application of caterdillar spark-ignited enrzines for landfill gas

7/27/2019 Application of CaterDillar Spark-Ignited Enrzines for Landfill Gas

1/9

Appl i c at i on of Cat er Di l l ar Spar k- I gni t ed Enrzi nes f or Landf i l l Ga s

BYCur t E. Chadwi ck

Seni or Appl i cat i on Consul t ant , Spark- I gni t ed Engi nesCat e r pi l l ar Engi ne Di vi s i on, Mos svi l l e, I l l i noi s

Cat er pi l l ar has decades of exper i ence oper at i ng spar k- i gni t ed engi nes onmedi um Bt u gas, a consi derabl e number of whi ch ar e perf orm ng successf ul l y on

l andf i l l gas r ec over y pr oj ec t s . A par t i al l i s t i ng of our l andf i l l gas engi neexper i ence i s gi ven i n At t achment A.spar k - i gni t ed engi nes t hat can be oper at ed successf ul l y on l andf i l l gas . Ourmodel 3516 l ow em ssi on Engi ne used i n si ngl e or mul t i pl e i nst al l at i ons seemst o bes t f i t t he pr of i l e of ec onom c al l y f eas i bl e l andf i l l power pr oj ec t s a ndhas been devel oped speci f i cal l y f or t hi s pur pose. The 3516 SI TA i s a 16cyl i nder engi ne wi t h a 170 x 190 mm bor e and st r oke, r at ed at 800 k W wi t h 130"af t er cool er wat er .

Cat er pi l l ar of f er s a compl e te r ange of

Al l Cat er pi l l ar spar k- i gni t ed engi nes ar e bui l t on a di esel f r ame.cr ank shaf t , bear i ngs, r ods, i n f ac t most of t he basi c component r y i s di ese ldesi gn. As one of t he l eadi ng di esel engi ne desi gners and bui l ders i n t hewor l d, i t makes econom c and engi neer i ng sense f or Cat erpi l l ar t o conver tt hei r di es el s t o a spar k i gni t ed conf i gur at i on. For t he user i t o f f er s evenmor e advant ages . He gai ns , wi t hout addi t i onal cos t , a bu i l t - i n s t r engt h no tf ound i n many ot her spar k- i gni t ed engi nes. The 3500 Di esel Engi ne has been i npr oduc t i on s i nce 1980. I t i s s t r uc tu ra l l y des i gned f or 200 hp per cyl i nder at1800 r pm1200 r pm Thi s i nherent st r uct ur al st r engt h combi ned wi t h speci f i c component sdes i gned f or l andf i l l gas oper at i on pr ovi des t hi s appl i cat i on wi t h anexc el l ent per f or m ng, ver y dur abl e spark- i gni t ed engi ne .

The bl ock,

4

The spark i gni t ed ver si on i s r at ed a t onl y 72 hp per cyl i nder at

Em ss i ons

The pr i mar y exhaust em ssi on concer n f or t he engi ne generat or i s t he amount ofNO em t t ed per y ear . Al l s i t es wi l l have a Feder a l l i m t wi t h 250 t ons peryear f or an at t ai nment area bei ng t he most l i beral t hat can be expect ed.St andar d ( r i ch bur n) engi nes wi l l r each t hi s l i m t wi t h to t a l i ns t al l ed powerof appr oxi mat el y 1200 kW wher eas l ow em ssi on ( l ean bur n) engi ne ar r angement sare abl e to s t ay be l ow i t wi t h up t o 10 MW of power . Many l ocal ar eas r equi r e" BACT" ( Best Avai l abl e Cont r ol Technol ogy) wi l l usual l y be def i ned as amaxi mum NO The 3516 SI TA Engi ne can be oper at eda t 1. 5 g NaX' bhp- h on l andf i l l gas .a t t ai n t hi s l evel s i nc e c at al yt i c conver t er s ar e no t c ompat i bl e wi t h l andf i l lgas and cannot be used to obt ai n l ower l evel s of NOx.

