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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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)
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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(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
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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
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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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
8/4/2019 1976 National Waste Processing Conference 03
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
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The paper orignally scheduled to be pr esented onpages 41 - 48 has been withdrawn.