research article influence of fuel moisture content and...

Research ArticleInfluence of Fuel Moisture Content and Reactor Temperatureon the Calorific Value of Syngas Resulted from Gasification ofOil Palm Fronds

Samson Mekbib Atnaw1 Shaharin Anwar Sulaiman1 and Suzana Yusup2

1 Mechanical Engineering Department Universiti Teknologi PETRONAS Bandar Seri Iskandar 31750 Tronoh Perak Malaysia2 Chemical Engineering Department Universiti Teknologi PETRONAS Bandar Seri Iskandar 31750 Tronoh Perak Malaysia

Correspondence should be addressed to Samson Mekbib Atnaw mekbibsamsyahoocom

Received 23 August 2013 Accepted 13 November 2013 Published 20 January 2014

Academic Editors R Maceiras G Madras and J N Sahu

Copyright copy 2014 Samson Mekbib Atnaw et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Biomass wastes produced from oil palm mills and plantations include empty fruit bunches (EFBs) shells fibers trunks and oilpalm fronds (OPF) EFBs and shells are partially utilized as boiler fuel while the rest of the biomass materials like OPF have notbeen utilized for energy generation No previous study has been reported on gasification of oil palm fronds (OPF) biomass for theproduction of fuel gas In this paper the effect of moisture content of fuel and reactor temperature on downdraft gasification ofOPF was experimentally investigated using a lab scale gasifier of capacity 50 kW In addition results obtained from equilibriummodel of gasification that was developed for facilitating the prediction of syngas composition are compared with experimentaldata Comparison of simulation results for predicting calorific value of syngas with the experimental results showed a satisfactoryagreement with a mean error of 01MJNm3 For a biomass moisture content of 29 the resulting calorific value for the syngaswas found to be only 263MJNm3 as compared to nearly double (495MJNm3) for biomass moisture content of 22 A calorificvalue as high as 557MJNm3 was recorded for higher oxidation zone temperature values

1 Introduction

A tremendous amount of sustainable and renewable rawmaterial for energy use exists inMalaysia in the form of palmoil biomass waste Oil palm plantation in Malaysia covered498 million hectares of plantation area as of 2011 [1] withestimated harvestable biomass of 50 to 70 tons per hectare peryear [2] Considering the entire life cycle of a palm tree only10 of the total plantation is converted to the final product(namely palm oil and palm kernel oil) while the remaining90 will be turned to biomass waste [3] Hence being amajor palm oil exporting country Malaysia is producing ahuge amount of oil palm biomass waste which can be usedas an ample and sustainable resource for renewable energygeneration [4 5]

The rise in prices of fossil fuels their finite and non-renewable existence and the need for energy independencecreated a prominent need for renewable and alternative

energy sources In addition the present extensively increas-ing use of fossil fuels and the subsequent high rate of pollutantemission is having adverse effects on the environment [6]Due to these reasons there is a need for adoption of renewableand environmentally friendly energy sources which aresustainable less costly andnot contributing to environmentalproblems [6ndash8] One form of renewable and environmentallyfriendly source of energy is biomass fuel As Malaysia hasan ample source of biomass waste generated from the palmoil industry it could be utilized as a sustainable cheaper-andpollution-free alternative energy source

The biomass waste from the oil palm industry includesempty fruit bunches (EFB) kernel shells palm oil milleffluent (POME) trunks and oil palm fronds (OPF) Morethan 53 million tons of oil palm biomass waste was reportedto be produced inMalaysia as of 2009 out of which OPF werefound to contribute 24 of the total annual production [4]To ensure good production rate of the fruit brunch the fronds

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 121908 9 pageshttpdxdoiorg1011552014121908

2 The Scientific World Journal

1 2

3

44

4

5

67

8

9

Figure 1 Schematic of the experimental setup (1) air blower (2) air distribution line (3) downdraft gasifier (4) gas flare points (5) raw gassampling point (6) cyclone for gas cleaning (7) cooling heat exchanger (8) oil bath filter and (9) clean gas sampling point

(OPF) must be pruned regularly OPF are available all yearround as pruning is done during collection of fresh brunchesat the average of two fronds per tree per month While someof the oil palm wastes like shells and EFBrsquos are partiallyutilized as boiler fuel the trimmedOPF are usually left insidethe plantations for a low value application of soil nutritionand erosion control Though there are a number of studieson thermochemical conversion of various biomass fuels veryfew numbers of studies exist on oil palm biomass materialsEven the few studies carried out on oil palm biomass arelimited to pyrolysis and liquefaction of EFBrsquos shells andfibers [3 9ndash15]Only a very recently limited number of studieswere reported on fixed bed and fluidized bed gasificationof oil palm biomass [16ndash19] while the studies and recordeddata on gasification or pyrolysis of OPF biomass are very fewHence the current study is focused on OPF

Comparison of lignocellulosic composition of OPF withother biomass shows its high potential as a fuel for thermo-chemical energy conversion Biomass materials are basicallycomposed of the chemical components cellulose hemicel-luloses lignin and ash The relative composition of thesechemical components varies depending on the type ofbiomass usually in the range of 40ndash60 cellulose 20ndash40hemicelluloses and 10ndash25 lignin on dry basis [3] Thechemical composition in weight percent of the different oil-palm biomass types reported in the work of Mohammedet al [4] and Kelly-Yong et al [20] were compared with thatof OPF The studies showed that OPF have higher cellulosecomposition and the least lignin content as compared to otheroil palm biomass materials A study on the effect of woodybiomass components on air-water gasification carried out byHanaoka et al [21] verified that cellulose has higher carbonconversion efficiency In addition higher carbon monoxidecomposition in the range of 355 in syngas was reportedcompared to hemicellulose and lignin Moreover lignin wasreported to have inferior qualities in gasification conversionas it mainly consists of fixed carbon compounds Hence thehigher cellulose composition of OPF (498) and its lowerlignin and ash composition (205 and 24 resp) indicatedthat OPF have a higher potential as a gasification feedstock

The current study focused on the study of downdraftgasification of OPF Studies on biomass gasification haveshown that themajor operating parameters that influence thegasification process include air fuel ratio moisture content offuel reactor temperature and particle size of feedstock [22ndash26] This paper studies the influence of moisture content and

reactor temperature on the composition and calorific valueof syngas making use of a lab scale downdraft gasificationsetup An equilibrium model of downdraft gasification ofOPF was developed in order to facilitate prediction of syngascomposition and calorific value Moreover simulation resultsfrom the equilibriummodel were compared with experimen-tal data The detail physical and chemical characterizationsand feasibility study of OPF feedstock and the full accountof the development of the equilibrium model of gasificationwere discussed in previous papers [27ndash35]

