Research Article Experimental Investigation of Biogas ...downloads.hindawi.com/journals/ijce/2014/609836.pdf · Research Article Experimental Investigation of Biogas Reforming in

Research ArticleExperimental Investigation of Biogas Reforming inGliding Arc Plasma Reactors

P Thanompongchart and N Tippayawong

Department of Mechanical Engineering Faculty of Engineering Chiang Mai University Chiang Mai 50200 Thailand

Correspondence should be addressed to N Tippayawong ntippayawongyahoocom

Received 17 February 2014 Revised 9 May 2014 Accepted 9 May 2014 Published 26 May 2014

Academic Editor Jinlong Gong

Copyright copy 2014 P Thanompongchart and N Tippayawong This is an open access article distributed under the CreativeCommons Attribution License which permits unrestricted use distribution and reproduction in any medium provided theoriginal work is properly cited

Biogas is an important renewable energy source Its utilization is restricted to vicinity of farm areas unless pipeline networks orcompression facilities are established Alternatively biogas may be upgraded into synthetic gas via reforming reaction In this workplasma assisted reforming of biogas was investigated A laboratory gliding arc plasma setup was developed Effects of CH

4CO2

ratio (1 233 9) feed flow rate (1667ndash8333 cm3s) power input (100ndash600W) number of reactor and air addition (0ndash60 vv) onprocess performances in terms of yield selectivity conversion and energy consumption were investigated High power inputs andlong reaction time from low flow rates or use of two cascade reactors were found to promote dry reforming of biogas High H

2and

CO yields can be obtained at low energy consumption Presence of air enabled partial oxidation reforming that produced higherCH4conversion compared to purely dry CO

2reforming process

1 Introduction

Concerns over energy demand and environmental deterio-ration are becoming increasingly serious due to accelerateddepletion of fossil fuel reserve and exhaust gases releasedfrom burning fossil fuels There is an urgent need to developand secure alternative energy sources At present our atten-tion is focused on biogas Biogas is produced from anaerobicdigestion of organicmaterials Normal composition of biogasis about 55ndash70methane 27ndash44 carbon dioxide 1 or lesshydrogen and 3 or less hydrogen sulfide depending on rawinput materials [1 2] Biogas is normally utilized for heatingmechanical power and electricity generation It is notice-able that biogas contains a significant fraction of an inertgas (CO

2) which reduces its energy content Furthermore

utilization of biogas is rather restricted to within and aroundfarm areas unless pipeline networks or compression facilitiesare deployed For wider utilization and application of biogasupgrading should be undertaken Therefore biogas may beconverted to synthetic gas a mixture of hydrogen and carbonmonoxide Synthetic gas can be used as fuel in combustion

process and fuel cells as well as for Fischer-Tropsch synthesisof clean liquid fuels [3 4]

There are several technologies available for syntheticgas production such as partial oxidation steam reform-ing autothermal reforming and catalytic reforming [5ndash8]However there are limitations of such technologies due toenergy requirement yields of product and economic costOne possible way to overcome these limitations is by usingplasma technique Plasma is high energy phase which cancause fast reactions [9] Plasma can be divided into thermaland nonthermal according to temperature and density ofelectrons [10 11] Nonthermal plasma has been used forproduction of synthetic gas Advantage of nonthermal plasmarelates to low temperatures (lt1000K) and low pressures(atmospheric pressure) that result in less energy consumptionand minimum electrode erosion Size and weight of non-thermal plasma reactors are relatively small and attractive formobile applications Gliding arc discharge plasma technologyis of great interest Gliding arc reactor consists of two ormoredivergent electrodes connected to AC or DC power supplyWhen a high voltage is applied a relatively low current arc

Hindawi Publishing CorporationInternational Journal of Chemical EngineeringVolume 2014 Article ID 609836 9 pageshttpdxdoiorg1011552014609836

2 International Journal of Chemical Engineering

discharge is generated across the electrodes It can be usedto encourage reforming reaction of biogas [12] The biogasdry reforming process can be described by an endothermicreaction (external energy is required) as shown in (1) and (2)[13 14] CO

2in biogas is used to react with CH

4 Synthetic

gas may be reformed in partial oxidation reaction of biogasEquation (3) shows reaction of methane partial oxidativeand exothermic reaction Equations (4)ndash(9) show interactionof CH

4and CO

2with electrons in plasma cracking process

after electrical breakdown

CH4+ CO2997888rarr 2CO + 2H

2ΔH = 247 kJmol (1)

CH4+ 2CO

2997888rarr 3CO +H

2+H2O ΔH = 288 kJmol

(2)

Partial oxidation reforming reaction is as follows

CH4+

1

2

O2997888rarr CO + 2H

2ΔH = minus36 kJmol (3)

Interaction of CH4and CO

2with electron in plasma cracking

process is as follows [15]

CH4+ eminus 997888rarr CH

3+H (4)

2CH4997888rarr C

2H2+ 3H2 (5)

CH3+H 997888rarr CH

2+H +H (6)

