Performance & Emission Analysis of blends of Karanja Methyl Ester in a Compression Ignition Engine

This is to certify that the work in this thesis report entitled "Performance and Emission Analysis of Mixtures of Karanja Methyl Ester in a Compression Ignition Engine" has been submitted by Saswat Rath in partial fulfillment of the requirements for the degree of Bachelor of Technology in Chemical Engineering , Session in the department of Chemical Engineering, National Institute of Technology, Rourkela, is an authentic work carried out by him under my supervision and guidance. Singh for introducing me to the topic and providing me with guidance, motivation and constructive criticism throughout the course of the project. Biswal, Head of Department, Chemical Engineering for providing the necessary opportunities for the completion of my project.

In the face of the coming energy crisis, vegetable oils have emerged as a promising fuel source. Many vegetable oils have been investigated in the compression ignition engine by fuel modification or engine modification. Vegetable oils have very high density and viscosity, so we used methyl ester of the oil to overcome these problems.

But limited supplies of fossil fuels are a major concern due to the rapid depletion of supplies due to the increase in global demand. In 1911 he stated 'the diesel engine can be fueled with vegetable oils and would contribute considerably to the development of agriculture in the countries which use it' [1]. Vegetable oils from crops such as soybean, peanut, sunflower, rapeseed, coconut, karanja, neem, cotton, mustard, jatropha, linseed, and castor have been evaluated in many parts of the world.

LITERATURE REVIEW

Engines
Need for Oil Treatment/Conversion
Biodiesel Production
Production Process

Mixing of alcohol and catalyst
Separation
Alcohol Removal
Glycerine Neutralization
Methyl Ester Wash
Product Quality

A fuel with a high energy content per gallon, such as diesel, should be able to react with most of the concentrated oxygen to provide more power per explosion if injected into the engine's cylinders at exactly the right time. As a result, although diesel engines have seen great improvements, the basic concept of the four-stroke diesel engine has remained virtually unchanged for over 100 years. Due to the relatively high viscosity of SVO, it leads to poor fuel atomization, incomplete combustion, fuel injector coking, ring carbonization, and fuel accumulation in the lube oil.

The best method to solve these problems is transesterification of the oil to produce biodiesel. The transesterification process is the reaction of a triglyceride (fat/oil) with an alcohol to form esters and glycerol. The properties of the fat are determined by the nature of the fatty acids attached to the glycerol.

The nature of the fatty acids can in turn influence the properties of the biodiesel. A common product of the transesterification process is the Oil Methyl Ester (OME) which is produced from crude oil reacted with methanol. The reaction between the fat or oil and the alcohol is a reversible reaction and so the alcohol must be added in excess to drive the reaction to the right and ensure complete conversion.

A successful transesterification reaction is indicated by the separation of the ester and glycerol layers after the reaction time. The reaction mixture is maintained just above the boiling point of the alcohol (around 160°F) to speed up the reaction and the reaction proceeds. An excess of alcohol is usually used to ensure complete conversion of the fat or oil to its esters.

Care must be taken to monitor the amount of water and free fatty acids in the incoming oil or fat. If the free fatty acid level or water level is too high, it can cause problems with soap formation and the separation of the glycerine byproduct downstream. The glycerin is much denser than biodiesel and the two can be separated by gravity with glycerin simply drawn off the bottom of the settling tank.

This is usually the end of the production process, resulting in a clear amber liquid with a viscosity similar to mineral diesel.

Figure 1 – Biodiesel Production Process Flowchart

MATERIALS & METHODS

MATERIALS AND METHODS

Since the viscosity of karanja oil is higher than that of diesel fuel, it is necessary to use a viscosity reduction technique to evaluate performance and emissions in a diesel engine. This process produces a uniform quality of the alkyl esters, reduces the viscosity and increases the cetane number [10]. If free fatty acids are present, they can be removed or converted into biodiesel using special pretreatment technologies.

Esterification is the reaction of an acid with an alcohol in the presence of a catalyst to form an ester. Transesterification, on the other hand, is the displacement of the alcohol from an ester by another alcohol in a process similar to hydrolysis, except that an alcohol is used instead of water. In the case of esterification processes, the karanja oil is preheated at different temperatures and then the solution of sulfuric acid and methanol is added to the oil and stirred continuously at different temperatures.

The physical properties of the Karanja methyl ester are compared with diesel fuel and are given in Table 2.

Table 1 - Fatty and unsaturated acids in karanja oil [11]

EXPERIMENTAL SETUP

The air supply was measured with an air flow sensor installed in the air box. Emissions such as unburnt hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NO) were measured with an AVL 444 exhaust gas analyzer. Combustion diagnosis was performed with a Kistler quartz piezoelectric pressure transducer (model type 5395A), mounted on the cylinder head in the standard position.