2 Methodology

21 Experimental Setup and Procedures Theexperimental rigused was a batch feed downdraft gasifier The operation wascarried out at atmospheric condition using air as a gasificationmedium The design capacity of the gasifier used was 50 kWof thermal output The reactor was cylindrical with a heightof 1000mm and diameter of 400mm A necking or throatof slope angle of 70∘ was provided near the grate of thegasifier in order to ensure smooth downflow of the biomassby gravity In order to decrease energy loss due to heattransfer the gasifierwall was insulatedwith refractory cementmaterial of thickness 25mmThedetails on the gasifier designwere presented in the work of Moni and Sulaiman [36] Theschematic of the experimental setup is shown in Figure 1Theexperimental setup consisted of a blower (1) for the supply ofair and a number of syngas conditioning units downstreamof the gasifier The conditioning units used for the coolingand cleaning of syngas include a cyclone (6) condenser (7)and oil bath filter (8)which were provided before the cleanedgas sampling point (9) In addition as shown in Figure 1 anumber of flare points (4) were provided on the outlet pipingin order to check the combustibility of produced syngas andto burn poisonous gases like CO produced from gasificationbefore being released to the atmosphere A multipurposeEmerson X2GP gas analyzer was used to measure volumepercentage of the major component gases CO CO

2 CH4

and H2in the syngas produced

The experimental procedure involved collection andrecording of temperature readings along the gasifier bedusing five type-N thermocouples of accuracy plusmn25∘C Thethermocouples were mounted in the middle section at fivedifferent points along the length of the gasifier The temper-ature readings were collected using USB based temperature

The Scientific World Journal 3

data logger at each minute and the readings were automat-ically stored in a computer The flow rate of inlet air wasmeasured making use of a VFC Series Dwyer rotameterwhich has an accuracy of plusmn10 lpm The particle sizes of thefeedstock used were between 10 and 25mm As the fixedbed gasifier is a batch fed type 12 kg of OPF was filled inthe reactor for experimental test operation An online gasanalyzer unit was used to measure the composition of syngasat the outlet pipe Besides the amount of ash char and liquidtar produced was collected and weighed at the end of eachrun to account for the total material balance of the systemand in order to determine the mass conversion efficiency ofthe gasification process Once combustion started at the gratethe air inlet blower was connected and started supplying airat a constant flowrate The gas compositions were recordedevery five minutes during the operationThe average of thesegas composition values recorded over the steady operationperiod was used to calculate the calorific value of syngasTheinfluence of reactor temperature was studied by recordingcomposition of produced syngas corresponding to values ofoxidation zone temperature While the effect of moisturecontent of fuel on the reactor temperature was studied bycarrying out gasification with fuels of different moisturecontent the air flow rate was kept constant at 180 lpm for allexperiments

22 Model Development Equilibrium model of gasificationwas developed based on ultimate and proximate properties ofOPF considering the batch fed operation which is commonlyused in fixed bed gasifiers The use of equilibrium model isreasonably justified as the batch process allows sufficientlylonger time for all the major gasification reactions to reachequilibrium Moreover the equilibrium model is knownto give sufficiently accurate prediction for processes likegasification that took place at temperature higher than 800∘C[37] The equilibrium model for downdraft gasification ofOPFwasmodeled using the unit operationmodels of ASPENPlus process simulation software [30] Advanced System forProcess Engineering (ASPEN) is a software tool that canbe used for modeling and simulation of various reactionengineering processes It is a helpful tool in designing andsizing of reactors as well as predicting chemical processoutputs ASPENwas selected as it handles chemical reactionsinvolving solids and allows the use of external FORTRANbased programing code to enhance the modeling capabilityThe simulation results from the model were used to predictthe composition and resulting heating value of syngas

The gaseous components considered in modeling of thegasification process include H

2 O2 CO CO

2 H2O N2

CH4 and S From the different stream classes in ASPEN the

conventional stream class was used for the gaseous reactantsand products while the char produced from gasification wasdefined as pure carbonThis assumptionwas adequately validas the char is known to be composedmainly of carbonThere-fore conventional solid stream class was used for char TheOPF feedstock and ash were defined as a nonconventionalsolid making use of the component attribute feature basedon ultimate and proximate analysis results of the biomass

Table 1 Ultimate and proximate analysis of OPF [2]

Proximate analysis ()lowast

Volatile matter (VM) 851Fixed carbon (FC) 115Ash 34

Ultimate analysis ()lowast

C 424H 58N 36O (by diff) 482lowastDry weight basis

The ultimate and proximate analysis results of OPF used asinput to the model are shown in Table 1 [2] Four differentunit operation blocks namely stoichiometric reactor yieldreactor and two Gibbs equilibrium reactors were used tomodel the drying zone pyrolysis zone and oxidation andreductions zones respectively Full account of the modeldevelopment and more details on the simulation results werediscussed in previous publications [27 30]

3 Results and Discussions

Experiments on downdraft gasification of OPF feedstockwith different initialmoisture content values were performedGenerally all the conditions tested resulted in successful gasi-fication operations of which syngas at the flare point couldbe ignited A stable flare was observed for OPF feedstockwith lower moisture content (22) implying that stable gasi-fication temperature was achieved throughout the operationtime Reactor temperature profiles and syngas compositionsfor gasification experiments with different initial moisturecontent values of feedstock are compared In addition resultsof the equilibrium model used for prediction of compositionand calorific value of syngas at different values of operatingparameters for downdraft gasification of OPF are comparedwith the experimental results

31 Typical Gasification Run Results Average values of themeasured syngas composition were used to calculate thecalorific value (CV) and gasification efficiency Summary ofthe operating parameters and experimental results for thegasification of OPF with moisture content of 22 is shownin Table 2 During the first 30 minutes of the experiment theoxidation zone temperature increased from 100∘C to above800∘C A stable oxidation zone temperature was observedduring the subsequent 40 minutes with an oxidation zonetemperature values higher than 900∘C implying a steadygasification operation The high oxidation zone temperaturewhich was comparable to that for gasification (downdraft)of other biomass fuels ensured breaking down of heavyhydrocarbon compounds like tar as the gas passed throughthe oxidation zone [23 25 38]The average calorific value forthe dried OPF was 495MJNm3 with a peak calorific valueof 557MJNm3 obtained for oxidation zone temperaturesabove 1000∘C The average calorific value was found to be