CH2+H +H 997888rarr CH

2+H2 (7)

CH2+H2997888rarr CH +H

2+H (8)

CH +H2+H 997888rarr C +H

2+H2 (9)

CO2+ eminus 997888rarr CO +O (10)

It can be seen that major gas products are H2and CO

Other products of gas such as hydrocarbon (C2H2) are also

produced but in very small amount [16 17] So in this workonly main components of synthesis gas (H

2and CO) are

consideredThere have been several reports on synthetic gas produc-

tion by gliding arc reactors Steam and catalyst are normallyused single gliding arc plasma reactor in reforming processHowever there appeared to be few studies using multistagereactors Rueangjitt et al [15] used a multistage gliding arcplasma system with four reactors connected in series toinvestigate combined reforming of natural gas to producesynthesis gas Sreethawong et al [18] used amultistage glidingarc discharge system to explore partial oxidation of methaneto produce synthesis gas Tippayawong and Inthasan [19]utilized two gliding arc plasma reactors for cracking of lighttar and subsequentlymodified to assist in oxidative reformingof biogas [20] Nonthermal plasma generated from glidingarc discharge has shown to have high potential in reformingreaction However investigation on biogas reforming inmultistage plasma reactors still remains very rare This workpresents an attempt to fill this gapTheobjective of thiswork isto parametrically investigate influential operating conditionson plasma assisted reforming of biogas

13

2

3

4

5 6 7

89

10

11

12

1

Figure 1 Experimental setup for biogas reforming (1) CH4tank (2)

CO2tank (3) air zero tank (4) flowmeter (5) bubble flowmeter (6)

gas filter (7) gas chromatography (8) power supply (9) resistance(10) high voltage probe (11) oscilloscope (12) gliding arc reactor and(13) thermometer

In this paper effects of biogas flow rate compositionof biogas power input and air addition on production ofsynthetic gas using gliding arc plasma reactor were studiedA comparison between one and two reactors was evaluatedIt may offer alternative route for utilization of biogas byproducing high content of synthetic gas

2 Materials and Methods

Typical composition of biogas contains 45ndash65 methane35ndash55 carbon dioxide 1 hydrogen and trace amount ofhydrogen sulfide around 1000 ppm For the current experi-ments simulated biogas was generated by mixing CH

4and

CO2at different fractions (CH

4CO2= 1 233 9) correspond-

ing to biogas compositions found typical and those afterupgrading by removal of CO

2

Gliding arc plasma experiments were carried out usinga laboratory scale setup at atmospheric pressure Schematicof the experimental setup specially developed is shown inFigure 1 A gliding arc plasma reactor has two knife-shapeddivergent electrodes made of stainless steel An electrode gapdistance was fixed at 4mm The gap distance was selected at4mm because it was maximum distance possible for electricjump between electrodes Gas input was injected betweenelectrodes via a cylindrical tube with diameter of 1mmThe reactor was designed to be flat shaped not cylindershaped similar to Bo et al [6 21] Flat shaped reactors haveadvantage over cylinder in reaction space The setup wascomposed of two gliding arc plasma reactors two powersupplies biogas feeding system measurement probes andcontrol and analysis systems Biogas feed was regulated bya flow meter (VFB-60-BV) between 1667 and 8333 cm3sThe two electrodes were connected to high voltage suppliesfrom two AC neon transformers (LEIP EX 230A 15N)

International Journal of Chemical Engineering 3

0 100 200 300 400 500 6000

5

10

15

20

25

30

Yiel

d (

)

Power input (W)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 100 200 300 400 500 6000

102030405060708090

100

Sele

ctiv

ity (

)

Power input (W)H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 100 200 300 400 500 6000

5

10

15

20

25

30

Power input (W)

CH4

conv

ersio

n

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(c)

0 100 200 300 400 500 60002468

1012141618202224

Power input (W)

CO2

conv

ersio

n (

)

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)

0 100 200 300 400 500 60000

05

10

15

20

25

30

35

40

Power input (W)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(e)

Figure 2 Effect of power input on biogas reforming performance


with maximum voltage and current of 15 kV and 30mA(nonbreakdown) respectively In this work thermocouplestype K were deployed to indirectly measure plasma reactiontemperatureThe temperature probes were positioned down-stream as close as possible to the plasma flame so that they didnot interfere with the reforming reaction Gas analysis wasundertaken by a Shimadzu GC-8A gas chromatography withTCD detector

Data analysis for performance evaluation of the reactorswas as follows [16 21ndash23]

Conversion of CH4and CO

2

CH4 conversion () =

[CCH4in] minus [CCH

4out]

[CCH4in]

times 100 (11)

where [CCH4in] is amount of CH

4input (mol) and [CCH

4out]

is amount of CH4output (mol)

CO2 conversion () =

[CCO2in] minus [CCO

2out]

[CCO2in]

times 100 (12)

where [CCO2in] is amount of CO

2output (mol) and [CCO

2out]

is amount of CO2output (mol)

