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

More documents

Recommendations

Info

Figure 4. SCANNING ELECTRON MICROGRAPH OF PSOC-1133 CHAR 330 msec Residence Time at 1000°C Figure 5. SCANNING ELECTRON MICROGRAPH OF A PREOXIDIZED COAL CHAR (PSOC-1133 1% Oxygen Added) 330 msec Residence Time at looooc 30
Introduction INFLUENCE OF PARTICLE STRUCTURE CHANGES ON THE RATE OF COAL CHAR REACTION WITH C02 K. A. Debelak, M. A. Clark and J. T. Malito Department of Chemical Engineering Vanderbi 1 t University Nashville, TN 37235 A coiiunon feature of gas-solid reactions is that the overall process involves several steps: (1) mass transfer of reactants and products from bulk gas phase to the internal surface of the reacting solid particle; (2) diffusion of gaseous reactants or products through the pores of a solid reactant; (3) adsorption of gaseous reactants on sol id reactant sites and desorption of reaction products from solid surfaces; (4) the actual chemical reaction between the adsorbed gas and solid. In studying gas-solid reactants, we are concerned with these four phenomena and other phenomena which affect the overall rate of reaction and performance of industrial equipment in which these gas-solid reactions are carried out. These other phenomena include: heat transfer, flow of gases and solids through reactors, and changes in the solid structure, all of which affect the rate of diffusion and surface area available for reaction. The reaction to be studied is the reaction between carbon and carbon dioxide to form carbon monoxide. This reaction is of importance for it is one o f the prime reactions occurring in coal gasifiers, and also it is a reaction on which there is data from other investigations (1-17). Considerable discrepancy has been found for activation energies which ranges from 48-86 kcal/mol and for reaction rate constants. This can be explained by the somewhat oversimplified view of the mechanism which was thought to be rate-controlling, and the simplification made in the corres- ponding reaction rate models. Gulbransen and Andrew (2) showed that the internal surface area of graphite increased during reaction with carbon dioxide and oxygen, Walker et al. (3) studied graphite rods for the possible correlations existing between reaction rates and changes in surface area during reaction. They concluded that the reaction develops new surface, to some extent, by enlarging the micropores of the solid but principally by opening up pore volume not previously available to reactant gas either because the capillaries were too small or because existing pores were unconnected. Surface area increased up to a point where rate of production of new surface equalled the destruction of old surface, after which surface area then continued to decrease. For the graphite-carbon dioxide reaction, Petersen (4) found that observed rates were not simple functions of the total available surface area as determined by low-temperature adsorptions prior to reaction, as might be expected if the reaction was chemical-reaction control 1 ed. 31
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 and 10: A comparison of the results obtaine
Page 11 and 12: was used, however, general trends a
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 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
Page 60 and 61: The mathematical model developed he
Page 62 and 63: si sio Fraction of solid species i
Page 64 and 65: Table 2. Differential Equations Mod
Page 66 and 67: 1 60 I I RUN KE-5 50 T.1121K(1557'F
Page 68 and 69: to condense excess steam, the press
Page 70 and 71: conversion-time data.* The integrat
Page 72 and 73: catalyzed and uncatalyzed runs were
Page 74 and 75: CATALYTIC EFFECTS OF ALKALI METAL S
Page 76 and 77: %me thermogravimetric measurements
Page 78 and 79: than in steam. Figure 9 shows data
Page 80 and 81:
C - C02 REACTION C - H20 REACTION L
