P. 1



# OAR Box 

# 1870 Prepped by Ollie Stewart



### Document

Number: 

# 26 ) ll-A-3 0 Docket Number: 

# A-90-1 9

Printed 11/28/20087:05:04 AM Sheet 26 of 67P. 2 

## A-90-1 9 ll-A-3 0



## JLE*AIRDO CKE T 

# OAQP S CONTRO L COS T MANUA L Fourt h Editio n

EP A 450/3-90-00 6 Januar y 199 0



# Sj g Unite d State s Environmenta l Protectio n Agency Offic e o f AirQualit

y Plannin g an d Standard s Research Triangl e Park , Nort h Carolin a 2771 1


# " 1 Ai rP. 3

« ^ 

# jj



# J •

• » ..

. - —



# OAQP S CONTRO

L COS T MANUA

L Fourt h Editio n

EP A 450/3-90-00 6 Januar y 199 0



# 2 £
Unite d State s Enrironmenta l Protectio n Agenc

y Offic e o f Ai rQualit y Plannin g and Standard s Researc h Triangle Park

, Nort h Carolina 2771 1P. 4

Thi s fourt

h editio n of

th e OA QPS Control

Cost Manual wa s prepared b y th e Emission s Standard s Divisio n o f th e Offic e of Ai rQuality Plannin g an d Standards , U.S . Environmental Protectio n Agency , Research Triangl e Park , N C 27711 . Mentio n of trad e name s o rcommercial product s i s no t intende d t o constitut e endorsemen to rrecommendatio n foruse . Copie s o f thi s reportare availabl e throug h th e Librar y Service s Offic

e (MD-35) , U.S . Environmental Protectio n Agency , Research Triangl e Par k N C 27711 , o r from th e Nationa l Technical Informatio n Service , 528 5 Por tRoya l Road , Springfiel d V

A 22161 . Question s an d comment s shoul d b e addresse d t o th e principa l author , William M . Vatavuk , OAQPS , phon e 919-541-530 9 (FT S 629-5309) . Th e technical edito rfo rth e fourt h editio n i s Ginny Moyer , OAQPS .P. 5



# Chapte r3 THERMA L an d CATALYTI C INCINERATOR S

Donal d R . va

n derVaar

t Jame s J . Spive y Research Triangl e Institut e Research Triangl e Park , N C 2770 9
Willia m M . Vatavuk A l Wehe Standard s Developmen tBranch , OAQP S U.S . Environmental Protectio n Agency Research Triangl e Park , N C 2771 1
Novembe r198 9


## Content s
3. 1 Introductio n . 3- 3 3. 2 Proces s Descriptio n 3- 4 3- 1P. 6

3.2. 1 Thermal Incinerator s 3- 7 3.2.1. 1 Direc tFlam e Incinerator s 3- 9 3.2.1. 2 Recuperativ e Incinerator s 3-1 0 3.2.1. 3 Regenerativ e Incinerator s 3-1 1 3.2. 2 Catalyti c Incinerator s 3-1 3 3.2.2. 1 Fixed-Be d Catalyti c Incinerator s 3-1 5 3.2.2. 2 Fluid-Be d Catalyti c Incinerator s 3-1 6 3.2. 3 Othe r Considerations—(Package d versu s Field-Erecte d Units , Auxiliary Equipment ) 3-1 7 3.2.3. 1 Package d vs . Field-Erecte d Unit s 3-1 7 3.2.3. 2 Ad d Ga s Scrubber s 3-1 7 3.2.3. 3 HeatExchanger s (Preheater s an d othe r Wast e Energy Recovery Units ) '3-1 8 3.2.3. 4 Othe r Auxiliar y Equipmen t3-1 8 3.2. 4 Technolog y Compariso n 3-1 9 3. 3 Genera

l Treatmen tof

Material an d Energ y Balance s 3-2 1 3. 4 Desig n Procedure s 3-2 2 3.4. 1 Step s Commo n t o Therma l an d Catalyti c Unit s . . " . 3-2 3 3.4. 2 Step s Specifi c t o Therma l Unit s 3-2 8 3.4. 3 Step s Specifi c t o Catalyti c Unit s 3-3 6 3. 5 Cos tAnalysi s 3-4 2 3.5. 1 Estimatin g Tota l Capita l Investmen t3-4 2 3.5.1. 1 Equipmen tCosts , E C 3-4 3

3- 2P. 7

3.5.1. 2 Installatio n Costs 3-5 1 3.5. 2 Estimatin g Total Annual Cos t3-5 1 3.5.2. 1 Direc tAnnual Costs 3-5 1 3.5.2. 2 IndirectAnnual Costs 3-5 7 3.5. 3 Cos tCompariso n fo rExampl e Cas e 3-5 8 3. 6 Acknowledgements 3-5 8 Appendi x 3

A - Propertie s o

f Selecte d Compound s . 3-6 0 Reference s . 3-6 4


## 3. 1 Introductio n
Incineration , like carbo n adsorption , i s on e of th e bes tknow

n method s o

f industria l ga s waste disposal . Unlike carbo n adsorption , however , inciner atio n i s a n ultimat e disposa l metho d i n tha tth e objectionabl e combustibl e compound s i n th e wast e ga s ar e converte d rathe rthan collected . On th e othe rhand , carbo n adsorptio n allow s recover y o f organi c compound s whic h may hav e mor

e valu e a s chemical s tha n jus tthei rheatin g value . A majo r advantag e of

incineratio n i s tha tvirtuall y an y gaseou s organi c strea m can b e incinerate d safely an d cleanly , provide d properengineerin g desig n i s used . Th e particula rapplicatio n of both therma

l an d catalyti c incineratio n t o gaseou s waste stream s containin g volatil e organi c compound s (VOC ) i s discusse d here . Th e U.S . Environmental Protectio n Agency define s an y organi c compoun d t o b e a VO C unles s i ti s specificall y determine d not t o b e a VOC . Indeed , a numbe rof organic s {e.g., methane ) ar e specifie d as no t bein g VOCs . Althoug h bot h VO C an d non-VO C organi c compound s ar e combustibl e and ar

e therefore importan ti n th e desig n o f th e incinerator , thi s distinctio n i s importan tsinc e i ti s th e contro l of VOC s tha ti s regulated . 3- 3P. 8



## 3. 2 Proces s Descriptio n
Seldo m i s th e wast e strea m t o b e combuste d a singl e organi c compound . Rather , i ti s commo n t o hav e a comple x mixtur e of organi c compounds . Thi s mixtur e i s typicall y analyze d fo rcarbon , hydrogen , oxygen , an d othe r elements ; an d a

n empirical formul a i s develope d which represent s th e mix ture . Combustio n of

suc h a mixtur e o f

organi c compound s containin g car bon , hydrogen , an d oxyge n i s describe d b y th e overal l exothermi c reaction :

C,H tf 0 , + 

# .• K *C0 3 + |H, 0 (3.1 )
Th e complet e combustio n product s CO j an d H 5 0 ar

e relativel y innocu ous , makin g indneratio n an attractiv e wast e disposa l method . Whe n chlo rinated o rsulfur-containin g compound s ar e presen ti n th e mixture , th e product s of

complet e combustio n indud e th e ad d component s HC I o rS0 3 , respectively , i n additio n t o Hj O an d CO3 . In general , thes e stream s woul d requir e remova

l of th e ad d component s b y a scrubbe runit , whic h coul d greatl y affec

tth e cos tof

th e indneratio n system . (Th e sizin g an d cost in g of thes e scrubber s i s covere d i n th e "We tScrubbers " chapte rof thi s Manual) Th e hear tof

an indnerato rsyste m i s a combustio n chambe ri n whic h th e VOC-containin g wast e strea m i s burned . Sinc e th e inle twast e ga s strea m temperatur e i s generall y much lowe rtha n tha trequire d forcom bustion , energy mus tb e supplie d t o th e indnerato rt o rais e th e wast e ga s temperature . Seldom , however , i s th e energ y release d b y th e combustio n of th e tota l organic s (VOC s an d others ) i n th e wast e ga s strea m suffiden tt o rais e it s own temperatur e t o th e desire d levels , s o tha tauxiliar y fuel (e.g., natura l gas ) mus tb e added . Th e combustio n o f

th e wast e gase s ma y b e accomplishe d i n a therma l indnerato ro ri n a catalyti c incinerator . I n th e catalyti c incinerato ra cat alys ti s use d t o increas e th e rat e o f th e combustio n reaction , allowin g th e combustio n t o occu ratlowe rtemperatures . Becaus e th e catalyti c proces s operate s a

ta lowe rtemperatur e tha n th e thermal process , les s auxiliar y fuel ma y b e require d i n th e catalyti c proces s t o prehea tth e wast e gas . Auxiliar y fue

l requirements ma y als o b e decreased , an d energ y effidenc y

3- 4P. 9

improved , by providin g hea texchang e betwee n selecte d inle tstream s an d th e effluen

tstream . Th e effluen

tstream containin g th e product s o f combus tion , alon g with an

y inert s tha tma

y hav e been presen ti n o radde d t o th e inle tstreams , can b e use d t o preheatth e incomin g wast e stream , auxiliary air , orboth vi a a "primary" , o rrecuperative , heatexchanger . I ti s usefu l t o define th e fractional energy recover y b y th e preheater , o rprimary , heat exchange ra

s follows :

_Energy actuall y recovered from flue ga s Encr S y =T7—- ~ l iT^7 5 u~ 3 ' 2 n Maximum energy recoverabl e i f flue ga s approache s lowes ttemperatur e availabl e t o hea texchange r Th e energ

y actuall y recovered , th e numerato ro f Equatio n 3.2 , i s th e in creas e i n sensibl e hea tof th e gas , i.e. , waste ga s o rwast e ga s plu s dilutio n air , bein g heated . Th e maximu m energ y recoverabl e woul d b e th e decreas e i n sensibl e hea to

f th e flue gas , if

i twer e coole d t o th e temperatur e o f th e incomin g wast e gas . Whil e thi s maximu m energy recover y woul d b e attaine d onl y with a ver y larg e heatexchanger , th e concep to f fractional energy recover

y i s useful i n expressin g th e exten tof th e improvementi n energy effidency usin g a "primary " hea texchanger . Energy effidenc y ca n b e furthe rimprove d b y pladn g anothe r("sec ondary " ) exchange rdownstream o f th e primar

y exchange rt o recoveraddi tional energy from th e effluen tstrea m [e.g., t o generate lo w pressure proces s stea m o rho twater) . However , secondary energy recover y i s generall y not used , unles s ther e i s a spedfi c on-sit e us e fo rth e stea m o rho twater . Th e majorit

y o f industria l gase s tha tcontai n VOC s ar e dilut e mixture s o f combustibl e gase s i n air . In som e applications , such a s airoxidatio n processes , th e waste ga s strea m i s ver y defiden ti n oxygen . Dependin g o n th e oxyge n conten tof

th e wast e stream , auxiliary ai rma y b e required to combus tth e tota l organi c conten tof th e waste ga s as wel l a s an y auxiliary fue l tha tha s bee n used . Th e concentratio n of

combustibl e ga s i n th e wast e ga s strea m play s a n integral rol e i n th e desig n an d operatio n of a n indnerator . Fro

m a cos tstandpoint , th e amoun tof ai ri n exces s o

f th e stoichiometri c amounts shoul d b e minimized . Forsafet y reasons , however , an

y mixtur e withi n th e flammability limits , o n eithe rth e fuel-ric h orfuel-lean sid e of

th e stoichio metri c mixture , presents an unacceptabl e fire hazard a s a feed stream t o th e indnerator . Th e lower , o rfuel-lean , explosiv e limi t(LEL ) of a give n 3-5organi c compoun d define s th e minimu m concentratio n o f tha tcompoun d i n ai rtha tca n produc e mor e energ y tha n i s neede d t o rais e it s ow n temper atur e t o th e ignitio n poin t(i.e. , ignite) . Similarly , th e upper , o rfuel-rich , explosiv e limi t(UEL ) represent s th e highes tconcentratio n o f th e organi c i n ai rtha ti s ignitable . I n th e latte rcase , ai ri s limitin g th e reaction . Bot h th e LE L an d th e UE L ar e measure d a tambien tconditions . Empirically , i t ha s bee n foun d tha tmixture s o f hydrocarbon s i n ai ra tthd rLE L hav e a heatin g valu e o f

approximatel y 5 0 Btu/scf . Sinc e th e majorit y o f

industria l wast e gase s tha tcontai n VOC s ar e di lut e mixture s o f

combustibl e gase s i n air , thd rheatin g valu e i s lo w an d thd roxyge n conten texceed s tha trequire d t o combus tbot h th e wast e or ganic s (VOC s an d others ) an d th e auxiliar y fuel . I f a wast e ga s abov e 5 0 percen tLE L (abou t2 5 Btu/scf ) i s encountered , i tmus tb e dilute d t o sat isf y fire insuranc e regulations . Generally , th e stream s ar e brough tt o bdo w 2 5 percen tLEL , althoug h concentration s from 2 5 percen tt o 5 0 percen tar e permitte d provide d th e wast e strea m i s continuousl y monitore d b y LE L monitors . Becaus e ai ri s th e usua l diluen tgas , car e mus tb e take n wit h preheatin g th e dilute d strea m s o tha ti tremain s bdo w abou t1200°F . (Se e discussio n belo w o n preheating. ) A tabl e showin g LEL , UEL , an d heat s o f combustio n fo rselecte d organi c compound s i s give n i n Appendi x 3A . Th e goa l o f

an y indneratio n syste m i s t o contro l th e amoun to f VOC s rdease d t o th e environment . Performanc e o f a contro l devic e suc h a s a n indnerato rca n b e describe d b y a contro l effidency , define d accordin g t o th e followin g equation :

* j . ,«.. . flnle tmas s rat e VO C - Outle tmas s rat e VOC 1 ,_
_.
_. . Contro l EfF.,% = =-r - 7777 = x 10 0 (3.3 ) I Inle tmas s rat e VO C J I ti s importan tt o note , however , tha tincomplet e combustio n o f th e inle t VOC s coul d resul ti n th e formatio n o f othe rVOC s no toriginall y present . Fo rexample , th e incomplet e oxidatio n o f dichloroethan e ca n yiel d viny l chloride . Bot h o f

thes e compound s ar e VOCs . Th e definitio n give n i n Equatio n 3. 3 woul d stil l b e meaningful , however , a s lon g a s th e newl y forme d VO C {e.g., viny l chloride ) i s detected . Thi s situatio n necessitate s th e complet e chemica l analysi s o f th e inle tan d outle tga s stream s t o confir m complianc e wit h Stat e an d Federa l regulations . 3- 6P.1 1

Emissio n Sourc e Dilutio n Ai r Au x Fue l Qa f AirrAi r Q a Combustio

n Chambe r «» . Tast

e Ge s Prebeater «v . Secondar y Energ y Recover y Stac

k

Figur e 3.1 : Therma l Indnerato r- Genera l Cas e Performanc e o f

a n indnerato rca n als o b e measure d solel y b y th e outlet VO C concentration , usuall y i n ppmv . Ther e ar e a numbe ro f differen tindnerato rdesigns . Thes e design s ca n b e broadl y dassifie d a s therma l system s an d catalyti c systems . Therma l system s ma y b e direc tflame indnerator s wit h n o energ y recovery , flame inrinerator s wit h a recuperativ e hea texchanger , o rregenerativ e system s whic h operat e i n a cydi c mod e t o achiev e hig h energ y recovery . Catalyti c system s includ e fixed-bed (packed-be d o rmonolith ) system s an d fluid-bed systems , bot h o f

whic h provid e fo renerg y recovery . Th e followin g section s discus s desig n aspect s o f thes e systems . 

