j b 2013 presentation tateo usui mod

8/14/2019 J B 2013 Presentation Tateo USUI Mod.

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IX JAPAN-BRAZIL SYMPOSIUM ON

DUST PROCESSING - ENERGY - ENVIRONMENT

IN METALLURGICAL INDUSTRIES

September, 8-11, 2013

Gorceix Fundation Auditorium, Ouro Preto, Brazil

THE STATE-OF-THE-ART EMPLOYMENT OF WOODY

BIOMASS AND BIOGAS IN MANUFACTURING INDUSTRIES

CENTERING AROUND STEEL INDUSTRY

Tateo USUI ( Osaka Univ., Japan; now at Univ. Federal de Ouro Preto, Brazil )

Hirok azu KONISHI , Kazuh ira ICHKAWA , Hideki ONO, Hiroto sh i KAWABATA

( Graduate School of Engneering, Osaka Univ., Japan )

Paulo Santos A ss is ( Univ. Federal de Ouro Preto, Brazil)


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1. INTRODUCTION

The purpose of this paper is to show the

idea of an excellent employment of woody

biomass and biogas in manufacturingindustries centering around steel industry.

In the beginning, how come to recognize

the present research themeis explained by

looking back on our previous works.


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2. BACKGROUND FOR THE PRESENT WORK

The first author and coworkers used to be,carried out experimental studies on

carbonization of coal and wood in Graduate

School of Engineering, Osaka University, in order

to use both carbonization gas and coal-char or

charcoalin the following ironmaking processes.

semi-coal-charor semi-charcoal


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2.1 Pre-reductionof iron oxide pellets by

coal carbonization gas

( Iron bath smelting reduction process)

In the first step, three sorts of bituminous

coal were carbonized under various rising

temperature conditions (see Figs.1and 2).


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Carbonization experiment

Carbonization furnace

Gas

chromatograph

155 I.D.100

320

850

N2inlet

Thermocouple

81 I.D.

Heater

Coal particles

280

Alumina balls

Ribbon heater

Water inlet

(273 K)

Condenser

Exhaust

gas

Tar filter

Carbonization conditionsCarrier gas: N2 1.0 L/min (s.t.p.) Heating rate: 200 K/hTC, max: 823 K, 873 K, 973 K, 1073 K, 1273 K

Experimental apparatusFig. 1


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Coal Pellets

Backgrounds (Iron bath smelting

reduction total process Image )

Carbonization furnace Pre-reductionfurnace

Exhaust gas

Carbonization gas

Fe

Smelting furnace

Coal

Char

Fe2O3

Utilization of V.M. of coal

in an iron bath smelting

reduction total process

Iron bath smelting reduction total process

Fe3O4, FeO, Fe

Smelting furnace Smelting furnace


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Reference

T. Usui, T. Yokoyama, T. Nakahashi and Z. Morita, 1993 Ironmaking ConferenceProceedings (Iron and Steel Society), pp. 389-398.

Application

Fig. Mole fraction of carbonization gas before

reduction as a function of carbonization time.

Tc, max=1073 K

Carbonization conditions

Coal: Muswellbrook coalCarrier gas: N2 1.0 L/min (s.t.p.)Maximum carbonization temperature

(TC, max): 1073 K

Heating rate: 200 K/h

Utilization of volatilematter (V.M.) of coal

Pre-reduction of iron oxide inan iron bath smelting reduction

total process

Backgrounds(Pre-reduction of iron

oxide with carbonization gas of coal)

Fig. 3


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Fig. Variations of final fractional reductionsFandFH with reduction temperature TR.

