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Importance and significance Complete dependence on HC fuel which is formed over millions of years for conversion of chemical to mechanical energy with increase of energy conversion devices led to over exploitation of these fuels.Oil peak has surpassed hence fuel prices have expected to increase as resources dwindle giving worst economical impact on world economy specially on developing countries like India, Srilanka and Bangladesh etcDue to instant use of HC fuels in couple of centuries has raised environmental impact creating air pollution and drastic changes of weather pattern due to large amount of Co2 by combustion of fuels. Above twin challenge of both impacts need immediate attention towards ensuring safe , healthy and prosperous environment for future.

OBJECTIVES:Study the effect of cooling and cleaning systems on tar reduction and gas quality for dual fuel diesel engines fueled with producer gas derived from coconut shell ,Bio diesel (ROME)and H2 gas mixtures adopted for stationary power generation application.Synthesis of alternate fuel (Bio diesel) from Non edible oil required for dual fuel engine operation.Evaluation of temperature, pressure drop and retention time of raw gases with selection of optimum parameters across cooling and cleaning systems for improvement in gas quality.Study of tar reduction techniques for removal of tar from raw producer gas which is to be used for operation of Duel fuelled diesel engine.Evaluation on Performance of engines and exhaust emission characteristics .

Indian Energy scenario :India is 4th largest energy consumer in world after U.S, China and Russia , energy consumption is still increasing due to population growth and economic development.Biomass has been main energy source for thousand of years and still today it contributes in the range of more than 14% to world energy supply ,38% of energy in developing countries of Asia ,Africa and ranks as 4th source of energy in the world.Biomass contributes over 4rd of primary energy and delivers most energy for domestic use (Rural 90% and Urban -40%) in India (NCAER,2012)

Biomass has been recognized as an ideal energy resource for Decentralized energy system and in tropical countries biomass grows more productively which can be converted into energy carriers such as gaseous ,liquid fuels and electricity that can be used in more affluent society.Modern Biomass Technologies in India:Gasifier technologies has penetrated the applications such as village electrification, captive power generation .Over 1600 gasifier systems, having 16MW total capacity have generated 42 million KWh of electricity replacing 8.8 million liters of oil annually (CMIE, 1996).Four Gasifier Action Research centers) ARCs tie up with national institutes and supported by MNES have developed 12 gasifiers models ranging from 3.5 to 100 KW specially for the rural purpose for water pumps and refrigeration .

Biomass clean energy source:Biomass is one of the most plentiful organic materials on earth which is produced by photosynthesis reaction in green plant in the presence of sunlight . It stores solar energy in its chemical bonds as chemical energy which can be further evolved by breaking down of bonds by thermo chemical conversions to release the stored energy.

Biomass takes carbon out of atmosphere while it is growing and returns it as it is burned.Main biomass sources are

Solar EnergyPhotosynthesisBiomass

Energy Generation

Utilization of biomass resource:

Harnessing of energy from biomass via gasification route is proven economical and environmentally benign (Mukunda et al, 1993)

Coconut shell Biomass:Global coconut production has been growing steadily in recent decades , india stands at 3rd place among top world leaders in coconut production.Coconuts are permanent crops and are available through out the year , so there will be constant supply through out year.Once coconuts are harvested , main products are seperated and processed such as coir, milk etc but coconut shells are being thrown.Taking into consideration that approximately 15 % of coconut consists of shell , total quantity of coconut shell is around 9.3 Mt/yr with calorific value of 5500 kCal/kg this can replace 6.9 Mt/yr of coal.Due to presence of porosity , surface area for reaction is high and diffusion of reactant would be easy which results in uniform temperature distribution.