### 3.2. 1 Therma l Incinerator s
Th e hear to f

th e therma l incinerato ri s a nozzle-stabilize d flame maintaine d b y a combinatio n o f

auxiliar y fuel , wast e ga s compound s an d supplemen ta l ai radde d whe n necessar y (se e Figur e 3.1) . Upo n passin g throug h th e flame, th e wast e ga s i s heate d from it s inle ttemperatur e {e.g., 100°F ) t o it s ignitio n temperature . Th e ignitio n temperatur e varie s fordifferen tcom pound s an d i s usuall y determine d empirically . I ti s th e temperatur e a t 3- 7P.1 2

which th e combustio n reactio n rate (an d consequentl y th e energ y produc tio n rate ) exceed s th e rat e of hea tlosses , thereb y raisin g th e temperatur e o f th e gase s t o som e highe rvalue . Thus , an y organic/ai rmixtur e wil l ignit e if it s temperatur e i s raise d t o a suffidentl y hig h levd . Th e organic-containin g mixtur e ignite s a tsom e temperatur e betwee n th e preheattemperatur e and th e reactio n temperature . Tha tis , ignition , a s define d i n thi s section , occur s a tsom e poin tdurin g th e heatin g of a wast e strea m a s i tpasse s throug h th e nozzle-stabilize d flame regardles s of it s concentration . Th e mixtur e continue s t o reac ta s i tflows throug h th e combustio n chamber . Th e require d lev d o

f VO C contro l of

th e wast e ga s tha tmus tb e achieve d withi n th e tim e tha ti tspend s i n th e thermal combustio n chambe rdictate s th e reacto rtemperature . Th e shorte rth e residenc e time , th e highe rth e reacto rtemperatur e mus tbe . Th e nomina l residenc e tim e of th e reactin g wast e ga s i n th e combustio n chambe ri s define d a s th e combustio n chambe r volum e divide d b y th e volumetri c flow rat e of th e gas . Mos tthermal units are designe d t o provid e n o more tha n 1 secon d o f residenc e tim e t o th e wast e ga s wit h typica l temperature s of 1,20 0 t o 2,000°F . Onc e th e uni t i s designe d an d built , th e residenc e tim e i s no teasil y changed , s o tha t th e require d reactio n temperatur e become s a functio n of th e particula r gaseou s spede s an d th e desire d leve l of control . Tabl e 3. 1 illustrate s th e variability i n (theoretical ) reacto rtemperature s tha ti s require d t o destro y 99.9 9 percen tof

th e inle tmas s of

variou s noxiou s compound s with exces s ai rfo ra 1-secon d reacto rresidenc e tim e [1] . Thes e temperature s canno tb e calculate d a priori , althoug h indnera to rvendor s ca n provid e guideline s base d o n thd rextensiv e experience . I n practice , mos tstream s ar e mixture s of

compounds , thereb y furthe rcompli catin g th e predictio n of thi s temperature . Othe rstudie s [2,3,4] , which ar e base d o n actua l field tes tdata , sho w tha tcommerda l indnerator s shoul d generall y b e ru n a t1600° F wit h a nomina l residenc e tim e of 0.7 5 second s t o ensur e 98 % destructio n of non-halogenate d organics . I n som e State s th e reacto rtemperatur e an d residenc e tim e o f th e uni tar e specifie d rathe r tha n attemptin g t o measur e actua l level s o f VO C control . Th e selecte d temperatur e mus tb e maintaine d forth e full , selecte d residenc e tim e fo r combustio n t o b e complete . Thes e thre e studie s als o condud e tha tmixing i s a critica l facto ri n de terminin g th e destructio n effidency . Eve n thoug h i tcanno tb e measured , 3- 8P.1 3

Tabl e 3.1 : Theoretica l Reacto r Temperature s Require dfo r 99.9 9 Percen t Destructio n b y Therma l Indneratio n for a1-Secon dResidenc e Time "
Compoun d acrylonitril e ally l chlorid e benzen e chlorobenzen e 1,2-dichloroethan e methy l chlorid e toluen e viny l chlorid e Temperature , ° F 1,34 4 1,27 6 1,35 0 1,40 7 1,36 8 1,59 6 1,34 1 1,36 9 'Referenc e [1 ]

mixin g i s afacto r

o f equa l o r eve n greate r

importanc e tha n othe r

parame ters , suc h a s temperature
. Th e mos t feasibl e an deffiden t

wa y t o improv e th e mixin g i n a n indnerato r i s t o adjus t

i t afte r start-up
. Th e 98 % contro l lev ddiscusse di n th e previou s paragrap h presume s suc h a n adjustment
. Ultimatdy , onc e th e uni t i s built , i t

i s th e responsibilit y o

f th e use r t o operat e an dmaintai n th e indnerato r t o insur e complianc e with applicabl e regulations
.
3.2.1. 1 Direc tFlam e Incinerator s Man y configuration s o

f therma l indnerator s exis t wit h th e sam e goal—t o rais e th e VOC-containin g strea mt o th e desire dreactio n temperatur e an d hol di t ther e fo r th e give n reactio n tim e t o achiev e th e require ddestruc

tio n effidency
. Th e simples t exampl e of

suc h asyste mi s th e direc t flame indnerator
. Wit h referenc e t o Figur e 3.1 , th e direc t flame indnerato r

i s comprise donl y of

th e combustio n chamber
. Th e wast e ga s preheate r an d th e secondar y energ y recovery hea t exchange r

ar e energ y recovery device s an dar e no t

include da s par t

o f th e direc t

flame indnerator
. 3- 9P.1 4

3.2.1. 2 R e operativ e Incinerator s Recuperativ e indnerator s hav e improve denerg y effidenc y a s aresul t of pladn g hea t

exchanger s i n th e ho t outle t ga s streams
. Wit h referenc e t o Figur e 3.1 , th e recuperativ e indnerato r i s comprise do

f th e combustio n chamber , th e wast e ga s preheater , and , if appropriate , th e secondar y energ y recover y hea t

exchanger
.
Primar y Energ y Recover y (Preheatin g Inle t Streams ) Consider

abl e fuel saving s ca n b e realize db y usin g th e exi t (product ) ga s t o prehea t th e incomin g fee dstream , combustio n air , o r bot h vi aahea t

exchanger , a s show n i n Figur e 3. 1 i n th e so-calle d"recuperative " indnerator
. Thes e hea t exchanger s ca n recove r

u p t o 70 % o

f th e energ y (enthalpy ) i n th e produc t gas . Th e tw o type s o

f hea t exchanger s mos t

commonl y use dar e plate-to-plate an dshell-and-tube. Plate-to-plat e exchanger s offe r hig h effidenc y energ y recover y a t

lowe r cos t tha n shell-and-tub e designs
. Also , becaus e of thei r modula r configuration , plate-to-plat e unit s ca n b e buil t t o achiev e avariet y o f effidendes
. Bu t

whe n ga s temperature s excee d1000°F , shell-and-tub e exchanger s usuall y hav e lowe r purchas e cost s tha n plate-to-plat e designs
. Moreover , shell-and-tub e exchanger s offe r bette r long-ter mstructura l reli

abilit y tha n plate-to-plat e units. [5 ] I n an y case , becaus e mos t indnerator s installe dar e package dunits , th e desig n (an dcost ) o f th e recuperativ e hea t exchanger s hav e alread y been incorporated
. Mos t hea t exchanger s ar e no t

designe dt o withstan dhig h temperatures , s o tha t mos t of th e energ y neede dt o reac h ignitio n i s supplie db y th e combustio n of

fu di n th e combustio n chambe r an donl y moderat e prehea t temperature s ar e sough t i n practic e (<1200°F)
. Secondar y Energ y Recover y (Additiona l Wast e Energ y Recov

ery ) I t shoul db e noted , however , tha t a t leas tsom e of

th e energ y adde d b y auxiliar y fue l i n th e traditiona l therma l unit s (bu t no t recovere di n pre heatin g th e fee dstream ) ca n stil l b e recovered
. Additiona l hea t exchanger s ca n b e adde dt o provid e proces s hea t i n th e for mo

f lo w pressur e stea mo r ho t wate r for on-sit e application
. Obviously , a n in-plan t us e fo r suc h lo w lev denerg y i s neede dt o realiz e thes e savings
. 3-1 0P.1 5

Th e nee d fo rthi s highe rleve l o f energ y recover y wil l b e dependen t upo n th e plan tsite . Th e additiona l hea texchange ri s ofte n provide d b y th e indneratio n uni tvendor . Th e cos to f thi s additiona l hea texchange r ma y b e estimate d vi a standar d hea texchange rcorrelation s an d shoul d b e adde d t o th e cost s estimate d usin g th e cos tcorrelation s i n thi s chapter .

3.2.1. 3 Regenerativ e Incinerator s
A distinctio n i n therma l incinerator s ca n no w b e mad e o n th e basi s o f thi s limitatio n i n th e prehea ttemperature . Th e traditiona l approac h t o energ y recover y i n therma l unit s (show n schematicall y i n Figur e 3.1 ) stil l require s a significan tamoun to f

auxiliar y fu d t o b e burne d i n th e combustio n chambe r whe n th e wast e ga s heatin g value s ar e to o lo w t o sustai n th e desire d reactio n temperatur e a tth e moderat e prehea ttemperatur e employed . Additiona l saving s can , underthes e conditions , b e realize d i n unit s wit h mor e complet e transfe ro f

exi tstrea m energy . Thi s i s th e concep tbehin d th e so-calle d excess-enthalp y o rregenerabl e burne rsystems . Thes e system s us e direc t contac thea texchanger s constructe d o f a cerami c materia l tha tca n tolerat e th e hig h temperature s neede d t o achiev e ignitio n o f th e wast e stream . Th e operatio n o f

th e regenerativ e syste m i s illustrate d i n Figur e 3.2 . Th e inle tga s firs tpasse s throug h a ho tcerami c be d thereb y heatin g th e strea m (an d coolin g th e bed ) t o it s ignitio n temperature . I f th e desire d temperatur e i s no tattainable , a smal l amoun to f auxiliar y fu d i s adde d i n th e combustio n chamber . Th e ho tgase s the n reac t(releasin g energy ) i n th e combustio n chambe ran d whil e passin g throug h anothe rcerami c bed , thereb y heatin g i tt o th e combustio n chambe routle ttemperature . Th e proces s flows ar e the n switched , no w feedin g th e inle tstrea m t o th e ho t bed . Thi s cycli c proces s afford s ver y hig h energ y recover y (u p t o 95%) . Th e highe rcapita l cost s assodate d wit h thes e high-performanc e hea tex changer s an d combustio n chamber s ma y b e offse tb y th e increase d auxiliar y fue l saving s t o mak e suc h a syste m economical . Th e cost s o f thes e regen erativ e unit s wil l b e give n separatd y i n th e cos tcorrdation s presente d i n Sectio n 3.5 . Regenerativ e indnerator s ar e no tpackage d unit s bu tar e fielderecte d only . Accordingly , th e cost s give n i n Sectio n 3. 5 fo rregenerativ e unit s ar e fo rfield-erected units . 3-1 1P.1 6

AaxAl r Mod e A

SUo k An x fua l

Uode B Aa z /M l

Figur e 3.2 : Regenerable-typ e Thermal Indnerato r

3-1 2P.1 7

Au x Fuel Q»

f Au x Ai rQ a Prebea t

Chamber « - t Catalys t

Chamber 

### \ 

### I Wast e Ga s Prebeate r *v . Emissio n Sourc e

Dilutio n Ai

r 9f . Secondary Energ y Recover y
L
- Stac k

Figur e 3.3 : Catalyti c Indnerato r 3.2. 2 Catalyti c Incinerator s Catalyti c indnerator s emplo y a be d o f activ e materia l (catalyst ) tha tfacil itate s th e overal l combustio n reactio n give n i n Equatio n 3.1 . Th e catalys t ha s th e effec to f

increasin g th e reactio n rate , enablin g conversio n a tlowe r reactio n temperature s tha n i n therma l indnerato runits . Nevertheless , th e wast e strea m mus tb e preheate d t o a temperatur e sufficientl y hig h (usuall y from 30 0 t o 900°F ) t o initiat e th e oxidatio n reactions . Th e wast e strea m i s preheate d eithe rdirectl y i n a preheate rcombustio n chambe ro rindirectl y b y hea texchang e wit h th e indnerator' s effluen to rothe rproces s hea to r bot h (Figur e 3.3) . Th e preheate d ga s strea m i s the n passe d ove rth e cat alys tbed . Th e chemica l reactio n (combustion ) betwee n th e oxyge n i n th e ga s strea m an d th e gaseou s pollutant s take s plac e a tth e catalys tsurface . Catalyti c indneratio n can , i n prindple , b e use d t o destro y essentiall y an y oxidizabl e compoun d i n a n ai rstream . However , ther e ar e practica l limit s t o th e type s o f

compound s tha tca n b e oxidized , du e t o th e poisonin g effect . som e spede s hav e o n th e catalyst . Thes e limit s ar e describe d below . I n addition , mos tconfiguration s requir e a lo w heatin g valu e o f th e inle tga s an d a particulat e conten twhic h i s les s tha n som e smal l value . Unti l recently , th e us e o f catalyti c oxidatio n for contro l o f gaseou s pel s'1 3P.1 8

lutant s ha s generall y bee n restricte d t o organi c compound s containin g onl y carbon , hydroge n an d oxygen . Gase s containin g compound s wit h chlorine , sulfur , an d othe ratom s tha tmay deactivat e th e supporte d nobl e meta l cat alyst s ofte n use d fo

rVO C contro l wer

e no tsuitabl y controlle d b y catalyti c oxidatio n systems . Catalyst s now exist , however , tha tar e toleran tof

such compounds . Mos tof

thes e catalyst s ar

e singl e o rmixe d meta l oxides , ofte n supporte d by a mechanicall y stron g carriersuc h as 7-alumina . Perhap s mos tof th e developmen to

f poison-toleran tcatalyst s ha s focuse d o n th e oxidatio n of

chlorine-containin g VOCs . Thes e compound s are widd y use d a s solvent s an d degreaser s an d are ofte n th e subjec tof concer n i n VO C con trol . Catalyst s suc h a s chromia/alumin a [6,7] , cobal toxid e [8] , an d coppe r oxide/manganes e oxid e [9] hav e bee n use d foroxidatio n o f gase s containin g chlorinate d compounds . Platinum-base d catalyst s ar e activ e foroxidatio n of sulfur-containin g VOCs , althoug h the y are rapidl y deactivate d b y th e presenc e o

f chlorine . Compound s containin g atom s suc h as lead , arsenic, . an d phosphorou s should , i n general , b e considere d poison s fo rmos toxida tio n catalysts . Neverthdess , thd rconcentratio n ma y b e suffidentl y lo w s o tha tth e rat e o f

deactivatio n an d therefore , th e catalys treplacemen tcosts , coul d b e lo w enoug h t o conside rcatalyti c oxidation . A s was th e cas e forthermal units , i ti s impossibl e t o predic ta priori th e temperatur e an d residenc e tim e (i.e. , invers e spac e vdodty ) neede d t o obtai n a give n lev d of

conversio n of

a VO C mixtur e i n a catalyti c oxidatio n system . Forexample, Tabl e 3. 2 from Pop e e tal [8] show s th e temperatur e neede d for80 % conversio n of a numbe rof

VOC s ove rtw o oxidatio n cat alyst s i n a specifi c reacto rdesign . Thi s tabl e show s tha tth e temperatur e required forthi s lev d of conversio n of

differen tVOC s o n a give n catalys t an d of th e sam e VO C o n differentcatalyst s ca n var y significantly . Particulat e matter , indudin g dissolve d mineral s i n aerosols , ca n rapidl y blin d th e pore s of

catalyst s an d deactivat e the m ove rtime . Becaus e essen tiall y al l th e activ e surfac e of th e catalys ti s containe d i n rdativd y smal l pores , th e particulat e matte rnee d no tb e larg e t o blin d th e catalyst . N o general guideline s exis ta s t o particulat e concentratio n an d particulat e siz e tha tca n b e tolerate d b y catalyst s becaus e th e por e siz e an d volum e of catalyst s var

y greatly . Th e volumetri c ga s flow rat e an d th e concentratio n of combustible s i n th e ga s flowing t o th e catalyti c indnerato rshoul d b e constan tforoptima l operation . Large fluctuations i n th e flow rat e wil l caus e th e conversio n 3-1 4P.1 9

Tabl e 3.2 : Catalys t

Temperature s Require dfo r Oxidizin g 80 % of

Inle t VO C t o COj , ° F fo r

Tw o Catalyst s Compoun dTemperature , ° F

C03O 4 P t

- Honeycom b acrolei n 38 2 29 4 n-butano l n-propylamin e toluen e n-butyri c ad d 1,1,1-trichloroethan e dimethy l sulfid e 41 3 46 0 47 6 51 7 66 1

