35 4 WASHINGTON DC 08-90-1418-Lime Injection

8/2/2019 35 4 WASHINGTON DC 08-90-1418-Lime Injection

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HIGH-SURFACE-AREA HYDRATED LIME FORSo, CONTROL

M. Rostam-Abadi, D. L. Moran, I l l i n o i s St a te Geolog ical Survey, Champaign,I 1V. P. Roman, R -C Environmental Servic es and Technologies , I r v i ne , CA

H. Yoon and J . A. Withum, C on so li da ti on Coal Company, Li b ra ry ,PA

KEYWORDS: SO, r em o va l, h y d r a t e d l i m e , d r y s o rb e n t i n j e c t i o n

INTROWCTION

F o r many s i t e s p e c i f i c a p p l i c a t i o n s , d r y s o rb e nt i n j e c t i o n t e c hn o lo g i es o f f e ra dv an ta ge s o v e r t h e we t f l u e ga s d e s u l f u r i z a t i o n sy ste ms f o r c o n t r o l l i n g t h e e m i s si on so f SO produced du r in g combust ion o f h igh s u l f u r coa l . These po te n t i a l advan tagesi n c l u s e ea se o f r e t r o f i t , d r y w as te , and l o w e r c a p i t a l i nv es tm e nt . The t e c h n o l og i e sth a t have been resea rched cons ide rab ly i n r ecen t yea r s in c lud e fu rnace so rben ti n j e c t i o n ( FS I ), b o i l e r e co no miz er i n j e c t i o n , and p o s t f u rn a c e d u c t -injection/humidification (Coo l side ). The main fa c t o r which d i s t i ngu i she s the d ryp ro ce ss es i s t h a t a calciu m-ba se d s or be nt i s i n j e c t e d i n t o d i f f e r e n t l o c a t i o n s w i t h i na pu lv e r i z ed coa l bo i l e r un i t . I n th e FSI, l imes tone (CaCO,) o r hydrated l i m e(Ca(OH),) i s in je c te d i n t o the upper furnace c a v i ty where temperatures range f rom1800-2ZOO'F. The sorb ent i s r a p id ly ca lc i ne d form ing CaO which rea ct s w i t hSO t o f o r mCaSO,. I n t h e b o i l e r economizer p rocess , Ca(OH), i s in je c t ed i n a lo ca t i on betweenthesuperhea te r and a i r p rehea te r where the t empera tu re i s i n the r ange o f 800-12OO'F.C o o ls i de d e s u l f u r i z a t i o n i n v o l v e s Ca(OH), i n j e c t i o n i n t h e d u c t w or k do wns tre am o fth $a i r p r e h e a t e r a t a bo ut 300'F f o l l o w e d b y f l u e ga s h u m i d i f i c a t i o n w i t h a w a te r s p ra y.SO, i s re mov ed b y t h e e n t r a i n e d s o rb e n t p a r t i c l e s i n t h e d u c t w ork a nd by t h e d en ses o rb en t bed c o l l e c t e d i n t h e p a r t i c u l a t e r em ov al system. U n li k e th e FSI where CaSO,i s formed, under b o i l e r economizer and Coo ls ide co nd i t io ns CaSO, i s the major product .

Bench- and p i lo t - sca le t e s t s have shown tha t typ ica l SO, c a p tu r e e f f i c i e n c i e s u n de r F S Ic o n d i t i o n s a r e a b o u t 35 and 55% f o r CaCO and com me rcii 1 Ca(0H), e ~ p e c t i v e l y , ~ , ~nd30-50% w it h commercial Ca(0H) under b o i l e r economizer and Cooqside con di t ions 6 ( a l la t Ca/S r a t i o o f 2). I n some t o o l s i d e p ro c e s s p i l o t t e s t s , an a d d i t i v e su ch a s so diu mh y d ro x id e o r s o di um c a rb o n at e h as be$; p j e c t e d w i t h t h e h u m i d i f i c a t i o n w a te r r e s u l t i n gi n SO removal o f about 70 t o 80%. Because these SO, removal l e v e l s c o r re s po n d