Table 2 Operation parameters and results for a typical gasificationtest operation

Type of feedstock OPFTotal operation time (min) 118Moisture content ( wet basis) 22Initial weight of feed (kg) 12Inlet air flow rate (lpm) 180Air fuel ratio (kg airkg fuel) 207Equivalence ratio (ER) 044Average oxidation zone temperature (∘C) 778Average reduction zone temperature (∘C) 510Average pyrolysis zone temperature (∘C) 456Average drying zone temperature (∘C) 222Estimated gas yield (lpm) 2812Average calorific value of syngas (MJNm3) 495Weight of ash and char (g) 620Amount of tar produced (g) 1078Gasification efficiency () 7054Mass conversion efficiency () 9394

Table 3 Comparison of heating value of syngas from gasification ofdifferent biomass

Biomass type LHV (MJNm3) ReferencesOPF 495 Current studyCoconut shells 49 [40]Hazelnut shells 470 [23]Furniture wood 562 [25]Woody biomass 502 [24]

comparable with those reported in the literature [23 25 3940] for other biomass types Shown in Table 3 is comparisonof the calorific values of other biomass materials which arecomparable to OPF As shown in Table 3 the heating valueof syngas obtained from gasification of OPF was comparablewith coconut shells and woody biomass materials and higherthan hazelnut shells For downdraft gasification of OPF withinitial moisture content of 22 a gasification efficiencyof 705 and a mass conversion efficiency of 939 wereobtained These efficiency values were found to be withinthe range of those reported in the literature for downdraftgasification of woody biomass that is gasification efficiencyof 47 to 886 [25 39] and mass conversion efficiency of 75to 98 [25 41] Hence the results showed that OPF havea good potential to be used as a gasification fuel and couldproduce syngaswith acceptable heating value In addition thegasification and mass conversion efficiencies are comparableto that of woody biomass

Summary of the typical ASPEN simulation results and theexperimental results is shown in Table 4 Both simulation andexperimental results were obtained for operating conditionsof air fuel ratio (AFR) of 207 and initial moisture contentof 22 The comparison of typical simulation results with

experimental results was obtained by using the sum squaredeviation method [42]

RSS =119873

sum119894=1

(119910119894119890minus 119910119894119901

119910119894119890

)

2

(1)

where 119910119894119890is experimental composition value of each syngas

component measured from experiment and 119910119894119901

stands forpredicted composition of each component from the simu-lation work The average mean square error was calculatedconsidering the total number of data119873

MRSS = RSS119873 (2)

Calculation for the mean error was obtained by square rootof (2)

The mean errors from the statistical analysis results forcomparison between the simulation and the experimentalresults are shown in Table 4 From the calculatedmean errorsit can be implied that the predictions of syngas compositionfrom the equilibriummodel are generally in good agreementwith those from the experimental results As shown inTable 4slightly highmean error between predicted and experimentalvalues was obtained for CH

4concentrationThis is due to the

prediction of only trace amount of CH4concentration from

the equilibrium model as compared to concentrations of 1to 25 obtained in actual gasification Similar observationswere reported in other equilibriummodeling studies [24 37]In the work of Gautam [37] CH

4concentration lower than

015 was predicted by equilibrium model as compared to3 to 4 concentration in actual gasification experimentsThe prediction from the equilibrium model of gasificationin the current study was shown in Table 4 to slightly over-estimate the concentration of H

2in syngas as compared to

experimental results Similar variations between equilibriummodel predictions and experimental concentrations of H

2

were reported in literature [24 37 43] The heating valueof syngas predicted by the equilibrium model was in goodagreement with results from actual gasification The meanerror for the prediction of lower heating value (LHV) ofsyngas was found to be 01MJNm3

32 Effect of Moisture Content on Reactor TemperatureShown in Figure 2 is variation of oxidation zone temperaturewith time from the start of batch operation for gasificationof fuel with moisture content of 22 and 29 The resultsshowed that the oxidation zone temperature in the case ofthe higher moisture content was consistently low duringthe entire operation duration with roughly half the averagevalue recorded for lower moisture content For both casesthe oxidation zone temperature showed a sharp rise in thefirst 10 minutes of operation after startup The oxidationtemperature continued to increase steadily with operationtime for the case of lower moisture content fuel while itremained relatively stable at an average of about 600∘C forthe case of higher moisture content fuel Typical for fixedbed gasification process variations in the temperatures wereshown during the operation time During the relatively stable


Table 4 Comparison of typical simulation results with experimental values

ComponentsTypical Experimental results at different operation time (min)

simulation 10 20 30 40 50 60 70 80 Meanlowast

results errorCO 1947 2102 1807 2812 2593 2622 2770 2889 2401 021CO2 1399 1334 1543 773 948 997 815 758 972 047H2 1557 1151 1259 847 973 1071 954 993 939 049CH4 001 176 251 091 120 131 115 136 107 086N2 5438 5237 5140 5477 5366 5179 5346 5224 5581 004LHV (MJNm3)lowastlowast 430 470 471 497 493 512 512 540 459 010lowastMean error between typical simulation results and experimental data based on sum square deviation methodlowastlowastLHV low heating value

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100 120Operation time (min)

MC 22MC 29

Oxi

datio

n zo

ne te

mpe

ratu

re (∘

C)

Figure 2 Dynamic temperature profiles of oxidation zone temper-ature for gasification of fuel with different initial moisture content

operation period between the 30th to 80th minutes theaverage temperature was 1048∘C (for lowmoisture OPF)Thereason for fluctuations in temperature could be due to thecomplex interactions between the number of endothermicand exothermic reactions taking place inside the reactor aswell as because of variations in the direct exposure of thethermocouples to the red hot fuel particles depending on thevariations in flow characteristics of the fuel with time [25]The oxidation zone temperature showed a sharp decreaseafter the 80th minute of operation due to depletion of thefeed material since the gasifier was under batch operationIn addition flaring of the syngas produced was hardlybeen possible during the experiment for the case of highermoisture content fuel implying that the high oxidation zonetemperature required for various endothermic gasificationreactions was not achieved

33 Effect ofMoisture Content on Gas Composition Theeffectof initial moisture content of fuel on the composition of syn-gas throughout the gasification period was studied Figure 3shows the variation of CO content with time from the startof gasification of OPF for different moisture content It isshown in Figure 3 that for gasification experiment with 22moisture content of fuel the CO content increases steadily