Reduction temperature

1173, 1273 K

Reduction of iron oxide by

hydrogen in hydrocarbons

800 1000 1200

0

0.2

0.4

Reduction temperatureTR(K)

Fra

ctinalreduction

F,

FH

()

Muswellbrook coal

Fractional reduction

(gravimetric method)

Fractional reduction due to H

Tar filter: room temperature

800 1000 1200

0

0.2

0.4

Reduction temperature TR(K)

Frac

tinalreduction

F,

FH

()

Newlands coal

Fractional reduction (gravimetric method)

Fractional reduction due to H

Tar filter: room temperature

Final fractional reductions Fand FH


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2.2Carbon composite iron oxide pellets

using semi-coal-char

It was found in the above-mentioned carbonizationexperiments under rising temperature conditions that when the

carbonization was interrupted halfway, the volatile matter

release was interrupted corresponding to the interrupted

carbonizing temperature, i.e., the maximum carbonizing

temperature Tc,max ; and that when the carbonization was

started again the release of the residual volatile matter began

at the very interrupted carbonizing temperatureTc,max and the

same total amount of carbonization gas was released as the

one without interruption.


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From these findings we proposed the novel

carbon composite pellets, in which the semi-coal-char

including the residual volatile matter was used ascarbonaceous material. When we use fully

carbonized coal char as carbonaceous material, the

reduction of carbon composite pellets starts at first assolid / solid reaction under rising temperature

condition like in a blast furnace. Whereas, when we

use the semi-coal-char as carbonaceous material,the reduction of carbon composite pellets starts from

the beginning as gas / solid reaction just after the

reduction temperature arrives at Tc,max .


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Therefore, the first merit is the decrease instarting temperature of reaction and the second

one is the rate enhancement of reduction reaction

by the residual volatile matter (see Fig.5). The

decrease in starting temperature of reduction

reaction of iron ore in a blast furnace leads to thedecrease in consumption of reducing agent.


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Heating pattern

0 120 240 360

400

600

800

1000

1200

1400

Carbonization time (min)

Carb

onizationtemperatu

re(K)

Tc,max = 1273 K

873 K

1073 K

973 K

823 K

TC, max = 1273 K

Carbonization time t (min)

Carboniz

ationtemperatureT

C

(K)

In order to obtain the semi-coal-char, Newcastle blend coal wascarbonized from room temperature to TC, max= 823, 873, 973, 1073and 1273 Kat200 K/h, and kept at TC, maxuntil arrival time of 6 h.

Fig. 2


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0

0.05

0.1

0.15

0.2

0.25

0.3

823 873 973 1073 1273

Totalgasvolume

[m3(s.

t.p.)]

Maximum carbonization temperature TC, max (K)

H2

CO

CO2

CH4

C2H4

C2H6

C3H8

Carbonization experiment (total gas volume)

Total gas volume ( Newcastle blend coal )H2gas releases more than any other gasesat TC, max= 873, 973, 1073, 1273 K.The higher TC, maxis, the more H2gas releases.Char contained much hydrogen at TC, max = 823 K.

Fig. 4


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F.C. V.M. Ash S C H O N

72.2 15.9 11.9 0.53 75.3 2.87 7.31 2.06

TC, max823 KTable. Analysis of Char carbonized at Tc, max = 823 K

(mass%)

TC, max1073 K

TC, max1273 K


82.7 4.43 12.9 0.42 81.5 1.54 1.91 1.74

Table. Analysis of Char carbonized at Tc, max = 1073 K(mass%)


83.2 2.51 14.3 0.52 81.7 0.90 1.34 1.27

Table. Analysis of Char carbonized at Tc, max = 1273 K

(mass%)

Analysis of the char obtained by carbonization


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Reduction of carbon composite iron oxide pellets

Ar gas inlet

Alumina

crucible

Gas outlet

Pellets

Thermo-

couple

Preparation of carbon compositeiron oxide pelletsChar : Fe2O3 = 1 : 4BinderBentonite (1 mass added)Particle size: under 4563 mPellets size: about 15 mmKeeping at 378 K for 24 hto remove waterReduction experiment and analysisReduction conditionsAr or N2gas atmosphereHeating rate: 0 or 3K/minAnalysisGas chromatography, SEM, XRD

Electric

furnace


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Relation between fractional reduction and reduction time of

carbon composite pellets at 1073 K in N2atmosphere

Semi-coal-char

Reduction behavior of carbon composite pellet atTC, max= 823Kwas higher thanany other pellets by about 10 .When TC, maxwas lower, namelythe pellet had more residual

V.M., the reduction of carboncomposite pellet was muchenhanced.

