Role of Biodiesel in Lhr Engine for Emission Reduction

8/12/2019 Role of Biodiesel in Lhr Engine for Emission Reduction

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ROLE OF BIODIESEL IN LHR ENGINE

FOR EMISSION REDUCTION

1*

M. Mohammed Jafar Sadiq,2

Dr.S. Sampath,3

M.Gowtham, C.4

Vikram

1*, 3, 4 Final year students, Rajalakshmi Engineering College

2Dean, Department of Automobile Engineering, Rajalakshmi Engineering College

Abstract-

The large increase in number of vehicles in recent

years have resulted in great demand for petroleumproducts. Growing concern regarding energy resources andthe atmosphere has increased interest in the study ofalternative sources of energy. To meet the increasing

energy requirements, there has been growing interest in

alternative fuels like biodiesel to provide a suitable dieseloil substitute for internal combustion engines. Biodieselsoffer a very promising alternative to diesel oil since they

are renewable and have similar properties. Biodiesel isdefined as a trans esterified renewable fuel derived fromvegetable oils or animal fats with properties similar or

better than diesel fuel.

A lot of research work has been carried out using vegetableoil both in its neat form and modified form. Studies haveshown that the usage of vegetable oils in neat form is

possible but not preferable. The objective of this study is to

evaluate performance, combustion and emissioncharacteristics of thermal barrier coated Direct Injection(DI) diesel engine with Bio diesel. Plasma spray coating(PSC) technique has been used to coat the cylinder head,

valves and piston crown with Partially Stabilised Zirconia(PSZ). The use of bio diesel leads to the substantial

reduction in PM, HC and CO emissions accompanyingwith the imperceptible power loss, the increase in fuel

consumption and the increase in NOx emission onconventional diesel engines with no or fewer modification.With the increasing concern of environmental protectionand more stringent emission regulations, reduction of dieselemissions has become a current issue in engine

development. It is difficult to reduce particulate andnitrogen oxide (NOx) emissions at the same time. On theother hand, modification of fuel composition through theaddition of oxygenate fuel to diesel fuel can reduce exhaust

gas emissions from diesel engines.

Keywords:Biodiesel, LHR Engine

Introduction:

Diesel engines are the dominating one primarilyin the field of transportation and secondarily in agriculturalmachinery due to its superior fuel economy and higher fuel

efficiency. The world survey explicit that the diesel fuelconsumption is several times higher than that of gasolinefuel. These fuels are fossil in nature, leads to the depletion

of fuel and increasing cost. It has been found that thechemically treated vegetable oil often called as biodiesel isa promising fuel, because of their properties are similar to

that of diesel fuel and it is renewable and can be easilyproduced. Compared to the conventional DI diesel enginethe basic concept of LHR engine is to suppress the heatrejection to the coolant so that the useful power output can

be increased, which in turn results in improved thermal

efficiency. However previous studies are revealing that thethermal efficiency variation of LHR engine not onlydepends on the heat recovery system, but also depends on

the engine configuration, operating condition and physicalproperties of the insulation materialThe drawback of an LHR engine has to be consideredseriously and effort has to be taken to reduce the increased

heat loss with the exhaust and increased level of NOxemission. The potential techniques available for thereduction of NOx from diesel engines are exhaust gasrecirculation (EGR), water injection, slower burn rate,reduced intake air temperature and particularly retarding

the injection timing. It is strongly proven that the increasingthickness of ceramic coatings arrest the heat loss from theengine cylinder, in contrast decreases the power and torque.