— 44 0

48 9 37 3 45 1 >66 1 51 2

o f th e VOC s t o fluctuate also
. Change s i n th e concentratio n o r typ e o f organic s i n th e ga s strea mca n als o affec t th e overal l conversio n o f th e VO C contaminants
. Thes e change s i n flow rate , organic s concentration , an dchemica l compositio n ar e generall y th e resul t o f upset s i n th e manu facturin g proces s generatin g th e wast e ga s stream
. I t ma y b e uneconomica l t o chang e th e proces s fo r th o sak e o f

makin g th e operatio n o f th e catalyti c incinerato r

feasible
. I n suc h cases , therma l indnerator s (discusse dearlie r i n thi s chapter ) o r

carbo n adsorptio n (discusse di n Chapte r 4 o f thi s Manual) shoul db e evaluate da s alternativ e contro l technologies
. Th e metho do f

contactin g th e VOC-containin g strea mwit h th e catalys t serve s t o distinguis h catalyti c indneratio n systems
. Bot h fixed-bedan d fluid-bedsystem s ar e used
.
3.2.2. 1 Fixed-Be d Catalyti c Incinerator s Fixed-be dcatalyti c indnerator s ma y us e amonolit h catalys t o r apacked

be dcatalyst
. Eac h o f

thes e i s discusse dbdow
.
Monolit h Catalys tIncinerator s Th e mos t widesprea dmetho do f con tactin g th e VOC-containin g strea mwit h th e catalys t i s th e catalys t

mono 3-1 5P.2 0

lith . In thi s schem e th e catalys ti s a porou s soli d block containin g par allel , non-intersectin g channel s aligne d i n th e directio n of th e ga s flow. Monolith s offerth e advantage s of minima l attrition du e t o thermal expan sion/contractio n durin g startup/shutdow n an d lo w overal l pressur e drop .
Packed-Be d Catalyti c Incinerator s A secon d contactin g schem e i s a simpl e packed-be d i n which catalys tpartide s ar e supporte d dthe ri n a tub e o ri n shallo w tray s throug h which th e gase s pass . Th e firstschem e i s no t i n widesprea d us e du e t o it s inherentl y hig h pressur e drop , compare d t o a monolith , an d th e breakin g o f catalys tpartide s du e t o thermal expansio n whe n th e confine d catalys tbe d i s heated/coole d durin g startup/shutdown . However , th e tray typ e arrangement , where th e catalys ti s pelletize d i s use d by several industrie s {e.g., heat-se tweb-offsetprinting) . Pelletize d catalys t i s advantageou s wher e larg e amount s o f such contaminant s a s phosphorou s o rsilico n compound s ar e present.[10 ]
3.2.2. 2 Fluid-Be d Catalyti c Incinerator s A thir d contactin g patter n betwee n th e ga s an d catalys ti s a fluid-bed. Fluid-bed s hav e th e advantag e of very hig h mas s transfe rrates , althoug h th e overal l pressur e dro p i s somewha thighe rtha n fora monolith . A n addi tiona l advantag e of

fluid-beds i s a hig h bed-sid e hea ttransfe ra s compare d t o a normal ga s hea ttransfe rcoeffident . Thi s highe rhea ttransfe rrate t o hea ttransfe rtube s immerse d i n th e be d allow s highe rhea treleas e rate s pe runi tvolum e of

ga s processe d an d therefore may allo w wast e gase s with highe rheatin g value s t o b e processe d withou texceedin g maximum-permis sibl e temperature s i n th e catalys tbed . I n thes e reactor s th e ga s phas e temperatur e rise from ga s inle tt o ga s outle ti s low , dependin g on-th e ex ten tof hea ttransfe rthroug h imbedde d hea ttransfe rsurfaces . Th e catalys t temperature s depen d o n th e rate of reactio n occurrin g a tth e catalys tsur face an d th e rat e o f

hea texchang e betwee n th e catalys tan d imbedde d hea t transfe rsurfaces . A s a general rule , fluid-bed system s ar e mor e toleran tof particulate s i n th e ga s strea m tha n dthe rfixed-bed o rmonolithi c catalysts . Thi s i s du e t o th e constan tabrasio n o f th e fluidized catalys tpellets , which hdp s remov e thes e particulate s from th e exterio rof th e catalyst s i n a continuou s manner . 3-1 6P.2 1

A disadvantag e o f

a fluid-bed i s th e gradua l los s o f catalys tb y attri tion . Attrition-resistan tcatalyst s hav e bee n develope d t o overcom e thi s disadvantage.[ll ] 

### 3.2. 3 Othe rConsiderations—(Package d versu s Field Erecte d Units , Auxiliar y Equipment )
3.2.3. 1 Package d vs . Field-Erecte d Unit s Wit h th e exceptio n o f regenerativ e indnerators , th e equipmen tcos tcor relation s include d i n thi s chapte rar e fo rpackage d unit s only . The y ar e not vali d fo rfidd-erected units . Fo rregenerativ e indnerators , th e correla tion s ar e vali d fo rfidd-erected unit s only . Package d unit s ar e unit s tha t hav e bee n sho p fabricate d an d contai n al l dement s necessar y fo roperation , excep tfo rconnectio n t o fadlitie s a tth e site , e.g., utilities . Th e element s indud e th e combustio n chamber , preheater , instrumentation , fan , an d th e necessar y structura l sted , piping , an d dectrica l equipment . Thi s equip men ti s assemble d an d mounte d o n a "skid " t o facilitat e installatio n o n a foundatio n a tth e plan tsite . Tie-i n t o th e loca l emissio n sourc e i s no tpar t o f th e package d unit . Unit s ar e usuall y size d t o handl e flow rate s o f <20,00 0 scfm , bu tca n b e buil tt o accommodat e flow rate s u p t o 50,00 0 scfm . Th e cos tcorrdation s i n thi s chapte rar e vali d t o 50,00 0 scf m fo rpackage d units , excep tfo rfluid-bed unit s whic h ar e vali d t o 25,00 0 scfm . Conversdy , field-erected unit s ma y b e buil tt o an y desire d size . Th e combustio n chamber , preheater , an d othe requipmen titem s ar e designe d an d fabricate d individually , an d assemble d a tth e site . However , bot h th e equipmen tan d installatio n cost s o f fidd-erected unit s ar e typicall y highe r tha n thos e fo requivalent-size d package d unit s becaus e th e factor s tha tim prov e effidenc y o f

shop-fabrication , suc h a s unifor m workin g environment , availabilit y o f

tool s an d equipment , an d mor e effiden twor k scheduling , ar e generall y no tavailabl e i n th e field.

3.2.3. 2 Aci d Ga s Scrubber s Th e final outle tstrea m o f an y indneratio n syste m ma y contai n certai n pol lutant s tha tmus tb e removed . Th e combustio n o f sulfur-containin g com 3-1 7P.2 2

pound s result s i n S0 3 , whil e chlorinate d compound s yid d Cl j an d HC

I i n th e produc tstream . Thes e ad d gase s mus tb e remove d from th e ga s strea m if the y ar e presen ta

tsignifican tconcentration s (regulation s forlimit s o n thes e gase s var

y from stat e t o state) . Thi s remova l can b e effecte d in , fo

r instance , a packed-be d vertical scrubbe ri n which th e flue ga s i s contacte d wit h a causti c scrubbin g liquid . Forfluid-bed catalyti c reactors , ventur i scrubber s ar

e ofte n use d becaus e the y provid e fo rparticulat e remova

l a s wel l as ad d ga s scrubbing . I n mos tcase s addin g a scrubbe rsignificantl y increase s th e cos to

f th e indneratio n unit , sometime s b y a facto rof

two . Costin g of

scrubber s i s discusse d i n th e "We tScrubbers " Chapte rof thi s Manual. I f chlorinate d VOC s ar

e presen ti n th e wast e gas , hea texchanger s ma y require speda l material s of construction . Thi s adde d expens e i s no tin dude d i n th e costin g procedure s outline d i n thi s chapter .

3.2.3. 3 Hea tExchanger s (Preheater s an d othe rWast e Energ y

Recover y Units )
Fo rth e therma l an d catalyti c unit s havin g som e degre e of energ y recovery , th e cos tof

th e primar

y hea texchange ri s indude d i n th e cost , an d it s de sig n i s usuall y don e by th e indneratio n uni tvendor . Th e cos tcorrdation s presente d i n thi s chapte rindud e unit s bot h wit h an d withou tenerg y re covery . Secondar y energy recovery , i f desired , require s a n additiona l hea t exchanger , whic h i s als o ofte n provide d b y th e incineratio n uni tvendor . Costin g procedure s forsecondar y energ y recovery are no tindude d i n thi s chapter .

3.2.3. 4 Othe rAuxiliar y Equipmen t
Additiona l auxiliar y equipmen tsuc h a s hoods , ductwork , precoolers , cy dones , fans , motors , an d stack s are addresse d separatd y i n othe rchapter s o f thi s Manual. 3-1 8P.2 3



### 3.2. 4 Technolog y Compariso n
Bot h th e therma l an d catalyti c indneratio n system s ar e designe d t o provid e VO C contro l throug h combustio n a ta leve l i n complianc e wit h applicabl e stat e an d federa l requirements . Give n th e wid e rang e o f option s available , however , i ti s obviou s tha tno tever y indnerato rwil l fulfil l thes e require ment s a tth e sam e cost . Thi s sectio n present s a firstste p towar d deddin g ho w bes tt o dea l wit h VO C emissio n abatemen tusin g indnerator s consider in g som e qualitativ e factor s pertinen tt o th e type s o f indnerator s describe d i n thi s chapter . I ti s th e inten to f th e remainde ro f

Chapte r3 t o provid e a metho d b y whic h th e cos to f VO C contro l fo ra particula rapplicatio n ca n b e calculated . A summar y o f

th e principa l type s o f indnerator s i s presente d i n Ta bl e 3.3 . Fro m th e earlie rdiscussions , th e followin g factor s relatin g t o th e presenc e o f

contaminant s shoul d b e considere d b y potentia l user s [12] :

e Th e foulin g o f

th e catalys ti n a catalyti c syste m i s a possibility . Poi son s t o th e syste m includ e heav y metals , phosphorous , sulfu ran d mos thalogens , althoug h catalyst s hav e bee n devdope d tha tar e chlo rine resistant . e Th e possibilit y o f

proces s upset s tha tcoul d releas e an y o f th e abov e poison s o rcaus e fluctuations i n th e heatin g valu e t o th e indnerato r woul d favo ra therma l system . e Excep tfo rth e No. 2 grade , fu d oi l shoul d no tb e considere d a s auxil iar y fu d t o a catalyti c syste m du e t o th e sulfu ran d vanadiu m i tma y contain.(10 ]
Al l o f th e abov e factor s woul d serv e t o increas e th e operatin g expens e o f a catalyti c uni tthroug h replacemen tcost s o f th e catalyst . A n additiona l fac to rrelates t o rdativ e energ y effidenc y o f th e variou s type s o f

indnerators :

e Therma l unit s generall y requir e mor e auxiliar y fu d tha n catalyti c unit s an d operat e a ttemperature s tha tar e roughl y 1000 ° F higher . Thi s differenc e i n fu d requiremen tincrease s a s th e heatin g valu e o f th e wast e strea m decreases . 3-1 9P.2 4

Tabl e 3.3 : Prindpa l VO C Indnerato r Technologie s
Therma l System s

e Direc t Flam e Indnerato r e Recuperativ e Indnerato r (Direc t Flam e wit h Recuperativ e Hea t Ex

changer )
e Regenerativ e Indnerato r Operatin g i n aCycli c Mod e

Catalyti c System s

e Fixed-Be d

- Monolit h

- Packed-Be d

• Fluid-Be d

3-2 0P.2 5

I n general , a trade-of

f exist s betwee n th e highe rcapita l cost s o f catalyti c indnerator s and th e highe roperatin g costs of thermal indnerators . Thi s differenc e wil l b e illustrate d b

y a desig n exampl e presente d i n Sectio n 3. 4 which treats both technologies . 

## 3. 3 Genera l Treatmen to f Materia l an d En erg y Balance s
I n th e sizin g and costin g of th e indnerato rand th e calculatio n o f th e auxil iar y fue l requirements , i ti s necessary t o mak e material an d energy balance s aroun d th e entir e indnerato runi tan d around certai n parts of th e unit , suc

h a s th e combustio n chambe ro r th e preheater . Thi s sectio n present s a genera l approac h t o makin g thes e balances . Thes e balance s ar

e base d o n th e law o

f conservatio n of

mas s and energy . The y can b e state d i n general equatio n for m as
In —Out

+ Generation — Accumulation (3*4) Becaus e th e indneratio n proces s i s a steady-stat e process , th e accumulatio n term i s zero and th e equatio n become s

In —Out

+ Generation = 0
Formcu j balance s i ti s useful t o restrictth e balance s t o b e mad e o n th e mas s of each atomi c spede s s o tha tfo rmas s balance s th e generatio n ter m become s zero . However , becaus e th e combustio n reactio n liberate s energy , th e energy balance s aroun d equipmen twher e combustio n take s plac e woul d indud e a generatio n term . Thus , th e simplifie d equation s ar e

In — Out s s 0 , fo rsteady-stat e mas s balance s (3.5 ) In —Out

+ Generation — 0 , forsteady-stat e energ y balance s (3.6 )

3-2 1P.2 6

Fo r th e indneratio n proces s th e tw o term s In an d Out ar e generall y mas s term s (fo r a mas s balance ) of th e for m PQ, where p — densit y (mas s pe r uni tvolume ) Q — volumetri c flow rate (volum e pe r uni ttime )
o r sensibl e hea tterm s (fo r an energy balance ) of th e form , P 

### QC,(T-T„,) where C

p = hea tcapadt y T = s temperature . Th e referenc e temperature , T„/, i s ofte n take n t o b e zer o o r th e tem peratur e of

a convenien tstream , e.g., th e inle tga s stream , i n whateve r unit s T i s in , s o th e T„ / ter m may no tappea r i n th e equations . Whe n th e reference temperatur e i s take n a s zero , th e sensibl e hea tterm s becom e PQCJ. Energy losses , H&

, are als o partof

th e Out term and , for th e indnerato r process , ar

e take n her e t o b e 10 % of th e tota l energ y tnpui t o th e indner ator . Fo r th e indneratio n process , th e generatio n term fo r energ y balance s account s for th e energ y release d throug h th e combustio n reactions . Thi s term i s generall y of

th e for m PSC-AA, ) •* where (—A&e

) = hea to f

combustion . 

## 3. 4 Desig n Procedure s
Th e followin g procedur e i s designe d t o provid e parameter s for us e i n devd opin g a stud y cos testimat e (accurac y ± 30%) . Th e prindpa l parameter s 3-2 2P.2 7

o f interes tar

e

e flue ga s flow rate , upo n whic h all th e equipmen tcos tcorrelation s ar e based . e auxiliary fue

l requirement , whic

h i s importan ti n estimatin g annua l operatin g costs . Fo rapplication s which involv e control o f wast e ga s stream s thatar e dilute mixtures of

VOCs in air(>20 % oxyge n i n th e wast e ga s stream) , th e flue ga s flow rate i s greate rtha n th e inle twaste ga s flow rat e b y th e amounto f auxiliary fue

l and th e increas e i n th e mole s o f ga s a s a result o f th e combustio n reaction . Becaus e thes e tw o factors usuall y caus e only smal l increase s i n flow rate , a numbero f simplifyin g assumption s ca n b e mad e i n th e desig n calculations . Fo rapplication s where diluen tairmustb e use d t o adjus tth e combustibl e concentratio n i n th e wast e ga s t o 25 % LE L and where auxiliary fu d and auxiliar y combustio n ai rar

e needed , mor

e complete mas s an d energy balance s mus tb e made . Th e desig n procedure illustrate d bdo w i s forwast e ga s stream s tha tar e dilut e mixture s of

VOC s i n ai r(>20 % oxyge n i n th e wast e ga s stream) . I n thi s discussio n th e desig n procedure wil l b e illustrate d by a sampl e problem tha twil l b e solve d step-by-step . 

