1976 National Waste Processing Conference 03

8/4/2019 1976 National Waste Processing Conference 03

1/23

THERMODYNAMIC FUNDAMENTALS FOR

THE PYROL YSIS OF REFUSE

F MCHAEL LEWSto Rsc sttt

ABSTRAT

Th pupos o t pap s o scuss us oposs o h thma pocssng omuncpaso wasts an o ma compasons bwnposs ssms an convntonawas ncn aon sstms Th tms poss an gascatona n,an th tmonamc pncps ous poss pocss a vop Svaus poss pocsss a scb an us

at,ncung possb nct hatngct poss,an poss wth h uso p us Th a pouon aspcts oposs a scuss an compa wh thos

,

oot tma pocsss na a tmonamc cmpasonbas on a pocss cost pocss c ato s ma btwn posssstms a convntona ssms o th hmapocssng o muncpa so wass

TRODTO

T us o poss n hma pocssng omuncpa so was has gna a gat a os ompa wt som xstng ncnatontcnqus,poss canb mo cv nucng h mass,bu,an putscb o tsowast an has mo potnta o ncasngsouc cov an casng a pouon

Poss s th tm us o an vsbchmca chang boug aboub h acton oa n an amosph vo ooxgn Sno nmous ms a thma composon,

suctv saton an cabonaton

9

T poss o oganc compouns sha Oganc qus pognous acs u gas Wat psn n qu o gasous sa

pnng on na poss cononsT cha conans an mna as o o non

combustb mata psn n h was pus was m h x cabon, whch psnts tcabonacous acon o ogna maa at

no voaz on atng Th cha aso usuaconans sma quants o ogn an oxgnan nogn s somms psnt

Th oganc qus a a compx mxu ocmcas an a on ca pognous acs,bcaus h a acc an w s poucbth sucv staton o woo T u gasconssts o a numb o combustb gass,suc ascabon monox mthan,ogn nan mno quans o oth hg ho cabons T u gas aso conans an appcabquant o cabon ox an ma conan watvapo t has no bn pvous conns outoth sam

Som cnt vop sstms o thmapocssng o muncpa so wast a capossbu a,n act mo cos at togascaon a gascaton mans to convt a so o qu substanc o a gas Spccat m s to xatonucon actonshat convt cabonacous sos o combustbgas poucs Th gas pouc s a unac spc ca sgn o gascaon pocss o mak

a combusb, gasous u om a vat o


2/23

cabonaceous mateias,such as bitumnous coa,chacoa and coe by eaction wth steam andsteam/ai mxtues.

Because both of these pocesses have becomeaccepted as pyoysis,they have been nclued nthe discussion,but une the foowng efnitons

yrlysis Thema pocessing of waste n theabsence of oxygen in (a) niecty heated etots,

an (b) funaces that ae dectly heate by fuegases fom a bune fing on a stoichometcai/fue atio

asificatin Themal pocessing of wastewhee a faction ofthe stoichometc oxygenequed by the waste is amitted iectly into thefuelbed to ibeate the heat equed fo enothemc gasficaton eactions. The volate potionofncomng waste wi be pyoyze by the heat ofthe fue gases,and the outet gas compostionwieflect both pocesses

n the laboatoy pyoysis pocesses fomunicipal soid waste have been eveope topoduce chemical feedstocs,iui bole fues,activate cabon,an fuel gas fo steam geneation.Ths discussion deals pmaily with municipalwaste pyolyss fo steam geneation.

One ofthe pmay avantages ofpyolysis sthat the combuston of the fuel gases taes pace a chambe physcally sepaate fom the soi

waste so that combuston can be completed athigh tempeatues an low excess ai fo maximumthemal effciency.

