effect of jatropha methyl ester on waste plastic oil fueled di diesel engine

Q5

Q1

Q2

Journal of the Energy Institute xxx (2015) 1e9

JOEI175_proof ■ 8 September 2015 ■ 1/9

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354

Contents lists available at ScienceDirect

Journal of the Energy Institutejournal homepage: http : / /www.journals .e lsevier .com/journal-of- the-energy-

inst i tute

Effect of Jatropha methyl ester on waste plastic oil fueled DI dieselengine

P. Senthilkumar a, *, G. Sankaranarayanan b, 1

a Department of Mechanical Engineering, Velammal Institute of Technology, Chennai, Tamilnadu, Indiab Department of Mechanical Engineering, SreeSastha Institute of Engineering and Technology, Chennai, Tamilnadu, India

a r t i c l e i n f o

Article history:Received 22 June 2015Received in revised form27 July 2015Accepted 28 July 2015Available online xxx

Keywords:Waste plastic oilJatropha methyl esterPyrolysis processDiesel enginePerformanceEmission

* Corresponding author. Tel.: þ91 9894335914.E-mail addresses: kallakurichisenthilkumar@gmail

1 Tel.: þ91 9444366717.

http://dx.doi.org/10.1016/j.joei.2015.07.0061743-9671/© 2015 Energy Institute. Published by Else

Please cite this article in press as: P. Senthilengine, Journal of the Energy Institute (2015

a b s t r a c t

Rapid demanding of conventional fossil fuels, increasing costs and environmental issues is the majorproblems for a substitute fuel. On the other hand waste plastic poses a very serious environmentalchallenges because of their disposal problems all over the world. The oil obtained by pyrolysis of wasteplastics can be utilized as an alternate fuel for diesel engine without any modifications to the enginewhich results, increase the emissions like carbon monoxide (CO) and oxides of nitrogen (NOx) andHydrocarbons (HC) compared with diesel. In this present study, the waste plastic oil mixed with 10% voland 20% vol of Jatropha methyl ester (JME) oil used as fuel for the DI diesel engine and the combustion,performance and emission characteristics were studied. The experimental results indicated that thebrake thermal efficiencies of waste plastic oileJME blends at full load conditions are higher as comparedto that of waste plastic oil. BTE increased by about 2.24% with PJ20 operation at full load compared towaste plastic oil. The Brake specific fuel consumption (BSFC) increases with an increase in the JME blendratio and decreases with an increase in engine load. The CO and HC emissions were decreased withincrease in percentage of JME in waste plastic oil blends. HC and CO emissions for PJ20 operation areabout 11 ppm and 0.13% lower than waste plastic oil at full load respectively. The NOx emission wasslightly increased with increase in percentage of JME in waste plastic oils. NOx emission is 20 ppm higherfor PJ20 operation than waste plastic oil. Smoke emission decreased by about 11.4% in the case of PJ20compared to waste plastic oil.

© 2015 Energy Institute. Published by Elsevier Ltd. All rights reserved.

1. Introduction

Higher thermal efficiency and ease of handling are the reasons behind wide acceptance of diesel for many industries like, automobile,agricultural and power generation sectors. Meanwhile, in the past four decades the demand of oil derived fuels had been tremendouslyincreased due to the enhancement of automotive vehicles usage, this tends to increase the economy value of the fossil fuel. Also growing ofan air pollution caused by burning of fossil fuels intensifies to search for alternative fuels for the internal combustion engines to ensuringenergy security and solving environmental issues. Plastics have become an essential part in today's world due to their lightweight, dura-bility, energy efficiency, coupled with a faster rate of production and design flexibility. At the same time, waste plastics have created a veryserious environmental challenge due to their huge quantities and disposal problems. Pyrolysis process is a better method for convertingwaste plastics into plastic oil because of their advantages such as independent feedstock, least amount of waste produced, low pressureoperation and high conversion efficiency in the order of 80% [1]. The use of vegetable oil in diesel engine has been enormously increasedbecause of the large production capacity and eco-friendly to the environment aspects. There are many vegetable oils like Pongamia oil,peanut oil, rapseed oil, Jatropha oil and sunflower oil can be used to run the diesel engine. The use of sole vegetable oil in diesel engineresults in reduction in performance because of higher viscosity. Out of various non-edible oil resources, Jatropha oil is considered as futurefeedstocks for biodiesel production by Transesterification process [2]. Through Transestrification, kinematic viscosity and specific gravity of