Selectivity of H2and CO

H2 selectivity () =

H2 produced

2 times CH4 converted

times 100 (13)

COselectivity () =COproduced

CH4 converted + CO2 converted

times 100 (14)

The 2 inH2selectivity is the number ofmoles of hydrogen

in methane that can produce H2is 2

Yield of H2and CO is as follows

H2 yield () =

H2 produced

2 times CH4 feedtimes 100 (15)

COyield () =COproduced

2 times (CH4 feed + CO2 feed)

times 100 (16)

Energy consumption per H2molecule product (EC) is as

follows

EC (JMolecule) = 119875 times 60

602 times 1023times (H2 produced)

(17)

where 119875 is power input (W)

3 Results and Discussion

31 Effect of Power Input and CH4CO2Ratio For the effect

on reforming reaction of biogas power input was variedbetween 100 and 600W while the biogas flow rate wasfixed at 1667 cm3s Composition of biogas was varied forCH4CO2between 1 233 and 9 Effects of power input and

CH4CO2ratio on the process performance are shown in

Figure 2 Reactor temperature was about 120ndash250∘C For a

given CH4CO2ratio yields of H

2and CO (Figure 2(a)) were

found to increase with power input Changes with powerinput were more pronounced at CH

4CO2ratio of 1 than that

at CH4CO2ratio of 9 For a given power input increasing

CH4CO2ratio from 1 to 9 appeared to downgrade H

2and

CO generation CO2in biogas reacted with CH

4 For a dry

reforming process appropriate molar ratios between CH4

and CO2would be one or two ((1) and (2)) Equation (1) was

more likely to occur compared to (2) because less energywas required It was therefore not surprising to find thatmaximum yields of H

2and CO were obtained at CH

4CO2

= 1 At this value yields of H2and CO were observed to

increase from 67 to 180 and 20 to 88 respectively whenpower input was increased from 100 to 600 W Selectivityof H2and CO is presented in Figure 2(b) Similar to yield

selectivity of H2and CO was maximum at CH

4CO2= 1

It was evident that increasing power input caused selec-tivity of H

2and CO to increase from 487 to 655 and

from 219 to 368 respectively For larger CH4CO2ratios

H2selectivity appeared to stay at around 45 while CO

selectivity was lower than 5 for CH4CO2= 9 As far as

conversion of CH4and CO

2was concerned similar patterns

with increasing input power (Figures 2(c) and 2(d)) wereobserved for CH

4and CO

2conversion Nonetheless it was

noted that change in CH4CO2ratio affected CH

4more

than CO2 Figure 2(e) shows that the energy consumption

per H2molecule product increased with increasing power

input Variation in CH4CO2ratio was not found to affect

energy consumptionThese results were consistent with thosereported in [22] Change in power input affected all reactionsin the plasma zone Increasing power input increased electrondensity and electron energy which affected formation ofactive free radicals in inelastic collisions between moleculesof CH

4andCO

2 resulting in higher degree of combination to

form synthesis gas molecules [20] Higher power is expectedto give higher conversions and yields However in this workincrease in power input resulted in increased coke formationin the reactor At higher power input coke formation becameclearly visible presenting a serious operation problem It maybe attributed to the fact that higher input power encouragedmore cracking of molecules (8) that led to more carbongeneration Additionally increased power input produceshigher temperature of the electrodesrsquo surface at which biogasmay be reacted to form carbon deposit on Coke formationmay be controlled by adding oxidants such as steam oxygenor air to the reforming reactants

32 Effect of Flow Rate Figure 3 shows variation of theprocess performance parameters with feed gas flow rateFor these tests power input was fixed at 100 W to avoidcoke formation The flow rate was varied between 1667and 8333 cm3s Reactor temperature was about 120ndash250∘CAs expected the highest yields and selectivities occurred atCH4CO2= 1 It was found that increasing flow rate resulted

in reduction of H2and CO yields (Figure 3(a)) from 63

to 13 and from 20 to 05 respectively Selectivities ofH2and CO are presented in Figure 3(b) Increase in flow

rate caused a decrease in H2and CO selectivity from 465


0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

Yiel

d (

)

Flow rate (cm3s)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 10 20 30 40 50 60 70 80 9005

1015202530354045505560

Sele

ctiv

ity (

)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

Flow rate (cm3s)

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60 70 80 900

2

4

6

8

10

12

14

Con

vers

ion

()

Flow rate (cm3s)

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

8

9

Flow rate (cm3s)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)

Figure 3 Effect of flow rate on biogas reforming performance

to 365 and from 227 to 152 This was largely due toreduction in residence time for the dry reforming reactionat higher flow rates Figure 3(c) shows that increasing flowrate led to decreased CH

4and CO

2conversions for all

CH4CO2considered Energy consumption per H

2molecule

product was minimal at the smallest flow rate of 1667 cm3sand the highest CH

4CO2ratio of 9 shown in Figure 3(d)

As the flow rate increases yield and selectivity of H2and CO

decreased and energy consumption perH2molecule product

was increasedThiswas anticipated because at high flow ratesit may not have enough time for CH