REFUSE OMPOSTO

A baseine efuse compostion must be estab ishebefoe a thema pocess fo municpalsoid waste can be anayze o compae with othepocesses,and the folowng composition has beenassumed hee

Moistuenets (Ash)Combustibes

CabonHydogenOxygen

25 pecent25 pecent50

pecent52 pecent7 pecent

4 pecent

Hghe Heating Vaue (HHV) 4,750 Btu/b(2634 Kgca/Kg)

Fo easie calculatons,the efuse s assumefee ofnitogen,sulfu chone and othe ele ments an compouns usualy foun n taceamounts

20

THERMODYAM FUDAMETALS

R VRI

The utimate yied an fina composition ofthesoi,iqui,an gaseous poucts fom pyolyssand gasfcaton depend on a numbe ofpocessvaiabes. Fo pyoyss pocesses the mao vaia

bes ae the chemcal compositon of the awmateas,heatng ate, and ultimate tempeatueveal studies [1,23,4,5] of these and othepocess paametes lead to the conclusion that

the complexty of these inteactions makes timpossble to pedict the fina pouct chaac teistics.

ENRI N XR

R

A pyolysis pocess may be endothemc (euieheat) o exothemic (give up heat),depending onthe ultimate tempeatue eached. n most mateials,the pocess s endothemic at lowe tempeatues and exothemic at highe tempeatues. In alcases,the heating value of the pyrolysis productsis the sumofthe heating value of the originalmaterial and the net energy added during pyrolysis.n many celuosc mateias,the amount ofenegyabsobe o libeatedby the pyoysis eacton isvey smal compaedwith the heating vaue of theoginal matea Unfotunately,in most pyoysis

studies pefomed to date,the emphass has beenon ientifcation of the many complex chemicasgeneated by pyolysis athe than on eat andmateialbalances fo pyolysis pocesses fo whichvey few data ae availabe

Howeve,snce the heating value of the pyoysspouct s always eual to the heating value of theoigna matea plus any heat added,a heat andmateia balance canbe pefomed base on evewof the availabe data. [6,7]

RNA T UNAR

To pefom a themodynamic anaysis a Themoynamc System Bounay must be awnaound the system to be analyzed Figue 1 showsa typcal themal pocessig system fo muncpalsolid waste,which can be eithe a pyolysis o anincineation system. The themodynamc systembounday is inicated fo all systems analyzed.

In these analyses,the system bounday hasbeen consideed to end upsteam of any ai pol


3/23

Fl G.

YN

I Y BUDY

II TYPICAL HERMAI

PROCENG SSEM

Wse

PROSSCombsion Ar OR

ICNERAION

uxiliry Fu.1

I -

sh

II r EnriTmyicI

Sy Bda

I

He Enterihrmync

Sy.m Bndry

M.r1 .nQ- T hrmnmic

Syte Bndary

Ht ig ermyn.ic

Sytem Bd.y

l TYPCAL TERMAL PRCSSN SYSEM

luto cotrol evice Aso zero heat loss or thesyste\s aalyze has bee assume,because thepurpose s to illustrate a methoology a to maecomparisos with other processes Assumg a heatloss o, say,5 percet o the reuse heat iputwoul ot serve ay particular purpose.

A AN ARIA AAN

The comparative aalyses evelope are baseo a balace o the materal a heat iputs aoutputs (Heat a Matera Balace:

Material i = Material outHeat i Heat out

These baaces provie a valuable tool that shouaways be use i thecoparative evaluato otherma processg systems

I a thermoyamic aalysis,ateral and heatareaounted for only when they ross the ther odyna syste boundary nteal reyle

loops, ithey are preset do not affet the overallheat and aterlbane

PYROLYSS PROESS -DRETY

HEATED ROTARY KL

Pyrolysis processes vary. I the process cosere i this paer,the reuse has bee irectyheate i a retort completely evoi o oxygeFgure 2 gves a cross sectio o a typica iirectly

heate rotary i The cyirica retort sectio o

2

this i is iclie sghtly a rotate slowly,usig the reuse to move rom the rot e tothe ischarge e o the retort The retort iseclose i a reractorylie rebox A portio othe pyrolyss uel gas is bure the aular spacebetwee the outsie wel o the cylrica retorta the iteror o the irebox. Heat is traserrethrough the aloy metal wall othe retort topyrolyze the reuse This type o retort wil re

quire shree reuse that ca pass through ascree with twoich opeigsBecause o the complexity o the pyrolysis

process,complete ata othe accuracy a etailthat woul be require to perorm a etaie heata materal balace arou the pyroysis processare ot avaiable However by use o reporteexpermetal ata, [ 2 3] a baace cabeevelope. The compositio o the ry uel gasrom this evelopebalace is

Compoet

COCOCHHCH

Volume Percet

19.635.020.416.3

8.7

The orgaic liquis ca be represete by thechemical ormula evelope by Kaiser: []

The assume heatig value o this orgaic liqui

14000 Btu/b (HHV) (7778 Kgcal/Kg)


4/23

Rfu

Fe

l.

