1978 National Waste Processing Conference 27

7/23/2019 1978 National Waste Processing Conference 27

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HEATING VALUE OF REFUSE DERIVED FUEL

STANLEY MRUSBuns and Ro Indusal Svics op

Paamus N.J

COVIS PRENDERGSDSI/Rsouc Ssms Goup nc

Boson Massachuss

ABSTRACT

Resure rever sstems hve ee d reei deveped s evirmet eptesutis fr sid wste diss Fue derivedfrm sid wste is imprtt prdut f these

sstems d i m istes represets theu f reveue reeived The fue reveue is futi f the qutit d heti vue fthe fue prdued frm the sid wste The imprtt fue hrterisi whih is heti vuem t sistet euse it is derived frmsid wste whih vries i mpsiti d heti vue A methd is preseted whih predit the heti vue d the irumstesd ftr whih impt heti vue redisussed

INTRODUCTION

The trditi methds f sid wste disps dumpi d iierti a prevusprtied re er epte euse ftheir ufvre evirmet impt Thesrh m mmuities fr stisftrtertive hs ed them t sider resurerever Suh suti thuh evirmet epte is pit itesive d iift irese the st f wste dispss mpred t the trditi methds Therefre t me the ept emi ttrtive reveues frm the revered prduts re

used t ffset sme f the resed stA exmiti f reveues fr suh ss

tem [1 shws tht fue ut fr pprximte 80 peret f the reveues whie ferrusriutes 0 peret ss 5 peret d umium 5 peret This retiship prett muh

hds true fr reveues either frm the diretse f fue r frm the se f stem prduedfrm the firi f the fue Therefre fr suh prpsed prjet it is imprtt t devep hih deree f fidee i the preti ffue reveue This reveue i tur depeds the heti vue f the fue prdued

PROBLEM DEFINITION

365

Fue prdued frm sid wste is eerreferred t s RDF (frm Refuse Derived FueIt is ew evv prdut devepmet whihdes t defe prtiur prdut ut ssf prdut RDF is vie s re r smtpe fetti pwder i desiQed frm

Withi eh ter the sid wste epressed thruh vrius press desis whihud prdue RDF t differet eves f puritCuped with these pssie vritis i RDFis the reizti tht the iput mteri r sid

wste is hetereeus d wi vr i mpsiti d d ses sis Athuh sever studies hve hrterized sid wste mpsiti muh mre remis t e de udereer epted testi d reprti pre


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dures before a standard omposition(s) is reognized

In the meantime state and muniipa offiiasmust proeed with the panning and impementingof soid waste management programs based onimited data For those systems where fue wi

be the most important soure of revenue a proedure is required to evauate ompeting proessdesigns and to vaidate revenues The text whihfoows desribes suh a proedure whih an beappied to the different forms of F

NPUT MATERAL

The performane riteria of a resoure reoverysystem is a fntion of its output in reation to the

input The suess of any suh system is ontingenton the ompeteness and reiabiity of the database ith reset to an F type system it is important to speify the omposition and higherheating vaue (HHV) of the input materia

COMPOSTON

review of the severa studieswhih examined

soidwaste ompostion reveas a ak of uniformityin the reporting proess Some inude a detaiedbreakdown on a dry weight basis [2] others areon a wetweight basis [ 3] some exude yardwaste [4, we others inde a ess detaidbeakdown of onstituents [ 5 These same repotsidentify variation in omposition whih an ourdue to seasona hanges regiona area ommere(industria ommeria agriutura) harater(urban surburban farm) and ity neighborhoods

though the referened stdies identify the

variations in waste omposition that an ouradditiona studies are required to update earierinformation determine waste omposition hangefor a broader range of fators and to vaidate thedata base

The more reiabe the data base of input materia and output produt the greater is the ondene in proposing and speifying systems However deision makers are faed with the reaityof moving ahead in an environment of unertainty beause for a variety of reasons the data

base unique to their irumstanes is not avaiabe Under suh onditions an eduated onstrution shoud be made from the information avaiabe whih most osey represents oa ondi-

366

tions hie this may not represent onditions inabsote terms it does estabsh a base ine foromparison purposes and a uniform riteria whihis important to a resoure reovery systemI order to evauate F the omposition of

the input materia shoud have as detaied a break

down of onstituents as is pratiabe The presentation of the waste omposition shod be suhthat the ombustibe nonombustibe and moisture omponents of waste are identifed or an bedetermined For iustration purposes a representative waste omposition is shown in Tabe 1 forthe northeast area whih is subjet to seasonahanges