4and CO

2to react

The trend was in agreement with the literature [16 23] It

should be noted that for the design of the present gliding arcreactor the inner diameter of the injection nozzle was rathersmall (1mm) compared to the electrode gap distance (4mm)Larger nozzle diameter whichwill allow slower feed gas speedmay produce better yields at high flow rates

33 Effect of Air Addition Air injection into the biogas wouldprovide oxygen to enable partial oxidative reaction This willbe completed with CO

2for dry reforming of CH

4to generate

H2and CO For the effect of air addition power input at 100

W and gas flow rate of 1667 cm3s were chosen Amount of


0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

20Yi

eld

()

Increase air ( by volume)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(a)

0 10 20 30 40 50 600

10

20

30

40

50

60

70

80

90

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60

0

5

10

15

20

25

30

35

40

45

Con

vers

ion

()


CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

minus5

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 6000

05

10

15

20

25


CH4CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)

Figure 4 Effect of air addition on biogas reforming performance

air in the gas feed was varied between 0 and 60 vv Reactortemperaturewas about 120ndash380∘C higher than previous casesof purely endothermic reaction It was shown in Figure 4 thatthe presence of oxygen in air promoted reforming of biogasFigures 4(a) and 4(b) show that H

2yield and selectivity were

increased with increasing air as long as there was plenty ofCH4 and short of competing CO

2 These were the case for

CH4CO2ratios of 233 and 9 At CH

4CO2= 1 drops in H

2

yield and selectivity after air was supplied beyond 40 wereevident These decreases of H

2yield and selectivity may have

contributed to the fact that the reaction was approachingsubstoichiometric combustion CO generation became morefavorable than H

2 It was clear that at higher air supply

rates (gt40) changes in yield and selectivity of CO wereopposite to those of H

2 This was confirmed by a negative

conversion of CO2 shown in Figure 4(c) at air supply of 60

showing that combustion took place Figure 4(d) shows thatless energy was consumed at high CH

4CO2ratios This was

contributed to the fact that greater amount of air was availablefor an exothermic partial oxidation reaction in line with thepublished literature [16 24 25]

34 Effect of Number of Reactor In this work the setupwith two cascading reactors was also tested against thesingle gliding arc plasma reactor The reacting flow may be


0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2

H2 1 reactorH2 2 reactors

CO 1 reactorCO 2 reactors

(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2

CH4 1 reactorCO2 2 reactors


(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20

One reactorTwo reactors

CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)

Figure 5 Effect of number of reactor on biogas reforming performance

viewed to have longer residence time for reforming reactionFlow rate and power input were fixed at 1667 cm3s and100 W respectively Reactor temperature was in similarrange of about 120ndash250∘C Results are shown in Figure 5Qualitatively the two cascading reactors produced similartrends of yield selectivity and conversion with respect tothe effect of increasing CH

4CO2ratio But quantitatively the

two cascading reactors were found to have higher yields andconversions than the single reactor for all CH

4CO2ratios

considered while selectivity in the single and two reactorswas in similar magnitude At CH

4CO2= 1 H

2and CO yields

in the two reactors were about twice as those found in thesingle reactor shown in Figures 5(a) and 5(c) At present itwas not conclusive why energy consumption found in the

single and the two reactors (Figure 5(d)) was not significantlydifferent Further investigation may be needed to clarify thisissue

Table 1 summarizes the optimumconditions found in thiswork Composition of biogas with CH

4CO2= 1 proved to

be the best in generating the highest yields of H2and CO

At this ratio it was very attractive since it represented actualbiogas composition in farms without upgrading With thetwo gliding arc plasma reactors in cascade higher residencetime for reforming reactionmay be achievedThis resulted inbetter performance in terms of yields and conversionThe twocascaded reactors setup appeared to consume slightly higherenergy input As far as air addition was concerned it wasclear that partial oxidation process offered alternative route in


Table 1 Performance of plasma assisted reforming of biogas

Flow rate Air Yield () Conversion () Energy consumption(cm3s) ( vv) H2 CO CH4 CO2 (times10minus19 JH2 molecule product)

Single reactorCH4CO2 = 1 1667 mdash 63 19 136 487 156CH4CO2 = 233 1667 mdash 56 11 126 69 128CH4CO2 = 9 1667 mdash 51 02 117 75 107

Single reactorCH4CO2 = 1 1667 40 147 75 231 81 122CH4CO2 = 233 1667 50 135 69 226 128 101CH4CO2 = 9 1667 60 140 68 236 145 094

Two reactorsCH4CO2 = 1 1667 mdash 117 49 258 107 170CH4CO2 = 233 1667 mdash 112 25 272 116 125CH4CO2 = 9 1667 mdash 110 06 276 130 101

reforming of biogas It was shown to have the highest yieldsof H2and CO obtained as well as the lowest energy input

for all conditions considered in this work In comparisonwith reported work by Sreethawong et al [18] for similarconditions (multistage gliding arc plasma reactor CH