I IRECYCLE

FUELG

AS

I

'

V

-

FIREBO

X

IPYROLYSIS

RE

ACTOR

(RETORT)

,.F

GAS

.

/

.BURNER

2COMBUSTON

AIR

RETLY

HEATE,RARY

K

YRLZER

t,

(\

.,

l

" "FUEL

GAS

t

CharDihage

To

Combston

System

/Bole


5/23

Te assumed compositio of te carboaceousfractio ofte car is

ComponentCarboHydroge

Oxyge

Weigt Percet

852

13Te assumed eatig value of te carboaceousfractio is 13000 Btu/lb (HHV) (7222 Kgcal/Kg)

A detailed eat ad material balace for tepyroysis processbased o te assumed compositioofte pyrolysis products is sow i Tabes ad2*.

a actual pyrolysis process were teobective is to produce steam te orgaic liquidswext wit te pyrolysis gas i a aerosol adte aerosolwi bur alog wit te combustible

gases Te pyrolyzer exaust temperature ofI400F(760C)wil prevet codesatio ofte aeroso if

te ies are propery isulated betwee te reactorad te burer Tabe 3 sows a material baacefor combustio ofte pyroysis gases at 20 percet excess air Te car from is process as otbee combusted

Te eatig vaue of te pyrolysis products wilalways be equal to te vaue of te origiamaterial plus ay eat added. Suc a detaiedaaysis of te composito ofte pyroysis gasesad te associated eat ad materia baace sur

roudig tat portio of te pyroysis is ot ecessary to perform a overall eat ad materialbaace but as bee icluded for ilstrativepurposes.

PROSS SSTEM DESGED OR STEAM

PRODCO

A typical pyrolysis system icorporatng teindirectly eated pyrolysis fue gasred rotaryki is sow i Figure 3. Te quatity of pyrolysis

fuel gas tat as bee recycled back to te retortto sustai te process as bee idicated but assow i te igure does ot iluece te overal eatbaace Te system as bee desiged toproduce steam ad te selected boiler exausttemperature is 500F (260C).

'In al the tables and igurs presnted in hs paper, thenumrical vaues ae shown o mor-than-sgnificantigues merey o cay and ase o gung and notwh h inen o impyng an quivalen dgee o

. .precson.

23

Covetioa aterburers represet combustiounits tat were origiay desiged to icierategases from solvet evaporatio processes ad igeeral te eatig value of te gases itr ucedito tese uits was of te order of8 to 5 Bt/t(71 to 133 Kgca/m). I te pyroysis system

described ere te fue gas eatig value is approximately 300 Bt/t (2669 Kgca/m). W ever te eatig value of a fume or fuel gas ap proaces 50 Btu/ft (445 Kgcal/m) te com

bustio process becomes selfsustaiig; ece tegas souldbebured i aburer of te type usedfor coke ove gas ad carbobakig processes [8] A burer of tis type ca be readily adapted to acovetioalboiler.

Te teoretica lame temperature at 20 per cet excess air for te pyrolysis gases from tisprocess is approximatey 3000F (I 649C) Ifcotro of itroge oxides becomes ecessarystaged combustio [6] may be advisabe. I acaseste burer sold fire ito aboier tat as aradiatio sectio to absorb some eat ad reducete temperature of te ue gas to approxmatelyI 600F (871C) before te gas eters a covec tiobak to miimize slaggig of te boier tubes.