ABLE 1 [4] * REFERENCE WASTE COMPOSTON

nstitent

Per

Pstcs

Lethe e

Texties

Wood

Food wste

Yrd wste

Su tot

Gss

Met

MisceneosMoisue

Tot

% Wet dr)

35.4

08

47

180

229

633

05

5516

862

853

176593

100

Daa an ro Tal 8 o rnc and adjd o

os n accordanc w "a-dcadd crrao a 9 o nc

HGHER HEATNG VALUE

To ompete the deition of the input materia an Hmust be determined for the wasteomposition shown review of the iterature

shows various HHV's for waste generay in therange of 45006500 [6 Bu/1b (10467-15119kJ/kg) of waste Therefore to determine the HHVof our referene omposition it wi have to beauated from the HHV of its onstitentsTabe 2 ists the range and seeted HHV foreah waste onstituent Using the data fromTabe 2 and appying it to Tabe 1 e an auate the HHV for the referene waste omposition as shown in Tabe 3

HGHER HEATNG VALUE -

REFUSE DERVED FUEL

ith the onstituents and the HHV of the ref-


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TABLE 2 [7] HGHER HEATING VALES

RANGE OF VALES SELECTED VALES

Constitent Bt/ dr kJ/k Bt/ dr kJ/k dr

Ppe podts 7000-8000 1,282-1808 7 1777 Psts 11 00018000 25584188 1400 959Lete er 10000-1000 22072 100 2288

Texties 8000 1808 8000 1808Wood 8000-9000 18-2094 800 9058

Food wste 8000-9000 18082094 8400 19584Yrd wste 5007500 15119-17445 7004 9798

TABLE HGHER HEATNG VALE REFERENCE WASTE COMPOSTON

HHV (Dr) [7] HHV (D) 7]Constitent % Weit (Dr) [4] Bt/

Pper 514 x 700

Psts 108 x 1400

eter re 147 x 1

Textes 180 x 8000

Wood 229 x 800

Food wste x 8400

Yd wste 705 x 700

Stot 551

Gss 82 x 5

Met 85 x 840Mseneos 7

Moiste 259

Tot 10000

rn wst omposton dnd w hv stbshd bsn from whh to stmt th HHVof th prosptv RD Bfor w stmt orvdt prosptv RD w nd som nfor

mton bout th output from th systm Thsnformton s vb from th proposs submttd by h ontrtor Gnry th proposnuds dsrpton of th pross dsgn proposd wth thr mtr bn fu nyssor both Th HHV of n b stmtd usngthr th mtr bn or fu nyss dt;howvr h rqurs dffrnt pproh

MATERIAL BALANCE

Th mtr bn provdd s prt of thpross dsgn doumntton shoud dntfy thombustb nonombustb nd mostur frtons of th RD It shoud b rognd tht

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kJ/k Bt kJ

1777 2709 21202

959 1578 7

2288 11 87

1808 - 14400 494

19058 9007 44210

19584 = 5172 278

19798 5100 118859

47127 1075

50 0

12 1482

44999 102741

th sod "nonombustb trm n ndhs bn rportd s norgns nrts t orpurposs of ths ppr th trm "nonombustb w b usd to nud thos mtrs suh

s mts gss drt t whh dhr to ndform th mpurty porton of RD nd r notusuy onsdrd ombustb

Bfor utng th HHV of RD w mustrst onvrt th ombustb frton of our rfrn wst omposton to 100 prnt wghtbss of ombustbs s foows:

HHVC

whr

HHVC

c= HHVWcl100 (1)

hghr htng vu of dryombustbs n rfrn

wst omposton on 100%wght bss s Tb 3


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HHVWC

C

therefore

HHVC

higher heating value of thedry combustibe fraction inthe reference waste composition_percent combustibe fractionin the reference waste com

position_

4371 275 = 7924.7

Btu/lb of dry combustible

10 167 57/5516

=, 100

8,43288 kJ/kg

Having determined HHVC we can now calculatethe HHV of RDF as follows:

HHVRDF N+M

HHV( - 100 ) (2)

where

HHVRDF higher heating value of refuse

derived fuelHHVC higher heating value of drycombustible in reference wastecomposition on a 100 percentweight basis

