liquefaction pathways of bituminous subbituminous coals andtheir

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90 s5 SO 2 15 v 5 70 .- $ 65 - 60 55 Fig. 1: Wyodak and Beulah-Zap Dried in N2, 40 C. WY13 & ND86, - 100 mesh, 80 cchin, SO rng, fbb 50 2 1002 2002 3002 4002 5002 6002 7002 8002 502 1502 2502 3502 4502 5502 6502 7502 Time (10 second intervals) ,WY13 ,ND86 7 c6 2 s 2 4 E 3 5v 2 I .5'1 2 0 -$ -1 L -2 3 -3 Fig. 2 Wyodak & Beulah-Zap Dried in N2,40 c. WY13 & ND86,40 C, in N2, -100 mesh, 80 cc/min, 80 mg, fbb -41l I ' ' I 2 1002 2002 3002 4002 5002 6002 7002 8002 502 1502 2502 3502 4502 5502 6502 7502 Time (10 second intervals) ,'AT13 ,NDS6 592
Influence of Drying and Oxidation 01 Coal on its Catalytic and Thermal Liquefaction. 1. Coal Conversion and Products Distribution. w, w e n Chunshan Song and Harold H. Schoben t of Material Science and Engineering, 209 Academic PwjecU Building. Fuel Science Program, The Pennsylvania State University. University Park, PA 16802. Keywads Dryiig, Oxidation. Coal liquefaction. INlRODUCIlON Most of the subbituminous coals contain more then 25 wt % of moisture and it is considered an economic necessity to dry !hex, coals prior to liquefaction. The drying of coal can have significant effect on the conversion reactivity of coal. Atherton (1) reponed hat the drying of low rank subbituminous coal in a gas atmosphere did not effect the total conversion except in air. The air-dryig gave somewhat lower conversion, which may be. a result of the adverse effect of preoxidation. The best conversion was obtained by vacuum and microwave drying. The oxidation of coal has been known to have an adverse effect on the coal conversion. Neavel(2) reported a significant reduction in the yield of benzene soluble products fmm hvC bituminous coal as a result of oxidation. Cmnauer el al. (3) reponed that partial drying of subbituminous coal in a mixture of nitrogen and oxygen or even io nimgen alone reduced the conversion as compared to that of the raw coal. On the other hand, Vorres et al. recently reponed that drying improves the oil yield in liquefaction of lignite samples (4) In the present study we repon the influence of drying Wyodak subbituminous coal in air and vacuum on the THFconversion in thermal and catalytic liquefactions. From our results it appears that the drying of coal in air to some extent, which has teen considered to be worse for liquefaction, may give a better conversion with dispersed Mo catalyst compared to the vacuumdried coal in the presence of a liquefaction solvent The raw coal was also subjected to liquefaction. Best conversion was obtained from the raw coal in the thermal and catalytic solvent-free run. In presence of solvents during catalytic runs the raw coal did not show any improvement over the thermal runs. EXPERIMENTAL ?he coal used was Wyodak subbituminous coal (DECS-8). This coal contains 32.4 % volatile matters, 29.3% fued carbon. 9.9 % ash and 28.4 % moisture. on as-received basis; 75.8% C, 5.2% H. 1.0% N. 0.5% S and 17.5% 0. on dmmf basis. The coal was dried under vacuum for 2 h at 100 "C. The drying of coal in air was done in an oven maintained at 100 and 1% OC with the door partially open. At 100 "C the coal was dried for 2.20 and 100 hours and at 150 T it was dried for '20 hm. The liquefaction was carried out at 3% OC for 30 minutes under 7 MPa (cold) H2 in 7.5 ml tubing bomb. Ammonium tetrathiomolybdate (Al'TM) was used as precursor for molybdenum sulfide catalyst It was loaded on to coal by incipient wemess impregnation method h m aqueous solution with 1 wt % Moon dmmf basis. The impregnated coal samples were dried in a vacuum oven at 100 OC for 2 h. The experimental details about the liquefaction and the product work up is given elsewhere (5). The toul conversion (TC) of the coal into soluble products have been calculated on the basis of the THF-insoluble residues The analysis of the gases evolved during liquefactions at 350 'C show that the major components of the gases are CO and C@. The total yield of the hydrccarbon gases produced is less than 1 wt % dmmf coal, in all the liquefaction NIIS. RESULTS AND DISCUSSION The products distribution for the solvent-free thermal liquefactions are given in Table 1. As compared to the vacuum-drying the air-drying of coal at 100 OC for up to 100 h did not effect the tal conversion on the basis of THF-insoluble residue. But the total gas yield increased with the drying time in air. This increase is mainly due to the increase in the CO and COz yields (Table 3) at the expense of other products which is undesirable. The drying in air. oxidizes the coal, increasing the carboxylic and carbonyl functionalities which upon thermolysis produce C@ and CO gases. Upon excessive oxidation at 150 "C for 20 h the coal conversion slightly deneased but the gas yield increased considerably. which was accompanied by the decrease in the oil. asphaltene and preasphaltene yields. Since the main constituent of the gas is C@ which is associated with air-oxidation. it would be more appropriate to see the effect of drying on the desirable products. Figure 1 shows the dismbutions of the liquid and solid products in the 593
Page 1 and 2:
LIQUEFACTION PATHWAYS OF BITUMINOUS
Page 3 and 4:
the conversion of A+P and O+G with
Page 5 and 6:
Asphaltcncs PrCasphaltenCS Cwr%, da
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NEW DIRECTIONS TO PRECONVERSION PRO
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ecause of incorporation of the coal
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should be considered more. The step
Page 13 and 14:
17 18 Run no. 0 cys I ToS-CyS TS-To
Page 15 and 16:
INTRODUCTION Effects of Thermal and
Page 17 and 18:
apid decline in modulus. The loss m
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-0.01- . 04 5 -0.03- E 6 -0.0s- c)
Page 21 and 22:
Assessment of Small Particle Iron O
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yields are calculated by subtractin
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conversion is greater than the corr
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Table 3. Effect of Superfine Iron O
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EFFECT OF A CATALYST ON THE DISSOLU
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inherent volatility of Mo(CO), perm
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Analysis of the quantity and compos
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$ EO .- 0 m L 0 c 0 0 > 40 300 350
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0 0 0 0 0.000 0.005 0.010 0.015 0.0
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of these studies indicate that cont
Page 41 and 42:
Different levels of adsorption occu
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Nominal 2 Table 1. Concentration of
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- iF m 1.6 1.4 1.2 - - - 1- 0 0.8 -
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RESULTS AND DISCUSSION Swelling of
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. . % . . 9 'HF 0 0 0 *. . 0 . . 0
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1.50 KQ 1.00 0.50 I / ' 02 525 I 1
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hydrogen atoms. The hydrogen atoms
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D to generate more D atoms. It is r
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12. a. Poutsma, M. L.; Dyer, C. W.