.com (P. Senthilkumar), [email protected] (G. Sankaranarayanan).

vier Ltd. All rights reserved.

kumar, G. Sankaranarayanan, Effect of Jatropha methyl ester on waste plastic oil fueled DI diesel), http://dx.doi.org/10.1016/j.joei.2015.07.006

mailto:[email protected]

mailto:[email protected]

www.sciencedirect.com/science/journal/17439671

http://www.journals.elsevier.com/journal-of-the-energy-institute

http://www.journals.elsevier.com/journal-of-the-energy-institute

http://dx.doi.org/10.1016/j.joei.2015.07.006



P. Senthilkumar, G. Sankaranarayanan / Journal of the Energy Institute xxx (2015) 1e92


1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

JME get reduced. Higher flash point of JME and its blends than diesel fuel, suggests their safe storage and handling [3]. A 10% biodiesel blendproduces the better engine performance in terms of engine torque, engine power, fuel consumption and brake thermal efficiency [4].Previous research works based on the waste plastic oil stated that, diesel engine can run with sole waste plastic oil without any modifi-cations. Carbon dioxide (CO2) and unburned hydrocarbon (UHC) were marginally higher than that of the diesel fuel. The toxic gas COemission of waste plastic oil was higher than diesel. Smoke is reduced by about 40e50% of waste plastic oil at all loads [5]. Waste plastic oilreleases higher cylinder pressure compared to diesel fuel due to evaporation of waste plastic oil in the cylinder by absorbing the heat fromthe combustion chamber [6]. The brake thermal efficiencies at all load conditions were lower as compared to that of diesel fuel, exhaust gastemperature increases with an increase in engine load. The NOx emission and CO emission increase with increase in percentage of wasteplastic oil in blends [7]. The effect of different flow rate of diethyl ether (DEE) on tyre pyrolysis oil (TPO) fuel in a diesel engine reported thatNOx emission in TPOeDEE operationwas reduced by 5% comparedwith diesel [8]. TPOwas blendedwith JME in different percentages as fuelfor a DI diesel engine and studied the combustion, performance and emission characteristics. Reported that up to 20% of JME blends withTPO produce the better combustion results, further increasing the percentage of the blends the ignition delay became longer [9]. Investi-gated the effect of waste plastic oil blended with DEE as a fuel for diesel engine. Addition of DEE with waste plastic pyrolysis oil (WPPO)decreased the viscosity and thereby increased the atomization of air fuel mixture which leads to the enhancement of brake thermal effi-ciency (BTE). Higher values of Cetane numbers and high heat of evaporation of DEE parameters led the reduction in the emission of NOx [10].Used emulsified wood pyrolysis oil with JME as a fuel for diesel engine. The 15% of the emulsion produces higher thermal efficiencies.Further, NO emissions were lowered addition of the WPO in JME [11]. The aim of this work is to compare the performance, combustion andemission characteristics of waste plastic oileJME blends with sole waste plastic oil and diesel fuel.

2. Materials and methods

2.1. Production of waste plastic oil

Pyrolysis is a thermal degradation process in the absence of oxygen, performed to obtain waste plastic oil by using silica alumina as acatalyst. The experimental layout of pyrolysis process is shown in Fig. 1. Different sizes and shapes of waste plastics were collected andcrushed with shredder for ease of handling the process. A 10 kg of fine crushed waste plastics were fed in a reactor chamber. The copper coilplaced around the burning chamber is heated and maintained at a temperature range of 320e500 �C for 3e4 h duration. At this hightemperature, waste plastic gets vaporized and passes through the condenser devices. Because of the cold water present in the condenser,latent heat transfer occurs by condensing thewaste plastic vapor [12]. The condensedwaste plastic vapor is then stored in the oil collector inthe form of plastic oil. The pyrolysis process involves the break down of large molecules to smaller molecules. From the pyrolysis treatmentthe following output products were collected: Waste Plastic Oil e 75e90% (mixture of petrol, diesel and kerosene), Gas e 5e20% andResidual coke e 5e10% [13].

2.2. Production of Jatropha methyl ester

Transesterification is a suitable method for utilizing vegetable oils in the DI diesel engine for long term applications without any majormodifications and durability problems. The conversion of methyl esters of triglycerides in the presence of a catalyst is shown in thefollowing equation.