N percent of noncombustiblefrom materia baance

M percent of moisture frommateria baance

Therefore, substituting the values for HHVC,

Nand M, the HHV of RDF can be determined forany range of compositions Calculations of HHVfor RDF based on various compositions can beplotted for convenience, into a series of curvesas shown in Fig 1 Therefore, using a definedinput and a specified output, the HHV of RDFcan be estimated

FUEL ANALYSIS

As previously stated, a fuel analysis may bepresented as part of the process design documentation For our purposes, a breakdown into combustibes, ash and moisture is sucient The in

368

8792

(lB.: !

15 PERCENT r I SlE

15

G1 HHVRD VR OCOMT

MOTR COTT

troduction of ash, in light of our discussion relative to the materia balance, present a complication in analysis and defnition of terms The combustibles listed in a fuel analysis are on an ashfree basis and therefore are different than thecombustibes listed in a material balance In addition, the ash listed in a fuel analysis consists oftwo constituents, ash contributed from the 5516'percent combustibe fraction plus the noncombustible porion of fuel shown in the material balance Therefore, to calculate HHV of RDF from

a fue analysis, it is necessary to determine thecombustibe in the reference waste compositionon an ash free basis as shown in Table 4 and tomodify Eqs. () and (2) as folows

where

HHVACCA

HHVWC/ 100 (3)

HHVAC higher heating value of combustibles in reference wastecomposition on a dry ashfree and 00 percent weightbasis

CA percent of combustible fraction in the reference wastecomposition on an ash freebasis

therefore

HHVAC 437127/ 51

83469

Btu/lb of dry ash free combustibles in waste

30


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TABLE 4 PERCENT ASH FREE COMBUSTIBLES N REFERENCE WASTE COMPOSTON

% Weight% Weight % Ash in [7 % Weght Ash Free

Consttuent (dry) [4 Combustibles n Ref Waste Combustbe

PaperPastcs

Leaer ubber

Textes

Wood

Food waste

Yard waste

Tota

354 x8 x

47

8 x

229 x

633 x

75 x

556

10 167 57/ 5237 100

1941487 kJ/k

Havn deterined HHVAC,we an auatethe HHV of RDF as foows

where

HHVRDF

A

M

A+M HHVAC (1 100)

perent of ash in RDF

(4)

perent of moisture in RDF

ith orretion made for ash in the equationsthe HHV of RDF an be auated from a fueanaysis The same proedure that was performedto produe Fi 1 an be repeated on an ash freebass to produe Fi 2

8347

(19.4)300

{ 608

o

- 000

. ,28

, 0& '-: 6000: 15

5'

>: 50( II

0L_

r

_

.

-

9.

3J4

)

10 1 0PERCENT MISURE

30

FG 2 HHVRDF VERSUS ASH AND MOSTURE CONTENT

t is reonized that on oasion proximateand utimate anayses are provided as part of afue anaysis HHV of RDF an be auated usintis inforation; however a disussion on the useof ths method is beyond the sope of this paper

5-

76 33381.5 - 02 6

15 22 25

3 5 75

3 7 222

5 32 6

5 35 67

279 5237

DSCUSSION

The anaytia method of derivin the HHV ofRDF has been presented however before onudin t wi be usefu to make a few observations onte prepared materiaA examination of Tabe 3 w show it an be

used for sensitivity anaysis on the effet of hanesin onstituents on RDF t shows the rankin andontribution of eah onstituent to the HHV ofRDF ith this information one an assess the impat on resoure reovery systems of suh dversedeveopments as nstitution of paper soure separation prorams inifiant inreases of pastisin waste et

Equaton 1 as ustrated by Fi 1 is interestinn that it determines the upper imit of the HHVfor RDF n addition to estabishn the proessdesin imit it provides a uide to the assessmentof exerimenta resuts Fiure 1 shows the reationship of moisture and nonombustibe removaon the HHV for RDF For more on this subjetthe reader is direted to referene eiht isted at

the end of this paperThe appiation of the anaytia method presented shoud be used with some disretion t isneessary to anayze the proess desin to determine if by its nature a ombustibe onstituent iseiminated Suh a possibiity oud our if RDFwas produed by an aerobi proess in whih pastis are not affeted and therefore oud be eiminated from the fue