The optimized coating thickness can be identified throughthe simulation techniques. One of the viable significance ofLHR engine is utilizing the low calorific value fuel such as

biodiesel. Studies have revealed that, the use of biodieselunder identical condition as that for the diesel fuel results in

slightly lower performance and emission levels due to themismatching of the fuel properties mainly low calorificvalue and higher viscosity. The problems associated withthe higher viscosity of biodiesel in a compression ignition

(CI) engines are pumping loss, gum formation, injectornozzle coking, ring sticking and incompatibility withlubricating oil. The above identified problems with the useof biodiesel in conventional diesel engine can be reduced in

LHR engines except for the injection problem. Thevegetable oil will be trans-esterified using methanol in the

presence of NaOH as a catalyst. The parameter involved inthe above processing includes the catalyst amount, molar

ratio of alcohol to oil, reaction temperature and reactiontime.The engine combustion chamber has to be coated with

partially stabilized zirconia (PSZ) of 0.5 mm thickness,which includes the piston crown, cylinder head, valves, and

outside of the cylinder liner. The equal amount of materialwill be removed from the various parts of the combustion

chamber and PSZ will be coated uniformly.


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What i s Biodiesel:

Bio diesels are the mono alkyl esters of long chainfatty acids derived from vegetable oils or animal fats.Biodiesel can be mixed with petroleum diesel in any

percentage, from 1 to 99, which is represented by a number

following a B. For example, B5 is 5 percent biodiesel with

95 percent petroleum, B20 is 20 percent biodiesel with 80percent petroleum, or B100 is 100 percent biodiesel, nodiesel. Since bio diesel is made from plants and animal oils,it is a renewable fuel. It is compatible to diesel engines.

Burning bio diesel doesntproduce harmful emissions likediesel. It is non-toxic and bio-degradable by nature. If itspills, it rapidly breaks into harmless substances. It has nosulphur content in it and so, sulphur emissions can be

greatly reduced. Biodiesel exceeds diesel in Cetane numberresulting in superior ignition characteristics. It has a highflash point making it more versatile where safety is a

concern. Horse power, acceleration and torque arecomparable with diesel. Lubricity is superior for biodiesel.

Production of biodiesel:Esters of higher fatty acids are termed as biodiesel.

Vegetable oils can be chemically treated with an alcohol(methanol) to produce biodiesel.it is obtained through a

process called transesterification. Here, the vegetable oil is

first filtered, then processed with alkali to remove fattyacids. It is then mixed with an alcohol and a catalyst(sodium or potassium hydroxide). The triglyceride of oilreacts to form esters and glycerol, which are separated and

purified. A by-product of the transesterification process isthe production of glycerol. For every 1 tones of biodieselthat is manufactured, 100 kg of glycerol are produced. Anyfatty acid can be used to make biodiesel. Waste animal fats,

used frying oil, peanuts, cotton seed, sun flower seeds aresome of the potential feed stocks for biodiesel production.Esters made from all the above feed stocks can be usedsuccessfully as automotive fuel, although they may differ

slightly in terms of energy content, Cetane rating and otherphysical properties.

The general process of bio diesel production is thetransesterification of higher fatty acids. It involves treating

vegetable oil with alcohol in presence of base type catalyst.The catalyst is typically sodium or potassium hydroxide. Itis dissolved in alcohol using a standard agitator or mixer.The alcohol/catalyst mixture is then charged into a vessel

and then oil is added. The system is now on closed to

atmosphere to prevent loss of alcohol. The reaction mixtureis kept at a temperature above the boiling point of alcohol.

Recommended reaction time varies from 1 to 8 hours.Excess alcohol ensures complete conversion of oil to esters.Care must be taken to monitor the amount of water and freefatty acids in the incoming oil or fat. If the free fatty acidlevel is too high it may cause problems with soap formation

and the separation of the glycerin by-product downstream.Once the reaction is complete, two products are formed.They are glycerin and biodiesel. The glycerin phase isdenser than biodiesel. So they can be gravity separated with

glycerin simply drawn off at the bottom of the vessel. Insome cases they can be separated using a centrifuge. Once

the glycerin and biodiesel phases are separated, the excessalcohol in each phase is removed using a flash evaporation

process or by distillation. The removed alcohol is re-used.

Care must be taken to ensure no water accumulates in thealcohol stream. The glycerin by-product contains unusedcatalyst and soaps that are neutralized with an acid and sentto storage facility as crude glycerin.