4O2=

3 feed flow rate of 25 cm3s) this work proved to have similarCH4conversion but with much less energy consumption per

H2molecule product

4 Conclusion

In this study gliding arc plasma was utilized to reformbiogas into synthesis gas Investigations were carried out forthe effects of biogas composition (CH

4CO2) power input

biogas flow rate presence of air and number of reactorson yield and selectivity of H

2and CO conversion of CH

4

and CO2 and energy consumption CO

2and CH

4in biogas

were reacted under a dry reforming process As anticipatedCH4CO2= 1 showed maximum reforming performance

High power input and lower flow rate were observed toenhance reforming reaction Adding air into biogas wasfound to encourage partial oxidation that would competewith CO

2in reforming CH

4and generating H

2and CO

A setup with the two cascade reactors was shown to havehigher yields and conversions than the single reactor Energyconsumedwas reported to be lower than that frompreviouslypublished work

Conflict of Interests

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

Acknowledgments

This work was supported by the Royal Golden Jubilee PhDProgramThailand Research Fund theOffice of the Commis-sion on Higher Education via National Research Programand Chiang Mai University

References

[1] X Tao M Bai X Li et al ldquoCH4-CO2reforming by plasmamdash

challenges and opportunitiesrdquo Progress in EnergyampCombustionScience vol 37 no 2 pp 113ndash124 2011

[2] PThanompongchart and N Tippayawong ldquoProgress in plasmaassisted reforming of biogas for fuel gas upgradingrdquo AmericanJournal of Scientific Research vol 76 pp 70ndash87 2012

[3] J B Holm-Nielsen T Al Seadi and P Oleskowicz-Popiel ldquoThefuture of anaerobic digestion and biogas utilizationrdquoBioresourceTechnology vol 100 no 22 pp 5478ndash5484 2009

[4] D J Wilhelm D R Simbeck A D Karp and R L DickensonldquoSyngas production for gas-to-liquids applications technolo-gies issues and outlookrdquo Fuel Processing Technology vol 71 no1ndash3 pp 139ndash148 2001

[5] Y N Chun and H O Song ldquoSyngas production using glidingarc plasmardquo Energy Sources A Recovery Utilization and Envi-ronmental Effects vol 30 no 13 pp 1202ndash1212 2008

[6] Z Bo J Yan X Li Y Chi and K Cen ldquoPlasma assisted drymethane reforming using gliding arc gas discharge effect of feedgases proportionrdquo International Journal ofHydrogenEnergy vol33 no 20 pp 5545ndash5553 2008

[7] M H Rafiq H A Jakobsen and J E Hustad ldquoModelingand simulation of catalytic partial oxidation of methane tosynthesis gas by using a plasma-assisted gliding arc reactorrdquoFuelProcessing Technology vol 101 pp 44ndash57 2012

[8] B Zhu X S Li C Shi J L Liu T L Zhao and A MZhu ldquoOptimized mixed reforming of biogas with O

2addition

in spark-discharge plasmardquo International Journal of HydrogenEnergy vol 37 no 6 pp 4945ndash4954 2012

[9] M Deminsky V Jivotov B Potapkin and V Rusanov ldquoPlasma-assisted production of hydrogen from hydrocarbonsrdquo Pure ampApplied Chemistry vol 74 no 3 pp 413ndash418 2002

[10] G Petitpas J-D Rollier A Darmon J Gonzalez-Aguilar RMetkemeijer and L Fulcheri ldquoA comparative study of non-thermal plasma assisted reforming technologiesrdquo InternationalJournal of Hydrogen Energy vol 32 no 14 pp 2848ndash2867 2007

[11] O Mutaf-Yardimci A V Saveliev A A Fridman and L AKennedy ldquoThermal and nonthermal regimes of gliding arcdischarge in air flowrdquo Journal of Applied Physics vol 87 no 4pp 1632ndash1641 2000


[12] A Fridman S Nester L A Kennedy A Saveliev andOMutaf-Yardimci ldquoGliding arc gas dischargerdquo Progress in Energy ampCombustion Science vol 25 no 2 pp 211ndash231 1999

[13] J R Rostrup-Nielsen ldquoSyngas in perspectiverdquo Catalysis Todayvol 71 no 3-4 pp 243ndash247 2002

[14] V Goujard J-M Tatibouet and C Batiot-Dupeyrat ldquoUse of anon-thermal plasma for the production of synthesis gas frombiogasrdquo Applied Catalysis A General vol 353 no 2 pp 228ndash235 2009

[15] N Rueangjitt W Jittiang K Pornmai J Chamnanmanoon-tham T Sreethawong and S Chavadej ldquoCombined reformingand partial oxidation of CO

2-containing natural gas using an

AC multistage gliding arc discharge system effect of stagenumber of plasma reactorsrdquo Plasma Chemistry and PlasmaProcessing vol 29 no 6 pp 433ndash453 2009

[16] A Indarto J-WChoiH Lee andHK Song ldquoEffect of additivegases on methane conversion using gliding Arc dischargerdquoEnergy vol 31 no 14 pp 2986ndash2995 2006