TC, max = 823 K

TC, max = 1073 K

TC, max = 1273 K

Char

Fr

actionalreductionF

(-)

Reduction time t (min)

0 10 20 30 40 50 600

5

10

15

20

25

10TR= 1073 K

( Fig. 5 )


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TC, max = 823 K

TC, max = 1073 KTC, max = 1273 K

Semi-coal-char

Fractionalreducti

onF(-)

Reduction time t (min)0 20 40 60 80

0

20

40

60

80

100

Fig. 5. Reduction curves for semi-coal-char

composite pellets ( TR= 1173 K ).

TR= 1173 K


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0 10 20 30 40 50 600

20

40

60

80

100

Char (TC, max = 823 K) (V.M. 15.9 %)

Coke (V.M. 0.6 %)Graphite (Purity 98 %)

Reduction time t [min]

Fractionalre

ductionF

[%]

Early stageChar Coke, GraphiteLater stageChar, Coke Graphite

Reduction rate

Effect of V.M. and crystallization Reduction rate

Influence of several kinds of carbon materials

Reduction at 1273 K in

N2gas atmosphere


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2.3Carbon composite iron oxide

pellets using semi-charcoal

The above-mentioned carbonization

experiments on coal were expanded into

those on charcoal; semi-charcoal including

the residual volatile matter was used as

carbonaceous material in the novel carbon

composite pellets.


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The rate enhancement effect of reduction

for semi-charcoal composite pellets isstronger than that for semi-coal-charcomposite pellets, because the gasification

rate of semi-charcoal is higher than that of

semi-coal-char. This is caused by the

following reasons: amorphous nature of

semi-charcoal is stronger than that of semi-

coal-char (see Fig.6) and the activationenergyof semi-charcoal is lower than that of

semi-coal-char (see Table 1).

R d i f i id b d bi


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A lot of steel engineers

researched various meansto decrease coke in a blast

furnace in order to reduce

CO2emission.

Carbon neutral(No CO2emission)Rich resources

Biomass

Reduction of iron oxide by woody biomass

Woody biomass

Japanese

cedar

Application(Carbonaceous material)

Injection into a blast furnace

Preparation of carbon com-

posite iron ore agglomerateJapanese

cypressBiomass

waste
http://www.dex.ne.jp/mantan/search/std2_search_preview.jhtml?start=15&lastServiceTime=1113451861319&number=13


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Sample

F.C. V.M. Ash T.S T.C H O N

8.12 90.8 1.05 0.014 50.7 6.16 41.1 1.01

Carbonaceous materialJapanese cypressTable. Analysis of Japanese cypress (mass%)

Iron oxide: Reagent grade hematite (Fe2O3)

(95 mass%, Wako Pure Chemical Industries Ltd.)

Sample for carbonization experiment

Sample for reduction experiment of iron oxide pellets

SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O

58.79 14.27 2.99 0.70 1.28 0.70 3.42

Table. Chemical analysis of Bentonite (mass%)

BinderBentonite(1 mass% added)


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Heating pattern of carbonization of Japanese cypress

Carbonization time t (min)

In order to obtain the semi-charcoal, Japanese cypress was

carbonized from room temperature to TC, max= 823, 1073 and

1273 K at 200 K/h, and kept at TC, maxuntil arrival time of 6 h.

Carbonizationtem

peratureTC(K

)

823 K

0 120 240 360

800

1000

1200

600

400

1400

1073 K

TC, max = 1273 K


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Total gas volume generated by carbonization

Totalg

asvolume[m3(s.t.p.)]

Maximum carbonization temperature Tc, max (K)

H2

CO

CO2

CH4

C2H4

C2H6

C3H8

Total gas volume generated by carbonizationH2 gas was released more than any other gases at TC, max = 1273 K,but was released less than CO, CO2and CH4gases at TC, max= 823 K.