t o l e ss t h an 50% o f t h e t h e o r e t i c a l s a t u r a t i o n c a p a c i t y f o r th e s or be nt s, a m a j o ro b j e c t i v e o f r e se a r ch i n t h e r e c e n t ye ar s h as been t o i d e n t i f y s o rb en t p r o p e r t i e s t h a tr e s u l t i n e nhanced SO cap tu re i n o rde r t o r educe ope ra t in g cos t s and the amount o fwaste products . I n + S I s tudie s , the s u p e r j o r i ty o f Ca(OH), over CaCO, has b ena t t r i b u t e d t o t h e s m a l le r mean p a r t i c l e s i f e , higher surface area and porosity', ' ,l a rg e r p ore s'a nd p l a t e - l i k e g r a i n s t r u c t u r e ' ( vs . s p h e r e - li k e ) o f t h e CaO d e r i v e d f r o mCa(OH), compared t o t h a t d e r iv e d from CaCO, I n b o i l e r economizer and Co ol si des tudies , improved SO, removal performance has a l so been rep or t ed f o r Ca(OH), w i t h h ig hp o r o s i t y, h i g h s u r f a c e a re a, and s m a ll p a r t i c l e s i z e . '* 5 *

This paper reviews recent work comparing the SO removal performance o f two commercialhydrated l imes and a h igh-surface-area ( H S X ) hydra ted l ime under F S I , b o i l e reconomizer, and Cools ide con d i t io ns . The p r op er t i e s o f the so rben t s and a d i sc uss iono f t h e r e s u l t s a r e p re se nt ed .

EXPERIMENTAL

Test Sorbents

The sorbents te s te d in cl ud ed a HSA hydra te and two commercial hydrated l i me s designa tedas A and 6. The HS A hydrate and commercial hydrate A were made from t h e same li m e .The HSA hydrated l i m e was prepared by a pr o p r i e ta ry hyd rat ion process developed a t t h e

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I l l i n o i s St a te Geologica l Survey. Three hundred pounds o f the sorbent was preparedus ing a bench-sca le hy dra to r capable o f p roduc ing seven pounds o f p roduc t s pe r ba tch .The HSA h yd ra te was n o t s ub je cte d t o a i r c l a s s i f i c a t i o n o r m i l l i n g p r i o r t o b e in gt e s te d f o r s u l f u r rem oval e f f i c i e n c y.

Chemical composi t ions o f sorbe nts were determined by X-ray f luorescence. Surfac e areaswere obta ined by N,-adsorption i n co nju nct ion wi th the one p oi nt BET method. Pore

volumes and pore s iz e d is t r ib u t i o n s (pores sm al ler than 0.25 micrometers) weredetermined by ni t ro ge n porosimetry. Sorbent p a r t i c l e s i ze analyses were performed ona Micro mer i t i c s sed ig raph 5100 us in g Micr ome r i t i c s d i spe r san t . HydrateA and the HSAhydra te were examined by X-ray d i f f r a c t io n (XRO) and the data were used ford e te r m in a ti o n o f c r y s t a l l i t e s i z e u s i n g t h e S c he rr er e qu at io n. "

P i l o t - S c a l e SO, Removal Tests

F S I t e s t s - These exper iments were performed i n th e Inn ova t ive Furnace Reactor ( IFR)loca ted a& the U. S. Environmental P ro te ct io n Agency, Research Tr ia ng le Park, N orthC a r ol in a . F SI t e s t s were p er fo rm e d b u rn i ng f o u r I l l i n o i s c o a l s f ro m t h e I l l i n o i s 0Ba sin Coal (IBC ) Sample Program.-102, -106 and -109 ar e pre sen ted i n t a b l e 1.

Te s ti n g i n t h e IF R c o n s i s t e d o f d e te r m in i ng t h e SO, c o n ce n tr a ti o n i n t h e f l u e g asd u r i n g so rb en t i n j e c t i o n w h i l e bu r ni n g each o f t h e co a ls a t f ee d r a t e s s u f f i c i e n t t oy i e l d a thermal r a t i n g o f approximately 14 kW. The te s t s were conducted wi th HSAhydrate and hydrate A a t Ca/S ra t i os o f approximate ly 1:l and 2 : l and a t a temperatureo f 2192'F.13 The d e t a i l s o f t e s t p rocedures and a de sc r ip t io n o f the IFR a re g ivene lsewhere.