The 3516 SI Engi ne i s avai l abl e i n t wo ver s i ons f or oper at i on on l andf i l l gas .T he f i r s t v er s i o n i s f or s i t es wher e EPA per m t s r equi r e NO em ss i on l evel s

be l ow 5 g NO hp- h Thi s ar r angement r equi r es 35 psi g gas pr essur e and i sr ef err ed to as t he hi gh pr essur e ar r angement . The second ver si on i s t he l owpr essur e gas ver si on f or oper at i on on as l ow as 2 psi g gas pr essur e. Thi sar r angement i s cur r ent l y not conf i gur ed f or oper at i on a t em ssi on l evel s bel ow5 g NOx hp- h . Bot h ver s i ons i nc l ude spec i al cor r os i on- r es i s t ant par t s andcool i ng syst ems t o m ni m ze mai nt enance cost s.

X

l evel o f 2. 0 or 1. 5 g/ hp- h.Onl y a l ow em ssi on engi ne i s abl e to

X

X


2/9

- 2 -

Landf i l l Gas as a Fuel

Opera t i on of engi nes on l andf i l l gas i s mor e di f f i cul t because of the s l o wbur ni ng char act er i st i cs of t he gas and the cont am nant s commonl y f ound i n t hegas . Si t e condi t i ons t hat wi l l r equi r e a ver y l ow em ss i on l evel wi l lr equi r e addi t i onal hor sepower f or gas compress i on and added f uel consumpt i on.For a di scuss i on of l andf i l l gas as f ue l , f uel t r ea tment , and consumpt i onr a t es , r e f e r t o At t achment B.

Engi ne Gener at or Mai nt enance

Engi ne mai nt enance wi t h l andf i l l gas i s a s i gni f i cant por t i on of t he t ot aloperat i ng expense. The cont am nant s f ound i n l andf i l l gas can pr oduce r api dengi ne wear i f not c l ose l y managed. A successf ul gas- t o- ener gy pr oj ec tr equi r es a comm t ment t o car ef ul mai nt enance management . Cat er pi l l ar hasspeci f i c mai nt enance schedul es f or engi nes oper at ed on l andf i l l gas . Forpr oj ec t s t hat r equi r e i t , a guar ant eed mai nt enance cont r ac t i s avai l abl et hr ough t he Cat er pi l l a r Power Prot ect i on Pl an.

Des t r uc t i on Ef f i c i enc y

Cat er pi l l ar Spar k - I gni t ed Engi nes ar e desi gned to ef f i ci ent l y bur n gaseoushydr ocar bons.EPA dest r uc t i on ef f i c i ency s tandar d of 98 % f or r eact i ve or gani c compounds,

Al l Cat er pi l l a r spar k- gni t ed Engi nes wi l l meet t he pr oposed

Our st at ement on dest r uct i on ef f i ci ency i s based on measur ement s wi t h var i ousgaseous f uel s and ac tual oper at i on dat a on l andf i l l gas . I t i s our opi ni ont hat hydr ocar bons such as benzene or t ol uene or any const i t uent wi t h ahydr ocar bon bond woul d be dest r oyed i n t he combust i on pr ocess wi t h an equalef f i ci ency. Ther ef or e, we f eel we adequat el y meet t he pr oposed EPA st andardof 98.0% des t r uc t i on ef f i c i ency f or ROCs.

Ref er ence Mat er i al

ASME Paper 87- I CE- 13 " Oper a t i on o f a Cat er pi l l ar 3516 Spar k- I gni t ed Engi ne onl ow bt u f uel " , by N. C. Macar i and R. D. Ri char dson.

Summar y

Ther e ar e l andf i l l pr oj ec t s i n exi s t ence t oday t hat have exper i encedunaccept abl e mai nt enance cost s on t hei r spar k- i gni t ed engi nes. I n many cases ,t hese cost s wer e t hought t o be t he r esul t o f I t badt t a s , but t he pr oj ec tmanager di d not have t he t echni cal r esour ces t o under st and why a gas was t t bad' rand cont r ol hi s cost s. Now, however , we have devel oped t he t echni calr esour ces t o not onl y pr edi ct t hese pr obl ems but corr ect t hem and cont r ol t hecos t s .amount o f cor r os i on i t coul d cause i n an engi ne. W t h thi s t es t dat a , i t c annow be det er m ned what causes a good gas t o become " bad" and make t henecessar y changes i n t he engi ne t o r esi s t t he cor r osi on. The r esul t has beent he devel opment of mai nt enance schedul es f or l andf i l l engi nes whi ch pr otect syour i nvest ment t hr ough cont r ol l ed cost s and al l ows t he pr oj ect managers t ohave a successf ul power generat i on pr oj ect .