[17] Y N Chun H W Song S C Kim and M S Lim ldquoHydrogen-rich gas production from biogas reforming using plasmatronrdquoEnergy amp Fuels vol 22 no 1 pp 123ndash127 2008

[18] T Sreethawong P Thakonpatthanakun and S Chavadej ldquoPar-tial oxidation of methane with air for synthesis gas productionin a multistage gliding arc discharge systemrdquo InternationalJournal of Hydrogen Energy vol 32 no 8 pp 1067ndash1079 2007

[19] N Tippayawong and P Inthasan ldquoInvestigation of light tarcracking in a gliding arc plasma systemrdquo International Journalof Chemical Reactor Engineering vol 8 article A50 2010

[20] P Thanompongchart P Khongkrapan and N TippayawongldquoPartial oxidation reforming of simulated biogas in gliding arcdischarge systemrdquo Periodica Polytechnica Chemical Engineer-ing vol 58 pp 31ndash36 2014

[21] Z Bo J H Yan X D Li Y Chi B Cheron and K F CenldquoThe dependence of gliding arc gas discharge characteristicson reactor geometrical configurationrdquo Plasma Chemistry andPlasma Processing vol 27 no 6 pp 691ndash700 2007

[22] Y N Chun Y C Yang and K Yoshikawa ldquoHydrogen genera-tion from biogas reforming using a gliding arc plasma-catalystreformerrdquo Catalysis Today vol 148 no 3-4 pp 283ndash289 2009

[23] Y-C Yang B-J Lee and Y-N Chun ldquoCharacteristics ofmethane reforming using gliding arc reactorrdquo Energy vol 34no 2 pp 172ndash177 2009

[24] M H Rafiq and J E Hustad ldquoSynthesis gas from methane byusing a plasma-assisted gliding arc catalytic partial oxidationreactorrdquo Industrial and Engineering Chemistry Research vol 50no 9 pp 5428ndash5439 2011

[25] G Xu andXDing ldquoSyngas production frommethane usingACgliding arc reactorrdquo in Proceedings of the Asia-Pacific Power andEnergy Engineering Conference (APPEEC rsquo11) pp 1ndash4 WuhanChina March 2011

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



discharge is generated across the electrodes It can be usedto encourage reforming reaction of biogas [12] The biogasdry reforming process can be described by an endothermicreaction (external energy is required) as shown in (1) and (2)[13 14] CO

2in biogas is used to react with CH

4 Synthetic

gas may be reformed in partial oxidation reaction of biogasEquation (3) shows reaction of methane partial oxidativeand exothermic reaction Equations (4)ndash(9) show interactionof CH

4and CO

2with electrons in plasma cracking process

after electrical breakdown

CH4+ CO2997888rarr 2CO + 2H

2ΔH = 247 kJmol (1)

CH4+ 2CO

2997888rarr 3CO +H

2+H2O ΔH = 288 kJmol

(2)

Partial oxidation reforming reaction is as follows

CH4+

1

2

O2997888rarr CO + 2H

2ΔH = minus36 kJmol (3)

Interaction of CH4and CO

2with electron in plasma cracking

process is as follows [15]

CH4+ eminus 997888rarr CH

3+H (4)

2CH4997888rarr C

2H2+ 3H2 (5)

CH3+H 997888rarr CH

2+H +H (6)

CH2+H +H 997888rarr CH

2+H2 (7)

CH2+H2997888rarr CH +H

2+H (8)

CH +H2+H 997888rarr C +H

2+H2 (9)

CO2+ eminus 997888rarr CO +O (10)

It can be seen that major gas products are H2and CO

Other products of gas such as hydrocarbon (C2H2) are also

produced but in very small amount [16 17] So in this workonly main components of synthesis gas (H

2and CO) are

consideredThere have been several reports on synthetic gas produc-

tion by gliding arc reactors Steam and catalyst are normallyused single gliding arc plasma reactor in reforming processHowever there appeared to be few studies using multistagereactors Rueangjitt et al [15] used a multistage gliding arcplasma system with four reactors connected in series toinvestigate combined reforming of natural gas to producesynthesis gas Sreethawong et al [18] used amultistage glidingarc discharge system to explore partial oxidation of methaneto produce synthesis gas Tippayawong and Inthasan [19]utilized two gliding arc plasma reactors for cracking of lighttar and subsequentlymodified to assist in oxidative reformingof biogas [20] Nonthermal plasma generated from glidingarc discharge has shown to have high potential in reformingreaction However investigation on biogas reforming inmultistage plasma reactors still remains very rare This workpresents an attempt to fill this gapTheobjective of thiswork isto parametrically investigate influential operating conditionson plasma assisted reforming of biogas

13

2

3

4

5 6 7

89

10

11

12

1

Figure 1 Experimental setup for biogas reforming (1) CH4tank (2)