B oi l e r economizer t e s t s - The Research-Cottrell Environmental Services andTechnologies (R-C EST) 15 0 kw p i l o t - s c a l e f u r n ac e l o c a t e d i n I r v i n e , C a l i f o r n i a wasused fo r b o i l e r economizer te s t s . The exper iments were conducted a t asnominal in pu tr a t e o f 7 5 kw. The furnacei s f i r e d on n a t u r a l gas and SO, i s a dded a t t h e p r o p e r c o n c e nt r a ti o n . A t i m e -t em p er at ur e h i s t o r y r e p r e s e n t a ti v e o f a u t i l i t y b o i l e r b ackpass i s g en er at ed b y u s in gthe upper sec t i on o f the fu rnace t o r educe the f lu e gas t empera tu re t o approximate ly

1300'F. The gas temp eratu re i s then decreased from 1300 t o 8OO'F i n approx imate ly 0.5seconds i n th e se c t ion o f the fu rnace where convec t ive tube banks a re loca t ed . Thef l u e gas i s c o n t in u o u s l y a na ly ze d f o r oxygen, s u l f u r d i o x i d e and c ar bo n d i o x i d e u s i n gt h e R-C EST continuous emissions monitor (CEM).

The t e s t p rogram invo lved t e s t ing HS A hydrate and hydrate A a t i n j e c t i o n t e mp er at ur eso f 900, 1000 and llOO'F, a Ca/S r a t i o o f2, and SO c o n c e n tr a t io n s o f 500 and 3000 ppm.The f lu e gas composi t ion was t y p i c a l l y4.0% 0 6.8% CO and 50 ppm CO.

C o o l s i d e t e s t s - These t e s t s w ere c on du ct ed i n a 100 kW p i l o t u n i t l o c a t e d i n t h eResearch and Development Department o f t h e Consol i d a t i o n Cfal Company, Li br ar y,Pennsylvania. The C o o l s id e p i l o t p l a n t i s d e s c r ib e d e ls ew he re . B r i e f l y, t h e ex ha us tf ro m a n a t u r a l gas b u r n e r i s mi xe d w i t h r e c y c l e ga s, i n t o w h ic hCO , SO N steam andf l y ash a r e i n j e c t e d t o p ro du ce th e s i m u la t ed f l u e gas f ro m a c o a f - f i r e d b o i l e r. Theh u m i d i f ie r i s an 8 . 3 - i n ch I O down-f low duc t i n s t a l l e d w i t h a wa te r- sp ray nozzle , andi s 20 f e e t l o n g fr om t h e n o z zl e l o c a t i o nt o t h e e x i t . The gas e x i t i n g t h e h u m i d i f i e renters a baghouse which separates th e so l i ds f rom the gas. The gas i s fu r t h e r cooledand dehum idif ied i n a condenser, and the process f an recy cle s most o f the f l u e gas f o rreuse. SO, removal i s ca lc ul a t ed f rom measurements o f SO, and 0, ana lyze r s a t t h eh u m i d i f i e r i n l e t and e x i t , and t h e bagh ouse e x i t .

The ana lyses o f the coa l s id en t i f i ed as IBC-101 ,

A d e t a i l e d d e s c r i p t i o n o f t h e u n i t i s g i v en else wh ere.

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HSA hydrated lime and hydrateB were teste d a t Ca/S ra t i o s of 0.5t o 2.0 and 25'Fapproach t o adia ba tic sa tur at i on temperature. The cond it ions selected represents tandard p i l o t p lant te s ts fo r evaluat ing a new sorbent t o provideSO, removal data attypical Coolside in-du ct in jec t io n operat ing condit ions.T h e common conditions were300'F in le t flu e gas temperature,1500 ppm i n l e t SO, con tent (dry b as is ), and 125'Fadia bati c sa tu ra tio n temperature. The flu e gas flow r a te was s e t a t 175 scfm, whichprovided a 2.0 sec humidifier residence time.

RESULTSAND DISCUSSIONTest Sorbents

The chemical and physical properties of hydratesA and B, the HSA hydrate and limeA(from which hydrateA and th e HSA hydrate were made) a re pres ented in ta b le2 . In theFSI and b oi le r economizer systems, the HSA hydrated lime was te st ed aga inst th e hydrateA . However, in t h e Coolside te s ts , HSA hydrate was tes te d ag ains t hydrateB , s incethis material has been shown to be the best-performing commercial sorbent underCoolside con dit ions .