PROLSS WTH PREDRED RESE

I discussios of pyrolysis processes predryig

ofte refuse is metioed as a meas of improvgte termal eficiecy ofte process. However itbe sow tat termal eciecy caot beimproved by tis metod witout vioating teFirst Law of Termodyamics.

A ypotetical refuse pyrolysis system witrefuse dryig is sow i Figure 4. Te refuse isdried to zero moisture cotet i a directcotactdryer usig 500F (260C) boiler exaust gasesTese gases pick up te refuse moisture ad eavete dryer at 300F 49C) Te solid portio ofte refuse as bee eated to 250F (21C). Some

pyrolysis of te lowboiling fractios will occureve at temperatures as low as 500F (260C) adte ue gases wil cotai trace quatities of pyro lysis products. Some odoriferous costituetswillalso be preset i te flue gases Te flue gases aretake to te burer sectio for reburig toelimiate tese odors

Tis system produces te same amout of steamad discarges te same quatity of lue gases aste system ot usig predried refuse. No icreaseas occurred i termal efciecy i.e i te

quatity ofsteam produced


6/23

ABLE1

YRLY

MAERIALBALANE

1onofWase)

Cab

Hydge

Oxyge

Ie

al

Ib

Ib

Ib

Ib

Ib

Ip

Cbble

2

7

1

1

Me

Ie

al

2

12

2

Op

Ca

17

2

7

t

Ogalqd

CHO

)

21

2

7

2

FelGa

CabdxdeCO2)

2

771

1

CabxdeCO)

1

12

MeaeCH)

1

HydgeH2)

EyleeC2H

)

27

bal

11

1

1

aevap

aee

yly

2

111

21

bal

7

71

al

2

12

2


7/23

(SIUTS)

YRLYSISMATERIABALAE

(90.2

Kg)

Carbon

H

Ox

In

erts

Total

In

Kg

Kg

Kg

Kg

Kg

Combustibles

235.9

31.7

186.0

4536

Moisture

25.2

201.6

2268

Inerts

22

6.8

2268

-

Total

235.9

56.9

387.6

22

6.8

9072

O Char

77.1

1.8

11.8

22

68

3175

I

Organiciquid(C

6H8)

97.0

10.8

21.5

1293

U

FuelGas

Carbondioxide

(CO2)

13.1

35.0

481

Carbonmonoxide

(CO)

233

31.1

54.

4

ethane(CH4)

13.7

4.5

182

Hydrogen

(H2)

1.8

1.8

Ethylene(C2H4)

11.7

1. 9

136

Subtota

61.7

8.2

661

136.1

Watervapor

Wastemoisture

25.2

201.6

2268

Pyrolysis

10.9

86.6

975

-

Subtotal

36.1

2882

3243

Total

235.8

56.9

3876

22

68

9072


8/23

Input Co

mbustible

Externally

supplied

Total

Output

Char

Organicliquids(C6O

Felgas

Carbondioxide(CO2)

Carbonmonoxide(CO)

Methane

(CH4)

Hydrogen

(H2

)

Ethylene

(C2

4

)