CO2tank (3) air zero tank (4) flowmeter (5) bubble flowmeter (6)

gas filter (7) gas chromatography (8) power supply (9) resistance(10) high voltage probe (11) oscilloscope (12) gliding arc reactor and(13) thermometer

In this paper effects of biogas flow rate compositionof biogas power input and air addition on production ofsynthetic gas using gliding arc plasma reactor were studiedA comparison between one and two reactors was evaluatedIt may offer alternative route for utilization of biogas byproducing high content of synthetic gas

2 Materials and Methods

Typical composition of biogas contains 45ndash65 methane35ndash55 carbon dioxide 1 hydrogen and trace amount ofhydrogen sulfide around 1000 ppm For the current experi-ments simulated biogas was generated by mixing CH

4and

CO2at different fractions (CH

4CO2= 1 233 9) correspond-

ing to biogas compositions found typical and those afterupgrading by removal of CO

2

Gliding arc plasma experiments were carried out usinga laboratory scale setup at atmospheric pressure Schematicof the experimental setup specially developed is shown inFigure 1 A gliding arc plasma reactor has two knife-shapeddivergent electrodes made of stainless steel An electrode gapdistance was fixed at 4mm The gap distance was selected at4mm because it was maximum distance possible for electricjump between electrodes Gas input was injected betweenelectrodes via a cylindrical tube with diameter of 1mmThe reactor was designed to be flat shaped not cylindershaped similar to Bo et al [6 21] Flat shaped reactors haveadvantage over cylinder in reaction space The setup wascomposed of two gliding arc plasma reactors two powersupplies biogas feeding system measurement probes andcontrol and analysis systems Biogas feed was regulated bya flow meter (VFB-60-BV) between 1667 and 8333 cm3sThe two electrodes were connected to high voltage suppliesfrom two AC neon transformers (LEIP EX 230A 15N)


0 100 200 300 400 500 6000

5

10

15

20

25

30

Yiel

d (

)

Power input (W)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 100 200 300 400 500 6000

102030405060708090

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 100 200 300 400 500 6000

5

10

15

20

25

30

Power input (W)

CH4

conv

ersio

n

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(c)

0 100 200 300 400 500 60002468

1012141618202224

Power input (W)

CO2

conv

ersio

n (

)

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)

0 100 200 300 400 500 60000

05

10

15

20

25

30

35

40

Power input (W)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(e)






2

CH4 conversion () =

[CCH4in] minus [CCH

4out]

[CCH4in]

times 100 (11)



4out]


CO2 conversion () =

[CCO2in] minus [CCO

2out]

[CCO2in]

times 100 (12)



2out]



H2 selectivity () =

H2 produced


times 100 (13)



times 100 (14)




H2 yield () =

H2 produced




times 100 (16)


follows



(17)













2and


4 For a dry





4CO2




4CO2= 1









4and CO



4more





4andCO








0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

Yiel

d (

)

Flow rate (cm3s)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 10 20 30 40 50 60 70 80 9005

1015202530354045505560

Sele

ctiv

ity (

)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

Flow rate (cm3s)

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60 70 80 900

2

4

6

8

10

12

14

Con

vers

ion

()

Flow rate (cm3s)

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

8

9

Flow rate (cm3s)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)



4and CO



2molecule






4and CO

2to react





4to generate




0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

20Yi

eld

()


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(a)

0 10 20 30 40 50 600

10

20

30

40

50

60

70

80

90

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60

0

5

10

15

20

25

30

35

40

45

Con

vers

ion

()


CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

minus5

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 6000

05

10

15

20

25


CH4CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)







4CO2= 1 drops in H

2









4CO2ratios This was




0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2



(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2



(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20


CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)





4CO2ratios


4CO2= 1 H

2and CO yields




4CO2= 1 proved to











4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0 100 200 300 400 500 6000

5

10

15

20

25

30

Yiel

d (

)

Power input (W)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 100 200 300 400 500 6000

102030405060708090

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 100 200 300 400 500 6000

5

10

15

20

25

30

Power input (W)

CH4

conv

ersio

n

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(c)

0 100 200 300 400 500 60002468

1012141618202224

Power input (W)

CO2

conv

ersio

n (

)

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)

0 100 200 300 400 500 60000

05

10

15

20

25

30

35

40

Power input (W)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(e)






2

CH4 conversion () =

[CCH4in] minus [CCH

4out]

[CCH4in]

times 100 (11)



4out]


CO2 conversion () =

[CCO2in] minus [CCO

2out]

[CCO2in]

times 100 (12)



2out]



H2 selectivity () =

H2 produced


times 100 (13)



times 100 (14)




H2 yield () =

H2 produced




times 100 (16)


follows



(17)













2and


4 For a dry





4CO2




4CO2= 1









4and CO



4more





4andCO








0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

Yiel

d (

)

Flow rate (cm3s)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 10 20 30 40 50 60 70 80 9005

1015202530354045505560

Sele

ctiv

ity (

)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

Flow rate (cm3s)

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60 70 80 900

2

4

6

8

10

12

14

Con

vers

ion

()