CH2OCOR1 CH2OH + R1COOCH3

CHOCOR2 + 3CH3OH CHOH + R2COOCH3

CH2OCOR3 CH2OH + R3COOCH3

Triglycerides Methanol Glycerol Methyl esters

H2SO4 KOH

Catalyst

Fig. 1. Experimental setup of pyrolysis process.

Please cite this article in press as: P. Senthilkumar, G. Sankaranarayanan, Effect of Jatropha methyl ester on waste plastic oil fueled DI dieselengine, Journal of the Energy Institute (2015), http://dx.doi.org/10.1016/j.joei.2015.07.006

Table 1Properties of diesel, waste plastic oil and waste plastic oileJME blends.

Properties Protocol Diesel WPO oil Jatropha oil PJ 10 PJ 20

Density @ 15 �C (kg/m3) IS1448, P16 860 835 916 845 854Kinematic viscosity @ 40 �C (cSt) ASTM D445 2.107 3.254 3.75 3.302 3.363Flash point (�C) IS1448, P20 50 41 178 59 71Fire point (�C) IS1448, P20 56 49 185 65 79Gross calorific value (kJ/kg) IS1448, P25 42,500 43,388 39,641 39,168 38,287Cetane number IS1448, P9 50 48 53 52 52.6

P. Senthilkumar, G. Sankaranarayanan / Journal of the Energy Institute xxx (2015) 1e9 3


1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

Jatropha oil was used in the Transesterification process to convert crude oil into Jatropha methyl ester oil. The oil conversion processparameters such as reaction condition, type of alcohol, amount of catalysts, reaction time and temperaturewere controlled bymanualmode.Single stage base catalyzed transesterification was used for Jatropha oil. Methanol used as a reagent; H2SO4 and KOH used as a catalyst forbase reaction. In the transesterification of vegetable oils, a triglyceride reacts with an intoxicant in the presence of a strong acid or base,producing a variety of fatty acid alkyl esters and glycerin. The optimum variables for effective Transesterification of Jatropha oil are 20%methanol (by weight of oil), a molar ratio of methanol to oil of 5:1, and 1.0% of H2SO4 and KOH as a catalyst (by weight of oil). Here,approximately 3e4 g of catalyst (H2SO4 and KOH)was dissolved in 100ml of methanol to preparemethoxide, whichwas required to activatethe methanol. Around 15e20 min vigorous stirring was done in a closed container until the alkali was dissolved completely, then, thismixture was then transferred to the reactor containing moisture free Jatropha oil. A continuous stirring of the resulting mixture of tem-perature between 60� and 65 �C was carried out for about 90 min. A maximum methyl ester yield of 98% was obtained after 90 min with a60 �C reaction temperature and this biodiesel obtained was found to be within the ASTM specified limits of biodiesel. Then, the mixture wastaken out and poured into the separating funnel to separate the glycerol and methyl ester of Jatropha oil. For the complete separation of thelayers, the mixture was allowed to settle for a minimum period of 8 h. The two layers were formed. The bottom layer consisted of glyceroland the top layer was the ester. After settling was complete, water was added at the rate of 5.5% by volume of themethyl ester of oil and thenstirred for 5 min and the glycerin was allowed to settle again. The washing cycle was repeated thrice to remove soaps, and methoxide thatwas not reacted. The washed ester was then electrically heated to 110 �C for removal of moisture. The properties of waste plastic comparedwith diesel and JME are given in Table 1.

2.3. Experimental setup

An experimental setup of 4.4 kW single cylinder, air cooled, direct injection diesel engine is shown in Fig. 2. U-tube pressure gauge wasfitted with anti-pulsating drum to observe the mass flow rate. A specification of the test engine is shown in Table 2. AVL software was usedfor combustion data analysis and DAQ card placed in between the computer and the engine converts the recorded analog signal into a digitalvalue. The AVL 365C angle encoder was attached to the engine to measures the crank angle for different piston positions. AVL Pressuretransducer GH14D was used to indicate the pressure level in the combustion chamber. K-2 type thermocouple was used to measure theexhaust gas temperature. The test engine coupled with electrical dynamometer to apply load on the engine. Electrical Dynamometerconsists of the electrical power bank, which applies 0%, 25%, 50%, 75%, 100% load on an engine and it is controlled with the aid of ammeterand voltmeter. The engine was connected to the computer (PC-IV) to record and analyze the output data. The combustion parameters suchas cylinder pressure, instant heat release rate and ignition delay were evaluated. AVL Digas 444 exhaust gas analyzer was used to measureengine emissions such as NOx, UHC, and CO. Smoke opacity of the exhaust gas was measured with the use of AVL 437C smoke meter.