### 3.4. 1 Step s Commo n t o Therma l an d Catalyti c Unit s Ste p 1 • Establis h desig n specification s Th e firstste p i n th e desig n procedure i s t o determin e th e spedfication s of th e indnerato rand th e waste ga s t o b e processed . Th e followin g parameters of th e wast e ga s stream a

t th e emissio n sourc e mus tb e available :

• Volumetri c flow rate , scfm—Standard condition s ar e normally 77° F an d 1 atm . pressure .

• Temperatur e tOxyge n conten t e Chemical compositio n o f th e combustible s 3-2 3P.2 8

e Inerts conten t e Heatin g value—I n som e case s th e heatin g valu e ma y ac tas a surrogate forth e chemica l compositio n of th e combustibles . Thi s i s particularl y tru e fo rdilut e mixture s o tcombustible s i n air . e Particulat e content—Th e particulat e conten ti s importan tif catalyti c indnerator s ar

e t o b e costed . A n upstrea m filtermay suffice if partic ulat e conten ti s to o high . Fluid-be d catalyti c indnerator s ca n tolerat e highe rparticulat e content s tha n fixed-bed catalyti c indnerators . Th e followin g parameter s mus tb e spedfie d fo rth e incinerator :
e Desire d contro l effidenc y - Thi s effidenc y shoul d b e base d o n require ment s dictate d b y relevantstat e an d federa l regulations . e Combustio n chambe routle ttemperatur e - Thi s temperatur e ma y als o b e base d o n requirements of a regulatio n o ro n recommendation s devdope d durin g regulatory devdopment .
• Derire d percen tenerg y recover y - Th e desire d percen tenerg y recov ery shoul d b e th e resul to f a proces s optimizatio n i n whic h cost s of incinerator s wit h several differen tlevel s o f

energ y recovery ar

e esti mate d an d th e minimu m cos tdesig n sdected . Th e tradeof f i s betwee n th e capita l cos tof

th e energy recover

y equipmen tan d th e operatin g (fud ) costs . Spedfication s forth e sampl e proble m ar e give n i n Tabl e 3.4 . Ste p 2 • Verif

y tha tth e oxyge n conten to f th e wast e ga s exceed s 20 % Ther e mus tb e suffiden toxyge n i n th e wast e ga s t o suppor tth e combustio n of

th e wast e organic s (indudin g VOCs ) an d th e auxiliary fud , if auxiliar y fu d i s needed . Itmay b e necessar y t o ad d auxiliar y ai rif th e oxyge n conten ti s les s tha n abou t20% . Thi s exampl e i s base d o n stream s tha tcontai n >20 % oxygen , as show n bdow : Ai rContent , Vol . % - 100. 0 - ~ x 10 0 - ^ ? x 10 0 (3.7 ) 10 s 10 *

- 99.8 % Oxyge n Content, % = Ai rConten tx 0.20 9 (3.8 )

= 20.86 % 3-2 4P.2 9

Tabl e 3.4 : Spedficatio n o f Sampl e Proble m
Variabl e Valu e Preheate r Inle t Wast e Ga s Vo

l Flo w Rate , Q„, , scf

m20,00 0 Preheate r Inle t Wast e Ga s Temp. , T„< , ° F 100 Compositio n Benzen e Content , ppm v 1000 Methy l Chlorid e Content , ppm v 1000 Ai r Conten t Balanc e Particulat e Conten t

Negligibl e Moistur e Conten t

Negligibl e Desire dContro l Effidency, % 9 8 Desire dPercen t

Energ y Recovery , HR, % 7 0

Ste p 3 • Calculat e th e LE L an dth e Percen t o f th e LE L o f

th e ga s mixtur e Note : I

f th e wast e strea mcontain s asignifican t amoun t o f inert s i n additio n t o th e nitroge n assodate dwit h th e oxyge n i n air , th e calculatio n o

f LE L (an dUEL ) lose s meanin g sinc e th e LEL (an dUEL ) i s measure di n mixture s o

f organi c wit h ai r

only
. A complet e chemica l analysi s i s necessar y t o complet e th e desig n procedur e i n suc h acase . Th e exampl e chose n her e i s typical , i n tha t ther e i s mor e tha n on e VO C componen t

i n th e ga s stream
. A n approximat e metho dt o calculat e th e LE L o f amixtur e o

f compounds , LEI*^ , i s give n b y Grdeck i [13 ] a s

LEU 

## * IjSt&t'dxLEL ^ (3.9 )
wher e LEL ;

n — volum e fraction o f combustibl e componen t i lower explosiv e limit s of

combustibl e componen t ; (ppmv ) numbe r o f combustibl e component s i n mixtur e 3-2 5P.3 0

Fo r th e exampl e case ,

J^Xi = (1,00 0 + 1,000 ) xl0~ a t a l s = 2,00 0 xlO - 6

» • Fro mstandar dreference s [14] o r fromAppendi x 3A ,
LELB « = 14,00 0 ppm v fo r benzen e LELM C = 82,50 0 ppm v fo r methy l chlorid e (3.10 )

LEU 1,00 0 

## + 1,00 0 1 - 1

2,00 0 x 14,00 0 2,00 0 x 82,50 0 23,93 8 ppm v (3.11 )

% LE L tota l combustibl e cone , i n mixtur e

2,00 0 23,93 8 LEL ^
x 10 0 s = 8.4 % x 10 0 (3.12 ) '(3.13 )
Th e percen t

LE L o f th e mixtur e i s therefor e 8.4%
. Becaus e thi s i s wel l belo w 25% , n o dilutio n ai r i s neede di n thi s example
. I f th e mixtur e ha d bee n abov e 25 % LEL , suffiden t dilutio n ai r

woul dhav e bee n neede dt o brin g th e concentratio n of

th e mixtur e t o les s tha n 25 % t o satisf y fire insuranc e regulations
. Ste p 4 • Calculat e th e volumetri c hea to f combustio n ofth e wast e ga s stream , (-A/O , Btu/sc f Th e energ y conten t

o f th e ga s stream , expresse di n term s of

th e hea t o f combustion , i s calculate da s follows : 

### (-AAe. ) - B-A/O* ; (3.14 )

3-2 6P.3 1

where (-A/ic. ) —bea to f combustio n o

f th e waste strea m (Btu/scf ) (-A/ie J = volumetri c hea tof combustio n of

componen ti at 25°C(Btu/scf

) X j s s volum e fraction of

componen ti i n th e wast e ga ? n = numbe ro

f combustibl e components i n th e waste ga s Th e heato

f combustio n tha tshoul d b e use d i n thes e calculation s i s th e "lower " heato

f combustion , i.e. , with gaseou s water , rathe rtha n liqui d water , a s a reactio n productsinc e wate rleave s th e indnerato ri n th e vapo r state . Fro

m Appendi x 3

A o rstandar d references [14,15 ] with appropriate conversio n o

f units , th e volumetri c hea to f combustio n a

t25° C fo rth e two components i s calculate d t o b e a s follows : (-A/teg. ) = 3,47 5 Btu/sc f fo rbenzen e (-AA^ ) = 705 Btu/sc f fo rmethy l chlorid e Th e composition s spedfie d earlie ra s ppmv ar

e converte d t o volum e fractions a

s follows : *B « —1»00

0 ppmv xlO" 6 s

s 10" 3 fo rbenzen e *M C - 1,00 0 ppm v xlO" * = IO" 3 fo rmethy l chlorid e Usin g thes e value s of

hea to f combustio n and composition , th e hea to f combustio n o

f th e wast e ga s strea m pe rstandard cubic foot

of incomin g ga s i s
(-AA*. ) s s (3,475 ) (l0" 3 )+(705 ) (lO -3 ) (3.15 ) s = 4.1 8 Btu/sc f Assumin g th e waste ga s i s prindpall y air , wit h a molecula rweigh to

f 28.9 7 an d a correspondin g dendt y o f 0.073 9 lb/scf

, th e heatof

combustio n pe rpound

of incomin g wast e ga s i s

(-A/ 0 = 56. 6 Btu/l b

3-2 7P.3 2

Th e negativ e hea to

f combustion , by convention , denote s an exothermi c reaction . Als o by convention , if on e refer

s t o hea to

f reactio n rathe rtha n hea tof combustion , the n a positiv e valu e denote s a n exothermi c reaction . Empirically , i tha s bee n foun d tha t5 0 Btu/sc f roughl y correspond s t o th e LE L of organic/ai rmixtures . Insuranc e code s require a valu e bdo w 25 % LEL , which correspond s t o abou t1 3 Btu/scf . However , if

LE L sensor s an d monitor s ar

e installed , on e ca n indnerat e a wast e ga s with a combustibl e organi c conten tbetwee n 25 an d 50 % LEL , which correspond s t o 1 3 t o 2 5 Btu/scf . Forcatalyti c application s th e hea tof combustio n mus tnormall y b e les s tha n 1 0 Btu/sc f

(fo rVOC s i n air ) t o avoi d excessivd y hig h temperature s i n th e catalys tbed . Thi s is , of course , onl y an approximate guidelin e an d ma y var y from syste m to system . Afte rSte p 4 , determinatio n of (-AA^) , th e desig n procedur e fo rther mal an d catalyti c indnerator s i s discusse d separatdy , beginnin g wit h Ste p 5 fo reac h typ e of

indnerator .


### 3.4. 2 Step s Specifi c t o Therma l Unit s Figur e 3. 1 show s a generi c therma l indnerato rwit h th e appropriate stream s labeled .

Ste p 5 t• Establis h th e temperatur e a twhic h th e incinerato rwil l operat e A s mentione d i n Sectio n 3.2.1 , bot h th e reacto rtemperatur e an d residenc e tim e of

th e wast e ga s i n th e reacto rdetermin e th e lev d of VO C destruction . I

n general , stat e an d loca l regulation s specif y th e require d lev d of destructio n tha tth e custome rmus tmeet . In thi s exampl e a destructio n effidenc y of

9 8 percen ti s spedfied . Studie s b y Mascon e [2,3,4 ] sho w tha t thi s destructio n effidenc y ca n b e me ti n a thermal incinerato roperate d a ta temperature , T/ { , o f 1,600° F an d a residenc e tim e of 0.7 5 second . (Note : Thi s highe reffidenc y lev d i s th e minimum achievabl e b y an y ne w properl y designe d an d operate d indnerator . Man y indnerator s ca n achiev e destructio n effidende s of 99 % o rhigher. )

3-2 8P.3 3

Ste p 6 t• Calculat e th e wast e ga s temperatur e a tth e exi to f th e preheate rTh e exten tof hea texchang e to b e carried ou ti n th e preheate r i s th e resul to

f a technical an d economi c optimizatio n procedur e tha ti s not illustrate d i n thi s example . A s th e VO C stream temperatur e leavin g th e hea texchanger , T w . , increases , th e auxiliary fue l requirementdecreases , bu ta tth e expens e o

f a large rhea texchanger . However , ther e ar e severa l importan tHmit

s o n T Wa . First , T w . mus tno tb e dos e t o th e ignitio n tem peratur e o

f th e organic-containin g ga s t o preventdamagin g temperatur e excursion s insid e th e hea texchange rshoul d th e ga s ignite. . Second , fo r gase s containin g halogens , sulfur , an d phosphorou s (o rothe rarid-formin g atoms) , th e flue ga s temperatur e afterth e heatexchanger,.T/ # , mus tnot drop below th e ad d dew . Both limitation s limi tth e amoun to f heatex chang e an

d thu s th e maximu m valu e o f T„. . Th e calculatio n o f th e aci d dew i s no tsimple . I

ti s recommende d tha tvendo rguidanc e b e sough tto ensure tha tth e dew i s no treached . Condensatio n o f ad d gase s will resul t i n corrosio n of

many o f th e metal s use d i n heatexchangers . A s a n example , fu d sulfurcontent s o

f 1 t o 2 percen tca

n giv e ad d de

w point s o

f abou t20 0 to 270 ° F . Increasin g th e sulfu rconten tt o 4 percentca n rais e th e dew t o abou t290 ° F . Chlorin e an d phosphorou s have a muc h smalle reffec

to n ad d dew elevation . With th e followin g assumptions , on e can estimat e T„ . usin g equatio n 3.2 , th e definitio n o

f fractional energy recover y fo ra hea texchanger .

e Th e fractional energy recover y i s spedfied . e Th e amoun to

f auxiliary fuel , Q«/ , and auxiliar y combustio n air , Q a , ar e smal l relativ e t o th e waste'gas , Q w , s o tha tth e mas s flow rate s o f gases , p w Q* an d P/Q/, o n both side s o f th e preheate rar

e approx imatd y th e same , o r PwQw * PtQt

• Th e hea tcapadtie s of th e gase s o n both side s o f th e preheate rar

e approximatd y th e same , regardles s of composition. Thi s i s tru e fo r wast e stream s which ar

e dilut e mixture s o

f organic s i n air , th e prop ertie s of th e stream s changin g onl y slightl y o n combustion . e Th e mean hea tcapadtie s abov e th e referenc e temperatur e of

th e gase s o n both side s of

th e preheate rar

e approximatd y th e sam e regardles s of temperature. 3-2 9P.3 4

With thes e assumptions , th e equatio n fo rfractional energ y recovery fo ra hea texchange rbecome s T - T

Fractiona l Energ y Recover y = -£r ——- (3.16 ) T/ < - T m Fo rthi s exampl e with a fractional energy recover y of 0.70 , an indnerato r operatin g temperature , T/< , of 1,600°F , an d a wast e ga s inle ttemperature , T^ , o f 100°F , th e wast e ga s temperatur e atth e exi to f th e preheate rbe come s T« . = 1,150° F
Th e temperatur e of

th e exhaus tgas , T/ a , ca n b e determine d b y a n energy balanc e o n th e preheater , which , wit h th e sam e assumption s as use d i n derivin g Equatio n 3.1 6 regardin g th e mas s flow rate s an d averag e hea tcapadtie s of

th e gase s involved , result s i n th e followin g equation :

T h - T f . * T„ . - T^ i.e., th e temperatur e rise i n th e wast e ga s i s approximatel y equal t o th e temperatur e decreas e i n th e flue ga s with which i ti s exchanged . Forthi s example , thi s result s i n
T u = 550° F Thi s valu e of

T/ s shoul d b e wel l abov e th e ad d de w o f th e flue ga s stream . Itshoul d b e remembere d tha tT w . shoul d b e wel l bdo w th e ignitio n tem peratur e of

th e VO C strea m t o preven tunwante d temperatur e excurdon s i n th e preheater . Thi s mus tb e verifie d eve n i f th e strea m i s wel l belo w th e LE L becaus e flammability limit s ca n b e expande d b y rairin g th e reactan t strea m temperature . A suffidentl y hig h prehea ttemperature , T w# , coul d initiat e reactio n (wit h hea trdease ) i n th e preheater . Thi s woul d ordinaril y b e detrimenta l t o th e material s o f constructio n i n th e hea texchanger . Th e on e exceptio n i s th e thermal indnerato rof th e regenerabl e typ e describe d 3-3 0P.3 5

•in Sectio n 3. 2 Th e 9 5 percen tenerg y recover y obtainabl e i n regenerabl e system s woul d resul ti n thi s exampl e i n a T w #o f 1,525°F . Th e significan t reactio n rat e tha twoul d occu ra tthi s temperatur e i n th e cerami c packin g o f th e hea texchanger/reacto ri s b y design .
Ste p 7 t- Calculat e th e auxiliar y fue l requirement , Q a / Auxiliar y fue l wil l almos tinvariabl y b e neede d fo rstartu p o f th e unit . However , a t stead y state , i f

th e energ y release d b y combustio n o f th e organic s presen ti n th e wast e strea m i s suffiden tt o maintai n th e reacto rtemperatur e (1,600° F i n th e example) , onl y a smal l amoun to f auxiliar y fue l ( < 5 % o f th e tota l energ y input ) i s neede d t o stabiliz e th e flame. I n mos tcases , however , mor e fue l tha n jus tthi s stabilizin g fue l wil l b e require d t o maintai n th e reacto r temperature . Wit h th e followin g assumptions , on e ca n estimat e Q„ / usin g a mas s an d energ y balanc e aroun d th e combustio n chambe ran d followin g th e prindple s discusse d i n Sectio n 3.3 , wit h referenc e t o Figur e 3.1 .