000

005

010

015

020

025

030

035

0 20 40 60 80 100 120

CO co

mpo

sitio

n (v

olum

e fra

ctio

n)

Operation time (min)

MC 22MC 29

Figure 3 Carbon monoxide content in syngas over operation timefor fuel of different initial moisture content

during the initial phase of the gasification but decreasessharply after around the 75th minute of operation The resultshowed that the CO content for OPF with 29 moisturecontentwas consistently lower than that of the lowermoisturecontent An earlier study suggested that CO content in syngaswould be favored by increase in the reactor temperature [16]and hence explains the reason for the observation in Figure 3that is low CO content for biomass with high moisturecontent The sharp decrease in CO composition after the75th minute of operation could most probably be due to thedepletion of the feedstock as the gasifier was batch operatedFor gasification of fuel with moisture content of 22 anaverage CO content of 25 was obtained during the first 75minutes of operation time as compared to only 114 for thecase of high moisture content fuel

Shown in Figure 4 is variation of CO2content in syngas

with operation time for gasification of fuel with moisturecontent of 22 and 29 The concentration of CO

2is shown

in Figure 4 to be lower for higher moisture content value offuel indicating that less combustion took place for highermoisture content fuel as evidenced from the lower temper-ature recorded The effect of initial moisture content of fuelon CH

4and H

2composition was only marginal as shown in

Figures 5 and 6 Only slightly higher contents of CH4and H

2


000

005

010

015

020

025


MC 22MC 29

CO2

com

posit

ion

(vol

ume f

ract

ion)

Figure 4 Carbon dioxide content in syngas over operation time forfuel of different initial moisture content

0000

0005

0010

0015

0020

0025

0030


MC 22MC 29

CH4 co

mpo

sitio

n (v

olum

e fra

ctio

n)

Figure 5 Methane content in syngas over operation time for fuel ofdifferent moisture content

000

002

004

006

008

010

012

014


MC 22MC 29

H2 co

mpo

sitio

n (v

olum

e fra

ctio

n)

Figure 6 Hydrogen content in syngas over operation time for fuelof different moisture content

0

1

2

3

4

5

6


MC 22MC 29

Calo

rific v

alue

of s

ynga

s (M

JNm

3)

Figure 7 Variation of calorific value with operation time for fuel ofdifferent initial moisture content

were observed for the case of lower moisture content of fuelwhile relatively a similar amount of volume concentration ofthe gases were found for both fuels The study of Sulaimanet al [34] on the effect of fuel moisture content reportedthat the concentration of H

2and CH

4increases slightly for

gasification of higher moisture content fuel due to steamgasification Considering the reduction zone reactions [3435]

C +H2O 997888rarr CO +H

2(ΔH = 119 kJmol) (3)

C + 2H2O 997888rarr CO

2+ 2H2(ΔH = 75 kJmol) (4)

C + 2H2997888rarr CH

4(ΔH = minus87 kJmol) (5)

the gasification process is expected to produce higher yieldof H2 CH4 and CO

2for the case of higher moisture content

fuel due to steam gasification However as the steam-carbonreduction reactions in (3) and (4) are endothermic in naturethe yield of product gases H

2 CH4 and CO

2is dependent on

the reactor temperature in addition to the moisture content(H2O) [34 35] Furthermore part of the H

2and CH

4in

syngas is expected to be produced by the thermal crackingof heavy hydrocarbon compounds like tar This thermalcracking of heavier hydrocarbons is also possible only athigher temperature However during gasification of highermoisture content fuel the oxidation zone temperature wasfound to be very low which may be due to the amount ofheat consumed during evaporation of the moisture in fuelinside the drying zone This could be the reason for theproduction of nearly similar concentration of H

2and CH

4in

syngas for gasification of both high and lowmoisture contentfuel Hence it can be concluded from the results that thegasification reaction is more influenced by the reduction inthe reactor temperature for highmoisture fuel rather than theeffect of steam gasification Sulaiman et al [34] also reportedthat improvement in H

2yield from steam-carbon reactions is

significant only at higher temperatures above 750∘C

34 Effect of Moisture Content on Calorific Value of SyngasShown in Figure 7 is the variation of calorific value of syngas


with operation time for gasification of OPF with moisturecontents of 22 and 29 As shown in Figure 7 consistentlylow calorific value was observed for gasification of fuel withhigher moisture content This is expected from the lowerconcentration of CO obtained during the experimental runusing high moisture content OPF The range of calorificvalues obtained for the case of higher moisture content wasbelow 4MJNm3 which was lower than the expected rangeof heating value (4ndash6MJNm3) for syngas produced fromtypical gasification of woody biomass [25] On the otherhand the average and peak lower heating values for thegasification experiment with lower moisture content were495 and 557MJNm3 respectivelyThis indicates that initialdrying of the feedstock to a lower moisture content value isnecessary in order to produce syngas of acceptable heatingvalue Sulaiman et al [34] also recommended the use ofbiomass having low moisture content in order to maximizethe heating value and quality of produced syngas In additionlow reactor temperature resulting fromhighmoisture contentfuel highly compromises the gas yield carbon conversionefficiency and gasification efficiency [34] The drying ofthe feedstock could simply be done under the sun withno additional energy expenditure and without incurringfurther cost during the moisture removal In case of usingartificial drying the additional energy expenditure could beminimized by recovering heat from various streams (such ashot furnace flu gas from engine or gas turbine warm air fromcondenser etc) in a commercial gasification power plant[36] Hence further studies need to be done in future in orderto reduce the impact of energy expenditure for pretreatmentof the feed in terms of drying on the overall efficiency of thegasification plant

35 Effect of Reactor Temperature on Syngas Calorific ValueThe calorific value (CV) of the producer gas is highlyimportant for consumption as fuel in engines for powergeneration As the main objective is to obtain a high calorificvalue fuel gas with consistent energy density the effect ofreactor temperature on the calorific value of producer gas wasinvestigated The experimental study on variation of syngascalorific value with temperature was carried out by record-ing the composition of produced syngas corresponding todifferent values of reactor temperature For the modelingstudy initially syngas composition was predicted using theequilibrium model of gasification Then the lower heatingvalue (LHV) of producer gas from OPF gasification wasestimated by using the predicted fractions of gases 119883