2.4. Error analysis and uncertainties

Error analysis is performed to identify the accuracy of the measuring instruments. Errors can occur due to many factors which includeenvironmental conditions, calibration, observation, instruments and test planning. The instruments and their percentage uncertainties ofNOx, HC, CO, CO2, O2, Exhaust gas temperature (EGT) and smoke opacity are given in Table 3.

Percentage of uncertainty present in the experiment is ¼ square root of ((uncertainty of pressure transducer)2 þ (uncertainty of angleencoder)2 þ (uncertainty of NOx)2 þ (Uncertainty of HC)2 þ (uncertainty of CO)2 þ (uncertainty of CO2)2 þ (uncertainty ofO2)2 þ (uncertainty of smoke opacity)2 þ (uncertainty of K-2 thermocouple)2 þ (uncertainty of stop watch)2 þ (uncertainty ofmanometer)2 þ (uncertainty of burette)2) ¼ square root of ((0.01)2 þ (0.2)2 þ (0.2)2 þ (0.2)2 þ (0.3)2 þ (0.2)2 þ (0.3)2 þ (1)2 þ(0.2)2 þ (0.2)2 þ (2)2 þ (1.5)2) ¼ square root of (7.6701) ¼ ±2.769%.

Fig. 2. DI diesel engine experimental setup.


Table 2Single cylinder DI diesel engine specifications.

Particulars Specifications

Name of the manufacturer Kirloskar TAF-1Bore and stroke 87.5 mm, 110 mmNumber of cylinder 1Rated speed 1500 rpmRated brake power 4.4 kWDisplacement volume 661.45 ccCooling system Air-cooledCompression ratio 17.5:1Nozzle opening pressure 200 barOrifice diameter 13.6 mmCo efficient of discharge 0.6Injection timing 23� bTDC

Table 3List of instruments and its range, accuracy and percentage uncertainties.

Instrument Measuring range Accuracy Percentage uncertainties

AVL pressure transducer GH14D 0e250 bar ±0.01 bar ±0.01AVL 365C angle encoder e ±1� ±0.2

AVL digas 444 (five gas analyzer)NOx (0e5000 ppm vol) <500 ppm vol: ±50 ppm vol

�500 ppm vol: ±10%±0.2

HC (0e20,000 ppm vol) <200 ppm vol: ±10 ppm vol>200 ppm vol: ±5%

±0.2

CO (0e10% vol) <0.6% vol: ±0.03% vol>0.6% vol: ±5%

±0.3

CO2 (0e20% vol) <10% vol: ±0.5% vol>10% vol: ±5% vol

±0.2

O2 (0e22% vol) <2% vol: ±0.1% vol�2% vol: ±5% vol

±0.3

AVL 437C smoke meterSmoke intensity (0e100%) ±1% ±1K-2 thermocouple (0e1250 �C) ±1 �C ±0.2Digital stop watch e ±0.2 s ±0.2U-tube Manometer e ±1 mm ±2Burette 1e30 cc ±0.2 cc ±1.5



1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

3. Results and discussion

3.1. Performance and emission parameters

3.1.1. Brake thermal efficiencyThe variation in the brake thermal efficiency with engine load for diesel; waste plastic oil and waste plastic oileJME blends is shown in

Fig. 3. The BTE for diesel is 24.96% at full load, which is the highest among all the fuels tested. For waste plastic oil, PJ10 and PJ20 are 22.61%,22.83% and 24.35% respectively at full load. The BTE of diesel, waste plastic oil and waste plastic oileJME increases with increasing engineload. As the Engine load increases the heat generated in the cylinder increases, and hence, the thermal efficiency increases. The thermalefficiency of the waste plastic oil is lower than that of diesel at full load, this may be due to the fact that at full load, the EGT and the heatrelease rate are marginally higher for waste plastic oil compared to diesel [14].