Chemical analy ses of hydrated limes in di ca te th at the s orb ents contained over 96w t %CaO a f t e r ashin g. The mass mean diam eters and sur fa ce ar ea s of th e HSA hydrated 1 mesvaried between 1.6 and2 .7 micrometers and 35t o 44 m2/g (ex cep t f o r one batch which

was 31 m2/g), respectively, dependingon the hydration batch. These samples, however,had su rfa ce ar ea s well above th e 20-23 m2/g su rfa ce a re ty pi ca l f o r commercialhy gra tes . The po re volume of th eHSA hy dr ate was 0.35 c$/g comparedt o only 0 .08cm/g fo r i t s commercial counterpart . TheXR D re su lt s showed th at th e HSA hydrate hadsma ller Ca(OH), gr ai n s iz e and lower c r y s t a l l i n i t i e s when compared t o commercialmateri a1.Pilot-Scale SO, Removal Tests

- The re su l t s fo r FSI te s ts a re presented in tab le 3 .The average baselineSO concentrations under the test conditions were 3140ppm f o r IBC-101, 2410ppm f o r ,IBE-102, 2890 pprn for IBC-106 and 1000ppm for IBC-109. The tre nd in th eSO ,concentrat ion i s consis tent wi th the to ta l su l fu r content of the co als repor ted intable 1 . Figure 1 shows the estimatedSO removal percentages a t Ca/S r a t i o of2. The

values were ca lcu lat ed by ext rap ol ati ng q in ea rl y from th e mean removalsa t both Ca/Sr a t i o s r u n for each coal/sorbent combination. For each coal tested, HSA hydrateremoved more SO than i t s comnercial counterpart . SO, removal obs erve d with th e HSAhydrate ranged from 72 t o 77% fo r th e co als te st ed (excluding IBC-102) comparedt o 55t o 66% for hydra te A.

The SO, capture levels for the IBC-102 coal were only 57 and42% with the HSA andcommercial hyd rates, re sp ectiv ely . The sub stan tial dec rease inSO, capture by theso rben ts f o r this coal could be relatedt o i t s h igher py r i t i c su l fu r con ten t than f o rthe other co als test ed . The pyri t ic/o rganic su lfu r ra t i o fo r IBC-102 was 2.3: lcompared to values less than1:l fo r the other coals . One explanation th a t could beoffered i s t h a t a major fract ion of the organic su l fur in coalsi s re leased as H,S i nthe in i t ia l s ta ge s of the combustion and i s rapidly captured by the fresh sorbent . TheSO, release d by th e oxidation of th e pyri te , which fol lows the pyro lysis s tag e, thenreacts wit) the p ar t i al ly u t i l iz ed sorbent a t a much slower ra te comparedt o th e H,Sreactio n. Therefore, su lf ur captu re by th e sorb ent i s lowered when coal with a highconcent ra t ion of py r i t i c su l fur i s burned. This sugges ts tha tFSI i s most ben ef ic ia lfo r coa l s t h a t are high in organic sulfur which cannot be removedby physical coalcleaning.

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The enhanced performance o f the HSA hydrate could be related t o its smaller particlesize and higher initial surface area. Laboratory test s conducted under FSI conditionsat 2012'F with CaO derived from Ca(OH), have reveal ed that t he CaO conyersio n to CaSO,is inversely related to particle diameter to the 0.2 to 0.35 po we r. In a recentstudy, however, the initial sulfation rate o f CaO (7 to 100 micrometers) derived fromseveral limestones and dolomites varied roughly inversely with th e particle size,indicating pore diffusion was the rate controlling step under these test conditions(1650.F). Based on th e data obtained in thi s work, SO, capture was inversely relatedto particle size to the 0.44 power (for captu re values estimated at Ca/S ratios of 1

and 2).

The higher SO, capture of the HSA hydrate can also be attributed in part to itsfavorable pore structure. Pore volume analyses of raw sorbents, shown in figure 2,indicate the volume o f pores between 0.01 and 0.1 micrometers (10 and 100 nm) issubstantially higher for th e HSA hydrate than for hydrate A. Pore volumes of hydratedlimes are expected to correlate with pore volumes of the corresponding calcines. Dueto the increase in molar volumes when converting from CaO to CaSO, (16.9 vs 46.0cn?/mole), por e plu ggi ng is kno wn, to limit t h e sul fati on reaction. The ref ore, sorbent swith a high volume of larger pores are expected to capture more SO,.