119894 and

heating value of themajor fuel components CO H2 and CH

4

making use of the relation

LHVsyngas = 119883CO times (LHV)CO + 119883H2

times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)

where the LHV of the major fuel components CO H2

and CH4were taken to be 131MJNm3 112MJNm3 and

371MJNm3 respectively [40 44] Shown in Figure 8 is thevariation of predicted and experimental values of calorificvalue of syngas over the range of oxidation zone temperature

0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200

OPF simulationOPF experimental

Calo

rific v

alue

(MJN

m3)

Oxidation zone temperature (∘C)

Figure 8 Variation of predicted and measured calorific value ofsyngas with oxidation zone temperature

between 500 and 1200∘C Both the equilibrium model andexperimental results showed an increase in heating value ofsyngas with increase in temperature as shown in Figure 8A similar trend of increase in heating value of syngas withreactor temperature was obtained in the work of Lahijani andZainal [16] for fluidized bed gasification of EFBs and sawdustbiomassThe experimental calorific value results were shownin Figure 8 to be slightly higher than the predicted valuesfor temperatures above 850∘C This could be explained interms of the increase in concentration of CO in syngas withoperation time At the start of the gasification operation thereactor temperature would be low and it started to increasesteadily with time The temperature exceeded 850∘C afterabout 30 minutes of operation Due to the batch fed nature ofthe gasifiermost of the fuelrsquos hydrogen based volatile contentsunderwent devolatilization and what remained at later oper-ation time (when the reactor temperature was higher than850∘C) was mostly char This contributes to the high rate ofCO production at higher reactor temperature and this wasnot captured in the ASPEN PLUS simulation As CO wasthe main fuel component with significant amount of heatingvalue in syngas its higher concentration resulted in a slightlyhigher calorific value of syngas for the experimental resultsas compared to model predictions at higher temperatureHowever the experimental and model prediction resultsshowed satisfactory agreement with a mean error of only0017MJNm3 for the range of oxidation zone temperature ofbetween 500 and 1200∘C

4 Conclusions

Experimental investigation on effect of moisture content offuel and temperature on syngas composition and calorificvalue was carried out Lower composition of carbon monox-ide was observed for higher moisture content fuel Theeffect of moisture content on H

2and CH

4concentrations

was only marginal with slightly higher values recorded forgasification of low moisture content fuel For a biomassmoisture content of 29 the resulting calorific value for


the syngas was found to be only 263MJNm3 as comparedto nearly double (495MJNm3) for biomassmoisture contentof 22 In addition all data points recorded for gasificationof acceptable moisture content fuel were within the rangeof 4ndash6MJNm3 as expected for atmospheric gasification ofbiomass This indicates that initial drying of the feedstockto lower moisture content value is necessary in order toproduce syngas of acceptable heating value and it has a hugeadvantage in terms of the production of a high calorificvalue In addition predictions from equilibrium model ofdowndraft gasification of OPF developed for the predictionof syngas composition and calorific value were shown tobe in good agreement with the experimental results Theexperimental and model prediction results when comparedover the range of oxidation zone temperature of between 500and 1200∘C showed satisfactory agreement with a mean errorof only 0017MJNm3 Both experimental and simulationresults ascertain that calorific value increases with reactortemperature Calorific value as high as 557MJNm3 wasrecorded at oxidation zone temperature of above 1000∘CTheresults of the study demonstrated that drying of the OPFfeedstock to low moisture content and maintaining a highoxidation zone temperature could significantly improve thegasification output

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

The authors would like to gratefully acknowledge the finan-cial support from the Fundamental Research Grant Scheme(FRGS) of the Malaysian Ministry of Higher Education andthe internal grant of Universiti Teknologi PETRONAS inconducting the present study

References

[1] W P Q Ng H L Lam F Y Ng et al ldquoWaste-to-wealth greenpotential from palm biomass in Malaysiardquo Journal of CleanerProduction vol 10 pp 57ndash65 2012

[2] C Wahid and C K Weng ldquoAvailability and potential ofbiomass resources from the malaysian palm oil industry forgenerating renewable energyrdquo inOil PalmBulletin vol 56 2008httppalmoilismpobgovmypublicationsopb56html

[3] H Yang R Yan H Chen D H Lee D T Liang and CZheng ldquoPyrolysis of palm oil wastes for enhanced productionof hydrogen rich gasesrdquo Fuel Processing Technology vol 87 no10 pp 935ndash942 2006

[4] M A A Mohammed A Salmiaton W A K G Wan AzlinaM S Mohammad Amran A FakhrursquoL-Razi and Y H Taufiq-Yap ldquoHydrogen rich gas from oil palm biomass as a potentialsource of renewable energy in Malaysiardquo Renewable and Sus-tainable Energy Reviews vol 15 no 2 pp 1258ndash1270 2011

[5] MZ JaafarWHKheng andNKamaruddin ldquoGreener energysolutions for a sustainable future issues and challenges forMalaysiardquo Energy Policy vol 31 no 11 pp 1061ndash1072 2003

[6] P Basu Biomass Gasification and Pyrolysis Practical Design andTheory Academic Press Burlington Mass USA 2010

[7] S Lee Alternative Fuels Taylor amp Francis Washington DCUSA 1996

[8] A K Sharma ldquoExperimental study on 75 kWth downdraft(biomass) gasifier systemrdquo Renewable Energy vol 34 no 7 pp1726ndash1733 2009

[9] J Akhtar S K Kuang and N S Amin ldquoLiquefaction of emptypalm fruit bunch (EPFB) in alkaline hot compressed waterrdquoRenewable Energy vol 35 no 6 pp 1220ndash1227 2010

[10] J Guo and A C Lua ldquoKinetic study on pyrolytic process of oil-palm solid waste using two-step consecutive reaction modelrdquoBiomass and Bioenergy vol 20 no 3 pp 223ndash233 2001

[11] D H Lee H Yang R Yan and D T Liang ldquoPrediction ofgaseous products from biomass pyrolysis through combinedkinetic and thermodynamic simulationsrdquo Fuel vol 86 no 3 pp410ndash417 2007

[12] H Yang R Yan T Chin D T Liang H Chen and C ZhengldquoThermogravimetric analysismdashfourier transform infrared anal-ysis of palm oil waste pyrolysisrdquo Energy and Fuels vol 18 no 6pp 1814ndash1821 2004

[13] F Abnisa A Arami-Niya W M A Wan Daud and J N SahuldquoCharacterization of bio-oil and bio-char frompyrolysis of palmoil wastesrdquo BioEnergy Research vol 6 no 2 pp 830ndash840 2013