• Th e referenc e temperature , T,,/ , i s take n a s th e inle ttemperatur e o f th e auxiliar y fud , T«/ . e N o auxiliar y air , Q a , i s required . e Energ y losses , EL, ar e assume d t o b e 10 % o f th e tota l energ y inpu tt o th e indnerato rabov e ambien tconditions.[16,17 ] Thus , i f th e referenc e temperatur e i s nea rambien tconditions ,

H L ^H.\p h q h C^ u (T }i -T^) (3.17 )

• Th e hea tcapadtie s o f th e wast e gase s enterin g an d leavin g th e com bustio n chambe rar e approximatd y th e same , regardles s o fcomposition. Thi s i s tru e fo rwast e stream s whic h ar e dilut e mixture s of organic s i n air , th e propertie s o f th e stream s changin g onl y slightl y o n combustion . e Th e mean hea tcapadtie s abov e th e referenc e temperatur e of th e wast e gase s enterin g an d leavin g th e combustio n chambe rar e ap proximatd y th e sam e regardles s o f temperature . Thu s th e mea n hea t capadt y fo rth e wast e ga s strea m enterin g o rleavin g th e combustio n chambe rshoul d b e evaluate d a tth e averag e o f T W aan d T/ rFo rai r 3-3 1P.3 6

thi s assumptio n introduce s a n erro rof , a tmost , 5 % ove rth e temper ature s o f interest . Wit h thes e assumptions , th e mas s an d energ y balanc e aroun d th e com bustio n chambe rreduce s t o th e followin g equation :



# „ 0

# p.;<?..[gp-^(i-ir/, - r. . - o.ir,., ) - (-A/Q I 

# '•'«•' = (-So-i.iWJi-JW— " (348 ) Inpu tdat a forthi s equatio n ar e summarize d below :

e Th e wast e strea m i s essentiall y ai rs o tha t

Pw. = pwi = 0.073 9 lb/scf , ai rat77"F , 1 atm . C^ . r= 0.25 5 Btu/l b °F , th e mea n hea tcapadt y of ai rbetwee n 77° F an d 1,375° F (th e averag e tem peratur e of

th e wast e ga s enterin g an d leavin g th e combustio n chamber )

• Othe rinpu tdat a t o Equatio n 3.1 8 indud e

Qw. = Qm = 20,00 0 scf m (-A&e., ) - 21,50 2 Btu/lb , formethan e 7/,, / ss T 9 f s = 77 * F , assum e ambien tcondition s p Mf s s 0.040 8 lb/ft 3 , methan e a t77°F , 1 atm . T fi s s 1,600°F , from Ste p 5 t T*. = 1,150°F , fro m Ste p 6 t (-AAc^ ) s s 56. 6 Btu/lb , from Ste p 4 Substitutin g th e abov e value s int o Equatio n 3.1 8 result s i n Q mf s = 16 7 scf m Th e value s of

th e parameter s i n th e energ y balanc e are summarize d i n Tabl e 3.5 . 3-3 2P.3 7

Tabl e 3.5 : Summar y o f Exampl e Proble m Variabl e Valuatio n T„, = = 77° F
Pj* Qi i Qpmji T, > Strea m Subscript, ; lb/sc f scf m Btu/l b ° F ° F I N - Sensibl e Hea t Auxiliar y Ai ra na * na ' na * na * Auxiliar y Fu d a f 0.040 8 16 7 " 7 7 Wast e Ga s w 9 0.073 9 20,00 0 0.25 5 1,15 0 OU T - Sensibl e Hea t Wast e Strea m f { 0.073 9 20,16 7 0.25 5 1,60 0 (-AA,) , wast

e ga s = 56.6 Bto/l b (-AA,) . auxiliar

y fue l = 21,50 2 Btu/l b 'No tapplicable. "Notuse d becaus e referenc e temperatur

e is take n equa l t o auxiliar y fue l temperature

.

I ti s instructiv e t o examin e th e magnitud e o f th e variou s term s i n th e energ y balanc e aroun d th e combusto rfo rth e sampl e problem . Thi s i s don e i n Tabl e 3.6 . Th e energ y balanc e show n doe s no tquit e ad d t o zer o du e t o round-of

f erro ran d simplifyin g assumptions . Tabl e 3. 6 show s tha tth e larges tinle tter m i s th e sennbl e hea to f th e incomin g wast e gas . Th e hea to f combustio n o f

th e organic s containe d i n th e wast e ga s strea m i s somewha t smalle rtha n tha to f

th e auxiliar y methan e becaus e o f th e rdativd y smal l amoun to f

organic s i n th e wast e ga s stream . Th e larges tter m i n th e outle t strea m i s th e sensibl e hea to f th e outgoin g wast e stream . Th e overal l energ y losse s ar e base d o n a n assumption , bu tar e rdativd y small . Becaus e th e sensibl e hea tcontent s o f th e enterin g an d leavin g wast e strea m ar e s o large , i ti s apparen ttha tenerg y recover y i s a n importan tfacto ri n achievin g energ y effidency . I n fact , wit h zer o energ y recover y i n th e sampl e problem , th e auxiliar y fu d requirement s woul d b e 60 5 scfm , abou tfou rtime s th e energ y requirement s base d o n 70 % energ y recovery .

3-3 3P.3 8

Tabl e 3.6 : Term s i n Energ y Balanc e aroun dCombusto r - Exampl e Prob

lem I

N - OUT + GENERATIO N = 0

Strea m I N - Sensibl e Heat , pjQjC^Ti - T„ f ) Auxiliar y Ai r Wast e Ga s OU T - Sensibl e Heat , pjQjC^Ti - T„ t ) Wast e Strea m OU T - Losse s 10 % o f tota l energy inpu t GENERATIO N -

Heato f Combustion , PjQ^—Ahq) Wast e Gas Auxiliar y Fu d Subscript , j

a
fi

a f Value , Btu/mi n 0 404,40 3 578,79 6 57,88 0
83,65 5 146,50 6

3-3 4P.3 9

Ste p 8 t - Verif y tha t th e auxiliar y fue l requiremen t i s sufficien t

t o stabiliz e th e burne r

flame Onl y asmal l amoun t o f auxiliar y fue

l ( < 5 % o f th e tota l energ y input ) i s neede dt o stabiliz e th e burne r flame. I n general , mor e fu dtha n jus t

thi s stabilizin g fu dwil l b e require dt o maintai n th e reacto r temperature
. I t

i s wis e t o verif

y tha t th e auxiliar y fue

l requiremen t calculate di n Ste p 7 t

i s suffiden t

fo r stabilization
. I

f i t i s insuffident , the n a minimu mamoun t

o f auxiliar y fue

l mus t b e used , an dth e amoun t o f energ y recovery spedfie dearlie r mus t b e reduce dt o avoi dexceedin g th e specifie d temperatur e a t

whic h th e indnerato r

wil l operat e (Ste p 5t)
. Thi s chec k

i s mad e b y calculatin g 5 % o f th e tota l energ y inpu t

t o th e indnerato r

an dcomparin g i t

wit h th e auxiliar y fue

l energ y input
. Th e tota l energ y inpu t

i s give n a s follows : Tota l Energ y Inpu t

= PuQifi^Tu - T„ f ) (3.19 ) Auxiliar y Fu dEnerg y Inpu t s s p./Q./(-An e#/ ) (3.20 ) Th e auxiliar y fu duse di n th e design , Q„/ , shoul db e th e large r o f 5 % of th e tota l energ y inpu t

(28,90 0 Btu/min. ) an dth e auxiliar y fue l energ y inpu t (146,50 0 Btu/min.)
. Th e auxiliar y fu duse deasil y meet s thi s crite

rion.
Ste p 9 t• Calculat e th e tota l volumetri c flow rat e o f ga s throug h th e incinerator , Q/ , Th e tota l volumetri c flow rat e o f ga s leavin g th e indnerato r

i s referre dt o a s th e flue ga s flow rate , Qj {1 an di s th e ga s rat e o n whic h th e indnerato r

sizin g an dcos t

correlation s ar e based
. Th e flue ga s flow rat e measure da t

th e standar dcondition s o f 77° F an d1 atmosphere , wher e th e increas e i n volumetri c throughpu t du e t o a n increas e i n th e num be r o f mole s o f ga s a s aresul t

o f combustio n i s neglected , i s th e su mo f th e inle t stream s t o th e indnerator
.



### Q h 

### = 

### <?. . + $ • + 

### <?.

/

= 20,00 0 + 0 + 167 s s 20,16 7 scf

m Thi s resul t

conform s wit h th e assumption s state di n Ste p 6t , i.e. , th e mas s 3-3 5P.4 0

(an d volume ) flow rate s o n bot h side s of th e preheate rar

e approximatel y equal . 

## 3.4. 3 Step s Specifi c t o Catalyti c Unit s Figur e 3. 3 show s a generi c catalyti c indnerato rwith th e appropriat e stream s labeled . Th e approach use d i n th e calculation s o n th e catalyti c indnera to ri s somewha tdifferen ttha n tha tuse d i n th e thermal indnerator . Thi s difference arise s becaus e of additiona l constraint s which are place d o n th e catalyti c indnerator . Thes e constraint s ar e as follows :

e Th e desire d catalys tbe d outle ttemperatur e i s typicall y 70 0 t o 90 0 °F . Th e maximu m temperatur e t o which th e catalys tbe d ca n b e expose d continuousl y i s limite d t o abou t1,20 0 "F . Therefore , th e combustibl e conten to f th e wast e ga s i s limited , an d th e amoun tof hea texchang e tha toccur s i n th e primar y hea texchange rma

y b e limited . e Th e inle ttemperatur e t o th e catalys tbe d itsel f mus tb e abov e th e catalyti c ignitio n temperatur e require d t o giv e th e derire d destructio n effidenc y i n th e indnerator . Therefore , th e combustibl e conten tof th e wast e ga s i s furthe rlimite d t o tha twhich , whe n combusted , wil l rais e th e temperatur e i n th e catalys tbe d n o mor e tha n th e A T betwee n th e required reacto rbe d inle ttemperature , an d th e dedre d reacto r be d outle ttemperature . e Auxiliary fud , i n combinatio n wit h th e preheatfrom th e primar y hea texchanger , i s use d y prehea tth e wast e ga s t o th e reacto rin le ttemperature . A mi ; au m amoun tof auxiliary fu d ( < 5 % of th e tota l energ y input ) mus tb e use d t o stabiliz e th e flame i n th e pre hea tcombustio n chamber . Thi s ha s th e effec tof farthe rlimitin g th e combustibl e conten tof

th e wast e ga s strea m an d th e amoun tof hea t exchang e permisnbl e i n th e primar y hea texchanger . Th e step s outline d bdo w represen ton e approach t o recognizin g thes e constraint s an d incorporatin g the m int o th e calculatio n procedures . Ste p 5 c • Establis h th e desire d outle ttemperatur e o f th e cata lys tbed , T / { Th e energ y rdease d by th e oxidatio n of th e VOC s i n th e 3-3 6P.4 1

catalys t be dwill rais e th e temperatur e o f th e gase s b y a n amount , AT , a s th e gase s pas s throug h th e catalys t bed
. An outle t

temperatur e fromth e catalyst , an dthu s fromth e reactor , mus t b e spedfie dtha t

wil l ensur e th e dedre dleve l o

f destructio n o

f th e VO C stream
. A s i n therma l indnerators , thi s valu e varie s fromcompoun dt o compoun dan dals o fromcatalys t t o catalyst
. Fina l desig n o

f th e indnerato r

shoul db e don e b y firms wit h expe rience i n indnerato r

design
. Guideline s give n b y Combustio n Engineerin g [12 ] indicat e tha t

value s from30 0 t o 900° F resul t i n destructio n efficiencie s betwee n 9 0 an d9 5 percent
. T o preven t deactivatio n o

f th e catalys t

amax imu mbe dtemperatur e o f 1,200° F shoul dno t

b e exceeded
. I n th e exampl e proble mth e catalys t

outle t temperature , Tf., i s sdecte dt o b e 900°F
. Ste p 6 c - Calculat e th e wast e ga s temperatur e a t th e exi t

o f th e preheate r

(primary ) hea t

exchange r

Th e wast e ga s temperatur e a t th e exi t o f th e primar y hea t

exchange r

i s estimate di n th e sam e manne r a s fo r th e therma l indnerator
. Th e equatio n fo r fractional energ y recovery , Equatio n 3.16 , i s used , wit h th e sam e assumption s a s use dfo r th e therma l indnerator
. Fo r

th e exampl e proble mwith afractional energ y recovery o f 0.70 , acatalys t

be doutle t

temperature , T/. , o

f 900°F , an dawast e ga s inle t temperature , T Wi, o f 100°F , th e ga s temperatur e a t th e exi t o f th e preheate r become s

r « . = 660° F Th e sam e consideration s regardin g th e dosenes s o f th e temperatur e o

f th e exhaus t

gas , T/ # , t o it s de w poin t appl y t o th e catalyti c indnerato r a s the y di dt o th e therma l indnerator
. Ste p 7 c • Calculat e th e auxiliar y fue l requirement , Q a / Th e aux iliar y fu drequirement , Q A / , i s calculate db y makin g mas s an denerg y bal

ance s aroun dth e preheate r combustio n chambe r

an dth e catalys t

chamber
. Th e auxiliar y fu drequiremen t calculate di n thi s manne r mus t b e checke dt o insur e tha t

i t fall s withi n th e constraint s impose db y desig n condderation s o f th e catalyti c indnerator
. Thes e constraint s ar e a s follows :

• Th e auxiliar y fu drequiremen t mus t b e podtive
. A negativ e fue l requiremen t

indicate s tha t

th e hea t o f combustio n o

f th e wast e gas , 3-3 7P.4 2

(—A/i e ) , i s to o hig h forth e fractional energ y recover y i n th e primar

y hea texchange rtha twas selected . e Th e auxiliar y fu d amoun tmus tb e hig h enoug h t o provid e a stabl e flame i n th e preheate rcombustio n chambe r(Se e Ste p 8 c below) . A n energ y balanc e aroun d th e preheate rcombustio n chambe ran d th e catalys tchamber , take n together , result s i n Equatio n 3.18 , th e sam e equa tio n use d i n th e therma l indnerato rcalculations . Th e inpu tdat a forEqua tio n 3.1 8 fo

rth e catalyti c indnerato rexampl e proble m are summarize d below :

e Th e wast e strea m i s essentiall y ai rs o tha t Pv. - P»i = 0.073 9 lb/scf , ai rat77°F , 1 at m C Pmair— 0.24 8 Btu/l b °F , th e mean hea tcapadt y of ai rbe twee n 77° F an d 780°F(the averag e of th e preheate rexi tan d catalys t be d outle ttemperatures )
e Othe rinpu tdat a t o Equatio n 3.1 8 indud e

Qw. - Qwt= 2

0 > 00 ° scf m (-AA e „ ) s s 21,50 2 Btu/lb , formethan e T a f = 77°F , assum e ambien tcondition s p 9f = 0.040 8 lb/ft 3 , methan e at , 77°F , 1 at m T h s = 900°F , from Ste p 5 c T w . ss 660°F , from Ste p 6 c (-Art,. ) * 56. 6 Btu/lb , from Ste p 4 Substitutin g th e abov e value s int o Equatio n 3.1 8 result s i n
<?« / s s 4 0 scfi n I f th e outle ttemperatur e of th e catalys tbed , T fn i s 800 ° F , the n Q a / decrease s t o -6. 7 scfm . I n othe rwords , n o auxiliary fu d would , theoreti cally , b e require d a tthi s be d temperature . However , a s discusse d abov e i n 3-3 8P.4 3