Boiler economizer test s - The results o f these experiments are shown in figure 3. Th eHSA hydrate showed significantly greater SO removals than hydrate A at all testconditions. The SO reduction achieved with t he HSA hydrate at 30 00 ppm SO and Ca/So f 2 wa s 58% at 9002F, 57% at 1OOO'F and 52% at 11OO'F compared to only 326, 30% and28% for the comnercial hydrate. At 500 ppm SO, and Ca/S ra tio of 2, the average SO,removals for hydrate A and t he HSA hydrate were 6.1 an d 17%, respectively (an increaseof 180%). The SO, removals observed for the HSA hydrate were also higher than forother comnercial hydrates examined under simil ar test conditions.

The superior perform ance o f the HSA hydrate observed in thi s study is attrib uted, inpart, to its high surface area and small particle size. The role of surface area andparticle size can be explained in terms of tw o competing reactions under boilereconomizer conditions,

Ca(OH), + SO, - - - - > CaS03 + H,OCa(OH), + COz - - - - > C a C q + H,O

(1)( 2 )

The intrinsic rates (which are related to pore surface area of sorbent) of reactions(1 ) and (2) are very fast even at 9OO'F. However, because of the low concentration ofSO, in the flue gas, rea cti pl (1) is control led by bulk diffusion of SO, for particleslarger than 5 micrometers ' (diffus ion rat e for spherical particl es is inverselyrelated to particle size to the second power), whereas reaction (2) is controlled byintrinsic rate. As a result, the relativ e rates for the reactio n of CaSO, and CaCO,depend both on pore surface area and particle size o f the sorbent. Increasing poresurface area would favor the carbonation reaction if particle diameter is heldconstant. Decrea sing partic le size and holding pore surfac e area consta nt would favordesulfurization reaction. Therefore, a sorbent with high pore surface area and smallparticle size would be expected t o show high SO, removal efficiency under boilereconomizer conditions. The average increase in sulfur capture observed for the twosorbents at 3 000 ppm SO, and Ca/S ratio of 2 was 83%. which corresponds approximatelyto the diffe rence in surface areas. However, at 500 ppm SO, and Ca/S ratio of 2, SO,captures wer e inversely related to particle diameter to the second power, indicatingbulk diffusion limitation under these test conditions.

coolside test s - Three different batches of HSA hydrate were examined in the Coolsidepilot unit. The surfa ce areas of the samples tested at Ca/S ratio s of 0.54, 1. 1 and

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2.1 were 31, 34 and 39 m2/g, re sp ec ti ve ly . Fig ure 4 shows th e e f f e c t o f the Ca/S molarr a t i o on SO, removal a t 25'F approach t o sa t ur a t ion . The valu e shown f o r hydrate B a t2.1 Ca/S was obtained i n t h i s study. The removals shown f o r the same hydra te at 1.0and 1.5 Ca/S a re fro m Re fere nce 2. The HSA hydrated l ime showed higher SO, removalsthan the bes t -per form ing comnercia l hydrate . With th eHSA hydra te a t Ca/S ra t i os o f0.54, 1.1 and 2.1, t h e SO, rem ova ls were 15, 25 and 46% i n t h e h u m i d i f i e r a nd 18, 33and 56% a cr os s t h e e n t i r e sy ste m ( h u m i d i f i e r t baghouse). Comparison o f th e data atCa/S of 2.1 i n d i c a t e t h a t t he HSA sorbe nt captu red 35% moreSO, t h a n h y d r a t e B i n t hehu mi di fi er and 15% more across t he e n t i r e system. The maximum perce nt calciu mu t i l i z a t i o n s f o r the HSA hydra te were 33.3, 31.7 and 26.3 as Ca/S r a t i o increased from0.54 t o 2.1.

Figure 4 shows a l inear SO, removal behavior a t th e Ca/S r a t io s tes te d. Normally, asi s e x h i b i t e d by h y d r at e B, a p l o t o f SO, removal vs Ca/S r a t i o i s curved because thee ff ec t d imin i shes a s the Ca/S r a t i o inc reases . The s t r a i g h t - l i n e b e ha v io r f o r t h eHS Ahydrate may be due t o th e sample s urface area va ri at io ns mentioned above.