[14] FAbnisa AArami-NiyaWMAWanDaud et al ldquoUtilizationof oil palm tree residues to produce bio-oil and bio-char viapyrolysisrdquo Energy Conversion and Management vol 76 pp1073ndash1082 2013

[15] CW Kean J N Sahu andWM AWanDaud ldquoHydrothermalgasification of palm shell biomass for synthesis of hydrogenfuelrdquo BioResources vol 8 pp 1831ndash1840 2013

[16] P Lahijani and Z A Zainal ldquoGasification of palm emptyfruit bunch in a bubbling fluidized bed a performance andagglomeration studyrdquo Bioresource Technology vol 102 no 2 pp2068ndash2076 2011

[17] M A A Mohammed A Salmiaton W A K G Wan AzlinaM S Mohammad Amran and A FakhrursquoL-Razi ldquoAir gasifica-tion of empty fruit bunch for hydrogen-rich gas production in afluidized-bed reactorrdquoEnergy Conversion andManagement vol52 no 2 pp 1555ndash1561 2011

[18] S M Atnaw S A Sulaiman and S Yusup ldquoSyngas productionfrom downdraft gasification of oil palm frondsrdquo Energy vol 61pp 491ndash501 2013

[19] FMGuangul S A Sulaiman andA Ramli ldquoGasifier selectiondesign and gasification of oil palm fronds with preheated andunheated gasifying airrdquo Bioresource Technology vol 126 pp224ndash232 2012

[20] T L Kelly-Yong K T Lee A R Mohamed and S BhatialdquoPotential of hydrogen from oil palm biomass as a source ofrenewable energy worldwiderdquo Energy Policy vol 35 no 11 pp5692ndash5701 2007

[21] T Hanaoka S Inoue S Uno T Ogi and T Minowa ldquoEffect ofwoody biomass components on air-steam gasificationrdquo Biomassand Bioenergy vol 28 no 1 pp 69ndash76 2005

[22] J K Ratnadhariya and S A Channiwala ldquoThree zone equi-librium and kinetic free modeling of biomass gasifiermdasha novelapproachrdquoRenewable Energy vol 34 no 4 pp 1050ndash1058 2009

[23] M Dogru C R Howarth G Akay B Keskinler and A AMalik ldquoGasification of hazelnut shells in a downdraft gasifierrdquoEnergy vol 27 no 5 pp 415ndash427 2002


[24] Z A Zainal R Ali C H Lean and K N Seetharamu ldquoPredic-tion of performance of a downdraft gasifier using equilibriummodeling for different biomass materialsrdquo Energy Conversionand Management vol 42 no 12 pp 1499ndash1515 2001

[25] Z A Zainal A Rifau G A Quadir and K N SeetharamuldquoExperimental investigation of a downdraft biomass gasifierrdquoBiomass and Bioenergy vol 23 no 4 pp 283ndash289 2002

[26] P Mathieu and R Dubuisson ldquoPerformance analysis of abiomass gasifierrdquo Energy Conversion and Management vol 43no 9ndash12 pp 1291ndash1299 2002

[27] S A SulaimanM R T Ahmad and SMAtnaw ldquoPrediction ofbiomass conversion process for oil palm fronds in a downdraftgasifierrdquo in Proceedings of the 4th International Meeting onAdvances in Thermofluids (IMAT rsquo11) Melaka Malaysia 2011

[28] S M Atnaw H A Sulaiman and S Yusup ldquoA simulationstudy of downdraft gasification of oil-palm fronds usingASPENPLUSrdquo Journal of Applied Sciences vol 11 no 11 pp 1913ndash19202011

[29] S A Sulaiman S Balamohan M N Z Moni et al ldquoStudyon the feasibility of oil palm-fronds for biomass gasificationrdquoin Proceedings of the 5th International Ege Energy Symposiumand Exhibition (IEESE-5 rsquo10) Pamukkale University DenizliTurkey 2010


[31] S A Sulaiman S M Atnaw and M N Z Moni ldquoA prelimiarystudy of oil palm fronds for gasificaion processrdquo in Proceedingsof the Power and Energy Systems (EUROPES rsquo11) Crete Greece2011

[32] S M Atnaw and S A Sulaiman ldquoModeling and simulationstudy of downdraft gasifier using oil-palm frondsrdquo in Proceed-ings of the 3rd International Conference on Energy and Environ-ment Advancement Towards Global Sustainability (ICEE rsquo09)pp 284ndash289 Melaka Malaysia December 2009

[33] S M Atnaw S A Sulaiman and S Yusup ldquoPredictionof calorific value of syngas produced from oil-palm frondsgasificationrdquo in Proceedings of the 3rd National PostgraduateConferencemdashEnergy and Sustainability Exploring the InnovativeMinds (NPC rsquo11) pp 1ndash4 Kuala Lumpur Malaysia September2011

[34] S A SulaimanM F KarimM Nazmi et al ldquoOn gasification ofdifferent tropical plant-based biomass materialsrdquo Asian Journalof Scientific Research vol 6 pp 245ndash253 2013

[35] F M Guangul S A Sulaiman M N Moni et al ldquoDeter-mination of equilibrium moisture content of oil palm frondsfeedstock for gasification feedstockrdquo Asian Journal of ScientificResearch vol 6 pp 360ndash366 2013

[36] M N Z Moni and S A Sulaiman ldquoDevelopment of a biomassdowndraft gasifier for oil palm frondsrdquo in National Postgradu-ates Conference on Engineering Science and Technology TronohMalaysia 2009

[37] G Gautam Parametric study of a commercial-scale biomassdowndraft gasifier experiments and equilibrium modeling [MSthesis] Graduate Faculty of Auburn University in partial fulfill-ment of the r equirements for the Degree of Master of ScienceAuburn University 2010

[38] L P L M Rabou R W R Zwart B J Vreugdenhil and L BosldquoTar in biomass producer gas the Energy researchCentre ofTheNetherlands (ECN) experience an enduring challengerdquo Energyand Fuels vol 23 no 12 pp 6189ndash6198 2009

[39] C-LHsi T-YWang C-H Tsai et al ldquoCharacteristics of an air-blown fixed-bed downdraft biomass gasifierrdquo Energy and Fuelsvol 22 no 6 pp 4196ndash4205 2008