Ste p 8t , acertai n quantit y o f auxiliar y fuel woul db e require dt o maintai n burne r stability
. At 70 % energ y recovery an d900° F outle t catalys t be dtemperature , a wast e ga s wit h ahea t

o f combustion , (-Arte,,) , o f abou t 79. 9 Btu/l b woul d caus e th e auxiliar y fu drequirement , Q a / , t o becom e negative , indicatin g th e catalys t

be dwoul dexcee d900°F
. At 70 % energ y recovery an d800° F outle t catalys t be dtemperature , thi s sam e resul t occur s wit h a(-AA CWS ) o f 52. 7 Btu/lb
. Bot h o

f thes e heat s o

f combustio n ar e rdativd y lo w fo r typica l wast e gases . Thes e result s are , o f course , dependen t

o n th e assumptio n o

f energ y losse s fromth e combustio n chamber
. Th e lowe r th e energ y losses , th e lower th e allowabl e wast e ga s hea t o f combustio n befor e overheatin g occur s i n th e catalys t

bed
. Ste p 8 c • Verif

y tha t th e auxiliar y fue l requiremen ti s sufficien t t o stabiliz e th e burne rflame Onl y asmal l amoun t o f auxiliar y fu d( < 5 % o f th e tota l energ y input ) i s neede dt o stabiliz e th e burne r flame. I n general , mor e fue l tha n jus t

thi s stabilizin g fue

l wil l b e require dt o maintai n th e reacto r temperature
. I t

i s wis e t o verif

y tha t th e auxiliar y fue

l requiremen t calculate di n Ste p 7 c i s suffiden t fo r stabilization
. I

f i t i s insuffident , the n a minimu mamoun t

o f auxiliar y fu dmus t

b e use dan dth e amoun t o f energ y recovery spedfie dearlie r mus t b e reduce dt o avoi dexceedin g th e specifie d temperatur e a t

whic h th e indnerato r

wil l operat e (Ste p 5c)
. Thi s chec k

i s mad e i n th e sam e manne r a s tha t i n Ste p 8 t

o f th e therma l indnerato r

calculation
. Th e result s o f thi s chec k

indicat e tha t

th e auxiliar y fu drequiremen t

i s mor e tha n suffiden t

t o stabiliz e th e burne r

flame.
Ste p 9 c • Estimat e th e inle t temperatur e t o th e catalys tbed , T,
. Th e inle t temperatur e t o th e catalys t be dmus t

b e calculate dt o ensur e tha t th e inle t temperatur e i s abov e tha t necessar y t o ignit e th e combustibl e organi c compound s i n th e catalys t tha t wa s sdecte dfor

use . Th e inle t temperatur e t o th e catalys t bed , T, { , shoul db e suc h that , whe n th e temperatur e rise throug h th e catalys t bed , AT , i s adde dt o it , th e resultin g temperatur e i s T fi, 900°F
. Thus , A T = T

fi - T u (3.21 ) 3-3 9P.4 4

Th e valu e of

A T i s determine d b y a n energ y balanc e aroun d th e pre heate rportio n of

th e combustor . Th e preheate ri s require d t o hea tth e gase s u p t o th e catalys tbe d inle ttemperatur e udn g auxiliar y fuel. 1 Thi s energ y balanc e i s mad e wit h th e assumption s mad e earlie ri n derivin g Equa tio n 3.1 8 an d furthe rassumin g tha tonl y auxiliar y fuel i s combuste d i n th e preheate rportion . Th e resultin g equatio n i s ver y simila rt o Equatio n 3.1 8 excep ttha t(1 ) th e term s wit h an fi subscrip tbecom e term s wit h r j sub script s t o denot e a catalyti c reacto rinle tstrea m rathe rtha n a combusto r outle t(/lu e ga s inle tt o th e primary hea texchanger ) an d (2 ) th e ter m forcombustio n of

th e wast e ga s organic s doe s no tappear . Th e resultin g equatio n i s as follows : 

## *..Q«.[c>,.,..(i-ir,,
. - T W 

## . - o.ir,./) ] (-Art^-i.ic^o^-r,,, ) p.tQ.t = ...r;: ? z; ; f 

## <3.»

)

Thi s equatio n ma

y b e rearrange d t o solv e forT r( explidtly . Thi s pro duce s a n equatio n tha ti s somewha tcomple x an d non-intuitive .

T 

## p*tQ*A{-^K,) + i-icy^rTM/ ! + PV.Q-.C^.JT*. 

## + o.ir,., )

l'lC 9m ^{p m ,Q mt + p„.Q m .) (3.23 ) Afte rsubstitutin g th e exampl e proble m parameter s int o Equatio n 3.23 , w e obtai n a valu e fo

rT r{ of 693°F . Base d o n ignitio n temperature s show n i n Tabl e 3.2 , thi s reacto rinle ttemperatur e shoul d b e satisfactory . Prio rt o a more definitiv e design , th e ignitio n temperature s fo rth e spedfi c chemical s shoul d b e verified . Th e temperatur e rise acros s th e catalys tbe d i s thu s (90 0 - 693 ) o r 207 ° F . Thes e temperature s ar e somewha tsen d tiv e t o th e assumptio n fo r energ y losse s from th e combustor . Th e assumptio n forenerg y losse s i s perhap s somewha tconservative , i.e. , i tcause s a large rQ« / t o b e estimate d tha n woul d a les s conservativ e assumption , an d become s more conservativ e a s th e combusto rsiz e and insulatio n ar e increased . 1 A tequilibrium , th e temperature o f th e catalys tbe d i s maintaine d withou trequiring auxiliary fuel . 3-40P.4 5

Ste p 10 c - Calculat e th e tota l volumetri c flow rat e o f ga s throug h th e incinerator , Q/ { Th e tota l volumetri c flow rat e of ga s leavin g th e indnerato ri s referre

d t o as th e flue ga s flow rate , Q/ { , an d i s th e ga s rat e o n whic h th e incinerato rsizin g and cos tcorrdation s ar e based . Th e flue ga s flow rate measure d a

tth e standar d condition s of 77 ° F an d 1 atmosphere , wher e th e increas e i n volumetri c throughpu tdu e t o an increas e i n th e num berof mole s of ga s a s a resul tof

combustio n i s neglected , i s th e su m of th e inle tstream s t o th e indnerator .

ss 20,00 0 + 0 + 4 0 ss 20,04 0 scf

m
Ste p li e - Calculat e th e volum e o f catalys ti n th e catalys tbe d I f th e volumetri c flow rate of ga s through th e catalys tbed , Q/, , an d th e nominal residenc e tim e (redproca l spac e vdodty ) i n th e catalys tbe d ar e known , the n th e volum e of catalys tcan b e estimated . Ther e exist s a com plex se to f relationship s betwee n th e catalys tvolum e an d geometry , overall pressure dro p acros s th e catalyst , converrio n of th e oxidizabl e components i n th e gas , ga s temperature , an d th e reactio n rate . Thes e relationship s ar e dependen to n th e catalys tan d th e typ e of compoun d bdn g oxidized . I t i s beyon d th e scop e i

f thi s Manual

t o discus s thes e rdationships , eve n i n a n approximate way . Fo rth e purpose s of

cos testimation , th e spac e ve lodty , <p i n redproca l tim e units , necessar y t o achiev e th e required level o f destructio n ca n b e use d t o approximate th e catalys tvolum e requirement . Th e spac e velodt y i s defined a s

wher e V^ s = Overall bulk volum e o f th e catalys tbed , indudin g interpartid e void s (ft 3 )
B y petro-chemical industr y convention , th e spac e vdodt y i s compute d a t th e condition s of

60° F (no t77°F ) an d 1 atm . Th e volumetri c flow rate ,

3-4 1Q/. , mus tb e correcte d to thes e conditions . Th e prope rspac e vdodt y t o

achiev e a desire d lev d of conversio n i s base d o n experimenta l dat a forth e syste m involved . Forpredou s meta l monolithi c catalysts , th e spac e vdodt y generall y lie s betwee n 10,00 0 h

_ 1 an d 60,00 0 h" 1
. (Bas e meta l catalyst s operat e atlowe rspac e velodties , rangin g from 5,00 0 t o 15,00 0 h~ l .)[10 ] Forth e example , usin g a spac e vdodt y of 30,00 0 h" 1 o r50 0 min' 1 , an d usin g Q A at60°F , /6 0 + 460 N Q h a t60 8 F = 20,04 0 ( l l

" - 1 *" V7 7 + 460 / ss 19,40 0 ft 3 /mi n 19,40 0 ft 3 /min
" * ~ 50 0 min" 1 s = 3 9 ft3
Ther e ar e a numbe ro

f catalys tbe d parameters , suc h a s catalys tconfigu ratio n an d be d design , tha tar e no trignificantforstud y typ e cos testimates . Accordingly , desig n o

f thes e factor s i s no tdiscusse d here .

• 

## 3. 5 Cos tAnalysi s Thi s sectio n presents procedure s and dat a fo restimatin g capita l an d annual cost s fo rfou rtype s of

indnerators:(l ) thermal-recuperative , (2 ) thermal regenerative , (3 ) fixed-bed catalytic , an d (4 ) fluid-bed catalytic .
3.5. 1 Estimatin g Tota l Capita l Investmen t, Total capita l investment , TCI , indude s th e equipmen tcost , EC , fo rth e indnerato ritself

, th e cos to

f auxiliary equipmen t{e.g., ductwork) , all direc t an d indirec tinstallatio n costs , and cost s forbuildings , dt e preparation , offsit e fadlities , land , an d working capital . However , th e las tfive cost s usuall y d o no tappl y t o indnerators . (Se e Chapte r2 of thi s Manual

fo ra detaile d descriptio n of

th e dement s comprisin g th e TCI. )

3-4 2 P.4 6

.

u.P.4 7

Tabl e 3.7 : Scop e o f

Cos t Correlation s

Tota l (Flue ) Ga s Indnerato r

Typ e Flowrate , scf mFigur e Numbe r Therma l - Recuperativ e 500 a -50,00 0 3. 4 Therma l - Regenerativ e 10,000-100,00 0 3. 5 Fixed-Be dCatalyti c 2,000-50,00 0 3. 6 Fluid-Be dCatalyti c 2,000-25,00 0 3. 7 'Althoug h Figur e 3. 4 cove n th e 1,00 0 t o 50,00 0 scf m range , th e correlatio n i s vali d forth e SO

O t o 50,00 0 scfi n range . 3.5.1. 1 Equipmen tCosts , E C
A s discusse di n Sectio n 3.2.3 , th e equipmen t costs , EC , give n i n thi s chap

te r appl y t o package dindnerators , excep t fo r regenerativ e indnerators
. Fo r regenerativ e indnerators , th e cost s appl y t o fidd-erectedunits
. Th e E C typicall y indude s al l flange-to-flange equipmen t neede dt o oxidiz e th e wast e gas , indudin g th e auxiliar y burners , combustio n chamber , catalyst , primar y hea t

exchange r

(excep t fo r th e "zer o hea t

recovery " cases) , weath

ertigh t housin g an dinsulation , fan , flow an dtemperatur e contro l systems , ashor t stack , an dstructura l supports
. Smalle r units , e.g. typicall y les s tha n 20,00 0 scfm , ar e typicall y preassemble dan dskid-mounte d[18]
. Th e variou s availabl e indneratio n system s ar e presente di n fou r group s delin

eate daccordin g t o thei r similarit y o f

design
. Thes e group s ar e outline di n Tabl e 3.7
. Wit h th e exceptio n o f regenerativ e therma l an dfluid-bedcat
alyti c indnerators , th e maximu msiz e fo r whic h cost s ar e give n i s 50,00 0 scfm
. Althoug h large r

unit s o f eac h technolog y ca n b e built , application s ar e rar e a t

flow rate s abov e 50,00 0 scfm
. Regenerativ e therma l incinerato r cost s ar e provide dfo r

flow rate s from10,00 0 t o 100,00 0 scfm
. Fluid-be d catalyti c indnerato r

cost s ar e provide dfo r flow rate s from2,00 0 t o 25,00 0 scfm
. Th e cos t curve s ar e least-square s regression s o f cos t dat aprovide db y differen t vendors
. I t

mus t b e kep t i n min dtha t

eve n fo r

agive n indner

atio n technology , desig n an dmanufacturin g procedure s var y fromvendo r t o vendor , s o tha t

cost s ma y vary . A s always , onc e th e stud y estimat e i s 

## J 3 

## " 4 3P.4 8

completed , i ti s recommende d tha tmore tha n on e vendo rb e solidte d fo ra more detaile d cos testimate . Th e additiona l expens e o f ad d ga s clean-u p o rparticulat e contro l i s no t treate d i n thi s section . Th e equipmen tcos tof a ga s absorbe rt o remov e any ad d gase s formed i n th e indnerato rca n b e quit e large , sometime s exceedin g th e equipmen tcos tof

th e indnerato ritsel f

eve n forsimpl e packe d towe r scrubber s [19] . Formore comple x absorber s tha tindud e ventur i scrubber s instea d of

, o ri n additio n to , packe d beds , th e cos tof th e scrubbe ralon e ma y b e u p t o 4 time s tha tof th e incinerato r[11] . Thes e mor e comple x absorber s are sometime s necessary whe n particulates , i n additio n t o ad d gases , mus tb e remove d from th e flue gas .
Therma l Incinerator s Amon g th e thermal units , th e direc tflame (0 % energy recovery ) an d recuperativ e system s ar e treate d togethe rbecaus e th e variou s level s of

energy recover

y ar e achieve d simpl y b y addin g hea t exchange rsurfac e area . Cost s fo rthes e unit s were provide d b y severa l ven dor s [12,20,21] . Th e E C of thes e unit s ar

e give n as a functio n of

total volu metri c throughput , Qt* , i n scfm . "Qtot " i s th e tota l volum e o f

th e gaseou s compound s exitin g th e combustio n chamber ; i ti s identica l t o th e term , u Q/ { " , use d i n Figure s 3. 1 an d 3.3 . Thi s indude s th e combustio n products , nitrogen , unbume d fu d an d organics , an d othe rconstituents . (Se e Figur e 3.4) . Not e tha tcost s are give n free o n boar d (F.O.B. ) i n Apri l 198 8 dollars . Base d o n a least-square s regressio n analyris , a log-lo g rdationshi p betwee n throughpu tan d E C wa s foun d fo ra give n lev d of

energ y recovery (HR ) ove rth e flow rate rang e from 50 0 t o 50,00 0 scfm . Thes e relationship s ar e as follows : EC

= 10294Q£f " H R= 0 % (3.24 ) EC = s 13149QJ2 60 9 H

R= 35 % (3.25 ) EC = 17056(?^ S M H R= 50 % (3.26 ) EC = 21342g£J M O HR=70 % (3.27 )
Th e regenerativ e (o rexces s enthalpy ) system s provid e u p t o 9 5 percen t hea trecover

y a tth e expens e of

highe rcapita l costs . Thd runiqu e desig n [22,23] , which combine s th e hea texchange ran d reactor , i s substantiall y differen tfrom traditiona l thermal unit s an d i s therefore treate d separatel y i n Figur e 3.5 . Th e EC s of thes e system s are give n a s a n approximatd y 3-4 4P.4 9

Q < in o X 1 — in cc 90 0

80 0 70 0 60 0 SO O 40 0 30 0 

## o a o o 0 0 c n


### a: a . < aa " o

t o O O

L U 0 . D 

## a L d 20 0

10 0 9 0 8 0 7 0 s o 5 0 4 0 30

2 0

10 1 * } i

! 1 i

i

. 0 0 X

ENERG Y RECOVER

Y •DM! !