Thi s pr i mar i l y i s a t es t f or t he gas whi ch det er m nes the re l at i ve

KCEC358. REP


3/9

Attachment A

Caterpillar Landfill Engine InstallationsDate/ODerator

1983 United Enviromental Services, Inc.

1983 Town of Brattleboro

1984 H. 0 . Penn Machinery

1984 H. 0. Penn Machinery

1984 Methane Development Corporation

1984 Norton Landfill

1984 Wayne Disposal


1984 Waste Management, Inc.


1985 Cleveland Bros.

1985 Maryland Recovery

1986 Garden Festival Site

1986 Waste Management

1986 OBrien Energy

1987 OBrien Energy

1987 Steinigand

1987 Ringpower Corp.

1988 OBrien Energy

1988 Energy Tachtics

1988 Blue Circle Landfll



1989. Blue Circle Landfill

*Under Construction

Location

Smithtown, NY

Brattleboro, V T

Brookhaven, NY

Huntington, NY

Babylon, NY

Broadview Heights, OH

Wayne, MI

Riverhead, NY

Calument City. IL

Depfford Township, N J

Enola. PA

Baltimore City. MD .

Liverpool. UK

Littleton, CO

Philidelphia. PA

Duarte, C A

Switzerland

Jacksonville, FL

Taylor, PA

Smithtown. NY

Kent, UK

Henrietta, NY

E. Peorla, IL

Kent, UK

EauiDment

1 G399 TA Generator Set

4-3306 SINA Generator Set

5-G399 TA Generator Set


3-3306 SITA Generator Set

1-3306 SINA Generator Set

4-C398 NA Generator Set

1-G399 TA Generator Se t

1-3306 SINA Blower

4 4 3 9 9 TA Generator Set

2-3306 SITA Generator Se t

1-3306 SINA Blower


1-3516

SITA Generator Se t

343398 TA Generator Set

4-G398 TALE Generator Set

1 G398 TALE Generator Set



2-G399 TA Generatoe Set



2-3516 SITA Generator Se t

2-3516 SITA Generator S et

Power

600 kW

3 20 kW

3000 kW

1800 kW

450 kW

100 kW

1300 kW

600 kW

135 hp

2400 kW

300 kW

135 hp

940 kW

800 kW

1350 kW

1800 kW

40 5 kW

800 kW

1800 kW

1200 kW

1330 kW

3200 kW

1600 kW

1330 kW


4/9

At t achment B

L andf i l l Gas Di sc us s i on

1. Met hane Concent r at i on

The met hane concent r at i on i n l andf i l l gas var i es f r om 45% t o 60% Theaddi t i onal gases ar e CO whi ch var i es f r om 37- 50% some N and a maxi mumof 2% 0 . W t h car ef ul l andf i l l gas col l ec t i on management , a gas ofst abl e gt u cont ent wi t hi n t he r ange of 450- 550 Bt u/ cu f t can be obt ai ned.I t i s us ual l y bet t er t o have excess gas avai l abl e f or an engi ne r at hert han t oo l i t t l e. Operat ors who t r y to ext r act t he maxi mum amount of gasf r om a l andf i l l c an dr aw on t he f i el d t oo har d and have ai r i nt r us i oni nt o t he f i el d. Thi s r esul t s i n l ow or er r at i c met hane l evel andr esul t i ng engi ne oper at i onal pr obl ems.r un on gas wi t h l ower t han 400 Bt u/ cu f t , addi t i onal mai nt enance andoper at i onal expense i s i nvol ved. For bes t r esul t s , Cat er pi l l ar does notr ecommend oper at i on on f uel gases wi t h l ess t han 400 Bt u/ cu f t .

2 2

Al t hough engi nes can be made t o

2. Fuel Sueci f i cat i ons and Consumpt i on Rat es

The f uel spec i f i c at i ons f or Cat er p i l l ar SI Engi nes oper at i ng on l andf i l lgas are gi ven i n At t achment C. The f uel consumpt i on i s dependent upont he NO em ss i on l evel r equi r ed as shown bel ow. Landf i l l gas i s a s l owbur ni ng f uel because of t he hi gh l evel s of car bon di oxi de.l evel s r equi r e a l ean a i r - f ue l r at i o whi ch al so s l ows t he combus t i onr at e . A combi nat i on o f bot h of t hese f ac to r s r esul t i n an i nc rease i nf uel consumpt i on as t he NOx l evel s decr ease.