The higher TC, maxwas, the more H2gas was released.Semi-charcoal retained much V.M., namely H2gas, at Tc, max = 823 K.

823 1073 1273

0.01

0.02

0.03

0.04

0


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Table Analysis of semi-charcoal obtained by carbonization of Japanese cypress.

Tc, max =

823 KTc, max =

1073 K

Volatile matter

(V.M.)Hydrogen

Tc, max =

1273 K

(mass%)

Analysis of the semi-charcoal obtained by carbonization

It was confirmed that the semi-charcoal of TC, max= 823 K

retained much V.M., namely hydrogen.

0.04 0.824.810.5692.61.167.0091.80TC,max= 1273 K

0.03 0.555.891.3391.21.019.6489.35TC,max= 1073 K

0.01 0.609.892.9385.80.7618.6580.60TC,max= 823 KSemi-

charcoal

S NOHCAshV.M.F.C.Component

Coke 87.1 0.97 11.97 84.6 0.26 1.35 1.220. 60

0.01 41.11.016.1650.71.0890.88.12Japanesecypress


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Semi-charcoal has many micro pores with the size of about 10 m.

Semi-charcoal obtained by carbonization

Tc, max = 823 K Tc, max = 1073 KT

c, max = 1273 K


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Semi-charcoalTc, max = 823, 1073, 1273 KCO2 1.0 L/min (s.t.p.)TG= 1073, 1173, 1273 K

Experimental conditions

Reaction rate

Weight loss measurement

6375 mBinder 2 mass% Pellets

CO2N2

TG

R.T.

600 [K/h]

Fig. Schematic of reduction furnace.

Gasification of semi-charcoal


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TG= 1173 K TG= 1273 K

Tc, max is low Reaction rate is high


Fig. Weight loss curves of semi-charcoals

obtained by carbonization at Tc, max = 823,

1073, 1273 K and coke at TG = 1173 K in

CO2 gas atmosphere.

0 20 60Reaction time [min]

We

ightloss[%]

0

-20

-60

40

CokeSemi-charcoal c max= 1273 K c max= 1073 K c max= 823 K

-40

-80

-100

Fig. Weight loss curves of semi-charcoals

obtained by carbonization at Tc, max = 823,

1073, 1273 K and coke at TG = 1273 K in

CO2 gas atmosphere.

0 20 60Reaction time [min]

We

ightloss[%]

0

-20

-60

40

-40

-80

-100

Gasification of semi charcoal


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Arrhenius plots of reaction rate of gasification

Tc, max

E[kJ/mol]

823 K1073 K 1273 K Coke

138 162 219139

Gradient Activation energy

Tc, max is low

Activation energy is low


-100.7 0.8 1.0

1/TG [K-1]

Reactionrate:ln

kC,

CO2

[1/min]

-6

0.9

-4

-2

[10-3]

TG[K]

11001200 100013001400

-8

Semi-charcoal

Tc,max= 823 K Tc,max= 1073 K Tc,max= 1273 K Coke

Fig. Reaction rate per unit mass at TG= 1073,

1173, 1273 K in CO2atmosphere.

This result of activation energy might

be influenced by specific surface area

and crystallizationof these samples.


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Carbonaceous material

Activation energy

(kJ/mol)

Graphite

Bintyo char

Bamboo char

Coke

Glassy carbon

Activated carbon

Semi-charcoalat Tc,max= 823 K

Semi-charcoalat Tc,max

= 1073 K

Semi-charcoal at Tc,max= 1273 K

Semi-coal-char at Tc,max= 1073 K

Coke

217(29)

182(29)

181(29)

200(29)

211(29)

149(29)

138 *

139*

162*

174*

219*

Table 1. Comparison of activation energies for

variouscarbonaceous materials.(27)