12

14

16

18

20

22

24

26

25 50 75 100

Brak

e th

erm

al effi

cien

cy (%

)

Engine load (%)

DieselWaste plas c oilPJ10PJ20

Fig. 3. Variation of brake thermal efficiency vs. engine load.


0.3

0.35

0.4

0.45

0.5

0.55

0.6

0.65

0.7

25 50 75 100Br

ake

spec

ific

fuel

con

sum

pon

(kg/

kW.h

r)

Engine load (%)

Diesel

Waste plas c oil

PJ10

PJ20

Fig. 4. Variation of specific fuel consumption vs. engine load.



1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

3.1.2. Brake specific fuel consumptionFig. 4 shows the curve between BSFC with the load. This figure reveals that diesel has the BSFC of 0.57 kg/kWh at 25% load and 0.35 kg/

kWh at full load. ForWaste plastic oil, the value is 0.62 kg/kWh at 25% and 0.36 kg/kWh at full load. The BSFC for PJ10 is 0.64 kg/kWh at 25%and 0.41 kg/kWh at full load. The BSFC for PJ20 is 0.67 kg/kWh at 25% and 0.40 kg/kWh at full load. The variation in brake specific fuelconsumption with load for different fuels shows decline with an increase in load. The BSFC in case of blends was higher compared to dieselin the entire load range, due to its lower heating value and hence higher bulkmodulus. The higher bulkmodulus results inmore discharge offuel for the same displacement of the plunger in injection pump, thereby resulting increase in BSFC. This is attributed to the combined effectof viscosity and lower heating values of waste plastic oileJMEwhich requires larger fuel consumption in order to release same energy as thatof diesel.

3.1.3. Exhaust gas temperatureThe variation in the EGT with engine load for diesel; waste plastic oil and waste plastic oileJME blends is shown in Fig. 5. The EGT varies

from 195 �C at no load to 470 �C at full load condition for diesel whereas in case of waste plastic oil it varies from 200 �C at no load to 480 �Cat full load condition. It is also observed from the results that EGT increases with an increase in engine load from no load condition to fullload condition.Whereas for PJ10, EGT varies from 195 �C at no load to 460 �C at full load condition, for PJ20 EGT varies from 195 �C at no loadto 470 �C at full load condition. The decrease of EGT in PJ10 and PJ20 is due to the lower heat release rate and water molecules present in theJatropha biodiesel. This resists the temperature of the working fluid in the combustion chamber. The EGT gives an indication about theamount of heat going waste with the exhaust gases [15]. As a result of increased combustion duration, a higher EGT is recorded in the wasteplastic oil.

3.1.4. Unburned hydrocarbonUnburned hydrocarbon consists of fuel that is in completely burned. The term hydrocarbon means organic compounds in the gaseous

state and solid hydrocarbons are the particulate matter. UHC emissions are caused by incomplete combustion of fueleair mixture. Thevariation in the UHC emissionwith engine load for diesel; waste plastic oil and waste plastic oileJME blends is shown in Fig. 6. For Diesel, itvaries from 22 ppm at 25% load and 29 ppm at full load. For Waste plastic oil, the values are 34 ppm at 25% load and 48 ppm at full load. ForPJ10 and PJ20, the values are 34 and 30 ppm, at 25% load and 38 ppm and 37 ppm at full load. The addition of JME with waste plastic oildecreases the HC emissions than waste plastic oil. The reason behind increased hydrocarbon in waste plastic oil may be due to higherfumigation rate.

3.1.5. NOx emissionOxides of nitrogen result from the reaction of nitrogen and oxygen at relatively high temperatures. NO is a major component in the NOx

emission. NOx emissions are formed throughout the combustion chamber during the combustion process due to the reaction of atomic

175

275

375

475

0 25 50 75 100

Exha

ust g

as te

mpe

ratu

re (˚

C)

Engine load (%)

Diesel

Waste plas c oil

PJ10

PJ20

Fig. 5. Variation of exhaust gas temperature vs. engine load.


15

20

25

30

35

40

45

50

0 25 50 75 100

UHC

em

issio

ni (p

pm)

Engine load (%)


Fig. 6. Variation of HC emission vs. engine load.