In some cases, salt formed in this phase isrecovered for use as a fertilizer. In most cases, it is left inglycerin. Water and alcohol are removed to produce 80-

90% pure glycerin. In some cases, it can be distilled to 99%purity for commercial purposes. Once the biodiesel isseparated from glycerin, it is purified by washing gentlywith warm water to remove residual catalysts and soap.

Then it is dried and sent for storage. This is end of theproduction process yielding a clear amber- yellow liquidwith a viscosity similar to petrodiesel. In some systems the

biodiesel is distilled in an additional step to remove small

amounts of color body to produce a colorless biodiesel.Prior to use as a commercial fuel, the finished biodiesel

must be analyzed using analytical equipment to ensure thatit meet its ASTM requirements.

Experimental Setup:The experimental setup and the specification of the test

engine are shown in Fig.1 and table 1 respectively.

Fig. 1 Experimental setup

i. Test engine

ii. Dynamometer

iii. Dynamometer controller

iv. Piezo electric pressure transducer

v. Charge amplifiers

vi. Data acquisition system

vii. Magnetic pickup

viii. Computer

The engine was coupled with an eddy current dynamometer

for performance and emission testing. A piezoelectrictransducer was mounted through an adopter in the cylindershead to measure the in-cylinder pressure. Signal from the

pressure transducer was fed to charge amplifier. Amagnetic shaft encoder was used to measure the TDC and


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crank angle position. The signals from the charge amplifierand shaft encoder were given to the appropriate channels ofa data acquisition system.

The analyzer used to measure the engine exhaust emissionwas calibrated before each test. Using the appropriatecalibration curve, the measurement error for each analyzerwas reduced as per the recommendation by the exhaust

analyzer manual. Exhaust gas temperature was measuredusing an iron-constantan thermocouple and mercury

thermometer was used to measure the cooling watertemperature. Diesel and biodiesel was used in theconventional diesel engine and the PSZ coated LHR

engine. The experiments were carried out in a singlecylinder, naturally aspirated, constant speed, water-cooleddirect injection diesel engine with the following

specifications

Meri ts and demerits:

Merits:

Biodiesel is biodegradable.

Biodiesel is safer to handle compared to standarddiesel.

Biodiesel can be easily blended with standarddiesel, and it can be used in most of today's

vehicles even in form of pure biodiesel B100.

Biodiesel has very good lubricating properties,significantly better than standard diesel whichcan prolong engine's life.

Biodiesel has shorter ignition delay compared to

standard diesel.

Biodiesel has no sulfur content, and so it doesn'tcontribute to acid rain formation.

Demerits:

Biodiesel is currently mostly produced from corn

which could lead to food shortages and increased

food prices. The end result of this could be morehunger in the world.

Biodiesel is 20 times more suspectible to watercontamination compared to standard diesel, and

this could lead to corrosion, rotten filters, pittingin the pistons, etc.

Pure biodiesel has significant problems with lowtemperatures.

Biodiesel is significantly more expensivecompared to standard diesel.

Biodiesel has significantly less energy content

compared to standard diesel, around 11% lesscompared to standard petroleum diesel.

Biodiesel can release nitrogen oxide which canlead to the formation of smog.

Conclusion:

The biodiesel produced from UNKNOWNoilby transesterification process reduces the viscosity of theoil in order to match the suitability of diesel fuel. The dieselengine is modified in to LHR engine by means of partiallystabilized zirconia (PSZ) coating. The various combustion

parameters such as cylinder pressure, rate of heat release,cumulative heat releases were analyzed and the followingconclusions were arrived it.

i. At full load condition, the cylinder pressure in the case ofbiodiesel fueled LHR engine was lower than that of thediesel fueled LHR engine. Even though this reduction

under identical condition is substantial. The absolute valueof this cylinder peak pressure is well within operatinglimits of the test engine.ii. The final analysis of the heat release shows that, the

value of net heat release in the case of biodiesel fueledLHR engine is substantially good enough for the effective

work done of the test engine.

The above comparative study clearly reveals the possibility

of using the biodiesel in LHR direct injection diesel engine.The combustion, performance and emission characteristicsshow the suitability of biodiesel in LHR engine

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Role of Biodiesel in Lhr Engine for Emission Reduction