* Present work


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2(Cu-K) /degree

Diffraction

intensity/arb.un

it

(b) Semi-charcoala) Semi-coal-char

20 30 40 50 60 7020 30 40 50 60 70

2(Cu-K) /degree

Diffractionintensity/arb.unit : Carbon

TC, max = 1273 K

1073 K

823 K

TC, max = 1273 K

1073 K

973 K

: Carbon: Unknown

The crystal structures of semi-coal-char and semi-charcoal

Semi-charcoalSemi-coal-char

Amorphous

structure

Crystalline

structureFig. 6

R d ti f i h l it i id ll t


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Reduction of semi-charcoal composite iron oxide pellets

Preparation of semi-charcoal composite iron oxide pelletsSemi-charcoal : Fe2O3= 1 : 4Binder Bentonite (1 mass%)Particle size: 2335, 6375, 105150 mPellets size: about 15 mmKeeping at 378 K for 24 h to remove water

Reduction experiment and analysis

Reduction conditionsN2gas atmosphereAnalysisGas chromatography

Reduction behavior of iron oxide in semi-charcoal composite


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TR= 1073 K

Fig. Reduction curves of semi-charcoal

composite pellets using semi-charcoal at

Tc,max= 823, 1073, 1273 K and coke at

TR = 1073 K in N2gas atmosphere.


Reduction time [min]

FractionalreductionF

[%]

0 30 60

15

30

Tc,max= 823 K

Tc,max= 1073 K

Tc,max= 1273 K

0

Particle size: 6375 m

Reduction behaviorF of semi-charcoal compositepellet at TC, max= 823Kwas 19 %

for 60 minand higher than any

other pellets by 78 %.When TC, maxwas lower, namelythe pellet had more residual

V.M., the reduction of semi-

charcoal composite pellet was

much enhanced.


pellets at TR= 1073 K in the N2gas atmosphere

Coke

823 K1073 K

1273 K

Tc,max

Coke



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TR =1173 K in N2gas atmosphere.

TR= 1173 K


Fractionalredu

ctionF

[%]

0 30 60

25

50

0



Reduction behaviorF of semi-charcoal compositepellet at TC, max= 823Kwas 40 %

for 60 minand higher than any

other pellets.When TC, maxwas lower, namelythe pellet had more residual

V.M., the reduction of semi-

charcoal composite pellet was

much enhanced.

TC,max= 823 K

TC,max= 1073 K

TC,max= 1273 K

Coke

823 K1073 K

1273 K

T

c,max

Coke


pellet at TR= 1173 K in N2gas atmosphere



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TR= 1273 K




TR = 1273 K in N2gas atmosphere.


Fractionalredu

ctionF

[%]

Tc,max= 823 K

Tc,max= 1073 K

Tc,max= 1273 K

0 30 600

50

100


Reduction behaviorF of semi-charcoal compositepellets at TC, max= 823, 1073 and

1273 K were over 90 % for 60 min

and indicated the same behaviorat TR= 1273 K.These reducibility of semi-charcoalcomposite pellets were high and

were not dependent on residual

V.M. at TR= 1273 K.


Coke

823 K1073 K

1273 K

Tc,max

Coke


pellets at TR= 1273 K in N2gas atmosphere

The influence of crystallinity of semi-charcoal on reduction of


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FractionalreductionF

[%]

823

1073

1273

CharCharcoal

0 10 20 30 40 50 600

20

40

60

80

100

Tc,max (K)

Fig. Reduction curves of carbon composite pellets

using semi-charcoal and semi-coal-char at

Tc,max = 823, 1073, 1273 K with time at TR =

1273 K in N2gas atmosphere.

Semi-charcoal composite pellet

Semi-coal-char composite pellet

The influence of crystallinity of semi-charcoal on reduction of

iron oxide in semi-charcoal composite pellet at TR= 1273 K


Reduction rateReduction rate of semi-charcoalcomposite pellets are higher

than that of semi-coal-char

composite pellets.

Semi-charcoal Semi-coal-char

Reducibility

Amorphous

structure

Crystalline

structure


37/48



38/48


Totalgasvolume[m3(s.t.p.)]