1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

oxygen and nitrogen. The reactions forming NOx are highly temperature dependent, so the NOx emissions have a close relation with theengine load. The formation of NOx for diesel, waste plastic oil, PJ10 and PJ20 is shown in Fig. 7. The NOx values for diesel vary from 251 ppm at25% load and 668 ppm at full load. For waste plastic oil, it varies from 266 ppm at 25% load and 685 ppm at full load. . For PJ10 and PJ20, itvaries from 302 to 292 ppm at 25% load and 694 ppm and 705 ppm at full load. The NOx formation is increasing as the load increases. TheNOx emissions of the blends were found to be slightly increase with increasing the blend percentage of a JME.

The reason for increasing the NOxwith thewaste plastic oileJME blends operation is that because of higher oxygen content present in thecombustion chamber. This excess oxygen promotes the NOx formations [16].

3.1.6. CO emissionThe carbon monoxide, a toxic gas produced during the combustion process, is mainly due to the lack of oxygen, poor air entrainment,

mixture preparation and incomplete combustion during the combustion process. Low flame temperature and too rich fuel air ratio are themajor causes of CO emissions from engine. Higher CO emissions result in loss of power in engine. Different factors can be at the origin of itsformation, insufficient residence time, too low or too high equivalence ratios are part of those reasons [17]. Fig. 8 shows the trend of COemission for diesel, plastic oil and plastic oileJatropha blends, with respect to engine load. Generally, CI engines operatewith a leanmixture.Therefore, the CO emission is found to be lesser than that in the SI engines. The amount of CO emission from diesel varies from 0.03% at 25percent load and 0.36% at full load. For plastic oil, it varies from 0.05% at 25 percent load and 0.26% at full load. For PJ10 and PJ20, the valuesare same 0.04% at 25 percent load and 0.17% and 0.13% at full load respectively. For all test fuels, the amount of CO is increasing with the

0

100

200

300

400

500

600

700

0 25 50 75 100

NO

Xem

issio

n (p

pm)

Engine load (%)

Diesel

Waste plas c oil

PJ10

PJ20

Fig. 7. Variation of NOx emission vs. engine load.

0

0.05

0.1

0.15

0.2

0.25

0.3

0 25 50 75 100

CO e

miss

ion

(%) v

ol

Engine load (%)


Fig. 8. Variation of CO emission vs. engine load.


0

10

20

30

40

50

0 25 50 75 100

Smok

e op

acity

(%)

Engine load (%)

Diesel

Waste plas c oil

PJ10

PJ20

Fig. 9. Variation of smoke opacity vs. engine load.



1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

increment in the load. The CO emission is lower for waste plastic oileJME blends compared to that of diesel at full load, the reason for thismay be the excess oxygen present in the JME is helpful for better combustion.

3.1.7. Smoke opacityThe smoke opacity of any fuel increases with the increase in engine load. With an increase in the engine load, the air fuel ratio decreases

as the fuel injected increases, and hence results in higher smoke. Fig. 9 shows the variation of smoke emissionwith respect to engine load fordiesel, plastic oil and plastic oileJatropha blends. The smoke opacity level of diesel is 8.60% at 25% load and 51.10% at full load. In case ofwaste plastic oil, the value is 14.90% at 25% load and 55.50% at full load. The smoke opacity for PJ10 and PJ20 at 25% load is 13.60% and 12.60%and 45.20% and 43.80% at full load. The addition of JME with waste plastic oil shows reduction in smoke opacity. This is due to the higheroxygen content of Jatropha promotes the formation of smoke during the diffusion phase of combustion. Smoke is the result of incompletecombustion, and is formed in the rich mixture zone in the combustion chamber [18]. But in case of waste plastic oil smoke emission getincrease this is because of longer ignition delay and combustion duration may the reason for higher smoke. Also the smoke opacity of wasteplastic oil is higher than that of diesel due to heavier molecules.

3.2. Combustion characteristics

3.2.1. Cylinder pressureThe variation of cylinder pressure with crank angle for diesel, waste plastic oil, PJ10 and PJ20 at maximum load is shown in Fig. 10. The

higher cetane number of JME shortens the ignition delay period when added to waste plastic oil. It is noted that the peak pressures of 63.82,68.05, 67.09 and 64.62 bar were recorded for standard diesel, waste plastic oil, PJ10 and PJ20 respectively and are shown in Table 4. It isobserved from the figure that the peak cylinder pressure is decreased with the increase of JME addition in thewaste plastic oil. However, thecombustion process of the test fuels is similar, consisting of a phase of premixed combustion following by a phase of diffusion combustion.