Lower NO x

3516 SI TA @ 800 k W, 1200 r pmFuel Consumpt i on CF/D

NO Level n/ bhu- h ( 512 Bt u/ cu f t )52

1. 5

392, 100400, 100408, 100

As seen f r om t he l i s t o f s i t es on At t achment A , t her e ar e ot her modelCat er pi l l ar Spar k- I gni t ed Engi nes i n s uc ces s f ul l andf i l l appl i c at i ons .They i ncl ude gener at ors , bl owers , pumps, and gas compr essor s. For si t est hat r equi r e smal l er g ener a t or uni t s , t he f ol l owi ng l i s t gi ves r at i ngsand f ue l consumpt i on f or uni t s equi pped f or opera t i on on l andf i l l gas:

Model Rat i ng Est i mat ed Fuel Cons umt i on i n c u f t Per Day

3306 SI NA 92 k W3306 SI T 125 kW3408 SI TA 290 kW3412 SI TA 430 kW

3. Cont am nant s

53, 11267, 000

160, 000240, 000

The l ow Bt u f ue l s , such as l andf i l l and di ges t er gas , can r out i nel ycont ai n cor r os i ve el ement s , wat er vapor, and sol i d par t i cul at es . Al l of


5/9


6/9

- 3 -

chl or i ne and f l uor i ne t hat ar e r el eased dur i ng the combust i onpr ocess f orm hydr ochl or i c aci d ( HCL) and the hydr of l uor i c ac i d ( HF).Bot h of t hese aci ds are ver y cor r osi ve t o i nt ernal engi ne component sand can r esul t i n accel er ated r i ng and l i ner wear and exhaust val vest em and gui de wear .

Ther e ar e over 200 di f f er ent compounds i dent i f i ed i n l andf i l l g a s .A l i s t of t he t op 25 compounds t hat cont ai n chl or i ne and f l uor i ne i sgi ven i n Tabl e A. The pr i mar y sour ces of t hese chl or i na ted or gani chydr ocar bons and chl or of l uor ocar bons are i ndust r i al and househol dsol vent s such as pai nt t hi nner s and degr easer s . Addi t i onal sour cesf or chl or of l uorocar bons ar e f r eons f r om ol d aer osol cans ,r ef r i ger at o r s , and ai r condi t i oner s . Ver y f ew of t he hal ogenat edhydr ocar bons ar e f or med f r om t he decomposi t i on of pl ast i cs and otherpet r ol eum based mat e r i al s .

The vol at i l e hydr ocar bons are heavi er mol ecul es t han t he met hane andCO and t end t o r emai n i n t he l andf i l l unt i l t he l andf i l l gas i s

c ol l ec t e d.o f t he vol at i l e hydr ocar bon i s no l onger sa t ur at ed. Addi t i onalvol at i l e hydr ocar bons ar e evaporat ed i nt o t he movi ng gas st r eamunt i l t hey are depl e t ed. Measur ement s f r ompr oduci ng l andf i l l si ndi cat e t he vol at i l e hydr ocar bons dr op t o 10- 25% of t hei r o r i gi nall evel s af t e r one or t wo years of gas pr oduct i on.

Onc e t he gas i s dr awn f r om t he f i l l , t he l oc al i z ed ar ea

C. Measur ement of Hal i des

The PPMV met hod commonl y used t o measur e t he hal i des i n t he f uel i sno t appr opr i at e t o det er m ne t he ef f ec t o f t he chl o r i ne and f l uor i neon the engi ne, The r eason i s each mol ecul e of gas occupi es t he samevol ume. Even t hough a gas mol ecul e may have a consi der abl e

di f f erent mol ecul ar wei ght or mass, i t s vol ume i s t he same.Consi der t he f ol l owi ng exampl es:

1. One mol ecul e of vi nyl chl or i de f ormul a C H CL cont ai ns one2 3chl or i ne a tom per mol ecul e .

2. Consi der one mol ecul e of perchl oroethene , f ormul a C H CL2 3 5 cont a i ns 5 chl or i ne at oms per mol ecul e.

3 . One mol ecul e of t r i chl oro t r i f l uor oet hane (Freon 1 1 3 ) has af ormul a C CL F- C CL F and cont ai ns t hr ee chl or i ne and t hr eef l uor i ne f or a t ot al o f s i x c or r os i ve at oms .