369

SUMMARY

For stte and uniipa ofias panners andpratitioners onerned with RDF as a resourereovery produt a method has been presented


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for an ordery evauation of suh a system A needhas been demonstrated for speifying a referene

waste on whih to estabish a omparabe basis forthe evauation of systems A need has aso beendemonstrated for a uniformity in the deitionand use of terms as we as in the presentation ofexperimenta resuts The importane of treatingF in the ompete ontext of input proessand output that is a systems approah has beenustrated As the work on standards and urrentexperimenta studies ome to fruition greaterpreision and ondene wi deveop in improvedmethods for the evauation of resoure reoverysystems

EFEEE

[1] Conncticut Rsourc Rcovry Authorty Oficia Statmnt Bidgort Projct Pags A21 A22

and A-2

2] AtMngG and Kasr E R "Chmica

Anayss of Oganc Potons of Houshod Rus; th

Efct of Crtan Emnts on ncnraton and Rsourc

Rcovy Solid Waste Management, Vo 64 No 10

Dc 194

[ Davdn G R Jr"A Study of Rsidnta

id Wast Gnatd n Lowncom Aas Rot

8ts S Envronmnta Protcton Agncy 192

4] NssnW R and Chansky S K Th Natu

of Rfus " Proceedings of the 1970National Incineratornference, ASME

[5] Kov N Y"Th Samng Chaactization

and Assssmnt o So d Wasts as a Fu" st ntna

toa C or ad chca Ehbo Coso

o Rfus to Engy Montux Swtzrand Nov 5

195

[6] Chmsno P H and MorsA CEnergy

from Solid Wastes, 1 st d Mac Dk Inc Nw Yor

196 28

[] Hoandr H Paramtrc Considatons in

tizing Rfus Drvd Fus n Estng Bo Furnacs "

Proceedings of the 196National Waste Processing Confer-

ence, Bosto Mas Ma 229 ASME[8 Atr H and Shng H P "Engy Rcovry

om Munca id Wast and Mthod o Comarig

Rfus Drvd Fu Resource Recoverand nsea

tion Vo 1195 859

Ky Ws

nasis

sh

Bt

omstle

omposition

efse erived Fel

Standard

370


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Discusson by

Roger S Hecklinger

Charles R Vezy Associates, Inc

Armonk New York

Te auor onern a a proedure be deve

oped o effeivey evauae ompeing RDF produing proee i ared by many Terefore imay be epfu o eaborae on e auor' nding in ree eparae area

1. Coniuen anayi of RDF2 Heaing vaue of ombuibe in RDF3 e quaniy of RDF produed from oid

waeTe auor propoe an evauaion of RDF

baed on eier a maeria baane or on a fueanayi of e RDF produed During e evauaion of e S Loui monraion a maeriabaane of e RDF wa deermined A] *. Beaueof e redding proe a arge quaniy of maeria oud no be araerized Terefore up o 30peren of e maeria wa araerized a mieaneou I may ao be difu o deveop amoiure fgure eparae from e variou maeriaaegorie However i oud no be diu odeveop a fue anayi for RDF oniing of peren moiure peren a and nonombuibeand peren ombuibe Terefore e anayireuing in Fig 2 woud probaby be e moreikey o be of praia ue

In deveoping i paper e auor drew onprior work by Hoander 7] ** and Nieen 4] Hoander drew on e ame work by Nieen However an nereng penomenon an be oberveda one foow e oupu from Nieen o Hoander o e preen auor Tere i an eroion

of eang vaue Tu Nieen' 7930 Bu/b ofdry paper a been eroded o 7600 Bu/bNieen 3500 Bu/b for dry mieaneou maeria a been eroded away o noing iin epreen paper 687 Bu/b diappeared omewerebeween Tabe 3 and quaion 3 Tu e eaing vaue for e referene wae ompoiion fabeow e genera range of 4500 o 6500 Bu/bquoed by e auor Furer e eaing vaueof ombuibe wi zero a and zero moiure given a 8347 Bu/b Te eaing vaue on e

ame bai for preiey e ame refue ompoion an be derived from eier Hoander or

Leters in backets refer to references at h e ed of sdiscussio.