Flow rate (cm3s)

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

8

9

Flow rate (cm3s)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)



4and CO



2molecule






4and CO

2to react





4to generate




0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

20Yi

eld

()


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(a)

0 10 20 30 40 50 600

10

20

30

40

50

60

70

80

90

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60

0

5

10

15

20

25

30

35

40

45

Con

vers

ion

()


CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

minus5

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 6000

05

10

15

20

25


CH4CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)







4CO2= 1 drops in H

2









4CO2ratios This was




0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2



(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2



(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20


CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)





4CO2ratios


4CO2= 1 H

2and CO yields




4CO2= 1 proved to











4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













2

CH4 conversion () =

[CCH4in] minus [CCH

4out]

[CCH4in]

times 100 (11)



4out]


CO2 conversion () =

[CCO2in] minus [CCO

2out]

[CCO2in]

times 100 (12)



2out]



H2 selectivity () =

H2 produced


times 100 (13)



times 100 (14)




H2 yield () =

H2 produced




times 100 (16)


follows



(17)













2and


4 For a dry





4CO2




4CO2= 1









4and CO



4more





4andCO








0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

Yiel

d (

)

Flow rate (cm3s)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 10 20 30 40 50 60 70 80 9005

1015202530354045505560

Sele

ctiv

ity (

)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

Flow rate (cm3s)

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60 70 80 900

2

4

6

8

10

12

14

Con

vers

ion

()

Flow rate (cm3s)

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

8

9

Flow rate (cm3s)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)



4and CO



2molecule






4and CO

2to react





4to generate




0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

20Yi

eld

()


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(a)

0 10 20 30 40 50 600

10

20

30

40

50

60

70

80

90

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60

0

5

10

15

20

25

30

35

40

45

Con

vers

ion

()


CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

minus5

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 6000

05

10

15

20

25


CH4CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)







4CO2= 1 drops in H

2









4CO2ratios This was




0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2



(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2



(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20


CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)





4CO2ratios


4CO2= 1 H

2and CO yields




4CO2= 1 proved to











4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

Yiel

d (

)

Flow rate (cm3s)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(a)

0 10 20 30 40 50 60 70 80 9005

1015202530354045505560

Sele

ctiv

ity (

)

H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

Flow rate (cm3s)

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60 70 80 900

2

4

6

8

10

12

14

Con

vers

ion

()

Flow rate (cm3s)

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 60 70 80 900

1

2

3

4

5

6

7

8

9

Flow rate (cm3s)

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

CH4 CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

(d)



4and CO



2molecule






4and CO

2to react





4to generate




0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

20Yi

eld

()


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(a)

0 10 20 30 40 50 600

10

20

30

40

50

60

70

80

90

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60

0

5

10

15

20

25

30

35

40

45

Con

vers

ion

()


CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

minus5

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 6000

05

10

15

20

25


CH4CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)







4CO2= 1 drops in H

2









4CO2ratios This was




0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2



(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2



(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20


CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)





4CO2ratios


4CO2= 1 H

2and CO yields




4CO2= 1 proved to











4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

20Yi

eld

()


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(a)

0 10 20 30 40 50 600

10

20

30

40

50

60

70

80

90

100

Sele

ctiv

ity (

)


H2 CH4CO2 = 1

H2 CH4CO2 = 233

H2 CH4CO2 = 9

CO CH4CO2 = 1

CO CH4CO2 = 233

CO CH4CO2 = 9

(b)

0 10 20 30 40 50 60

0

5

10

15

20

25

30

35

40

45

Con

vers

ion

()


CH4 CH4CO2 = 1

CH4 CH4CO2 = 233

CH4 CH4CO2 = 9

minus5

CO2 CH4CO2 = 233

CO2 CH4CO2 = 9

CO2 CH4CO2 = 1

(c)

0 10 20 30 40 50 6000

05

10

15

20

25


CH4CO2 = 1

CH4CO2 = 233

CH4CO2 = 9

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)







4CO2= 1 drops in H

2









4CO2ratios This was




0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2



(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2



(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20


CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)





4CO2ratios


4CO2= 1 H

2and CO yields




4CO2= 1 proved to











4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0 1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

14Yi

eld

()

CH4CO2



(a)

0 1 2 3 4 5 6 7 8 9 1005

10152025303540455055

Sele

ctiv

ity (

)

CH4CO2



(b)

0 1 2 3 4 5 6 7 8 9 100

5

10

15

20

25

30

Con

vers

ion

()

CH4CO2



(c)

0 1 2 3 4 5 6 7 8 9 1000

05

10

15

20


CH4CO2

mol

ecul

e pro

duct

)En

ergy

cons

umpt

ion

(times10minus19

JH2

(d)





4CO2ratios


4CO2= 1 H

2and CO yields




4CO2= 1 proved to











4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation

















4O2=


H2molecule product

4 Conclusion


4CO2) power input



4


2and CH

4in biogas



2in reforming CH

4and generating H

2and CO




Acknowledgments


References










2addition
























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation




























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









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