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

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Table 2. Ash Size Distribution and Carbon Content in Various Parts of Flue Gas _____ Granularity Ash separated in Ash in precipitating Ash in dust mm cyclone furnace chamber col 1 ector proportion carbon proportion carbon proportion carbon by weight content by weight content by weight content % % % % % % 1.87 1.18 1-2 5.83 1.76 0.5-1 36.4 1.08 4.64 0.28-0.5 25.8 1.3 15.4 18.48 1.25 35.86 0.09-0.28 24.8 0.93 59.3 9.91 33 18.89 0.09 5.2 1.05 20.66 4.12 65.18 8.53 In a typical boiler, a two-stage dust collector is used. About 60% of the total fly-ash is collected in the precipitating chamber. The remaining ash is then removed by the dust collector. Based on the above data, we can draw the following conclusions: (1) The ash particle size in precipitating chambers and dust collectors is scarcely larger than 0.5 mm. It is reasonable to assume that particles greater than 0.5mm will not leave the cyclone furnace. This is in accordance with the results from the cold modeling experiment. (2) Ash particles with diameters of 0.25 - 0.5mm in the fly-ash have the highest carbon content. However, most of this fly-ash size fraction has been separated from the gas flow in the cyclone furnace and its proportion by weight in the fly-ash is not high. When a boiler operates at normal capacity, the average carbon content for fly-ash is 11.85%. This value may be considered relatively low. (3) The ash particles separating from the gas flow in the cyclone furnace have a significantly lower carbon content than that observed in the ash overflow. In general, the medium particles of fly-ash have higher carbon content, while the carbon content of ash particles ranging from 0.28 to 0.5 mm separated in the cyclone furnace is only 1.3%. This shows that the degree of burn-up for ash separated within cyclone furnaces is rather high. (4) Since the separation efficiency for cyclone furnaces is rather high (about 50%), the ash particles burn more completely with the result that the boiler combustion efficiency increases. During operation periods at rated capacity, the unburned combustible solid losses are 3.8% and the unburned gas losses are 0.67% while the combustion efficiency can be as high as 95.47%. When the temperature of fluidized bed section is 900°C at rated capacity, the gas temperature measured at the cyclone furnace exit is 92OoC, that is the temperature difference between the latter and the former is 2OoC. This shows that there are some combustibles still burning in the suspension chamber and in the cyclone furnace. According to calculations, the total fraction burned in the suspension chamber and cyclone furnace is 0.3. In experimental tests with another lignite fluidized bed boiler of the same type, the fraction burned in the cyclone furnace itself was found to be 0.172. The results of the data for the above two experiments are basically the same. It can be seen from the above summary that the total fraction of combustion in 186
! suspension chambers and cyclone furnaces in fluidized bed boilers is relatively high. Thus the organization of the combustion process is highly significant in obtaining better boiler combustion efficiency. The separation efficiency for cyclone furnaces, 'If, is the ratio of ash separated in the cyclone furnace, AG, to ash leaving the cyclone furnace, G", plus the ash separated, AG, that is AG x 100% nf = G"+aG The unburned carbon content of the ash is included in the above expression. The results of the tests are summarized in Table 3. Table 3. Separation Efficiency for a Cyclone Furnace as a Function of Ash Particle Size Granularity mm >1 0.5-1 0.28-0.5 0.09-0.28
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I / The Coking Properties of Coal a
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Procedure : Hand picked lunips of c
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Apparatus: The equipment for this t
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the total pressure on the swelling
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A comparison of the results obtaine
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was used, however, general trends a
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1 D 13 3 G
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Table 8 L_ Effect os FaeO Compo.lrl
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i-l SPARE SAblPLE Plortlc 209 Figur
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- z c 100,000 50,000 10,000 0 n 5,0
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Flnure 9 SWELLltlG PROPERTIES OF PI
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Fi ure 13 EFFECT OF TOTAL PRESSQRE,
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TABLE 1. OPERATING CONDITIONS Opera
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1. . 2. 3. 4. 5. 6. 7. 8. 9. REFERE
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Figure 4. SCANNING ELECTRON MICROGR
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Turkgodan et al. (18) studied the p
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Materidl balance on packed bed Boun
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These phenomena iiiay be described
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Walker, P. L., Rusinko, F., and Aus
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-""I- *I,".. I Dlrf".,on Co.1flcl.n
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After a variable residence time, th
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Changes in Char Chemistry The infra
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20. 21. 22. 23. 24. 25. 26. 27. 28.