The Cools ide da ta suggest th a t a ma jo r f r a c t io n o f the SO cap tu re occur red dur ing thetwo second reside nce t im e i n th e duct work. The high erSd, capture achieved by the HS Ahydra te i n the hu m id i f i e r sec t ion and across the en t i r e system suggest s h igher over a l la c t i v i t y o f t h e s o rb en t r e l a t i v e t o h yd ra te B.

SumARY AND CONCLUSIONSThe HS A hydrated l im e prepared by a pro pr i e t ary process had considerably high er surfacea re a and p o r o s i t y, s m a l l e r p a r t i c l e s i z e , and f i n e r C a(0H ) g r a i n s i z e t h an t y p i c a lco nn ne rc ia l h y d ra t e d l i m e . The r e s u l t s o f t h e p i l o t - s c a l e t e s t i n g u nd er F SI, b o i l e reconomizer, and Cools ide co nd i t ions - ind ica te tha t the HSA hyd rate d 1 me removed,depending on th e t e s t sys tem, 15-180% more SO, than the commercia l hydrated l imest e st e d u nd er s i m i l a r c o n d i t i o n s . The su per i or performance o f th e HS A hydrate wasa t t r i b u te d t o i t s f a vo r ab le p h ys ic a l p r o p e r t ie s .

ACKNOWLEDGMENTS

This work was funded i n pa r t by gran ts f rom th e I l l i n o i s Coal Development Board throughthe Center for Research on Su lf ur i n Coal . D r . B r i a n K . G u l l e t t o f t he U. S.Environmental P ro te ct io n Agency provide d theF S I data.

REFERENCES

For hydra te 8 a 23.2% u t i l i z a t i o n was obse rved a t Ca/S r a t i o o f 2 .1.

1. Bortz, S.J.; Roman, V. ; Offen, G. R. F i r s t Combined FGO and Orv SO, ControlSvmoosium. S t . Louis. MO. Oct. 25-28, 1988, Paper no. 10-7.

2. Yoon, H. ; S t o u f f e r , M. R.; Rosenhoover, W.A. ; Withum, J.A.,; Burke, F.P. Ena. Proa.1988, L(JJl 82-89.

3 . B e i t t e l , R.J.; Gooch, J.; Dismukes E . ; Muzio, L. Proc. S m . on D r SO and Simul.&&QX Control Technol. 1985, I., 16, EPA-600/0-85-020a ;NS PB85y232353).

4. Snow, G.C.; Lor ra in , J.M.; Rakes, S.L. Proc. Joint S m . on D r SO and Simul.&LN!lX Co ntr ol Technol. 1986, 1, 6-1, EPA-600/9-86-02& '(NTIS PBi7- l j0465) .

5. Bortz , S.J.; Roman, V.P. ; Yang, C.J.; Offen, G.R. Proc. Joint Svmo. on Orv S O , ASimul. SO,,&& Control Technol. 1986, 2, 31.

6. Withum, J.A.; Lancet, M.S.; Yoon, H. Paper presented a t th e AIChE 1989 Sprin g Na t.Mtg, Houston, Texas. 1989

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G u ll e tt , B.K.; Bruce, K.R. F i r s t Combined FGD and Drv SO, Control SvmDosium, S t .Louis. MO. Oct 25-28 1988, 6-7, EPA-600/9-89-0369(NTIS PB89-172159).

Newton, G.H.; Chen, S.L.; Kra mlich ,J.C. AIChE J, 1989, u, 88-994.

S t o u f f e r, M.R.; Yoon, H. AIChE J. 1989, 1253-1262.

lO.Bruce, K. R.; G u l l e t t . B.K.; Beach, L.O. AIChEJ . 1989, 37-41

l l .Yoon, H.; S t o u f f e r , M.R.; Rosenhoover, W.A.; S t a t n i c k , R.M. Proc. Second Pit tsburqhCoal Con ference . P it ts bu ra h. PA. Seot 16-18 1985, 223-242.

12.Klug, H.P.; Alexander, L.E. "X-ray D i f f r a c t i o n Procedures f o r Po lyc rys ta l1 ne and

1 3 . G u l l e t t , B.K.; Briden, F.E. U. S. Environ menta l Pr ot ec ti on Agency, AEERL, Research

14.Borgwardt. R.H.; Roache, N.F.; Bruce, K.R. h v i r o n . P roq. 1984 129.