Combustion parameters such as mechanical efficiency, brake thermal efficiency, brake specific fuel consumption, ignition delay and maximum heat release rate, and emission parameters such as exhaust gas concentrations and temperature were evaluated. The engine performance test was performed twice for all blends except KME100, averaged, and emission readings were taken three times and averaged.

RESULTS & DISCUSSION

Performance Parameters

Brake Thermal Efficiency (BTE)
Brake Specific Energy Consumption (BSEC)
Exhaust Gas temperature (EGT)
Mechanical Efficiency

Emission Parameters

Nitric Oxide (NO)
Carbon Monoxide (CO)
Carbon Dioxide (CO 2 )
Hydrocarbons (HC)

The higher thermal efficiency may be due to the additional lubrication provided by the fuel. When two different fuels with different heating values are mixed together, the fuel consumption may be unreliable, since the heating value and density of the two fuels are different. Specific brake energy consumption was determined for caranja methyl ester-diesel fuel blends as the product of specific fuel consumption and calorific value.

The availability of oxygen in the karanja methyl ester diesel fuel blend may be the reason for the lower BSEC. An engine's exhaust gas temperature is an indication of the conversion of heat into work. In the case of karanja methyl ester diesel fuel blends, the heat release may occur in the later part of the power stroke.

Most (about 90%) of the nitrogen in the exhaust is in the form of nitric oxide. The slower burning character of the fuel causes a slight delay in power release, which results in higher temperature in the later part of the power stroke and exhaust stroke. At higher loads, more fuel is burned and the higher exhaust gas temperature results in higher nitric oxide production.

This can be attributed to the higher viscosity of the fuel, which results in poor atomization and incomplete combustion of the fuel. At a higher load, more fuel is consumed, resulting in a relatively lower availability of oxygen for fuel combustion, resulting in a slightly higher amount of carbon monoxide. Since the calorific value of the fuel is low, more fuel must be burned to obtain the equivalent power output.

Hydrocarbons in exhaust gases are the result of incomplete combustion of the carbon compounds in the fuel. But as load increases, fuel consumption increases, resulting in a relative reduction of oxygen in the fuel-air mixture and higher exhaust emissions compared to diesel.

Figure 4 shows the variation of the brake specific energy consumption with load. When two different fuels of different heating values are blended together, the fuel consumption may not be reliable, since the heating value and density of the two fuels are

CONCLUSIONS

Karanja methyl ester appears to have a potential to be used as an alternative fuel in diesel engines. The thermal braking efficiency of the engine with the caranja methyl ester-diesel mixture was slightly better than with the pure diesel fuel. Brake specific energy consumption is lower for methyl ester-kerosene blends than diesel over full load.

It was found that the exhaust gas temperature increases with the concentration of methyl ester carbonation in the fuel mixture due to the formation of coarse atomized fuel and delayed combustion. The emission characteristics are higher than that of pure diesel, but KME30 has relatively better performance compared to other blends. 2] Vijaya Raju N, Amba Prasad Rao G and Ramamohan P, Esterified jatropha oil as a fuel in diesel engines, J.

6] http://www1.eere.energy.gov/vehiclesandfuels/pdfs/basics/jtb_diesel_engine.pdf [7] http://en.wikipedia.org/wiki/Biodiesel_production. 9] Sahoo P.K, Das L.M., Combustion analysis of Jatropha, Karanja and Polanga based biodiesel as fuel in a diesel engine, Fuel s. 13]Raheman H., Phadatare A.G., Diesel engine emissions and performance from blends of karanja methyl ester and diesel , Biomasse og Bioenergi pp.

14] Bajpai S, Das L.M., Feasibility of using Fatty Acid Ethyl Esters-Diesel Blends as a reaction to Fatty Acid Methyl Esters Blends-Diesel, Proceedings of the 7th International Conference of Biofuels organized by Winrock international (2010) : p. 15 ] Prakash R., Singh R.K., Murugan S., Performance and emission studies in a diesel engine using bio oil-diesel blends, Second International Conference on Environmental Science &. Karanja (Pongamia Pinnata) biodiesel production in Bangladesh, Characterization of karanja biodiesel and its effect on diesel emissions.

18] Banapurmatha N.R., Tewaria P.G., Hosmathb R.S., Experimental investigations of a four stroke single cylinder direct injection diesel engine operated on dual fuel mode with producer gas as induced fuel and honge oil and its methyl ester (HOME) as injected fuels, Renewable Energy p. 19] Sahoo P.K., Das L.M., Babu M.K.G., Arora P., Singh V.P., Kumar N.R., Varyani T.S., Comparative evaluation of performance and emission characteristics of jatropha, karanja and polanga based biodiesel, fuel in a tractor engine, pp.

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