Subtotal

Watervapor

Waste

Pyrolysis

Subtotal

Total

ABLE

YRLY

HEABALANE

1Ton

ofWse;100

Sen

sible

Latent

B

u

Bu

1,37

8,635

1,37

8,635

26

1,300

19

0,950

71,250

3

7,070

4

2,515

4

3,760

1

8,915

2

6,130

16

8,390

32

7,500

530,000

14

0,825

227,900

46

8,325

757,900

1,08

8,965

829,150

Chemical

Total

Bu

Bu

9,500,000

9,500,000

1,378,635

9,500,000

10,878,635

2,600,000

2,86,300

3,990,000

4,252,200

37,070

521,640

564,155

955,160

998,920

244,400

263,15

649,320

675,450

2,360,520

2,538,910

857,500

368,725

1,226,225

8,940,520

10,878,635


9/23

I Cmbustibl

xtallysuppli

Ttal O Ca

N

OgaicliquisC6H8O

Fulgas

CabxiCO2

CabmxiCO

Mta

CH4

HygH2

tylC2H4

ubttal

Watvap

Wast

Pylysis

ubttal

Ttal

IUN

YRLYH

ABAAN

90Kg;0

sib

l

Latt

Kg-ca

l

Kgcal

3 347,388

6,84

2

48,11

6

17,93

9,34

1

10,71

3

11,02

7

4,76

6 642,43

1

82,2

4

133,49

3

5

118,00

9

190,97

274,39

8

208,928

mical

Tal

Kg-cal

Kg-cal

2,393,810

2,393,810

3

2,393,810

2,741,98

6,148

720,90

1,00,400

1,071,469

9,341

131,443

142,16

240,681

21,708

61,84

66,30

1

1

97,324

639,7

216,73

9308,984

2,27,872

2,741,198


10/23

I0

Input

Pyrolysis

g

ases

CO2

CO

CH4

H2

C2

H4

Organic

liq

uids

(C

H

0)

6

8

Watervapor

Pyrolysis

Waste

Air

Total

Output

CO2

N2

2

H2O

Total

TABLE

MATERIALBA

LANCE-COMBUSONOF

PYROLYSSPRODUCTSATEXCESSAR

Carbon

b

289

51.5

300

257

2139

3500

3500

3500

Hydrogen

b

100

40

43

238

239

55

6

121

6

121

6

121

6

Oxygen

b

771

685

473

1911

4444

1,2928

2,1212

9334

2155

9723

2,1212

Nitrogen

b

4,2914

4,2914

4,2914

4,294

Total

b

1060

1200

00

40

300

2850

2150

5000

5,5842

6,8842

1,2834

4,2914

2155

1,0939

6,

6842


11/23

t\

IPyrolysis

gases

C02

CO

CH4

H2

C2H4

Organic

liquids

(C6H8

O)

Water

vapor

Pyrolysis

Waste

Air

Total

OCO2

N2

2

H2

O

Total

(

T)

MTERBEOMBTOO

PYROLYPRODT

T20%EXER

Carbon

Kg

13.

1

23.

4

13.

6

11.

7

97

158.

8

158.

8

158.

8

HKg

4.

6

1

8

1.

9

1

.

8

1

.

8

2

5.

2

5

5.

1

5

5

1

5

5.

1

OxKg 35 31 21.5 867 216 586.4 962.2 423.4 977 41.1 962.2NKg

1 1,946.

5

1,9

46.

5

1,9

46.

5

Total

Kg

48

1

54

4

18.

2 .1'8

13

6

129.

3

97.

5

226

8

2 3,122.

6

582

2

1

946.

5 ,

97

7

496

2

3.

122.

6


12/23

wo

MATIAINPUT

WteAirlereedwte

Tt

MATIAOUTPUT

leG

ChrteTtl

OI

WAT AR

b2

55843865 4 688

47

3865

I4

leG r-

6884Ib

211tu

5

2xceAr

TAM

3865b

4637,55

t

-

435Ib

268457

5t

4)

re

317Ib

66387

t

elG

235Ib

1354

t

13b

817335t

ATIPUT

te

ATOUTPUT

rtemeGt

U

2b

I

5

t I

__

TMONAMCTMOUNA

FIG.3

INDIRCTHATDPRO

A

7Ib

23t

1

AI t

5,

213

46375

21

50


13/23

w.

MATERIAL

INPUT

Waste

Air

BoerFeedwate

ota

FlueGas

kg

5050

kg-cal

(260C)

STEAM

175

kg

1168570

kg-cal

_

'

-

kg907

5

.75

519

8

kg

IR

MATERAL

OUTPUT

67080

kg-ca

leGas

Cha

SeamTotal

7

75

59

0%

ExcessAr

eGas

05

kg

9071

kgca

BOER

EEDWATER

197

kg

67659

kg-ca

HEAT

INPUT

Waste

(760C

AR-

Bner

590

kg

0008

kgca

90

7

kg

0

98

0

kgca

I

NDRECLY

HEATED,ROTAR

Y

KILN

760C

REFSE

I

PY

ROLIZER

I

L_

____

HEAT

OUTPUT

Cha

Sea

FleGas

Toa

THERMODYNAMIC

SYSTEM

BONDARY

CH

AR

FIGURE

3

NDRECTLY

HA

ED

PYROLYSS

(S

UNS)