Amorphous Mat er ia ls ," John Wi ley and Sons,Ne w York 1974, 657-659.

Tr iang le Pa rk , NC, 1989, 62 pages, EPA-600/2-89-065.

Table 1. Average analyses o f the coa ls (mols ture f re e values) .' .'

IBC-101 IBC-102 IBC-106 I BC-109M oi st u re 14.8 14.3 10.5 9.2Vol M at te r 40.7 39.9 39.7 35.0Fi xe d Carbon 48.8 53.3 51.3 56.8H-T Ash 10.5 6.8 9.0 8.2

Carbon 69.30 74.10 71.86 75.05Hyd rogen 5.18 5.32 4.93 4.89Ni t rogen 1 .31 1.50 1.67 1.74

Oxygen 9.31 8.92 8.76 8.53S u l f a t i c S u lf u r 0.05 0.06 0.01 0.00

Py/Or R a t io 0.40 2.30 0.98 0.80

P y r i t i c S ul fu r 1 .22 2.26 1.86 0 .50Organic S u lf u r 3.08 0.98 1.90 0.63

To ta l S u lf u r 4.36 3 .30 3.77 1.13To ta l Ch lor in e 0 .12 0 .02 0.02 0.42

B t u / l b 12659 13628 13226 13324

A l l values i n wtX except where notedAnalyses were performed by LECO analyze rs and are d i f f e r e n t th an thoseob tai ne d by th e ASTM methods and rep ort ed i n ref ere nc e 13.

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Table 2. P r o p e r ti e s o f t e s t s or be nt s

Ash Mean BET su rfa ce Pore C r y s t a l l i t e

Sorbent CaO MgO (micrometers) (m /g) (c d/ g) (angst roms)AnalYSes . fw t% l diameter area VOI ume' size

- _ - _ - -ime A 96.1 0.52 - - - 1.6HSA hydrate 96.5 1.20 2.02 38.0' 0.35 150Hydrate B 97.7 0.55 3.1 23.2

Hydrate A 99.0 0.57 3.5 20.6 0.08 220

- - - _ - _

' Pores smal ler than 0.25 micrometers.The v al u e i s an average. The range was 1.6 t o 2.7 micrometers.The v al u e i s an average. The range was 35 t o 44 m2/g.

Table 3 . Furnace Sorbent In je ct io n (FSI) data .'

Base1 n e SO, Removal RatioCoal Sorbents (PPm)

(% I Ca/S

IBC-101

IBC-102

IBC-106

IBC-109

Hydra te AHydrate AHSA hydrateHSA hydrate

Hydra te AHydra te AHSA hydrateHSA hydrate

Hydra te AHydra te -AHSA hydrateHSA hydrate

Hydra te AHydra te AHSA hydrateHSA hydrate

3161316131203120

2541254122882288

2918291828622862

10321032

960960

28.856.636.661.4

Q

25.642.132.850.3

36.563.759.878.7

40.852.7

47.180.6

0.851.700.791.58

0.881.750.851.70

1.102.211.072.14

0.921.84

1.162.32

' Data f rom re fe rence 13.

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80

0 .4

E:1

be- 7 0a,Ll

3 60a

50 -

--

Q,

x40

30 -z20

21 10 -

vl

-

-

W HSA h y d r a t e0 C o m m e r c i a l h y d r a t e A-

0Commercial hydrate A HSA hydrate

S o r b e n t t y p e

Figure 1 . Furnace sorbent injection pilot-plant data

h

bn

0t.Y

b)

Coals

IBC-IO1

IBC-102

IBC-106

IBC-109

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I HS A hydrate, 3000 ppm SO,= commercial hydrate, 3000 ppm SQ= HSA hydrate, 500 ppm SO2= commercial hydrate, 500 ppm SQ

7 0c

6 0

H 50

$ 40

h

1

40 t

- Humidifier System- 0 HSA hydrate

-0

-

1100 1000 900Temperature ( F )

Figure 3 . Boiler economizer pilot-plant data

N

v,0 20

10

-

- 1500 ppm Sq2 5 T Approach to Adiabatic Saturation Temperature

a I I I I I

1426

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35 4 WASHINGTON DC 08-90-1418-Lime Injection