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0s-a 00-a OS'S 00-E os-2 00-2 02.1
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COAL PYROLYSIS AT HIGH TEMPERATURES
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actions, decreasing the secondary c
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01 40 60 TI MEISeC) 80 100 120 140
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Reaction Temperature OC In-situ Ini
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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
Page 135 and 136: FIG. 1. TEM MICROGRAPH OF A HIGH VO
Page 137 and 138: \ \ FIG. 5. SEM MICROGRAPH SHOWING
Page 139 and 140: \ , species. In fact, combustion ex
Page 141 and 142: 1, It is possible to make a reasona
Page 143 and 144: \ i SURFACE AND BULK ENRICHMENT OF
Page 145 and 146: I Coal Ash Sintering Model and the
Page 147 and 148: 5 carried out such sintering measur
Page 149 and 150: I this ash and other bituminous coa
Page 151 and 152: forming propensity. However, none o
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Page 155 and 156: CENTRAL ELECTRICIN RESEARCH LABORAT
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Page 159 and 160: temperature, sulfur species concent
Page 161 and 162: The facility is fired with coal usi
Page 163 and 164: Tests have been carried out to dete
Page 165 and 166: under which conditions sulfur speci
Page 167 and 168: I TITANIUM L Corn AS A TRACER FOR D
Page 169 and 170: E 6 i i h \ 1 1 \ on the XRF is cau
Page 171 and 172: \ ? CONCLUSIONS Titanium can accura
Page 173 and 174: NY) m * oa
Page 175 and 176: GFETC constructed a 0.2 square mete
Page 177 and 178: \: Stage 3. Sulfated ash-cemented a
Page 179 and 180: I FIG. 1. Initial ash coating on qu
Page 181 and 182: FIG 9. Limestone bed material alter
Page 183 and 184: (4) Since the operating temperature
Page 185: I I maximum particle diameter leavi
Page 189 and 190: Pilot Plant of a Coal Fired Fluidiz
Page 191 and 192: After the fiscal year 1982, the fol
Page 193 and 194: MBC CBC Fig. 1 Boiler Structure 193
Page 195 and 196: \ i Table 2. Coal Properties Planne
Page 197 and 198: -2- more than 3 years, since 1977.
Page 199 and 200: , I B. 2 which temporarily raised t
Page 201 and 202: -6- abrasion rate at the bottom of
Page 203 and 204: \if F3.3 - Particulate Circulation
Page 205 and 206: \' I/O. analog 1/13. industrial I/O
Page 207 and 208: ACQUISITION DATA UNIT < I L- J (T)
Page 209 and 210: SAMPLING SYSTEM FOR FLUIDIZED BED A
Page 211 and 212: GAS SAMPLING WITH ORIGINAL PROBE-FI
Page 213 and 214: Remove the quartz tube (gas sample
Page 215 and 216: ' ' The modifications have been com
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Page 219 and 220: With regard to the similarity parti
Page 221 and 222: i \ ' 2.2. soz Emission and NOx Emi
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Page 225 and 226: Figure 9: Sulphur captLTre as 0 fun
Page 227 and 228: P SUMMARY OF TESTS Testing complete
Page 229 and 230: I Table 1 Comparison of Sulfur Capt
Page 231 and 232: , NITROGEN OXIDE REDUCTION Single-S
Page 233 and 234: 0 The addition of air at the 96-inc
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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
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UNBURNT FRACTION UNBURNT FRACTION m
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