF of the OA Total DOF Required for the experiment. Since Two parameters are selected for the study and each factor have four levels, the DOF for each parameter is ( - ) =. So, the total degree of freedom required will be 6 = x Thus, most appropriate array in this case is L 6 ( 5 series) with 5 = (6 - ) DOF and has been selected for experimentation.. Results and Discussion The data obtained from the experiments have been analysed. The main effects i.e. the effect of operating parameters on response characteristics are plotted accordingly. The Response Curves (Brake power, Engine speed, BSFE, BTE, NO emission, NOX emission, CO emission & HC emission) are the average value of quality characteristicsand average S/N values versus levels of operating parameters. Effect on Brake power BRAKE POWER KW BRAKE POWER Signal-to-noise: Larger is better.0 Fig. : Plot for Main effect for Means: Brake Power Fig. : Plot for Main Effects for S/N Ratios: Brake Power Analysis of Variance To establish the relative significance of the individual process, ANOVA has been performed on raw data which gives the values of MSV, F-ratio and P%. It is found from Fig and Fig. that the influence of brake load is more on brake power compared to other fuel type. Therefore, it can be concluded that jatropha blends JEE 0 derives slightly higher brake power compared to other fuel types.

6 Effect on Engine Speed ENGINE SPEED ENGINE SPEED Signal-to-noise: Larger is better Fig. 5: Plot for Main effect for Means: Engine Speed Fig. 6: Plot for Main Effects for S/N Ratios: Engine Speed From Fig. 5 & Fig 6 it is clear that the brake load has got significant effect on engine speed as compared to type of fuels though there may be a slight decrease in engine speed with increasing percentage of jatropha oil blends in diesel. Effect on Brake Specific Fuel Consumption (BSFC) BSFC 0.5 BSFC Signal-to-noise: Smaller is better Fig. 7: Plot for Main effect for Means: BSFC Fig. 8: Plot for Main Effects for S/N Ratios: BSFC From Fig 7 & Fig 8 it can be concluded that brake load has got larger significance as compared to fuel type on BSFC. However, a decrease in BSFC is observed with the increase in the percentage of jatropha oil in diesel.

7 Effect on Brake Thermal Eficiency(BTE) BTE 0 5 BTE 6 5 Signal-to-noise: Larger is better Fig. 9: Plot for Main effect for Means: BTE Fig. 0: Plot for Main Effects for S/N Ratios: BTE From Fig. 9 & Fig 0 it can be concluded that the fuel type has got marginal significance on BTE. Effect on Nitrogen Oxides( NO) NO EMISSION NO EMISSION Signal-to-noise: Smaller is better Fig. : Plot for Main effect for Means: NO Fig. : Plot for Main Effects for S/N Ratios: NO From fig and Fig it is clear that NO emission is more dependent on brake load compared to fuel type. However, a slight increase in NO is observed with the increased percentage of jatropha oil in diesel. This is due to the increase in oxygen with the increasing percentage of jatropha oil. The availability of oxygen initiates oxidisation of nitrogen thereby forming Nox

8 Effect on Carbon Monoxide(CO) 0.00 CO EMISSION CO EMISSION Signal-to-noise: Smaller is better Fig. : Plot for Main effect for Means: CO Fig. : Plot for Main effect for S/N Ratios: CO From Fig and Fig it is observed that CO emission decreases with the increase in percentage of jatropha oil in diesel. The available oxygen in jatropha oil (being vegetative) assures better combustion of the fuel mixture thereby reduces CO emission. However, CO emission will progressively increase with the increase in load irrespective of the fuel being used. Effect on Hydro Carbon(HC) HC EMISSION HC EMISSION Signal-to-noise: Smaller is better Fig. 5: Plot for Main effect for Means: HC Fig. 6: Plot for Main effect for S/N Ratios: HC From Fig 5 and Fig 6 it is observed that HC emission decreases with the increase in percentage of jatropha oil in diesel. The available oxygen in jatropha oil (being vegetative) assures better combustion of the fuel mixture thereby reduces HC emission. However, HC emission will progressively increase with the increase in load irrespective of the fuel being used.. Conclution In this work the various output responses of the diesel engine was studied with reference to the selected operating parameters of the engine. It is found that all the ester blends were compatible with diesel engine. The performance of a.7 kw constant speed diesel engine during the fuel consumption test on blended fuels containing 5 to 0 percent jatropha in respect of brake power, BFSC, brake thermal efficiency and emission of CO, HC, and NOx was found comparable with diesel. Results indicated that JEE0 have closer performance to diesel. Moreover, the emission characteristic of JEE0 is better compared to other chosen parameters. Other blends like JEE5, JEE0 may also be recommended for CI engines in Oil India Limited.

9 References Pramanik, K. (00), 'Properties and use of jatropha curcas oil and diesel fuel blends in compression ignitionengine', Renewable Energy 8(), Chaturvedi Sandeep, Bio-diesel: Indian scenario. Paper presented at International Conference on Biofuels, New Delhi, Sept. 6-7, 00.. Investigations on a diesel engine fuelled with biodiesel blends and diethyl ether as an additive M. Pugazhvadivu and S. Rajagopan Dept. of Mechanical Engineering, Dept. of Chemistry, pondicherry Engineering College, Puducherry, India Indian Journal of Science and Technology Vol. No 5 (May 009). Experimental investigations on jatropha biodiesel and additive in diesel engine Y.V.Hanumantha Rao, Ram Sudheer Voleti, A.V.Sitarama Raju and P.Nageswara Reddy Indian Journal of Science and Technology Vol. No (Apr. 009) 5. Biodiesel as an alternative fuel for CI engines: environmental effect Niraj Kumar, Varun and Anoop Kumar Indian Journal of Science and Technology Vol. No. 5 (May 00) 6. Standardization of Jatropha Oil Ethyl Esterification Process Parameters and Evaluation of a CI Engine on Esterified Fuel by K Kundu.