20

25

30

35

40

45

50

55

60

65

70

-20 -15 -10 -5 0 5 10 15 20

Cylin

der p

ress

ure

(bar

)

Crank angle (θ)

Diesel

Waste plas c oil

PJ10

PJ20

Fig. 10. Variation of cylinder pressure vs. crank angle.

Table 4Combustion characteristics of diesel, waste plastic oil and waste plastic oileJME blends.

Fuel/fuel blends Start of injection (�) bTDC Start of combustion (�) bTDC Ignition delay (�) Peak pressure (bar) Heat release rate (J/CA�)

Diesel 23 15.4 7.6 68.052 71.562Waste plastic oil 23 14.3 8.7 63.823 91.933PJ10 23 14.8 8.2 64.621 86.502PJ20 23 14.9 8.1 67.094 79.326


Q3

Q4

-40

-20

0

20

40

60

80

100

-20 -10 0 10 20

Heat

rele

ase

rate

(J/C

A)

Crank angle (θ)

Diesel

Waste plas c oil

PJ10

PJ20

Fig. 11. Variation of heat release rate vs. crank angle.



1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465

Premixed combustion phase is controlled by the ignition delay period and spray envelope of the injected fuel [19]. One can observe that withincreasing percentage of Jatropha in the blend, the start of combustion occurs later (the pressure rise due to combustion starts later), whilethe maximum pressure falls and occurs later. The start of combustion is delayed as a consequence of the interaction of the lower dynamicinjection timing and increased ignition delay. In a diesel engine, the peak pressure depends on the combustion rate in the initial stages,which is influenced by the amount of fuel taking part in the uncontrolled combustion phase that is governed by the delay period. It is alsoaffected by the fuel mixture preparation during the delay period.

3.2.2. Heat release rateRate of heat release developed inside the cylinder during the combustion stroke was analyzed based on the in-cylinder pressure for the

various engine loads. The formula used to calculate the rate of heat release is given by,

dQn

dq¼ g

g� 1pdVdq

þ 1g� 1

V þ dpdq

where g is the ratio of specific heats, Cp/Cv. The appropriate range of g (for diesel) heat release analysis is 1.3e1.35. dQn/dq is the heat transferin kJ/m3.degree, P is the instantaneous cylinder pressure (bar), V is the instantaneous cylinder volume (m3).

The variation of heat release rate with crank angle for diesel, waste plastic oil, PJ10 and PJ20 at maximum load is shown in Fig. 11. Themaximum heat release rate of diesel, waste plastic oil, PJ10 and PJ20 is 71.56, 91.93, 86.50 and 79.32 J/CA� respectively. It can be noticed thatinwaste plastic oil, most of the heat release occurs only during the premixed combustion. The ignition delay period for test fuels is shown inTable 4. Longer ignition delay results in higher heat release during the premixed combustion phase. The heat release rate is higher in the caseof waste plastic oil due to the higher fueleair ratio. The decrease in cylinder temperaturewill also decrease the ignition delay. This reductionin ignition delay period minimizes the heat release rate of waste plastic oileJME blends.

4. Conclusion

Waste plastic oil exhibits a higher cylinder peak pressure compared to diesel because of evaporation of waste plastic oil inside thecylinder by absorbing heat from the combustion chamber. The heat release rate with waste plastic oil is higher compared to diesel fuel dueto better combustion. With an increase in percentages of JME, NOx increase due to the presence of oxygen molecule in biodiesel that lowerheat release rate and combustion temperature.

From the experimental investigation the following conclusions were drawn:

� Brake thermal efficiency, increased by about 2.24% with PJ20 operation at full load compared to waste plastic oil.� NOx emission is 20 ppm higher for PJ20 operation than waste plastic oil at full load.� HC emission for PJ20 operation is about 11 ppm lower than waste plastic oil at full load.� CO emission for PJ20 operation is about 0.13% lesser than waste plastic oil at full load.� Smoke emission decreased by about 11.4% in the case of PJ20 compared to waste plastic oil at full load.

Acknowledgment

Author sincerely thanks Sri Venkateswara College of Engineering for offering the setup of IC engine for experimental studies.