[40] S C Bhattacharya S Shwe Hla and H-L Pham ldquoA studyon a multi-stage hybrid gasifier-engine systemrdquo Biomass andBioenergy vol 21 no 6 pp 445ndash460 2001

[41] Y Cao Y Wang J T Riley and W-P Pan ldquoA novel biomass airgasification process for producing tar-free higher heating valuefuel gasrdquo Fuel Processing Technology vol 87 no 4 pp 343ndash3532006

[42] M B Nikoo and N Mahinpey ldquoSimulation of biomass gasifica-tion in fluidized bed reactor using ASPEN PLUSrdquo Biomass andBioenergy vol 32 no 12 pp 1245ndash1254 2008

[43] S Jarungthammachote and A Dutta ldquoEquilibriummodeling ofgasification gibbs free energy minimization approach and itsapplication to spouted bed and spout-fluid bed gasifiersrdquoEnergyConversion andManagement vol 49 no 6 pp 1345ndash1356 2008

[44] T B Reed and A DasHandbook of Biomass Downdraft GasifierEngine Systems Solar Energy Research Institute Golden ColoUSA 1988

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

FuelsJournal of


Journal ofPetroleum Engineering


Industrial EngineeringJournal of


Power ElectronicsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Advances in

CombustionJournal of


Journal of


Renewable Energy

Submit your manuscripts athttpwwwhindawicom


StructuresJournal of


RotatingMachinery


EnergyJournal of


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Nuclear InstallationsScience and Technology of


Solar EnergyJournal of


Wind EnergyJournal of


Nuclear EnergyInternational Journal of


High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


1 2

3

44

4

5

67

8

9

Figure 1 Schematic of the experimental setup (1) air blower (2) air distribution line (3) downdraft gasifier (4) gas flare points (5) raw gassampling point (6) cyclone for gas cleaning (7) cooling heat exchanger (8) oil bath filter and (9) clean gas sampling point

(OPF) must be pruned regularly OPF are available all yearround as pruning is done during collection of fresh brunchesat the average of two fronds per tree per month While someof the oil palm wastes like shells and EFBrsquos are partiallyutilized as boiler fuel the trimmedOPF are usually left insidethe plantations for a low value application of soil nutritionand erosion control Though there are a number of studieson thermochemical conversion of various biomass fuels veryfew numbers of studies exist on oil palm biomass materialsEven the few studies carried out on oil palm biomass arelimited to pyrolysis and liquefaction of EFBrsquos shells andfibers [3 9ndash15]Only a very recently limited number of studieswere reported on fixed bed and fluidized bed gasificationof oil palm biomass [16ndash19] while the studies and recordeddata on gasification or pyrolysis of OPF biomass are very fewHence the current study is focused on OPF

Comparison of lignocellulosic composition of OPF withother biomass shows its high potential as a fuel for thermo-chemical energy conversion Biomass materials are basicallycomposed of the chemical components cellulose hemicel-luloses lignin and ash The relative composition of thesechemical components varies depending on the type ofbiomass usually in the range of 40ndash60 cellulose 20ndash40hemicelluloses and 10ndash25 lignin on dry basis [3] Thechemical composition in weight percent of the different oil-palm biomass types reported in the work of Mohammedet al [4] and Kelly-Yong et al [20] were compared with thatof OPF The studies showed that OPF have higher cellulosecomposition and the least lignin content as compared to otheroil palm biomass materials A study on the effect of woodybiomass components on air-water gasification carried out byHanaoka et al [21] verified that cellulose has higher carbonconversion efficiency In addition higher carbon monoxidecomposition in the range of 355 in syngas was reportedcompared to hemicellulose and lignin Moreover lignin wasreported to have inferior qualities in gasification conversionas it mainly consists of fixed carbon compounds Hence thehigher cellulose composition of OPF (498) and its lowerlignin and ash composition (205 and 24 resp) indicatedthat OPF have a higher potential as a gasification feedstock

The current study focused on the study of downdraftgasification of OPF Studies on biomass gasification haveshown that themajor operating parameters that influence thegasification process include air fuel ratio moisture content offuel reactor temperature and particle size of feedstock [22ndash26] This paper studies the influence of moisture content and

reactor temperature on the composition and calorific valueof syngas making use of a lab scale downdraft gasificationsetup An equilibrium model of downdraft gasification ofOPF was developed in order to facilitate prediction of syngascomposition and calorific value Moreover simulation resultsfrom the equilibriummodel were compared with experimen-tal data The detail physical and chemical characterizationsand feasibility study of OPF feedstock and the full accountof the development of the equilibrium model of gasificationwere discussed in previous papers [27ndash35]

2 Methodology

21 Experimental Setup and Procedures Theexperimental rigused was a batch feed downdraft gasifier The operation wascarried out at atmospheric condition using air as a gasificationmedium The design capacity of the gasifier used was 50 kWof thermal output The reactor was cylindrical with a heightof 1000mm and diameter of 400mm A necking or throatof slope angle of 70∘ was provided near the grate of thegasifier in order to ensure smooth downflow of the biomassby gravity In order to decrease energy loss due to heattransfer the gasifierwall was insulatedwith refractory cementmaterial of thickness 25mmThedetails on the gasifier designwere presented in the work of Moni and Sulaiman [36] Theschematic of the experimental setup is shown in Figure 1Theexperimental setup consisted of a blower (1) for the supply ofair and a number of syngas conditioning units downstreamof the gasifier The conditioning units used for the coolingand cleaning of syngas include a cyclone (6) condenser (7)and oil bath filter (8)which were provided before the cleanedgas sampling point (9) In addition as shown in Figure 1 anumber of flare points (4) were provided on the outlet pipingin order to check the combustibility of produced syngas andto burn poisonous gases like CO produced from gasificationbefore being released to the atmosphere A multipurposeEmerson X2GP gas analyzer was used to measure volumepercentage of the major component gases CO CO

2 CH4

and H2in the syngas produced

The experimental procedure involved collection andrecording of temperature readings along the gasifier bedusing five type-N thermocouples of accuracy plusmn25∘C Thethermocouples were mounted in the middle section at fivedifferent points along the length of the gasifier The temper-ature readings were collected using USB based temperature





2 O2 CO CO

2 H2O N2




















RSS =119873

sum119894=1

(119910119894119890minus 119910119894119901

119910119894119890

)

2

(1)




MRSS = RSS119873 (2)










2








0

200

400

600

800

1000

1200

1400


MC 22MC 29

Oxi

datio

n zo

ne te

mpe

ratu

re (∘

C)