2

As seen i n t he above exampl es, one PPMV of per chl or oet hene has f i vet i mes t he chl or i ne of vi nyl chl or i de and Fr eon 113 has si x t i mes t hec or r os i ve l evel s of v i nyl c hl or i de.di f f er ences i n chl o r i ne l evel and f l uor i ne per mol ecul e, t he l evelof hal i des i s gi ven i n m cr ogr ams of chl or i ne and f l uor i ne/ Bt u o fgas.

To account f or t hese

Each of t he chl or i nat ed hydr ocar bon and chl or of l uor ocar bon gases arei n r el at i vel y l ow c onc ent r at i ons wi t hi n t he l andf i l l gas .because of t he var yi ng number s of compounds and t hei r cumul at i ve

However ,


7/9

- 4 -

.

e f f e c t , t he l evel of chl or i ne can be consi derabl e. Ther e i scur r ent l y no st andard t est among l andf i l l operat ors f or measuri ngt he chl ori nat ed hydr ocar bons and chl orof l uorocar bons. The t estwhi ch i s most wi del y used i s t he EPA624 t est f or vol at i l ehydr ocar bons. Thi s i s an EPA wat er st andar ds t est whi ch has beenadapt ed f or measur i ng gases. The EPA624 t es t i s accept abl e f ordet er m ni ng t he chl or i ne l evel pr ovi ded t he m ni mum t hr eshol d ofdet ect abi l i t y i s 5 PPMV.

The EPA624 t est i s expensi ve at appr oxi mat el y $1, 000 U. S. , and t her e sul t s can var y consi der abl y f r om l abor at or y t o l abor at or y.Cater pi l l ar has devel oped a l abor at or y t est f or measur i ng t he l evel sof chl or i ne wi t hi n a sampl e of l andf i l l gas . Thi s t est measur es them cr ogr ams of chl or i ne per l i t er of gas by f i r s t deposi t i ng a sampl eof t he gas i n t he test equi pment . The sampl e, i ncl udi ng t hehal ogenat ed or gani c c ompounds, i s oxi di zed i n a COatmosphere. The hydr ogen hal i de by- pr oduct of t he pyrol ysi s i smeasur ed el ec t r i cal l y us i ng m crocoul omet r i c t i t r at i on. Theaccur acy of t hi s equi pment i s 2 0 . 0 0 2 % , not i nc l udi ng i naccur acyi nt r oduced at t he sampl e wi t hdr awi ng and deposi t i ng. To obt ai nf ur t her i nf ormati on r egardi ng t hi s t ot al organi c hal i de measur ement ,cont act :

and O22

Cor e Labor at or i es , I nc .At t ent i on: Gas Anal ysi s Chem st1300 Sout h Pot omac St r eet , Sui t e 130Aur or a, CO 80012Tel ephone: ( 303) 751- 1780

C. Aci ds

Low Bt u f uel gasesi n t hei r nor mal s t at e ar e usual l y sa tura t ed wi t h

wat er vapor . Thi s wat er vapor combi nes wi t h or gani c compounds tof orm organi c aci ds as wel l as carboni c ac i d because of t he hi ghconcent r at i ons of CO Thi s wat er vapor can have a PH f r om t wo t osi x and can be very cor r osi ve t o t he gas handl i ng equi pment as wel las t he engi ne. To el i m nat e t hi s cor r osi on caused by ac i d i n t hegas, i t i s r ecommended t hat t he moi st ur e cont ent be r educed t o115 l b of wat er oper MMSCF of gas. The gas shoul d t hen be heat ed t oa m ni mum of 60 F i n or der t o pr event any r ecur r ence of f r ee wat er.