7

kg

7

0990

kg-ca

76

0C

kgca

980

70990

68570

5050

980

TA-361S2216R


14/23

Wt

MATERALNP

Waste

Air

BoieFeedwa

oa

MATERLOU

FeGas

Cha

SeaT

oal

OLEREEDWATER

AR

UT

Lb000

5584

er

3865

4

49

pU

T

68

84700

3865

4

49

3865Ib

60b

\000Ib

9500000B

REFUSE

FLUEGAS

STEAM

6884Ib

3865Ib

0050Bu

4637550tu

,

85

04b

5,3

789

00B,BURNERANDBOLER

(500")

.\?.

6

0Ib

3377750B

10Ib

3,3

5

00B

87b

8350Bu

(5"

(300

BURNR

250

ICCONC

RYR

1500Ib

957150B

/

NC

DOTRY

KINYOLZER

.

.

THERMODYNAMCSYSTM

BONARY

FURE4

PYROLYSISTREFUSEDRY

l 44b

40Ib

670950

Bt

HEATNPUT

697b

Wase

33465

tu

HEOUTPUT

FlueGa

Char

Seam

ota

4

00F

T 14

00F

9, 49

AR B

50

0050

863

637550

500000

TA-3615224


15/23

ww

MAERAN

WasteAirBoilerFw

ota

MAERIAOU

FueGa

ChaSteamotal

BOERFEEDWAER AI

RUT I P

U / 0

REFUSE

FLUEGAS

SEAM

3123kg

1753kg

kg

.2

kgca

1.168.570kgcal

7

I

1

2.533

1753

9

22

kg

,

-

8394kg

640kg

1355.375kgcal

1.6.7

73kgca

323

8URNERAND8LER

317

(260C)L

.753

5191527

kg

85125kg-ca

HEANPU

1753kg

36kg

Waste

i

HEAOUPU

83.7

75kgca

FueG

5498kg

833.1

72kgca

1Cha

3

kg

Seam

I277kg

197137kgcal

Toa

26fC

(149C)

8URNER

907kg

I

2.39380kgcal

DRECCONAC

21C)

DRYER

680

kg

L

2.41763kgca

/

NDRECYEA

EDRO

Y/

L

KNPYROZER

ERMODYNAMCSYSEM8UNDARY

G.4

PYROLYSS

WHREUSEDRYNG

SUNS)

(760C)

76

0C

: 1AIR

kgca

393B10

2

720.

5

70

-2380


16/23

EXCE AI R - pcto 10 2 3040r--------o-

o 10 2 3 4SOHOMETRC AR p

FIG.5 THORETA FAE TEPERATREVERSUS PEENT OF STOIHIOETRIAIR

From a practical viewpoint,reue drying maybe a viabe aternative to the ingle,multipurpoeunit i a eparate dyer can be contructed andoperated at le cot The aving realized mut bebalanced againt the reuirement o handling aninternal recycle loop conting o a large amount o

ue gaThe direct contact dryer operate in an internal recycle loop in the ytem hown whch illu trate that the overall heat balance i not aectedby internal recycle loop

GASFCATON PROCESSES

A number o gaiication procee or thetermal proceing o municpal olid wate areunder development. Mot gaiicaton procee are

baed on ubtoichometric combution in a pri

mary combution chamber and complete combu tion n a econdary combuton chamber Small ncinerator incorporatng thi prinple have oper ated or a number o year andare nown atarvedair and controlledair incnerator 9 . Figure 5 graphcally illutrate the relatonhp betweenpercent o toichometrc ar and theoretical lametemperature or the aumed reue compoitionand alo how the typical operating conditon ora tarvedair ncnerator. Some procee ue oxy

34

genenrchment or preheated air to acheve laggingtemperature at low air rate With oxygen or preheated ar,the hape o the curve i dentical,butthe temperare are higher n pporton to thepercentage ooxygen or ar preheat temperature.