Nmbers n brackes refe o efereces In e paperunder dscsso

371

Nieen a 8750 Bu/b By way of omparione average moiure and a free eaing vauebaed on 97 ampe a S Loui i 8840 Bu/bA] and e moiure and a free eaing vauebaed on 14 ampe a Ame i 9450 Bu/b B]

Terefore i woud eem a Fig 2 woud be amore aurae repreenaion if e zero a zeromoiure poin wa 8750 or perap even a igernumber ike 9000 Bu/b

In e Abra e auor poin ou a fuerevenue i a funion of e quaniy of ue produed from oid wae Bu in e body of epaper e imporane of deermning e poundof RDF produed from a on of raw oid wae ino reed Te urve oud onain adve oe evauaor for deermning e amoun of ea

energy a i avaiabe from e inoming unproeed oid wae

Oerwie Fig 2 oud be a vauabe oo fore proe evauaor if:

1 I wa inreaedi ize2 A bakground gid wa provided for eae of

ue3 Peren moiure wa exended o 40 peren

a moiure onen i ig ave been experiened A]

4 Te peren a urve wa exended o 20peren a a perenage i i ave beenexperiened [A]

5 Kiojoue per kiogram wa indiaed on aeparae ordinae on e rig and ide of epo

REFERENCES

A sus D E et l. St Lous Demostrto

Fl Report: Refuse Proess Plt Equpmet Fl

tes d Evrometl Evlutos S Envonmenta

Poteton Aeny Washnton DC 1977, EPA ContatNos 68021324 an 68021871.

[B Van Mete D et l. Eluto of the Ames

Sold Wste Reover Sstem - Pat : Peomane o

the Stoe e Steam eneatos S Envonmenta

Poteton Aeny Cininnat Oho1977 EPA ant

No 80390301

AUTHORS' REPLY

Te auor wi o expre er appreiaiono Mr Hekinger for i ommen and i

opporuniy o eaborae on our paperTe expeiene of e auor a required e

ue of bo e fue anayi and maeia baanemeod for deermining e eaing vaue of RDF i expeed i wi oninue o be a ommon


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ourrene for others and therefore eah methodwi have its appiation as the need arises

Mr Hekinger notes an interesting phenomenonwhereby an erosion of heating vaue appears toour from the referened Niessen paper to that ofthe authors Euay interesting to the authors is

that we an find no uoted heating vaues in thereferened paper other than a passing ommentthat the heating vaue of refusewi ontinue torise toward the year 2000. The referened paper sentited The Nature of Refuse and deas exusiveywith the testing and determination of RefuseComposition for the referene year of 1968 andgoes on to projet refuse omposition hanges tothe year 2000 n the referened paper the miseaneous ategory in refuse is defned as inorganiash stones and dust The authors assme that

Mr Hekinger must be uoting data from a soureother than the referened Niessen paper

Mr Hekinger goes on to suggest that based onsome operatng data the zero moisture zero ashheating vaue of RF shoud be higher than thatdetermined in our paper perhaps as hgh as 9000Btu/b To make suh a suggestion misses the pointof our paper The authors have presented a methodoogy and a reommendation to use the systemsapproah for determining the heatng vaue of RFThis reuires reating a heating vaue of RF to aninput refuse omposition as outined in our paperbefore one an say whether the heating vaue

shoud be hgherA additiona point to be made is the observa

tion from Tabe C of our paper that the buk ofRFs euosi in nature The materia with thehigher heating vaue ontributes ess than 8 perent to the overa vaue t woud reuire a 100

perent inrease or more of these onstituents inthe input waste to resut in zero moisture zero ashheating vaues over 9000 Btu/b Considering theabove and rognizing the refuse omposition inthe Niessen paper as fairy typia the authors wereunabe to resove the anomay of the reporteddata Thus the motivation for deveoping a methodoogy whih we aso thought oud be hepfu tothe soid waste ommunity

It shoud be reognized that the Niessen work snow a deade od and signiant hanges havetaken pae whih pae the projetions in thereferene work in uestion Therefore the authorssimpy used the Niessen and Hoander works asvehies to ustrate the methodoogy withoutregard to the urrent appiabiity of the databeause as aknowedged in our paper the determination of heating vaue with greater preisionand ondene wi have to await the resuts ofurrent experimenta work and the effort onstandards

The determination of the uantity of RFprodued from a ton of raw soid waste weritiay important is a subjet for another paper

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Documents

1978 National Waste Processing Conference 27