the coking properties of coal at elevated pressures. - Argonne ...

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2. 'The density 01' the coke produced I'roln thc studied coals depends little on the hydrogen partial pressure. IiOWeVer, a slight increase in density with increased hydrogen pressure is seen for the high fluidity coals. 3. As cx1,ected increased gob contents lead to increased particle densi ties. 4. The atidition of 10 WC % tar to low fluidity coals did not have any effect on the density of Lhe c.oke. IloWeVCr, the Same addition to medium fluidity coals doped with 10% gob caused the coke density to increase significant,ly. A slight increase is observed for two of the three high fluidity coals (EPI11 and Westland) while a decrease was found for the Noblc County coal. Interestingly, his rather complex picture of coke strength and density may, as appears to be the case for the fluidity and swclling data, be explainable in terms of a few petrographic parameters. More data on different coals will show just how good a correlation can be obtained. Yield data were collected for cach 01 the over 100 coker runs in this program, llowever, as mentioned earlier thc majority 01 these data arc of little value. Only the data obtained with clean coal samples give useful yield data. A summary of the yield data lrom the runs made at simulated gasifier conditions (i.e., 365 psia total pressure and 115 psia hydrogen pressure) on 1/4" x 12 mesh coal is g~ven in Table 10. These data arc based on the average measured coke, tal- and liquid yields for all runs at thcse COIldi~ionS for each coal (On a moisture and ash free basis), with the gas yield calculated by difference. In all eases the coke yield at simulated gasifier c.onditions of 365 psia total pressure and 115 psia hydrogen partial pressure is greater than the fixed carbon content determined for each coal at 1 atm (Table 1). This is not surprising since at elevated pressure the release of volatile components is retarded. ( 1 3 2 9 3 ) The slowing of volatile release allows more of this material to be converted 1.0 colic at the expense of liquid and/or gas yield. The yield data lor Frances coal, 'Table 11, where only clean coal was used, shows that both coke and gas yields are increased at the expense of the liquid yield in going from 1 atm N2 pressure to 365 psia of NZ. Here the coke yield increases from - GS$ to - 67.5% and the gas yield increases from - 25% to 29yo while the liquid yield decreases from - 10% to - 4%. Possibly liquid evolution repression can account for both the increased coke atid gas yields. If the liquid is held in the coal matrix some of it is coked and some is further converted to gas by the longer residence time at elevated temperatures thus rcdtrcing thc overnll liquid yicld and increasing 1.hc cokc and gas yields. A1 elevated hydrogen pressures (115 psia and 365 psia total pressure) the coke yield is about the same as when 365 psia of nitrogen is used, however, the liquid yield is greatly enhanced at the expense of the gas yield. Undoubtedly react.ion between the added hydrogen and the coal are responsible for the higher liquid yield. Figure 13 shows a comparison of produced gas composition with respect to CH4, co and & at various conditions. Since most of these data were obtained with coal doped with gob the results may not bc as 1.eliable as if only clean coal 10
was used, however, general trends are not expected to differ from those observed here. The methane content of the product gas is SO-lOO% higher than for the case with no added hydrogen while the hydrogen content of the product is considerably lower. Qualitatively this suggests that hydrogen evolved irom the coal escapes before it has time to react further wit.h 1.hc remaining coal matrix. The CO content of the product appears virtually unaCf‘ected by pressure and the addition 01 gob and/or tar has little or no cffect 011 the gas composition. CONCLUSIONS Thc experimental data presented herein should provide a start 011 the required data base which will ultimately permit the prediction of the coking properties of coals being considered as potential gasifier feedstocks. The limited data obtained pertaining to pyrolysis yields and gas composition are encouraging and suggest hat accurate gas yield predictions may also he possible at the conclusion of his program. The cffccts or process variables on coal swelling and fluidity has been fairly well established, but more work is needed to get predictive mathematical correlations of these as well as coking and pyrolysis properties or Coals. Acknowledgement This work was supported in part by the Electric Power ‘Research Institute (EPRI). Contract. ?io. 1tP 1267-7. REFERENCES 1. Kaiho, M. and ‘l’oda, Y., Changes in Thermoplastic Properties of Coal Under Pressure 01 Various Gases. Fuel 5X, 397 (hlay, 1979). - 2. Lancet, !VI. S. and Sim, F. A., The ECfect of Pressure and Gas Composition on the Fluidity of Pittsburgh No. 8 Coal, Preprints of Fuel Chemistry Div. ACS, Vol 26, No. 3 (August, 1981). - 3. Van Krevelen. U. W., Ilitntjcns, F. S. and Dormans, H. N. hl., Chemical SLructurcs and Propcrties of Coal XVI - - Plastic Behavior on Heating, Fuel 35, 462 (1955). - 4. Lewellen, P. C., Product Decomposition Effects in Coal Pyrolysis, hlasters Thesis, Department of Chemical Engineering, MIT, (1975). 5. ASTN Standard hlethod D720-67, Free Swelling Index of Coal (1977). 11
Page 1 and 2: I / The Coking Properties of Coal a
Page 3 and 4: Procedure : Hand picked lunips of c
Page 5 and 6: Apparatus: The equipment for this t
Page 7 and 8: the total pressure on the swelling
Page 9: A comparison of the results obtaine
Page 13 and 14: 1 D 13 3 G
Page 16 and 17: Table 8 L_ Effect os FaeO Compo.lrl
Page 18 and 19: i-l SPARE SAblPLE Plortlc 209 Figur
Page 20 and 21: - z c 100,000 50,000 10,000 0 n 5,0