Maximum carbonization temperature TC, max (K)

H2

CO

CO2

CH4

C2H4

C2H6

C3H8

Total gas volume generated by carbonizationH2 gas was released more than any other gases at TC, max = 1273 K,but was released less than CO, CO2 and CH4gases at TC, max= 823 K.

The higher TC, maxwas, the more H2gas was released.Semi-charcoal retained much V.M., namely H2gas, at TC, max = 823 K.

823 1073 1273

0.01

0.02

0.03

0.04

0

Japanese

cypress

O/C H/C mole ratio (Van Krevelen diagram)


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moleratio

mole ratio

demethanation

Dehydration, decarboxylation

Calorific power low Semi-coal-charTC, max = 823 KTC, max = 873 KTC, max = 973 KTC, max = 1073 KTC, max = 1173 KTC, max = 1273 KSemi-charcoal

TC, max= 823 KTC, max= 1073 KTC, max= 1273 KCoke

TC, max = 823 K

873 K

973 K

1173 K

1073 K

1273 K

Tc, max = 823 K

1073 K

1273 K

Semi-coal-char

Coke

Semi-charcoal

The higher TC, maxwas,the lower O/C and H/C

values were.

0 0.05 0.10

0.2

0.4

0.6

O/C, H/C mole ratio (Van Krevelen diagram)


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3. OUTLINE OF THE PRESENT STUDY

From the accumulated date mentioned-above on semi-charcoal, in the first step, the

first author is going to study the optimum

conditions for the use of both semi-charcoal

and carbonization gas (biogas) released at

carbonization in ironmaking such as carboncomposite agglomerates by data analyses in

Univ. Federal de Ouro Preto with Prof. Assis;


41/48

we can expect that the lower the

carbonizing temperature Tc,max is, the

better the reactivity of semi-charcoal

becomes but the less the amount of

carbonization gas releases in the

carbonizing step.


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As the carbonizing temperature Tc,max

decreases, the activation energy of semi-

charcoal decreases gradually, while the

amount of carbonization gas release in the

carbonizing step, namely, the amount of

biogas, decreases rather drastically. There

will be some optimum carbonizing

temperature Tc,max in an actual process forboth preparing reactive semi-charcoal and

producing much biogas.


43/48

In the second step, the experimental

program will be proposed to search theoptimum conditions for the use of both

semi-charcoal and carbonization gas

released in the carbonizing step. Of

course, the experimental program has

to be expanded from wood to variouskinds of biomass.


44/48

In addition, literatures on various

kinds of biomass will be collected andanalyzed. Application of semi-

charcoal to another manufacturing

industry will also be searched.

In the third step, the experimental

apparatus will be designed for thenext year research period.

CONCLUDING REMARKS


45/48

CONCLUDING REMARKS

From the previous study on pre-reduction of

iron oxide pellets by coal carbonization gas, we

proposed a novel carbon composite pellets; semi-coal-char was used as carbonaceous material to

enhance the rate of reduction and at the same

time to decrease the starting temperature ofreduction reaction. We expanded these results to

semi-charcoal.

The first author is going to study the optimumconditions for the use of both semi-charcoal and

carbonization gas released at carbonization in

ironmaking by data analyses in Univ. Federal de

Ouro Preto with Prof. Assis.


46/48

Muito obrigado.


47/48

O/C, H/C mole ratio (Van Krevelen diagram)


48/48

moleratio

mole ratio

demethanation

Dehydration, decarboxylation

Calorific power low Semi-coal-charTC, max = 823 KTC, max = 873 KTC, max = 973 KTC, max = 1073 KTC, max = 1173 KTC, max = 1273 KSemi-charcoal

TC, max= 823 KTC, max= 1073 KTC, max= 1273 KCoke

TC, max = 823 K

873 K

973 K

1173 K

1073 K

1273 K

Tc, max = 823 K

1073 K

1273 K

Semi-coal-char

Coke

Semi-charcoal

The higher TC, maxwas,the lower O/C and H/C

values were.

0 0.05 0.10

0.2

0.4

0.6

/ , / ( g )

j b 2013 presentation tateo usui mod

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