2'

D. Sol i d Par t i cul at e Mat t er

Dependi ng upon t he l andf i l l cover mater i a l , t he c l i mat e , and t he

vel oc i t y of t he gas wi t hi n t he f i l l , s i gni f i c ant l evel s o fm c r o sc opi c s i l i c a c an be car r i ed wi t h t he gas . Ge ne r a l l y, t hi ss i l i c a i s l es s t han f i ve m c r ons i n s i z e wi t h s i gni f i c ant l evel sl ess t han one m cron. The par t i c l es ar e gener al l y too smal l tocause s i gni f i cant abr asi ve wear wi t hi n the engi ne; however , i f t hes i l i ca par t i c l es ar e i n hi gh enough dens i t y, t hey can coagul at e i nt he combust i on pr ocess and f or m l ar ger par t i c l es .par t i c l es can r esul t i n abr asi ve wear of t he exhaust val ve f ace andval ve s eat . The c oagul at ed s i l i c a par t i c l es c an al so f or mi ndent at i ons on t he exhaust val ve f ace and seat i f t hey become

These l ar ger


8/9

- 5 -

t r apped bet ween t hose sur f aces dur i ng val ve cl osure.i ndent at i ons or pi t t i ng o f t he val ve f ace and seat may r esul t i nevent ual l eakage and bur ni ng of t he val ve.

These

E. Removal of Par t i cul ates

F i l t r at i on i s r ecommended t o cont r ol t he s i l i ca.ef f ec t i veness of one m cr on- s i zed par t i c l es and l ar ger and 98%ef f i c i ency of par t i c l es 0 . 4 m cr ons and l ar ger ar e r ecommended.Even wi t h t hi s f i l t r at i on equi pment , o n s ome l andf i l l s s i gni f i c antamount s of s i l i c a c an s t i l l ent er t he engi ne. The l evel s of s i l i caar e det ect ed i n t he oi l anal ys i s r e sul t s . Si l i c a l evel s up t o 100par t s m l l i on ar e not i nf r equent and can be t ol er at ed pr ovi ded t heyar e l ess t han one m cr o and do not cause any exhaust val ve f ace wearor bur ni ng.

Fi l t er s wi t h 100%

KCC167. EDS

Table A

IFORMULA IMOEW T. ICIAToMS I%Cl B Y WT . IFAToMSI%F B Y M.1


9/9

At t achment C

Cat er pi l l ar Landf i l l Fuel Gas Spec i f i c at i ons

Lower heat val ue:

4 0 0 - 5 5 0 Bt U( LHV) / SCFMaxi mum var i at i on + 2% f rom set poi nt r equi r ed to mai nt ai n em ss i onl evel .

-

Tr ace amount s of ot her hydr ocarbons, hal ogenat ed hydr ocar bons, and s u l f u rcompounds may al so be present . The engi ne can t ol erat e t he l evel s l i st edbel ow wi t h t he appr opr i at e mai nt enance schedul e.

L i m t :

Sul f ur 47. 5 ug/ Bt uChl ori ne andFl uor i ne 40 ug/ Bt u

A gas cl ean up syst emmay be r equi r ed i f val ues exceed t hese l i m t s;c ons ul t Cat er pi l l ar f or t ec hni c al as s i s t anc e.

Lab resul t s ar e f r equent l y r epor t ed i n ug/ L.t he f ol l owi ng exampl e: C 1 = 160 ug/ L ( Lab Resul t s)

To cal cul at e ug/ Bt u, use

Fuel Gas Sampl e LHV = 535 Bt u/ SCF

X SCF - 8 . 5 ug/ Bt u8 . 3 LSCF 535 Bt u60 xSuppl y press ure t o engi ne:

Low pr essur e f uel ar r angement s:

6 51 i n H 0 gauge at r at ed f l ow t o m xer body, t he st andard r egul at or ssuppl i ed wi t h engi ne wi l l mai nt ai n t hese condi t i ons wi t h 2 psi g suppl ypressure.t emper at ur e.

2

Temper at ur e cont r ol l ed t o 20F +F above combust i on ai r

Hi gh press ure f uel arr angement s:

50 psi a, t emper at ure 60- 120F at engi ne wi t h no mor e t han 20Ft ot a l f l uct uat i on.

Moi st ur e cont ent :

115 l bs/ MMSCF

Oi l cont ent :

2 . 5 l b/ MMSCF of gas - maxi mum

Par t i c ul at es :

No mor e t han 0 . 0 0 0 5 l b/ MMSCF of 80 m c r on s i z e or s mal l er par t i c l es

Revi sed 8 - 1 6 - 8 9

application of caterdillar spark-ignited enrzines for landfill gas

Documents