In ome gaication procee team i added

to the air admitted to the gaier The team reactwith the carbon in the reue

Thi reaction i very endothermic,and t ha beenuggeted [7 that lue ga rom a wet crubberwth t high water vapor content could be mxedwith the underire air in conventonal grate ncnerator to reduce particulate emion byreducing the uantity o ga reured to cool thereuebed For typical reue bed conditon a

cubic oot owater vapor can aborb 99 Btu(50 Kgcal) A cubc oot o exce air under theme condition can aborb only 35 Btu (9 Kgcal).

D RECTCONTACT, 01 L-FRED PYROYSS

PROCESS

A drectcontact,oilred pyrolyzer i hownn Figure Aburner ired wth uel oil at the rateo7 galton (29 Q000 Kg) o reue upple the


17/23

wV

MATERIALNPUT

Waste

ArBoilerFeedwater

Total

MATERIALOUTPUT

FueGas

CharSteamTotal

Lb2,0

0,744r-

42

16806

12044

742/

168

10018b

AFTERBURNER

8F-20F

A

r

'

STEAM

2b

4,874,3

90Btu

10ExcessA

BOILER-

5F J

WasteOToal

Flueas

CharSteamTotal

4062b

726b

2000Ib

Refu

950Btu I_PYOLIZER

i

50b(7gl)

975,0Btu

I

I

BURNERI

THEDYSYSEBOUDY

CHAR

700b

2978Btu

(20F

G.6

DETOTT'OLED

OLZE

Btu

9,5

975,0

10,475,000

2,622310

2,978300

4,874390

0475,0

AR

-FUOIL


18/23

W

MARAL

INPU

Waste

Ol

A

Bole

eedwate

Tota

MARAL

OUPU

ue

as

Cha

teamota

/A

\

Lb

907

23

i

4,873

1,843

7,4

5486

317

1,843

7,646

,544

k

907

kg

2393

810

kgcal

Refue

AFRBURNER

982C-1093C

SEAM

1843

kg

1,228

,249

kgcal

FLUE

GAS

5486

kg

660,769

kgcal

1

00%

I

HEA

T

IN

PU

ExcessAir

I

-_,. .26

0C

I

BO

ILR

I7"

I

r y \.iWaste

O

ota

HEAO

UPU

ue

as

Cha

team T

otal

kgca

2,393,810

24680

2,,40

66079

750472

28,249

20

1843

kg

BOILR

DWATER

329

kg

lr--__-.

23

kg(2

.5

)

4,80

kgcal

A

IR

PYROL

ZR

FU

OIL

,BURNR

'.

L____

__>

ERMODNAMC

SSEM

BOUNDAR

CHAR

317

kg

70472

kgca

093C

FRE

6

REC

CONAC

OIFIRE

ROLIE

SIS)

TA-3

615225R


19/23

heat for the pyrolyi proe. eae thi i apyrolyi proe the brner i red on toihometri ratio o that no oxygen i admitted intothe pyrolyzer. The har proded i ameddental in antity and ompoition to the har the previoly derbed proee

Here an afterbrner i ed intead ofa brnerring into the boiler. The ombtion proe mtbe arried ot at 00 perent exe air to limit thetemperatre of the afterbrner to 8002000F(982093 In atal proee the exe arrate an be mot ikly determined by mearngthe onentration of oxygen in the dry fle gaOxygen i le enitive than arbon doxide tohange in arbontohydrogen ratio and i a betterhoie fr determinng exe ar Seleted vale ofoxygen onentration and perent exe air are

Perent Exe Air

2040080

00

Perent Oxygen

3.5.07.99.4

05

In thi diion only the material that roethe ytem bondary ha been onidered illtrating the point made earlier that the proe anbeevalated withot knowing the detail of the

proee taking plae inide the ThermodynamiSytem ondary

AR PO LLUON CONROL FOR

PYROL YSS PROCESSES

omparion of emiion potential frompyrolyiwith that from onventional ininerationproee hold be made ptream of any airlltion ontrol devie beae otherwie h adeve might nene the relt of the evalationofthe proe omparion between onventionalinerator that inorporate little or no air polltion ontrol meare and a pyrolyi proethat e a hgh energy ventri rbber for airlltion ontrol wold yield a biaed relt

Unfortnately very few "hard data are avalable on eiion from ontino pyrolyi proee (ptream of the air polltion ontrol devieTherefore the information mtbe extrapolatedfrom firt priniple and imilar proee.

