liquefaction pathways of bituminous subbituminous coals andtheir

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40 I RerrpMlenc 0 Asphalunc rn oil AD Airdried VD Vacuumdried T Thermal C Catalytic Drylng Condltlons Figure 3. Products distribution from the thermal and catalytic liquefactions in the presence of 1-methylnaphthalene at 350 OC of the raw and coal dried in different conditions. Figure 4. and tetralin. 21- 1 H,-Consumotion Drying Condltlons - Thermal Solvent-free Catalytic Solvent-free Thermal Tetralin Catalytic Tetralin Thermal I-MN Catalytic 1 -MN Thermal Catalytic Hydrogen consumption profiles during thermal and catalytic liquefactions from H2 600
Influence of Drying and Oxidation of Coal on Its Catalytic and Thermal Liquefaction. 2. Characterization of Dried and Oxidized Coal and Residues. eiay K. Saini, Chunshan Song and Harold H. Schoben Department of Material Science and Engineering, 209 Academic Projects Building, Fuel Science hh. The Pennsylvania State University, University Park. PA 16802. Keywords: Drying, Oxidation,Swctural characterization. INTRODUCTION Because of the high moisture content of the low rank coals it is desirable to dry coal before liquefaction. It has been recognized that drying of coal could adversely affect the reactivity of subbituminous coal for liquefaction (1,2). 'Ihis study has been carried out with a view to undersmd the effect of low temperature oxidative and non- oxidative drying on coal structure and liquefaction residues. In the preceding paper the impacts of coal drying on the liquefaction have been discussed (3). Several papers have been devoted to understanding the oxidation of cod (4-10) but very little has been reponed on the effect of oxidation on the structures of liquefaction residues which could lead to an insight of the oxidative effect on liquefaction. In the present work we have analyzed the residues from thermal as well as catalytic Liquefactions of the raw and dried coal under vacuum and in air. The analysis of the residues reveal that although there is a significant decrease in the aliphatics upon oxidative drying of coal compared to the vacuum dried coal the residues from the air-dried coal are more. aliphatic rich, and as the oxidation proceeds more longerchain aliphatics ars lost during liquefaction. The raw coal shows an enhanced loss of carbonyls during liquefaction, which may be the cause of its higher conversion. EXPERlMENTAL The coal used was Wyodak subbituminous oblained from the Penn State Sample Bank (DECS-8). The characteristics of coal are given elsewhere (1 1). For the raw coal liquefaction it was used as received. For the drying experiments the coal was dried under vacuum at 100 "C for 2 h and in air at 100 "C for 2.20 and 100 h. At 150 OC coal was dried for 20 h. The airdrying of coal was done in a preheated oven at desired temperature with the door slightly open to ensure the sufficient air supply. The thermal and catalytic liquefactions of coal were carried out at 350 "C under 6.9 Mpa (cold) H2 pressure. for 30 minutes. Ammonium tetrathiomolybdate (A?-ru) was used as catalyst. It was loaded on to coal by incipient wetness impregnation method from aqueous solution, with 1 wt % Moon dmmf coal. After the reaction, the liquid and solid products were separated by sequential extraction with hexane, toluene and THE After the extraction the THF-insoluble residues were washed first with acetone and then pentane in order to remove all the THF, followed by drying at 1 IO 'C for 6 h under vacuum. The coal and residues were analyzed by F'y-GC-MS, solid state CPMAS 13C NMR and mIR techniques discribed elsewhere (12,13). RESULTS AND DISCUSSION o m t p CPMAS '3C NMR Figure. 1 compares between lheCPMAS I3C NMR spectra of the raw coal and the vacuum and air-dried coal. The raw coal and the dried coal show similar NMR features. The region between 0-80 ppm consists of aliphatic carbons which may include methoxy carbons and the second region between 90 to 170 ppm is due to the aromatic carbons including two shoulders due to catechol-like and phenolic carbons (I I). The carboxylic band appears at 170-190 ppm and carbonyl gmup between 190-230 ppm. Upon drying coal under vacuum there was no noticeable difference in the NMR spectrum as compared to that of the raw coal. When the coal was dried in air a slight difference seems to be apparent but not very significant until the coal was dried at 100 "C for 100 h or at 1% "C for 20 h. It appears that as the coal was dried under oxidative conditions there was a decrease in the intensity of the catechol shoulder. The other change seems to be the broadening in the carboxyl and carbonyl bands. These changes in the coal ~trtl~ture becomes amarent when the coal was dried in air under severe conditions. After drvinp -,- 0 coal at 150 'C for 20 h the CPMAS 13CNMR shows a complete disappearance of the catechol peak and the 601 1
Page 1 and 2:
LIQUEFACTION PATHWAYS OF BITUMINOUS
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the conversion of A+P and O+G with
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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
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17 18 Run no. 0 cys I ToS-CyS TS-To
Page 15 and 16:
INTRODUCTION Effects of Thermal and
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apid decline in modulus. The loss m
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-0.01- . 04 5 -0.03- E 6 -0.0s- c)
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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
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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
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Figure 5. Product distribution for
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THQ at somewhat higher temperatures
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areas of the particles and the SEM
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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 and 118: 2. The mechanism of drying is a uni
Page 119 and 120: Influence of Drying and Oxidation 0
Page 121 and 122: "c gives W conversion mpared to the
Page 123 and 124: Table 1. Products dismbutions (dmmf
Page 125: - 50 45 40 E 35 2 30 E T) 25 ap 20
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
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I- z W 0 K W n PROTONATED AROMATIC
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ZAP WIO SIDE CHAINS IN PYRIDINE EXT
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ORGAFlIC VOLATILE MATER AND ITS SUL
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(Figure 1). They indicated that the
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Table 3. Elemental analysis of arom
Page 187:
1- 700'C Figure 3. GClFID chromatog
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