References

[1] A.V. Bridgewater, G.V.C. Peacocke, Fast pyrolysis process for biomass, Renew. Sustain. Energy Rev. 4 (2000) 1e73.[2] Siddharth Jain, M.P. Sharma, Biodiesel production from Jatropha curcas oil, Renew. Sustain. Energy Rev. 14 (2010) 3140e3147.[3] Bhupendra Singh Chauhan, Naveen Kumar, Haeng Muk Cho, A study on the performance and emission of a diesel engine fueled with Jatropha biodiesel oil and its

blends, Energy 37 (2012) 616e622.[4] Hwai Chyuan Ong, H.H. Masjuki, T.M.I. Mahlia, A.S. Silitonga, W.T. Chong, Talal Yusaf, Engine performance and emissions using Jatropha curcas, Ceiba pentandra and

Calophyllum inophyllum biodiesel in a CI diesel engine, Energy (2014) 1e19.[5] M. Mani, G. Nagarajan, S. Sampath, Characterisation and effect of using waste plastic oil and diesel fuel blends in compression ignition engine, Energy 36 (2011)

212e219.




1234567891011121314151617181920

[6] M. Mani, G. Nagarajan, S. Sampath, An experimental investigation on a DI diesel engine using waste plastic oil with exhaust gas recirculation, Fuel 89 (2010) 1826e1832.[7] Sachin Kumar, R. Prakash, S. Murugan, R.K. Singh, Performance and emission analysis of blends of waste plastic oil obtained by catalytic pyrolysis of waste HDPE with

diesel in a CI engine, Energy Convers. Manag. 74 (2013) 323e331.[8] S. Hariharan, S. Murugan, G. Nagarajan, Effect of diethyl ether on tyre pyrolysis oil fueled diesel engine, Fuel 104 (2013) 109e115.[9] Abhishek Sharma, S. Murugan, Investigation on the behaviour of a DI diesel engine fueled with Jatropha methyl ester (JME) and tyre pyrolysis oil (TPO) blends, Fuel 108

(2013) 699e708.[10] J. Devaraj, Y. Robinson, P. Ganapathi, Experimental investigation of performance, emission and combustion characteristics of waste plastic pyrolysis oil blended with

diethyl ether used as fuel for diesel engine, Energy (2015) 1e6.[11] R. Prakash, R.K. Singh, S. Murugan, Experimental studies on combustion, performance and emission characteristics of diesel engine using different biodiesel bio oil

emulsions, J. Energy Inst. (2014) 1e12.[12] Rajesh Guntur, et al., Experimental evaluation of a diesel engine with blends of dieseleplastic pyrolysis, Int. J. Eng. Sci. Technol. 3 (2011) 0975e5462.[13] M. Mani, C. Subash, G. Nagarajan, Performance, emission and combustion characteristics of a DI diesel engine using waste plastic oil, Appl. Therm. Eng. 29 (2009)

2738e2744, http://dx.doi.org/10.1016/j.applthermaleng.2009.01.007.[14] Jerzy Walendziewski, Continuous flow cracking of waste plastics, Fuel Process. Technol. 86 (2005) 1265e1278.[15] C.W. Yu, S. Bari, A. Ameen, A comparison of combustion characteristics of waste cooking oil with diesel as fuel in a direct injection diesel engine, Proc. Inst. Mech. Engr.,

Part D: J. Automob. Eng. 216 (2002) 237.[16] Pi-qiang Tan, Zhi-yuan Hu, Di-ming Lou, Zhi-jun Li, Exhaust emissions from a light-duty diesel engine with Jatropha biodiesel fuel, Energy 39 (2012) 356e362.[17] G. Balaji, M. Cheralathan, Experimental investigation of antioxidant effect on oxidation stability and emissions in a methyl ester of neem oil fueled DI diesel engine,

Renew. Energy 74 (2015) 910e916.[18] S. Murugan, et al., Performance, emission and combustion studies of a DI diesel engine using distilled tyre pyrolysis oilediesel blends, Fuel Process. Technol. 89 (2008)

152e159.[19] P.K. Devan, N.V. Mahalakshmi, Study of the performance, emission and combustion characteristics of a diesel engine using poon oil-based fuels, Fuel Process. Technol. 90

(2009) 513e519.


http://dx.doi.org/10.1016/j.applthermaleng.2009.01.007

effect of jatropha methyl ester on waste plastic oil fueled di diesel engine

Documents