Page 22 and 23: Flnure 9 SWELLltlG PROPERTIES OF PI
Page 24 and 25: Fi ure 13 EFFECT OF TOTAL PRESSQRE,
Page 26 and 27: TABLE 1. OPERATING CONDITIONS Opera
Page 28 and 29: 1. . 2. 3. 4. 5. 6. 7. 8. 9. REFERE
Page 30 and 31: Figure 4. SCANNING ELECTRON MICROGR
Page 32 and 33: Turkgodan et al. (18) studied the p
Page 34 and 35: Materidl balance on packed bed Boun
Page 36 and 37: These phenomena iiiay be described
Page 38 and 39: Walker, P. L., Rusinko, F., and Aus
Page 40 and 41: -""I- *I,".. I Dlrf".,on Co.1flcl.n
Page 42 and 43: After a variable residence time, th
Page 44 and 45: Changes in Char Chemistry The infra
Page 46 and 47: 20. 21. 22. 23. 24. 25. 26. 27. 28.
Page 48 and 49: 0s-a 00-a OS'S 00-E os-2 00-2 02.1
Page 50 and 51: COAL PYROLYSIS AT HIGH TEMPERATURES
Page 52 and 53: actions, decreasing the secondary c
Page 54 and 55: 01 40 60 TI MEISeC) 80 100 120 140
Page 56 and 57: Reaction Temperature OC In-situ Ini
Page 58 and 59: and the gas velocity is often repre
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The mathematical model developed he
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si sio Fraction of solid species i
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Table 2. Differential Equations Mod
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1 60 I I RUN KE-5 50 T.1121K(1557'F
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to condense excess steam, the press
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conversion-time data.* The integrat
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catalyzed and uncatalyzed runs were
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CATALYTIC EFFECTS OF ALKALI METAL S
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%me thermogravimetric measurements
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than in steam. Figure 9 shows data
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C - C02 REACTION C - H20 REACTION L
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1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
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n 'm L u. t m - L 84
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i 5360-096bw \ KINETICS OF POTASSIU
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t 5360-096pj There is an interactio
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1 I > \ i I 5360-096bw bed data. Be
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I 1. I 5360-096bw ranging from atmo
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uY.ku ICHlMAlIC OF MINI-FLUID BE0 R
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800-12-1133 -9 FIGURE IO CALCULATED
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Mexico coal. Table 1 shows an analy
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', Complete results from all runs c
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I the methanol down to atmospheric
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TABLE 3 -----______________________
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\ "I N z 107 c. . 0 0
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I. INTRODUCTION DIRECT METHANATION
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The catalyst development program fo
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Preparing process flow diagrams and
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\ \ i 1. 2,000 4,000 6,000 8,000 10
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(JMS-OlBM-2). The mass spectra were
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I I Fairbridge, R.W. (ed.) 1972, En
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v- W V z d 3 z m 4 ? P m W c3 W m N
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e. \ I , W 2 m 4 t- CI 99-79 noooo
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L Table I: Compositions of High Tem
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\ " \ I For all three coals, the pr
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4 , 1024 1024 3a 3b J Mineral Parti
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The Determination of Mineral Distri
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pyrite crystals in framboids locate
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FIG. 1. TEM MICROGRAPH OF A HIGH VO
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\ \ FIG. 5. SEM MICROGRAPH SHOWING
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\ , species. In fact, combustion ex
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1, It is possible to make a reasona
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\ i SURFACE AND BULK ENRICHMENT OF
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I Coal Ash Sintering Model and the
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5 carried out such sintering measur
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I this ash and other bituminous coa
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forming propensity. However, none o
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t I 153
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CENTRAL ELECTRICIN RESEARCH LABORAT
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157 18 I I a I
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temperature, sulfur species concent
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The facility is fired with coal usi
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Tests have been carried out to dete
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under which conditions sulfur speci
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I TITANIUM L Corn AS A TRACER FOR D
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E 6 i i h \ 1 1 \ on the XRF is cau
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\ ? CONCLUSIONS Titanium can accura