000

005

010

015

020

025

030

035

0 20 40 60 80 100 120

CO co

mpo

sitio

n (v

olum

e fra

ctio

n)


MC 22MC 29





2is shown


4and H



2


000

005

010

015

020

025


MC 22MC 29

CO2

com

posit

ion

(vol

ume f

ract

ion)


0000

0005

0010

0015

0020

0025

0030


MC 22MC 29

CH4 co

mpo

sitio

n (v

olum

e fra

ctio

n)


000

002

004

006

008

010

012

014


MC 22MC 29

H2 co

mpo

sitio

n (v

olum

e fra

ctio

n)


0

1

2

3

4

5

6


MC 22MC 29

Calo

rific v

alue

of s

ynga

s (M

JNm

3)



2and CH




2(ΔH = 119 kJmol) (3)


2+ 2H2(ΔH = 75 kJmol) (4)






2 CH4 and CO

2is dependent on


2and CH

4in


2and CH

4in








119894 and


4



times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)




0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200


Calo

rific v

alue

(MJN

m3)




4 Conclusions


2and CH

4concentrations






Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















2 O2 CO CO

2 H2O N2




















RSS =119873

sum119894=1

(119910119894119890minus 119910119894119901

119910119894119890

)

2

(1)




MRSS = RSS119873 (2)










2








0

200

400

600

800

1000

1200

1400


MC 22MC 29

Oxi

datio

n zo

ne te

mpe

ratu

re (∘

C)




000

005

010

015

020

025

030

035

0 20 40 60 80 100 120

CO co

mpo

sitio

n (v

olum

e fra

ctio

n)


MC 22MC 29





2is shown


4and H



2


000

005

010

015

020

025


MC 22MC 29

CO2

com

posit

ion

(vol

ume f

ract

ion)


0000

0005

0010

0015

0020

0025

0030


MC 22MC 29

CH4 co

mpo

sitio

n (v

olum

e fra

ctio

n)


000

002

004

006

008

010

012

014


MC 22MC 29

H2 co

mpo

sitio

n (v

olum

e fra

ctio

n)


0

1

2

3

4

5

6


MC 22MC 29

Calo

rific v

alue

of s

ynga

s (M

JNm

3)



2and CH




2(ΔH = 119 kJmol) (3)


2+ 2H2(ΔH = 75 kJmol) (4)






2 CH4 and CO

2is dependent on


2and CH

4in


2and CH

4in








119894 and


4



times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)




0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200


Calo

rific v

alue

(MJN

m3)




4 Conclusions


2and CH

4concentrations






Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

























RSS =119873

sum119894=1

(119910119894119890minus 119910119894119901

119910119894119890

)

2

(1)




MRSS = RSS119873 (2)










2








0

200

400

600

800

1000

1200

1400


MC 22MC 29

Oxi

datio

n zo

ne te

mpe

ratu

re (∘

C)




000

005

010

015

020

025

030

035

0 20 40 60 80 100 120

CO co

mpo

sitio

n (v

olum

e fra

ctio

n)


MC 22MC 29





2is shown


4and H



2


000

005

010

015

020

025


MC 22MC 29

CO2

com

posit

ion

(vol

ume f

ract

ion)


0000

0005

0010

0015

0020

0025

0030


MC 22MC 29

CH4 co

mpo

sitio

n (v

olum

e fra

ctio

n)


000

002

004

006

008

010

012

014


MC 22MC 29

H2 co

mpo

sitio

n (v

olum

e fra

ctio

n)


0

1

2

3

4

5

6


MC 22MC 29

Calo

rific v

alue

of s

ynga

s (M

JNm

3)



2and CH




2(ΔH = 119 kJmol) (3)


2+ 2H2(ΔH = 75 kJmol) (4)






2 CH4 and CO

2is dependent on


2and CH

4in


2and CH

4in








119894 and


4



times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)




0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200


Calo

rific v

alue

(MJN

m3)




4 Conclusions


2and CH

4concentrations






Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of






















0

200

400

600

800

1000

1200

1400


MC 22MC 29

Oxi

datio

n zo

ne te

mpe

ratu

re (∘

C)




000

005

010

015

020

025

030

035

0 20 40 60 80 100 120

CO co

mpo

sitio

n (v

olum

e fra

ctio

n)


MC 22MC 29





2is shown


4and H



2


000

005

010

015

020

025


MC 22MC 29

CO2

com

posit

ion

(vol

ume f

ract

ion)


0000

0005

0010

0015

0020

0025

0030


MC 22MC 29

CH4 co

mpo

sitio

n (v

olum

e fra

ctio

n)


000

002

004

006

008

010

012

014


MC 22MC 29

H2 co

mpo

sitio

n (v

olum

e fra

ctio

n)


0

1

2

3

4

5

6


MC 22MC 29

Calo

rific v

alue

of s

ynga

s (M

JNm

3)



2and CH




2(ΔH = 119 kJmol) (3)


2+ 2H2(ΔH = 75 kJmol) (4)






2 CH4 and CO

2is dependent on


2and CH

4in


2and CH

4in








119894 and


4



times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)




0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200


Calo

rific v

alue

(MJN

m3)




4 Conclusions


2and CH

4concentrations






Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















000

005

010

015

020

025


MC 22MC 29

CO2

com

posit

ion

(vol

ume f

ract

ion)


0000

0005

0010

0015

0020

0025

0030


MC 22MC 29

CH4 co

mpo

sitio

n (v

olum

e fra

ctio

n)


000

002

004

006

008

010

012

014


MC 22MC 29

H2 co

mpo

sitio

n (v

olum

e fra

ctio

n)


0

1

2

3

4

5

6


MC 22MC 29

Calo

rific v

alue

of s

ynga

s (M

JNm

3)



2and CH




2(ΔH = 119 kJmol) (3)


2+ 2H2(ΔH = 75 kJmol) (4)






2 CH4 and CO

2is dependent on


2and CH

4in


2and CH

4in








119894 and


4



times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)




0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200


Calo

rific v

alue

(MJN

m3)




4 Conclusions


2and CH

4concentrations






Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




















119894 and


4



times (LHV)H2

+ 119883CH4

times (LHV)CH4

(6)




0

1

2

3

4

5

6

500 600 700 800 900 1000 1100 1200


Calo

rific v

alue

(MJN

m3)




4 Conclusions


2and CH

4concentrations






Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















Acknowledgments


References


















































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of











































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

















research article influence of fuel moisture content and...

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