From firt priniple it an be deded that ahgh temperatre proe wll volatilize more of the

heavy metal h a lead zin and admjm. The

37

boiling point of merry i o lw that merry ilely to volatilize in any thermal proeingytem Where ombtion of the fel gae takeplae in a hamber that i phyally eparated from

the olid fel bed a gnifiant redton n thepartilate normallyentrained n the ombtion

air hold be ahievable Indiretly heated pyrolyiproee offer the greatet potential n thi areabeae no ombtion air i introded n theolid fel regon.

When the ombtion hamber i eparated fromthe old fel bed and the danger of laggng andlinkering i remove the ombtion anbeompleted at low exe air rate and high temperatre f< maxmm thermal efieny. When theombtion i ompleted at a lower exe air ratethe volme of fle gae i gnfantly rededallowing a greater level of ontrol for the ameenergy inpt to a rbber 0 .

COMPARSON OF ALERNAVE PROCESSES

.

In a omparatve evalation of vario mniipalolidwate thermal proeing ytem fatorh a eonomi air pollton and reorereovery old be ed a parameter Howeverine thi paper deal prmarilywth the thermodynami of the proee thi parameterwill beed a a bai for omparon f alternative pro

eeommonly ed for evalating pyrolyi proee i the heating vale of the fel ga proded(t/ft (Kgal/m Volmetri heating vale ionly importantwhen the ga i to be moved overlong ditane in a pipelie or blended with natralga. f 000 t/f(8898 Kgal/mwere to beed a the tandard for omparing fel gaehydrogen whih ha a heating vale of only 325t/ft (2892 Kgal/m wold not fare verywell On the other hand nbtane with a heatingle of 3370 t/ft (29985 Kgal/mwoldexel

A more fndamental approah ing the ratioproe ot/proe reditwill provide abetterbai for omparion. A low ratio i a proeadvantage

In the ytem died here all the proeot annot be determined bt the antity of

wate and the antity of e ga that mt gothrogh the boiler and ltimately throg an airpolltion ontrol deve an be determined andonidered a ot The antity of team proded

i onidered a a redit The ot/redit ratio


20/23

w

ABLE4

MPARN

ALERNAIVEREE

PeDept

Cetert

t800F;

2%exessr

Idetl

eatedplpewt

bt

at0%exea

Giitwttxygeed

petf

wate;btat%exe

xge

Cbt

at5exea

Detetedfedss

pe10%exea

N.el

l0%exea

(fefeeel)

*06F,

99iHg

bwste

pe

lbtea

x12

35.3

38.5.

34.6

35

.5

49.4 8

.6

3

*

ft

flega

pe

lbtea

41.8

4.4

18.7

27.1

39.9

20.7


21/23

T

AB4

SUTS)

OMPASOOA

LTATVPOSSS

Process

D

Conventona

ncneraton

&9C

12

%

excess

ar

Indrectyh

eated

pyroyss

process

wth

combustona

t

2%

excess

ar

Gasfcaton

wth

kg

of

oxygen

added

per

kg

of

waste;

combuston

at

2%

excess

ox

ygen

Cobustona

t

%

excess

ar

Drety

hea

ted

o-red

yroy

process;

1

%

excess

ar

No

2

feo

;

2%

excess

(for

referen

ce

ony)

0

1

6

C

6

g

ar

Kg

waste

per

Ksteam

x

2

35

3

38.5

34

6

35.5

494

8

6

*

gas

M3

fue

per

Ksteam

2

61

1

2

1

1

1

6

2

4

1

2


22/23


23/23

The paper orignally scheduled to be pr esented onpages 41 - 48 has been withdrawn.

Documents

1976 National Waste Processing Conference 03