. A 5 0 X

•7 0 X i

4 S S 7 8 9 1 0 2 0 3 0 4 0 S O 6 0 70809 0 

### FLU E GA

S VOLUMETRI C FLO

W RATE , SCF M (THOUSANDS ) Figur e 3.4 : Equipmen tCost s o f Therma l Indnerators , Recuperativ e

3-4 5P.5 0

v > Q <f l 3 O 

### j E tf l
o Q 0 0 O O 0 1

0 3 O U . (f l o o U J 2 0 . O U i 

# o o C N —



## o C O400



## o 0 o 9 5 % ENERG

Y RECOVER

Y

» • 

## . 0 i r0 

## 6

0 . i

-:• •



## 8 0 10 0 FLU E GA

S VOLUMETRI C FLO

W RATE , SCF M (THOUSANDS ) Figur e 3.5 : Equipmen tCost s of Therma l Indnerators , Regenerativ e

3-4 6P.5 1

linea rfunctio n o

f tota l flow rate ove ra 10,00 0 t o 100,00 0 scf m rang e by th e followin g equation : EC = 2.20 4 x IO

8 + 11.5 7 (?« * (3.28 ) Again , th e highe rcapital cost s o f thes e unit s can b e substantiall y offse t b y th e substantia l saving s i n auxiliary fu d costs . Catalyti c Incinerator s Th e E C fo ra catalyti c indnerato ri s a functio n of th e typ e of

catalys tcontactin g patter n use d an d th e tota l ga s flow rate , Qtot, fo ra give n level o

f energy recovery . Ther e ar e thre e type s o

f contactin g configuration s used i n catalyti c systems : fixed-bed, catalyti c monolith , and fluid-bed. Th e E C fo

rth e firsttwo ar

e generall y comparabl e and ar e give n i n Figur e 3.6 . Th e dat a provide d b y several vendors [12,20,21,24 ] exhibite d curvilinea rrdationship s wit h Qu* for each of

th e energy recover

y rates . Leas tsquare s regression s o f th e dat a yidde d th e followin g correlation s fo r tota l flow rate s betwee n 2,00 0 an d 50,00 0 scfm :



### EC EC EC EC = 1105QTM 4 n

= 3623<?£ 41 W

= 1215C?^ 8T 8 s = 1443g£ 8a 7 H

R= s 0 % H R= 3 5 % H R= 5 0 % H R= 70 % (3.29 )

(3.30 ) (3.31 ) (3.32 ) Fluid-be d catalyti c indnerator s affor d certai n advantage s overfixed-bed catalys tunits i n tha tthe y tolerat e wast e stream s with (1 ) highe rheatin g values , (2 ) particulate contents , an d (3 ) chlorinate d spedes . Fo rthi s en hance d flexibility o

f fee d streams , a highe rcapita l cos ti s incurred , a s in dicate d b y th e E C shown i n Figure 3.7 . Th e dat a show n wer e provide d b y vendors [11,19 ] an

d exhibite d a linea rrdationshi p overth e range o f flow rate s from 2,00 0 to 25,00 0 scfm . The y ca n b e approximate d by th e followin g equations :

EC = 8.4 8 x 10 4 + 13.2C?* * H R= 0 % (3.33 ) EC = 8.8 4 x 10 4 + U.6Q M H

R= 35 % (3.34 ) EC = 8.6 6 x 10 4 + 15.8*?* * H R= 5 0 % (3.35 ) EC - 8.3 9 x 10 4 + 19.2C?* , H R= 7 0 % (3.36 ) A compariso n o

f th e E C of

thermal , catalyti c fixed-bed, and catalyti c fluid-bed system s wit

h 5 0 percentenergy recover y i s shown i n Figure 3.8 . 3-4 7P.5 2

t n o z < in O X 1 — t o OL 

## 5

_ j o o G O 0 0 c n f M

_ l ca C L < C D O u _ > - o C J h - z U J 2 a . D O 90 0 80 0 70 0 60 0 50 0 40 0 30 0

20 0

10 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0

2 0

1 0 i

- 'V ^

• ^ ?x * V : I1

I1 1 |

••••• ; .-" . - " 1 - •

• = • • ' 

## y^ ^~^

-
0 0 % ENERG

Y RECOVER

Y
a 3 5 % A 5 0 % " "

• 7 0 X

• 4 5 6 7 8 9 1 0 2 0 3 0 4 0 5 0 6 0 7 0 809 0 

### FLU E GA

S VOLUMETRI C FLO

W R E , SCF M (THOUSANDS ) Figur e 3.6 : EquipmentCost s of Catalyti c Indnerators , Fixed-Be d

3-4 8Y-Ht^^Bv ^ v^^FV^ ^ P.5 3

(f l 

### a o X tf l


### o a a o a o OS 

## k O L u (f l 

### o o . z * U l 2 Q L O U l600



### o o ^ *



### o C N



### o o 0 % ENERG

Y RECOVER

Y • 3 5 % " A 

### 5 0 % " •7 0 % "

•



### 1 0 2 0 3 0 4 0 5 0 FLU E GA S VOLUMETRIC
. FLO

W RATE
. SCF

M (THOUSANDS ) Figur e 3.7 : Equipment

Cost s o f Catalyti c Incinerators , Fluid-Be d

3-4 9P.5 4

c n a 

## z < c n 

## o X H c n a : 

# 5

_ i o a 0 3 a o c n ^ » • _ i c r a . < C D O u . H c n o o z U J 2 C L 3 O 90 0

80 0 70 0 60 0 50 0 40 0 30 0
20 0

10 0 9 0 8 0 7 0 6 0 5 0 4 0 3 0
2 0

i n i

1 1 

## — - i

1 1 i ! 1 i

i

. 0 CATA

L

. A THER I 50 % E h * • r
1 YU C - FLUI 0 BE D YT1 C - FIXE D BE D JAL - RECUP . ^ERG Y RECOVER

Y !

4 5 6 7 8 9 1 0 2 0 3 0 4 0 S O 6 0 70809 0 

### FLU E GA

S VOLUMETRI C FLO

W RATE

. SCF M (THOUSANDS ) Figur e 3.8 : Equipmen t Cos t Compariso n o f Indnerato r Type s

3-5 0P.5 5 -TI P"W^T P •^r , "~—rr~ - ^ '

3.5.1. 2 Installatio n Cost s A s explaine di n Chapte r 2 , th e purchase dequipmen t cost , PEC , i s calcu

late db y takin g th e su mo f th e E C an dth e cos t

o f auxiliar y equipmen t {e.g., ductwork) , taxes , freight, an dinstrumentation
. Averag e value s o f direc t an dindirec t

installatio n factor s [25 ] t o b e applie dt o th e PE C ar e give n i n Tabl e 3. 8 fo

r bot h recuperativ e therma l an dfixed- an dfluid-bed catalyti c indnerators
. Tabl e 3. 9 show s th e itemize dinstallatio n cost s tha t ar e obtaine dwhe n thes e installatio n factor s ar e applie dt o th e PEC s fo r th e exampl e indner

ators
. Dependin g o n th e sit e conditions , th e installatio n cost s fo r agive n indnerato r

coul ddeviat e significantl y fromcost s generate db y thes e aver ag e factors
. Vatavu k

an dNeveri l [25 ] provid e som e guideline s fo r adjustin g th e averag e installatio n factor s t o accoun t fo r other-than-averag e installa

tio n conditions
. Fo r

unit s handlin g tota l ga s flow rate s lower tha n 20,00 0 scf mth e installatio n cost s are . minimal , amountin g normall y t o onl y util

it y tie-in s (electrica l and , i f necessary , combustio n o r dilutio n air)
. Th e installatio n cost s fo

r thes e smalle r

indnerator s woul db e 2 0 t o 2 5 % o f th e PEC
. Smalle r

unit s ma y b e installe do n th e roof s o f manufacturin g build

ing s rathe r

tha n a t groun dlevd
. I n suc h case s th e installatio n factor s coul d b e a s hig h a s (o r

highe r than ) th e factor s show n i n Tabl e 3.8 , eve n thoug h th e unit s woul db e "packaged"
. 

### 3.5. 2 Estimatin g Tota l Annua l Cos t Th e tota l annua l cos t

(TAC ) i s th e su mo

f th e direc t

an dindirec t

annua l costs
. Th e TA C fo

r bot h exampl e system s i s give n i n Tabl e 3.10 , alon g wit h suggeste dfactor s fo r calculatin g them
.
3.5.2. 1 Direc tAnnua l Cost s Direc t annua l cost s fo

r indnerator s indud e labo r (operatin g an dsupervi

sory) , maintenanc e (labo r an dmaterials) , fud , electridty , an d(i n catalyti c units ) replacemen t

catalyst
. Fo r

therma l an dcatalyti c units , th e fu dusag e rat e i s calculate da s show n i n Section s 3.4. 2 an d3.4.3 , respectively , wher e 3-5 1P.5 6

Tabl e 3.8 : Capita l Cos tFactor s fo rThermal an d Catalyti c Indnerators " Cos tIte m Direc tCost s Purchase d equipmen tcost s Indnerato r(EC ) + auxiliar y equipment * Instrumentation 0 Sale s taxe s Frdgh t Purchase d equipmen tcost , PE C Directinstallatio n cost s Foundation s & support s Handlin g & erectio n Electrica l Pipin g Insulatio n fo

rductwork' ' Paintin g Direc tinstallatio n cos t Sit e preparatio n Building s Tota l Direc tCost , D C IndirectCosts (installation ) Engineerin g Constructio n an d Ad d expense s Contracto rfee s Start-u p Performanc e tes t Contingende s

Tota l Indirec tCost , I C Total Capita l Investmen t= D C + I C Facto r

A s estimated , A

0.1 0 A 0.0 3 A 0.0 5 A B a 1.1 8 A
0.0 8 B 0.1 4 B 0.0 4 B 0.0 2 B 0.0 1 B 0.0 1 B 0.3 0 B A s required , S P A s required , Bldg . 1.3 0 B + S P + Bldg .

0.1 0 B 0.0 5 B 0.1 0 B 0.0 2 B 0.0 1 B 0.0 3 B 0.3 1 B 1.6 1 B + S P + Bldg .
* Referenc e (38j . 'Ductwor k ta d aa y othe r equipmen tnormall y no tinclude d wit h uni tfamished b y indnerato rvendor . 'Instrumentatio n aa d control * ofte n famished wit h th e incinerator , aa d Un a ofte n include d i a th a BC . 4 I f ductwor k dimension s hav e bee a estabUshed , coa tms y b e estimate d baae d o a tl O t o S13/ft * o f surfac e fo rfiel d application . Fa n housing s ca d stock * mop clo o b o iaselated . 3-5 2P.5 7

Tabl e 3.9 : Capita l Cost s fo rTherma l an d Catalyti c Indnerator s Exampl e Proble m Cost , S Cos tIte m Thermal - Fluid-Be d Recuperativ e Catalyti c DirectCoat

s Purchase d equipmentcost s Incinerato r(EC ) 1254,20 0 $468,20 0 Auxiliary equipment 4 Su m = A Instrumentation , 0. 1 A Sales taxes , 0.03 A Freight , 0.05 A Purchase d equipmentcost , B Directinstallatio n cost s Foundatio n an d supports , 0.08 B Handling and erection , 0.14 B Electrical , 0.04 B Piping , 0.02 B Insulatio n (fo rductwork) , 0.01 B Painting , 0.01 B Directinstallatio n cos t$90,00 0 $165,60 0 Site preparation 4 Buildings 4 $254,20 0 25,40 0 7,63 0 12,70 0 $300,00 0 24,00 0 42,00 0 12,00 0 6,00 0 3,00 0 3,00 0 $468,20 0

46,80 0 14,00 0 23,40 0 $552,40 0 44,20 0 77,30 0 22,10 0 11,00 0 5,52 0 5,52 0

Tota l DirectCos t Indirec tCosts (installation ) Engineering , 0.10 B Construction-an d field expenses , 0.05 B Contracto rfees , 0.10 B Start-ap , 0.02 B Performanc

e test , 0.01 B Contingencies , 0.03 B

Tota l IndirectCos t
Total Capital Investment(rounded ) $390,00 0
30,00 0 15,00 0 30,00 0 6,00 0 3,00 0 9,00 0 $93,00 0 $483,00 0 $718,00 0

55,20 0 27,60 0 55,20 0 11,00 0 5,52 0 16,60 0 $171,10 0 $889,00 0 .'Non e o f thes e item s i

a required . 3-5 3P.5 8

Tabl e 3.10 : Annual Cost s forTherma l an d Catalyti c Indnerator s Exampl e Proble m

Cos tItem
DirectAnnua

l Costa*,D C Operatin g Labor Operato r Superviso r Operatin g material s Maintenanc e Labor Material Catalys treplacement Utilitie s Natural Ga s Electricit y Tota l D C IndirectAnnua

l Costs , I C Overhead

Administrativ e charges Propert y taxe s Insurance Capita l recovery * Suggeste d Facto r

0. 5 h/shif

t 15 % o f operato r

— . 0. 5 h/shif

t 100 % o f maint . labo r 100 % o f catalys t replace d e a 2 y

r

—
—

60 % o f sum o f operating , supv. , k maint . labo rJ

c maint . materials . 2% TC I 1% TC I 1%TC I CRF [TC I - 1.0 8 (Cat . Cost) ] Uni tCost *

$12.96/h

—
$14.26/ h ^ ~ 3650/ft 3 fo

r metal oxid e $3.30/kft * $0.059/kW h

-

—
—
—

-snes a Thermal

6,48 0 97 3
7,13 0 7,13 0 0
264,50 0 35,00 0 $321,20 0
13,00 0
9,66 0 4,83 0 4,83 0 78,60 0 Fluid-Be d

Catalyti c
6,48 0 * 97 2
7,13 0 7,13 0 14,60 0
83,40 0 42,30 0 3142,00 0
13,00 0

i . 17,80 0

- 8,90 0
, „ 8,90 0 "142,20 0 Tota l I C 8110,90 0 8190,80 0 Tota l Annual Coa

t(rounded ) 8432,00 0 $352,00 0 *19S S dollars . 'Assume s 8,00 0 h/yr . 'Th e capita l recovery cos tfactor , CRF , i a a (unctio n o f

th e catalys to requipmen tlif e (typically , 3 an d 1 0 years , respectively ) an d th e opportunit y coo to f th e capita l («.«. , interes trate) . Fo rexample , fo ra 1 0 yea r equipmen tlif

e an d a 10 % interes trate , CR F s 0.1838 . 3-5 4P.5 9

Tabl e 3.11 : Typical Pressur e Dro p Acros s Selecte d Equipmen t EquipmentTyp e Thermal Indnerator s Catalyti c Fixed-be d Indnerator s Catalyti c Fluid-be d Indnerator s Hea texchangers n n » » Energy Recovery , % 0 0 0 3 5 5 0 7 0 A P 

### , 

### in . H, 0

4 6 6-1 0 4 8 1 5

natural ga s (methane ) i s assume d t o b e th e fud . (Othe rfuel s coul d b e use d fo rthermal units. ) Th e electridt y cost s ar

e primaril y assodate d wit h th e fa n neede d t o mov e th e ga s through th e indnerator . Th e powe r(i n kilowatts ) neede d t o mov e a give n volumetri c flow rate of ai r{Qu* pe rSection s 3.4. 2 an d 3.4.3 ) ata tota l flange-to-flange pressur e dro p of A P inche s of

wate ran d combine d motor/fa n effidency , e , i s adapte d from Equatio n 2-7 , as follows :
Paw „ lm _ 1-1 ? * 10-<Q,.,AJ > ( J 3? ) Fa n effirienrie s var

y fro m 4 0 t o 70 percen t[15] whil e moto reffidende s ar e usuall y 9 0 percent . Th e tota l pressure dro p acros s a n indnerato rsyste m depend s o n th e numbe ran d type s o

f equipmen telement s indude d i n th e syste m an d o n desig n condderations . Th e estimatio n of actual pressure drop requirements involve s comple x calculation s base d o n th e spedfi c system' s wast e ga s an d flue ga s condition s and equipmen tused . Fo rth e purpose s o

f thi s section , however , th e approximat e value s show n i n Tabl e 3.1 1 ca n b e used . Fo rth e exampl e cases , w

e wil l assum e 8,00 0 hours pe ryea roperatio n an d a 60 % effidency fo

rth e fa n an d moto rtogether . Udn g pressure drop s o f 4 an d 8 inche s o

f water , respectively , fo

rth e therma

l and fluid-bed catalyti c indnerators 3 , and addin g th e pressure dro p of 1 5 inche s of

wate rfo r70 %

' A fluid-bed catalyti c incinerato ri s used becaus e th e wast e gas contain s a chlorinate d compoun d whic

h woul d poiso n th e catalys ti n a fixed-bed incinerator .

