2003 ASME International Mechanical EngineeringCongress and Exposition

Takashi YAMAMIYADepartment of mechanical engineering, Tokyo metropolitan university, Japan

Masahiro OTA　Hoque Md. MOZAMMEL　Kazuhiko MURAKAMI

Pyrolysis Characteristics of Biomass Resources

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Contents

1.Introduction

2.Experiments

3.Results and discussions

4.Conclusions

Background, Purpose

TG and DTGComposition of pyrolysis gases

Analysis of

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World wide problems

Increasing of atmospheric CO2 level caused global warming

Exhaustion of fossil fuels

It is important to use of biomass resources

For improvement these problems

1.Introduction

3

Renewable energy

No emission of CO2

The actual condition

In Japan, the availability of waste wood of industries other than lumber industry is under 30%

The availabilities of biomass resources

Biomass resources are not used effectively

The availability and actual condition of Biomass resources

4

So this research was aimed at effective use of biomass resources.

There are some applications, such as solid fuel and gasification for effective use of biomass resources.

Problems and focus

There is not enough information of understanding pyrolysis mechanisms of biomass resources,especially about various types of biomass, such as dead leaves, coffee grounds and paper.

However

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Understanding pyrolysis mechanism of various samples such as wood chips, dead leaves, coffee grounds and paper.

The purpose of this study is

Purpose of this study

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The methods of understanding pyrolysis mechanisms are analysis of

weight loss

compositions of decomposed gases

2.Experiments

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under pyrolysis.

TG（Thermo gravimetric weight loss）　The TG is weight loss of the samples when heated at constant ratio.The temperature in which the reaction has occurred is revealed by analyzing TG.

DTGThe DTG is derivative TG. The DTG indicate the intensity of pyrolysis reaction clearly.

Description of TG and DTG

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For the purpose of weight loss measurement under pyrolysis, TG/DTA devices were used.

Fig.1 TG/DTA 300

Experimental devise of TG and DTG analysis

Fig.2 Enlarged view of TG/DTA 300

Sample holder

Reference holder

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Sample weight 　 : about 0.8mg

Temperature range :RT-1273K

Heating ratio :10K/min

Carrier gas :N2 　

Reference :Platinum

The conditions of TG and DTG analysis

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Cylinder

Gas syringe

Atmosphere

Vacuum pump

Pressure gage

Recorder

Gas blender

Temperaturecontroller Reaction

Tube

Furnace

Fig.3 schematic view of the thermal decomposition systems

Experimental devise of pyrolysis gases analysis

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sampling unit

Sample weight 　 : about 10g

Pyrolysis atmosphere : vacuum

Pyrolysis temperatures : 773K, 1023K, 1273K

Sampling times : 0, 20, 40, 60, 90, 120, 150min

The kind of analyzing gases : CO, CO2, CH4, H2, C2H4, C2H6

The conditions of pyrolysis gases analysis

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400 600 800 1000 12000

20

40

60

80

100

TG [w

t%]

Temperature [K]

Wood Chips Dead Leaves Coffee grounds Paper

The result of TG analysis

Fig.4 The results of TG analysis13

The result of DTG analysis

400 600 800 1000 120002468

10121416

D

TG [w

t%/m

in]

Temperature [K]

Wood Chip Dead Leaves Paper Coffee

14Fig.5 The results of DTG analysis

Coffee grounds

Wood chip

Paper

Dead leaves

Pyrolysis gas analysis at 773K

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0 20 40 60 80 100120140160

0

10

20

30

40

50

60

70

Con

cent

ratio

n [%

]

Time [min]

H2 CO CH4 CO2 C2H4 C2H6

Fig.6 Compositions of pyrolysis gases of wood chips at 773K

The compositions of each gas approached stably as time increase.

The compositions of C2H4and C2H6 are little.

These tendencies are seen at not only wood chips but also other samples and all temperature ranges.

05

1015202530354045

Fig.7 The concentrations of each gas at 773K

PaperCoffeeDeadWood

Con

cent

ratio

n [%

]

The kinds of sample

H2 CH4 CO CO2 CO2

The main pylolysis gas Except for coffee grounds

So the only coffee grounds was pyrolyzedmost actively around 580K that CH4 was decomposed largely from this pyrlolysis reaction.

The concentration of each gas at 773K

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Coffee grounds

CH4

05

1015202530354045

Fig.8 The concentrations of each gas at 1023KThe kinds of sample

PaperCoffeeDeadWood

Con

cent

ratio

n [%

]

H2 CH4 CO CO2

The characteristics by difference in samples

Coffee groundsThe concentration of CH4is large quantity.This characteristic is same as 773K.

Dead leavesThe concentration of CO is large quantity.

PaperThe concentration of CO2is large quantity.

The concentrations of each gas at 1023K

The main pyrolysis gases change to H2.

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800 850 900 950 1000 1050-0.2

0.0

0.2

0.4

0.6

0.8

1.0

DTG

[wt%

/min

]

Temperature [K]

Wood Chips Dead Leaves Coffee grounds Paper

Speculation from DTG from 770K to 1050K

18Fig.9 The results of DTG from 770K to 1050K

Dead leavesSome peaks appear in this temperature range.

Coffee grounds and paper

So CO is decompose by the pylolysis reaction of these peaks.

The remarkable characteristics of DTG cannot be seen .

The characteristics by difference in samples

05

10152025303540455055

Fig.10 The concentrations of each gas at 1273KThe kinds of sample

PaperCoffeeDeadWood

Con

cent

ratio

n [%

]

H2 CH4 CO CO2

The characteristics by difference in samples

Coffee groundsThe composition of CH4 is somewhat large quantity.The characteristic is same as 773K.

Dead leavesThe concentration of H2 is somewhat small quantity.

The concentrations of each gas at 1273K

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The main pylolysis gases are H2 and CO.And other gases are a little.

1100 1150 1200 1250

0.0

0.2

0.4

0.6

0.8

1.0

DTG

[wt%

/min

]

Temperature [K]

Wood Chip Dead Leaves Coffee grounds Paper

Speculation from DTG at 1050K-1230K

Dead leaves

20Fig.11 The results of DTG from 1050K to 1230K

The characteristics by difference in samples

The pyrolysis reaction is more intensity than the others. So the pyrolysis reaction of this peak decomposed some gases other than H2.

Coffee groundsThe remarkable characteristics of DTG cannot be seen .

4.Conclusions

The pyrolyzed level, the intensity order of pyrolysis reaction, and the temperature of active pyrolysis of each sample are revealed.

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CO, CO2 and CH4 were decomposed mainly until 773K, and as temperature increase, pyrolysis reaction is shifted decomposed H2.

The characteristics of pyrolysis gases of each material were revealed and related with DTG analysis.

Thank you for your Thank you for your attention.attention.

Takashi YAMAMIYADepartment of mechanical engineering, Tokyo metropolitan university, Japan

Masahiro OTA　Hoque Md. MOZAMMEL　Kazuhiko MURAKAMI