Page 82 and 83:
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.
Page 84 and 85:
n 'm L u. t m - L 84
Page 87 and 88:
i 5360-096bw \ KINETICS OF POTASSIU
Page 89 and 90:
t 5360-096pj There is an interactio
Page 91 and 92:
1 I > \ i I 5360-096bw bed data. Be
Page 93 and 94:
I 1. I 5360-096bw ranging from atmo
Page 95 and 96:
uY.ku ICHlMAlIC OF MINI-FLUID BE0 R
Page 97 and 98:
800-12-1133 -9 FIGURE IO CALCULATED
Page 99 and 100:
Mexico coal. Table 1 shows an analy
Page 101 and 102:
', Complete results from all runs c
Page 103 and 104:
I the methanol down to atmospheric
Page 105 and 106:
TABLE 3 -----______________________
Page 107 and 108:
\ "I N z 107 c. . 0 0
Page 109 and 110:
I. INTRODUCTION DIRECT METHANATION
Page 111 and 112:
The catalyst development program fo
Page 113 and 114:
Preparing process flow diagrams and
Page 115 and 116:
\ \ i 1. 2,000 4,000 6,000 8,000 10
Page 117 and 118:
(JMS-OlBM-2). The mass spectra were
Page 119 and 120:
I I Fairbridge, R.W. (ed.) 1972, En
Page 121 and 122:
v- W V z d 3 z m 4 ? P m W c3 W m N
Page 123 and 124:
e. \ I , W 2 m 4 t- CI 99-79 noooo
Page 125 and 126:
L Table I: Compositions of High Tem
Page 127 and 128:
\ " \ I For all three coals, the pr
Page 129 and 130:
4 , 1024 1024 3a 3b J Mineral Parti
Page 131 and 132:
The Determination of Mineral Distri
Page 133 and 134:
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
Page 153 and 154:
t I 153
Page 155 and 156:
CENTRAL ELECTRICIN RESEARCH LABORAT
Page 157 and 158:
157 18 I I a I
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 and 186:
I I maximum particle diameter leavi
Page 187 and 188:
! suspension chambers and cyclone f
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
Page 217 and 218:
n n D 217
Page 219 and 220:
With regard to the similarity parti
Page 221 and 222:
i \ ' 2.2. soz Emission and NOx Emi
Page 223 and 224:
223
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
Page 235 and 236:
m- Y i? 4: BO n 8 c Y l0- Bo- I I I
Page 237 and 238:
E! w 2 z e Y 100 - 3 t 5 80- 0, 40
Page 239 and 240:
0 f 0.so o'm: 0.300 0.zo - - A 5m 4
Page 241 and 242:
&e- -A \ \ \ : ERCENT OVERBED AIR I
Page 243 and 244:
PARTICLE ENTRAINMENT AND NITRIC OXI
Page 245 and 246:
i 1' 1 ! I. i Chaung (15) showed th
Page 247 and 248:
The maximum height that a large par
Page 249 and 250:
3.0 Nitric Oxide Reduction in the F
Page 251 and 252:
assumed to be identical to that of
Page 253 and 254:
Nomenclature A *t cD ‘NO $3 _ _ _
Page 255 and 256:
TABLE 2. OPERATING CONDITIONS AND E
Page 257 and 258:
i 1 \ ', References 1. 2. ( 3. 1 4.
Page 259 and 260:
\ ” Y) I 259
Page 261 and 262:
t I 100 - - I I ] , I , I , I 'ii 9
Page 263 and 264:
Feeding of the carbonaceous materia
Page 265 and 266:
! Table 2 Proximate and ultimate an
Page 267 and 268:
lb, , --pp---p-- 4 p? CHAR 1 Tu-IWO
Page 269 and 270:
I CHAR Y Y /I TIME O i ' ' ' ' 1 '
Page 271 and 272:
could not be assumed constant. Thus
Page 273 and 274:
\ greatly acknowledged. Literature
Page 275 and 276:
constructed and operated to demonst
Page 277 and 278:
The experimental procedure for the
Page 279 and 280:
atmospheric pressure fluidized bed
Page 281 and 282:
1' TABLE 2 Screen Analysis of Sand
Page 283 and 284:
n RECORDER I Ill I ’ NO. NOX THER
Page 285 and 286:
\ 285 Y 0 I- 5 B 5 3 m "9 E5 3 uz 0
Page 287 and 288:
CHAR1 TOC 0.85 M3/k 600 0 700 V 750
Page 289 and 290:
f Durin all the experimental runs t
Page 291 and 292:
Assuming that large coal particles
Page 293 and 294:
i 7 -_ 0 m\o --n 0 W i 293 a\o 0
Page 295 and 296:
The influence of particle size dist
Page 297 and 298:
all the initial values of x for whi
Page 299 and 300:
\ - + 1) x. = 1 bL/n YO Defining di
Page 301 and 302:
$ m. 1 Results and Discussion Evalu
Page 303 and 304:
kl k2 k' KC KD m m. m P N P R R g t
Page 305 and 306:
UNBURNT FRACTION UNBURNT FRACTION m
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?