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

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7. Ruth, L.A., Squires, A.M, Gratt, R.A., "Desulfurization of Fuels with Half- Calcined Dolomite: First Kinetic Data", Environmental Science & Technology, Vol. 6, p. 1007, 1972. 8. Yang, R.T., Chen, J.M., "Kinetics of Desulfurization of Hot Fuel Gas with Calcium Oxide. Reaction Between Carbonyl Sulfide and Calcium Oxide", Environmental Science & Technology, Vol. 13, p. 549, 1979. Acknowledgments This work has been supported under EPA Contract 68-02-2667. The authors are pleased to acknowledge the encouragement and ideas provided by Dr. D. C. Drehmel and G. B. Martin of EPA and the contributions of their colleagues at EER in the execution of the experiments. 166
I TITANIUM L Corn AS A TRACER FOR DETERMINING COAL BURNOUT Ray S. Pace, Paul 0. Hedman, and L. Douglas Smoot bu s t i on La bora tory Department of Chemical Engineering Brigham Young University Provo, Utah 84602 I li 1' INTRODUCTION Background. Extensive research on coal combustion at this laboratory (1-6) has focuse on developing an understanding of the physical and chemical mechanisms and reactidon rates of coal burnout and nitrogen and sulfur pollutant formation. ( Local samples of combustion products have been extracted from the pulverized coal 'i combustor using water-quenched sample probes. To complete mass balances and 1 I: deternine important local parameters, chemically inert tracers have been used in the reactor. Argon added to the primary air has been used as the gas phase tracer to determine the mixing rates of the primary and secondary air streams and the volume of combustion gases from the coal. Carbon conversion i s also determined from gas composition, coal feed rate, and a forced argon balance. \ Coal burnout has been calculated from the percent ash in the residual char and in the raw coal in previous phases of this study (4-6). However, the use of ash as a particle tracer has not been satisfactory. Ash is not a suitable tracer because it contains many inorganic compounds which decompose and/or vaporize. Kobayashi , et al. (7) and Sarofim, et al. (8) have shown that as much as 20-60 percent of the original coal ash can be volatilized depending on the temperature history of the ash. Collecting samples of combustion products with a water-quench probe produces a char-water mixture which is filtered and dryed to obtain the solid char sample. Hany constituents of ash are soluble in the water and more losses are incurred in the total measured ash content. Harding, et al. (6) have shown that up to 10 percent of the ash can be dissolved in the probe quench water. High losses of ash negate its usefulness as a solid tracer by introducing large errors into the mass balance and burnout calculations. Consequently, there has been an interest in finding another particle tracer which could more accurately determine coal burnout, and also to help understand the fate of the ash and slag. Hims, et al. (9) have characterized the volatilization of ash with temperature. At higher temperatures, compounds formed from elements such as arsenic, manganese, magnesium, sodium and antimony showed strong vaporization trends. A1 uminum, si1 icon and other known refractory compounds a1 so showed significant losses at high temperatures. Compounds formed from such elements as titanium, scandium, barium and lanthanum were found to be more stable. Because of their low concentrations in the coals, scandium and lanthanum were not considered as feasible tracers. Titanium was selected as a possible tracer because it forms relatively stable high boiling point compounds (i.e., TiO, Tic, TiO2, Ti4071, and is found in most coals in easily detectable amounts. Objectives. The purpose of this study was to develop an analytical procedure which could be used to measure the concentration of a solid particle tracer and apply the techniques to representative samples from the pulverized coal combustor. Techniques commonly used to analyze elements in the ash are atomic absorption (AA), instrumental neutron activation analysis (INAA), x-ray diffraction (XRD), and x-ray fluorescence (XRF). XRF was chosen because of the ease of analysis (sample preparation time 10-15 minutes and analysis time of 40-120 seconds), and availability of a suitable instrument. Comparison of M, INAA and XRF results for 167
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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
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: under which conditions sulfur speci
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
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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
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UNBURNT FRACTION UNBURNT FRACTION m
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