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NY) m * oa
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GFETC constructed a 0.2 square mete
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\: Stage 3. Sulfated ash-cemented a
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I FIG. 1. Initial ash coating on qu
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FIG 9. Limestone bed material alter
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(4) Since the operating temperature
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I I maximum particle diameter leavi
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! suspension chambers and cyclone f
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Pilot Plant of a Coal Fired Fluidiz
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After the fiscal year 1982, the fol
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MBC CBC Fig. 1 Boiler Structure 193
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\ i Table 2. Coal Properties Planne
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-2- more than 3 years, since 1977.
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, I B. 2 which temporarily raised t
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-6- abrasion rate at the bottom of
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\if F3.3 - Particulate Circulation
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\' I/O. analog 1/13. industrial I/O
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ACQUISITION DATA UNIT < I L- J (T)
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SAMPLING SYSTEM FOR FLUIDIZED BED A
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GAS SAMPLING WITH ORIGINAL PROBE-FI
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Remove the quartz tube (gas sample
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' ' The modifications have been com
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n n D 217
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With regard to the similarity parti
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i \ ' 2.2. soz Emission and NOx Emi
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223
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Figure 9: Sulphur captLTre as 0 fun
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P SUMMARY OF TESTS Testing complete
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I Table 1 Comparison of Sulfur Capt
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, NITROGEN OXIDE REDUCTION Single-S
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0 The addition of air at the 96-inc
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m- Y i? 4: BO n 8 c Y l0- Bo- I I I
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E! w 2 z e Y 100 - 3 t 5 80- 0, 40
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0 f 0.so o'm: 0.300 0.zo - - A 5m 4
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&e- -A \ \ \ : ERCENT OVERBED AIR I
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PARTICLE ENTRAINMENT AND NITRIC OXI
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i 1' 1 ! I. i Chaung (15) showed th
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The maximum height that a large par
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3.0 Nitric Oxide Reduction in the F
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assumed to be identical to that of
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Nomenclature A *t cD ‘NO $3 _ _ _
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TABLE 2. OPERATING CONDITIONS AND E
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i 1 \ ', References 1. 2. ( 3. 1 4.
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\ ” Y) I 259
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t I 100 - - I I ] , I , I , I 'ii 9
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Feeding of the carbonaceous materia
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! Table 2 Proximate and ultimate an
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lb, , --pp---p-- 4 p? CHAR 1 Tu-IWO
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I CHAR Y Y /I TIME O i ' ' ' ' 1 '
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could not be assumed constant. Thus
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\ greatly acknowledged. Literature
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constructed and operated to demonst
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The experimental procedure for the
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atmospheric pressure fluidized bed
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1' TABLE 2 Screen Analysis of Sand
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n RECORDER I Ill I ’ NO. NOX THER
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\ 285 Y 0 I- 5 B 5 3 m "9 E5 3 uz 0
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CHAR1 TOC 0.85 M3/k 600 0 700 V 750
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f Durin all the experimental runs t
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Assuming that large coal particles
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i 7 -_ 0 m\o --n 0 W i 293 a\o 0
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The influence of particle size dist
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all the initial values of x for whi
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\ - + 1) x. = 1 bL/n YO Defining di
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$ m. 1 Results and Discussion Evalu
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kl k2 k' KC KD m m. m P N P R R g t
Page 305 and 306:
UNBURNT FRACTION UNBURNT FRACTION m
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