3-5 5P.6 0

hea trecovery , th e fan powe rrequirements ca n b e calculate d a s follows : Therma l Indnerato r

_1.1 7 x 10~ 4 (20,00 0 sc£m)(1 9 inche s water ) Power 

## "» = 

## 61b ~

= 74. 1 k

W Catalyti c Indnerato r

_1.1 7 x 10" 4 (20,00 0 scfm)(2 3 inche s water ) P9W€r 

## ^ = 

## —b^ o

= 89. 7 k

W Th e annual dectridt y cost s woul d b e th e product s of thes e usages , th e annual operatin g hours , an d th e dectridt y cos t(S/kWh) , or : Electridt y Cos t(Thermal ) = 74. 1 kW x 8,00 0 hours/y rx $0.059/kW h

= .35,00 0 pe ry r Electridt y Cos t(Catalytic ) s 89. 7 k W x 8,00 0 hours/y rx $0.059/kW h

= 142,30 0 pe ry r

V Th e catalys treplacemen tcost s an d schedulin g ar e highl y variabl e an d depen d o n th e natur e of th e catalyst , th e amoun tof "poisons " an d par ticulate s i n th e ga s strea m (includin g th e auxiliar y fud) , th e temperatur e histor y o f th e catalyst , and th e desig n of th e unit . Iti s impossibl e t o pre dic tth e cost s i n a general sense . However , nobl e meta l monolith catalyst s operatin g o n pure hydrocarbo n gase s i n ai rwil l las tlonge rtha n fluid-bed bas e meta l catalyst s operatin g o n chlorinate d hydrocarbon s i n air . Nobl e meta l catalyst s ar

e als o more expensiv e tha n bas e meta l oxid e catalysts . Th e catalys tlif

e formany fidd unit s i s from 1 t o 4 years . Th e cost , i n Apri l 198 8 dollars , of

th e replacemen tcatalys tmus tb e obtaine d fro m th e vendor , buti tma

y b e estimate d a t$3,000/ft 3 fornobl e meta l catalyst s an d $650/ft 3 fo

rbas e meta l oxid e catalysts . Forth e exampl e case , th e catalys t i s a bas e meta l oxid e becaus e th e wast e ga s contain s a chlorinate d com pound . W

e wil l assum e a tw o yea rcatalys tlife . Knowin g tha tth e catalys t volum e i s 3 9 ft

3 (Sectio n 3.4.3 ) an d usin g a cos tof $650/ft 3 an d a capita l 3-5 6P.6 1

recover y facto ro

f 0.576 2 (2-yea rlif

e ata 10 % interes trate) , th e annual expens e forcatalys treplacementi s Annual Catalys tReplacemen tCos t= 3 9 ft 3 x 650 p x 0.576 2

= $14,60 0 pe ryear
T o calculat e th e fue

l o rdectridt y annual cost , multipl y th e fue l usag e rate (scfm ) o rth e electridt y usag e rate (kW ) b y th e tota l hours peryea rof operatio n {e.g., 33 3 d/y rx 2 4 h/ d = 8,00 0 h/yr ) an d b y th e appropriate uni tcos t{e.g., S/sc£m fo rfu d an d S/kW h fordectridty) . Forth e exampl e cases , th e fu d cost s ca n b e calculate d fro m th e fue

l usag e rate s an d th e natural ga s uni tcos tof S0.0033 0 /scf. . Fo

rth e thermal indnerato rexample , th e annual fu d cos ti s calculate d a s follows : Annual Fu d - «*

—$ .«. - sc f „,,mi n „ ^^h r .T- , . = 0.00330

—x 167-r - x 60-r- - x 8,000 — v^ost , lnerma l sc f mm h ry r = $264,50 0 pe ry r Fo rth e catalyti c indnerato rexample , th e annual fu d cos ti s found similarly : Annua

l Fu d Cost , Catalyti c = $63,40 0 pe ryea r Operatin g an

d maintenanc e labo rar

e estimate d a s 0. 5 hours per8-hou r shif teach , supervisory labo rat1 5 % of operatin g labor , an d maintenanc e material as 10

0 % of maintenanc e labor . 3.5.2. 2 Indirec tAnnua l Cost s Th e indirec t(fixed ) annua l cost s indud e capita l recovery , overhead , an d propert y taxes , insurance , an d administrativ e (G&A ) charges . Th e las t thre e of thes e can b e estimate d a t1% , 1% , an d 2 % of th e tota l capita l investment , respectivdy . Th e syste m capita l recover y cos ti s base d o n a

n estimate d 10-yearequipmentlife . (Se e Sectio n 2 fora thoroug h discussio n of th e capita l recover

y cos tan d th e variable s tha tdetermin e it. ) Th e syste m

3-5 7P.6 2

capita l recovery cos ti s th e produc tof th e syste m capita l recovery facto r (CRF ) an d th e tota l capita l investmen t(TCI ) les s th e purchase d cos to f th e catalys t(Cos

tx 1.0 8 where th e 1.08 i s forfrdgh tan d sale s tax) . Thes e value s calculate d fo rth e exampl e case s ar e give n i n Tabl e 3.10 . 

### 3.5. 3 Cos tCompariso n fo rExampl e Cas e Th e exampl e v O C strea m define d i n Sectio n 3.4. 1 serve s t o illustrat e som e typica l characteristic s of thermal an d catalyti c systems . Th e tota l annual cost s show n i n Tabl e 3.1 0 sho w tha tth e catalyti c system' s auxiliar y fu d cost s are significantl y lowe rtha n thos e of th e therma l unit . Th e disparity i s enoug h t o offsetth e highe r capita l cost s o f th e catalyti c indnerato rove r th e assume d 10-yea rlifetim e o f th e units . Tw o factor s tha tshoul d b e note d i n th e compariso n of thes e tw o system s ar e (1 ) th e 9 8 percen tlev d of destructio n me tby th e thermal indnerato rmay b e difficul tt o reac h b y th e catalyti c syste m (thi s may b e importan ti n som e cases) , an d (2 ) th e exampl e wast e strea m i s of particularl y lo w heatin g valu e ( 4 Btu/scf ) which favors th e catalyti c syste m du e t o th e lowe rauxiliar y fu d requirements . 

## 3. 6 Acknowledgement s
Th e author s gratefull y acknowledg e th e followin g companie s fo rcontribut in g dat a t o thi s chapter :

• Peabod y Engineerin g (Stamford , CT )

• Combustio n Engineerin g - Ai rPreheater , Inc . (Wellsville , NY )

• TE C Systems , In c (DePere , WI )

• Ai rResearch , Inc . (ARI ) (Palatine , IL )

• Energy Developmen tAssodate s (EDA ) (Itasca , IL )

• Pilla rTechnologies , Inc . (Hartland , WI )

• Huntingto n Energ y Systems , Is c (Unioe , NJ ) 3-5 8P.6 3

• Regenerativ e Environmental EquipmentCo . (REECO ) (Morri s Plains , NJ )

• Englehard Corp . (Edison , NJ )

3-5 9P.6 4



# Appendi x 3 A Propertie s o f

Selecte d Compound s

% 3-6 0P.6 5

Tabl e 3.12 : Limits of

Flammabilit y of

Combustibl e Organi c Compound s i n Ai ratAtmospheri c Pressure , Roo m Temperature *

Compoun d Methan e Ethan e Propan e Butan e Pentan e Hexan e Octan e Nonan e Decan e Ethylen e Propylen e Acetylen e Cydohexan e Benzene * Toluen e Molecula r

Wdgh t 16.0 4 30.0 7 44.0 9 58.1 2 72.1 5 86.1 7 114.2 3 128.2 5 142.2 8 28.0 5 42.0 8 26.0 4 84.1 6 78.1 1 92.1 3 LEL a ,

vol . % 5.0 0 3.0 0 2.1 2 1.8 6 1.4 0 1.1 8 0.9 5 0.8 3 0.7 7 2.7 5 2.0 0 2.5 0 1.26 1.4 0 1.27 UEL* , vol . % 15.0 0 12.5 0 9.3 5 8.4 1 7.8 0 7.4 0

28.6 0 11.1 0 80.0 0 7.7 5 7.1 0 6.7 5 'Referenc e [14 ] "Lowe r Explosiv e Limi t *Uppe r Explosiv e Limi t

3-6 1P.6 6

Tabl e 3.13 : Mola

rHea tCapadtie s of

Gase s a tZer o Pressur e *

C ^ a + aT + cT ' + dT 3 ; Tin' K

fl C.a T
" • (T a - T O C p i n calories/g-mol e ° Ko rBtu/lb-mol e ° R

\ Compoun d

Methan e Ethan e Propan e Butan e Pentan e Hexan e Cyclopentan e Cydohexan e Benzen e Toluen e Nitroge n Oxyge n Ai r Carbo n dioxid e a

4.75 0 1.648 -0.96 6 0.94 5 1.61 8 1.657 -12.95 7 -15.93 5 -8.65 0 -8.21 3 6.90 3 6.08 5 6.71 3 5.31 6 b xl0 a 1.20 0 4.12 4 7.27 9 8.87 3 10.8 5 13.1 9 13.08 7 16.45 4 11.57 8 13.35 7 -0.0375 3 0.363 1 0.0469 7 1.428 5 c xlO *

0.303 0 -1.53 0 -3.75 5 -4.38 0 -5.36 5 -6.84 4 -7.44 7 -9.20 3 -7.54 0 -8.23 0 0.193 0 -0.170 9 0.114 7 -0.836 2 d xlO 9

-2.63 0 1.74 0 7.58 0 8.36 0 10.1 0 13.7 8 16.4 1 19.2 7 18.5 4 19.2 0 -0.688 1 0.313 3 -0.469 6 1.784 Temperatur e Range , 9 K 273-150 0 273-150 0 273-150 0 273-150 0 273-150 0 273-150 0 273-150 0 273-150 0 273-150 0 273-150 0 273-180 0 273-180 0 273-180 0 273-180 0 'Referenc e (26

)

3-6 2P.6 7

Tabl e 3.14 : Heat

s o f Combustio

n o f Sdecte d Gaseou

s Organi c Compounds , —A/i

e , a t25° C an

d constan

tpressur e t o for m gaseous wate

r an d carbo n dioxide. '

Compoun d Methan e Ethan e Propan e Butan e Pentan e Hexan e Octan e Nonan e Decan e Ethylen e Propylen e Cydopentan e Cydohexan e Benzen e Toluen e Molecula r

Weigh t 16.0 4 30.0 7 44.0 9 58.1 2 72.1 5 86.1 7 114.2 3 128.2 5 142.2 8 28.0 5 42.0 8 70.1 3 84.1 6 78.1 1 92.1 3 -AA ,

cal/g . 11,953. 6 11,349. 6 11,079. 2 10,932. 3 10,839. 7 10,780. 0 10,737. 2 10,680. 0 10,659. 7 11,271. 7 10,942. 3 10,563. 1 10,478. 7 9,698. 4 9,784. 7 Btu/l b

21,50 2 20,41 6 19,92 9 19,66 5 19,49 9 19,39 1 19,25 6 19,21 1 19,17 5 20,27 6 19,68 3 19,00 1 18,84 6 17,44 6 17,60 1 •Reference [IS ]

3-6 3

# Reference s

[1 ] Prudent

Practices for

Disposal

of Chemicals from Laboratories, Na tional Academ y Press , Washington , D.C , 1983 . [2 ] Memo fro

m Mascone , D.C , EPA , OAQPS , t o Farmer , J . R. , OAQPS , EPA , Jun e 11 , 1980 , Thermal Indnerato rPerformanc e forNSPS . [3 ] Memo fro

m Mascone , D.C , EPA , OAQPS , t o Farmer , J . R. , OAQPS , EPA , Jul y 22 , 1980 , Thermal Indnerato rPerformance fo rNSPS , Ad dendum . [4 ] Memo from Mascone , D.C , EPA , OAQPS , t o Farmer , J . R. , OAQPS , EPA , Augus t22,1980 , Thermal Indnerator s an d Flares . [5} Lette rfrom Thoma s Schmid t(ARI International , Palatine , IL ) t o Willia m M . Vatavuk (EPA , OAQPS , Researc h Triangl e Park , NC) , Augus t16 , 1989 . [6 ] Weldon , J . an d S . M . Senkan , Combustion Sci. Technol, 1986 , 47 . [7 ] Manning , P. , Hazard

Waste, 1984 , 1(1) . [8 ] Pope , D. , Walker , D . S. , Moss , R. L. , Atmos. Environ., 1976 , 10 . [9 ] Mudck , J . K. , an d F . W . Williams , Ind. Eng. Chem. Prod. Res. Dev., 1974 , 13(3) . [10 ] Lette rfrom RobertM . Yarringto n (Englehar d Corporation , Edison , NJ ) t o Willia m M . Vatavuk (EPA , OAQPS , Research Triangl e Park , NC) , Augus t14 , 1989 . [11 ] Personal communicatio n fro m Bil l Sheffer(ARI , Inc. , Palatine , II ) t o Donal d R . van de rVaar t(RTI , Research Triangl e Park , NC) , Marc h 30 , 1988 . 3-6 4[12] Persona l communicatio n from Ralp h Stettenben z (Combustio n Engi neering , Ai rPreheater , Inc. , Wellsville , NY ) t o Donal d R . va n der Vaar t(RTI , Research Triangl e Park , NC) , Marc h 28 , 1988 . [13 ] Grelecki , C , Fundamentals of Fire and Explosion Hazards Evaluation, AICh E Today Series , Ne w York, 1976 . [14 ] Weast , R . C (ed.) , CRC Handbook of

Chemistry and

Physics, 49t h ed. , CR C Press , Cleveland , Ohio , 1968 . [15 ] Perry , R . H. an d C . H. Chilton(eds.) , Chemical Engineers Handbook, 5t h ed. , McGraw-Hill , Ne w York , 1973 . [16 ] Persona l Communicatio n from Rober tYarringto n (Englehar d Corp. , Edison , NJ ) t o Willia m M . Vatavu k (EPA , OAQPS , Research Triangl e Park , NC) , Jun e 6,1989 . [17 ] Persona l Communicatio n from Thoma s Schmid t(AR I International , Palatine , IL ) t o Willia m M . Vatavuk (EPA , OAQPS , Research Triangl e Park , NC) , Jun e 7 , 1989 . [18 ] Githens , R . E . an d D . M . Sowards , Catalytic Oxidation of Hydrocarbon Fumes, PB-29 9 132 , Nationa l Technica l Informatio n Service , Spring fidd, VA . [19 ] Personal Communicatio n from Andre w Jone s (Energ y Developmen t Assodates , Itasca , IL ) t o Donal d R . va n de rVaar

t(RTI , Researc h Triangl e Park , NC) , Marc h 4 , 1988 . [20] Personal Communicatio n from C L . Bumfor d (Peabod y Engineering , Stamford , CT ) t o Donal d R. va n de rVaar

t(RTI , Research Triangl e Park , NC) , Marc

h 28 , 1988 . [21 ] Personal Communicatio n from C . M . Martinso n (TE C Systems , De Pere , WI ) t o Donal d R . van de rVaar t(RTI , Researc h Triangl e Park , NC) , Marc

h 28,1988 . [22] Persona l Communicatio n from Ronal d J . Renk o (Huntingto n Energy Systems , Inc. , Union , NJ ) t o Donal d R . va n de rVaar t(RTI , Researc h Triangl e Park , NC) , Marc h 16 , 1988 . [23 ] Personal Communicatio n from Jame s H . Muelle r(Regenerativ e Envi ronmenta l Equipmen tCo. , Inc. , Morri s Plains , NJ ) t o Donal d R . van de rVaar t(RTI , Research Triangl e Park , NC) , January 13 , 1988 .

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[24 ] Personal Communicatio n fro m Rober tHablewit

z (Pilla rTechnologies , Hartland , WI ) t o Donal d R. va n derVaar

t(RTI , Research Triangl e Park , NC) , Marc

h 20 , 1988 . [25] Vatavuk , W . M . an d R. Neveril , "Estimatin g Cost s of Ai rPollutio n Control Systems , PartII : Factor s fo rEstimatin g Capita l an d Operat in g Costs" , Chemical

Engineering, Novembe r3 , 1980 , pp . 157-162 . [26 ] Kobe , K. A . an d assodates , "Thermochemistr y forth e Petrochemica l Industry" , Petroleum Refiner, Jan . 194 9 thru Nov . 1954 .

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