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Figure 3. Minimum Steps to Explin D
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Apoaratus and Procedure Microflow R
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Model ComDound Test Figure 5 shows
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Figure 1. High resolution gas chrom
Page 67 and 68: Figure 5. Product distribution for
Page 69 and 70: THQ at somewhat higher temperatures
Page 71 and 72: areas of the particles and the SEM
Page 73 and 74: Experimental Catalyst Precursors an
Page 75 and 76: impregnating solvent. Table 3 shows
Page 77 and 78: of MoCo-TC2 at the level of 0.5 wt%
Page 79 and 80: Table 4. Effect of Temperature Prog
Page 81 and 82: In the past, chemical treatments in
Page 83 and 84: The effect of Corn20 preaatment on
Page 85 and 86: Reaction Time Figure 1 - Schematic
Page 87 and 88: DISSOLUTION OF THE ARGONNE PREMIUM
Page 89 and 90: A much more def~tive trend is seen
Page 91 and 92: EFFECT OF CHLOROBENZENE TREATMENT O
Page 93 and 94: same conditions and an extraction t
Page 95 and 96: ACKNOWLEDGEMENT The authors thank t
Page 97 and 98: THE STRUCTURAL &=RATION OF HUMINlTE
Page 99 and 100: to be originally derived from demet
Page 101 and 102: 145 30 I --/---Jh I , , I I , 250 2
Page 103 and 104: THE EFFECTS OF MOISTURE AND CATIONS
Page 105 and 106: 1 for the Zap lignite. These result
Page 107 and 108: content of the samples ion-exchange
Page 109 and 110: Table 1. F'yrolysis Results of Vacu
Page 111 and 112: 585 I
Page 113 and 114: EFFECT OF TEMPERATURE, SAMPLE SI2E
Page 115 and 116: of some of the thermobalance runs.
Page 117: 2. The mechanism of drying is a uni
Page 121 and 122: "c gives W conversion mpared to the
Page 123 and 124: Table 1. Products dismbutions (dmmf
Page 125 and 126: - 50 45 40 E 35 2 30 E T) 25 ap 20
Page 127 and 128: Influence of Drying and Oxidation o
Page 129 and 130: FTIR . . of the L m To investigate
Page 131 and 132: CONCLUSIONS The characexizntion of
Page 133 and 134: A b S 0 r b a n C e A b s 0 r b a n
Page 135 and 136: An NMR Investigation of the Effd of
Page 137 and 138: for determining the area of the pea
Page 139 and 140: of the ronl roniponcnte nnd (2) the
Page 141 and 142: 2w 180 160 9 140 120 P loo f 80 P O
Page 143 and 144: 25 I 20 ' + 0 Drying lime, hours Fi
Page 145 and 146: substructure have been identified a
Page 147 and 148: Pyridine extraction showed that 60
Page 149 and 150: Figure 1. Reflected white-light pho
Page 151 and 152: Table 3. Pyridine Extraction Sample
Page 153 and 154: A bang-bang control strategy was us
Page 155 and 156: increased from 120°C to 135”C, r
Page 157 and 158: * wt% based on the amount of naphth
Page 159 and 160: Use of Biocatalysts for the Solubil
Page 161 and 162: Results Enzyme Modification with Di
Page 163 and 164: Conclusions Reducing enzymes can be
Page 165 and 166: Dynamics of the Extract Molecular-W
Page 167 and 168: where yi = (x-xi !/pi. The zero mom
Page 169 and 170:
satisfactory agreement between theo
Page 171 and 172:
0.8 0.6 0.4 0.2 “E \ bo Y, - 1 0
Page 173 and 174:
The Use of Solid State C-13 NMR Spe
Page 175 and 176:
differences lie in the fact that th
Page 177 and 178:
I- z W 0 K W n PROTONATED AROMATIC
Page 179 and 180:
ZAP WIO SIDE CHAINS IN PYRIDINE EXT
Page 181 and 182:
ORGAFlIC VOLATILE MATER AND ITS SUL
Page 183 and 184:
(Figure 1). They indicated that the
Page 185 and 186:
Table 3. Elemental analysis of arom
Page 187:
1- 700'C Figure 3. GClFID chromatog
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