Non edible oil:Non edible oil from plant seeds has long chain saturated, unbranched HC is the most promising alternative fuel for CI engine(Murugesan .A et al,2009 ) because it is:1.Renewable , environment friendly , non toxic & biodegradable with low emission profile.2. It has no sulphur content and aromatics3. It poses some problems when directly used as substitute for engine due to large molecular mass ,chemical structure of oil, higher viscosity , low volitility and unstaturated character of oil (Murugesan .A et al,2009 ).It can chemically modified to biodiesel (liquid HC fuel composed of fatty acids monohydric alcohol esters) ( Alessandro Schondorn et al,2009)

Problems faced by non edible oils:Presence of fatty acids greatly affects the properties of bio diesel , the different fatty acids such as palmic ,steric , lignoceric and linoleic etc these components greatly affects viscosity of oil .Increase of viscosity reduces fuel atomization , increase fuel penetration as a result partial engine deposites, piston rings sticking, injector coking and thicking of oil.

Remedy :Viscosity of oil can be reduced by dilution,transestrification ,Pyrolysis (thermal cracking) and micro emulsification.

Producer gas:Producer gas fuel has thermo-physical properties which are different from conventional fuels.Producer gas is a mixture of combustible (Hydrogen, Methane and Carbon Monoxide) and non combustible (Nitrogen, Carbon dioxide) gases.It is produced by gasification(Thermo-Chemical conversion) of carbonaceous material such as coal or biomass when atmospheric air is used as gasification agent.Constituents % of gas Carbon monoxide 18-22Hydrogen 13-19Methane1-5Carbon dioxide9-12Nitrogen45- 55Water Vapour4

Heating Value: 4.5 6 MJ/m3Octane number: 100 105 Properties:Low flame temperature Better knock resistivityLow calorific value Auto ignition tendency at high C.R. High laminar flame speed 50 cm/s

Methyl esters of rice bran oil(ROME) Rice is the main cultivation in sub tropical countries like india and srilanka. It it is the most consumed cereal grain.It is extracted from germ and inner husk (bran) of the rice. It is mostly oily inner layer of rice grain which is heated to produce ROME. Properties of Diesel and ROME:Property parametersDiesel fuel ROMEDensity at 20 C , g/cm30.820.8742Viscosity at 40 C,mm2/s3.44.63Flash point, C71165Auto ignition temp, C225320Cetane number4556.2Oxygen content max wat %0.411.25Net Heating Value,MJ/Kg43.538.725

Concept of dual fuel technology:Diesel alone accounts for 42% of total oil import bill of india ,use of producer gas biodiesel fuel combination can result in significant reduction of oil import bill ( Ramdas et al,2008)Limited fossil fuels ,stringent emission norms , rapid hike of fossil fuels led use of renewable and alternative fuels.Dual fuel technology offers number of potential benefits such as fuel flexibility, lower emission levels and easy conversion of existing diesel engines without major modifications (Bhanapurmath et al, 2011, Singh and Pathak 2007)it uses both injected liquid and induced gaseous fuel for power generation application .

Need for cooling and cleaning:Producer gas as it comes out from gasifier is hot and contains tar, soot particles and other particulates these are cooled and reduced before it is being let intoContaminant presence in gas and relative problems(Belgiorno , 2

ContaminentPresenceproblemsTarComplex mixture of organic HC by partial oxidation in vapor phase in producer gas Difficult to remove by simple condensation , clog filter and valve, metallic corrosionsParticulatesDerived from ash, char and bed material of reactors.Corrosion of metallic compounds and pollutionAlkali metals Sodium, potassium exsists in vapour phase. Thermal corrosion by stripping of protective oxide layerSuphur and chlorineNot a problem from biomass gasificationAcid corrosion of metals.

Gas cooling:Cooling increases volumetric efficiency of gas and assist in cleaning of gas, it has been found that with every reduction of gas temperature on 10% increase max. output of engine by 2%.Avoids moisture condensation of producer gas after mix with with air before it is let into engine.Equipments used for cooling:Natural cooling : fine pipes cooled by natural air.Forced cooling: Fans are used (external source of power required)Water coolers: heat exchangers simultanious cooling and cleaning in one operation.

Gas cleaning:Cleaning is essential otherwise impurities will cause excess wear , carbon deposits, deterioration of lubricant oil ,low starting and heat build up in engines.Producer gas for I.C engine application requires impurities to be removed to acceptable levels ( dust