liquefaction pathways of bituminous subbituminous coals andtheir

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c1 F 0 z j 3 Y 100 90 80 70 =I 60 I 30 I I I Run no. I Gas 0 cys I ToS-CyS mm0 TS-ToS S TI Figure 5 Coal conversion by the proposed procedure for DECS-2 coal (Runs 19 and 20) and DES8 coal (Runs 21 and 22) (Run 19; 200"C(lh)/430"C(2h), Run 20, calculation from Runs IO and 18, Runs 20 and 21 under the same conditions as Runs 19 and 20, see the text in detail) 488
INTRODUCTION Effects of Thermal and Solvent Pretreatments on the Elastic Properties of Coal Yongseung Yun and Eric M. Suuberg Division of Engineering, Brown University Providence, RI 02912 (Keywords: Elastic property, Dynamic Mechanical Analysis, Pretreatment) It is now well established that thermal pretreatment in a range of temperatures lower than those needed for pyrolysis can significantly affect the penemability and swellability of coals. This suggests that judicious use of heat together with effective swelling solvents for coal, can affect mass transport of reagents or catalysts into or out of the coal, during the early stages of liquefaction. The present study is concerned with the effects of heatholvent pretreatments on the elastic constants of the coal network structure. This, in turn, tells one about how the non-covalent interactions in coal are being broken down. Studies of the elastic properties of coal are nothing new [e.g. 1-10]. Because of the compressibility of coal, the application of mercury porosimetry to pore characterization in coal has involved careful corrections, so that the actual pore size dismbution could be calculated [ 1.1 1,121. However, the limitation caused by compressibility of bulk coal structure can be an advantage in revealing the structural changes during pretreatment processes and in establishing a suitable elastic model for macromolecular coal structure. It is known that dynamic mechanical methods are ca. 1000 times more sensitive for detecting molecular relaxations such as the glass transition temperature, Tg, than are differential scanning calorimetry (DSC)/differential thermal analysis (DTA) techniques [13]. Weller and Wert [7-101 have extensively applied the torsion pendulum technique, one of the dynamic mechanical methods, for elucidating the elastic properties of coal in the temperature range below 200 'C. They employed square rods cut from whole coal. Since the relevant temperature range for the structural relaxation by heat is generally higher than 200OC. we decided to study the thermal structural relaxation at temperatures higher than 2M°C by employing dynamic hechanical analysis (DMA). This technique involves constant amplitude oscillation of the solid to determine stress-strain properties. EXPERIMENTAL A DuPont 982 DMA was employed for mechanical analysis. A detailed description of the equipment has been given elsewhere L13.141. The sample for the DMA was prepared by pressing the as-received coal powder (-100 mesh) obtained from the Argonne Premium Sample Bank with a press normally used for making FTIR sample pellets, at 15 kpsi for 6-12 hr, which results in a sample of ca. 4 mm thickness with 12.8 mm diameter. Slippage of the samples from the clamps inside the DMA, especially during oscillation in the high temperature range (>300"C), was noted to be a main cause for irreproducibility. and special care was taken to make certain that the sample was tightly clamped. The pelletizing process used here clearly creates a solid tablet of different macroscopic mechanical properties than the original solid. The choice to work with samples prepared in this way was dictated by a desire to continue to use the Argonne Premium Coal Samples, that are generally only available in powdered form. The gross macroscopic 489
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
Page 7 and 8: NEW DIRECTIONS TO PRECONVERSION PRO
Page 9 and 10: ecause of incorporation of the coal
Page 11 and 12: should be considered more. The step
Page 13: 17 18 Run no. 0 cys I ToS-CyS TS-To
Page 17 and 18: apid decline in modulus. The loss m
Page 19 and 20: -0.01- . 04 5 -0.03- E 6 -0.0s- c)
Page 21 and 22: Assessment of Small Particle Iron O
Page 23 and 24: yields are calculated by subtractin
Page 25 and 26: conversion is greater than the corr
Page 27 and 28: Table 3. Effect of Superfine Iron O
Page 29 and 30: EFFECT OF A CATALYST ON THE DISSOLU
Page 31 and 32: inherent volatility of Mo(CO), perm
Page 33 and 34: Analysis of the quantity and compos
Page 35 and 36: $ EO .- 0 m L 0 c 0 0 > 40 300 350
Page 37 and 38: 0 0 0 0 0.000 0.005 0.010 0.015 0.0
Page 39 and 40: of these studies indicate that cont
Page 41 and 42: Different levels of adsorption occu
Page 43 and 44: Nominal 2 Table 1. Concentration of
Page 45 and 46: - iF m 1.6 1.4 1.2 - - - 1- 0 0.8 -
Page 47 and 48: RESULTS AND DISCUSSION Swelling of
Page 49 and 50: . . % . . 9 'HF 0 0 0 *. . 0 . . 0
Page 51 and 52: 1.50 KQ 1.00 0.50 I / ' 02 525 I 1
Page 53 and 54: hydrogen atoms. The hydrogen atoms
Page 55 and 56: D to generate more D atoms. It is r
Page 57 and 58: 12. a. Poutsma, M. L.; Dyer, C. W.
Page 59 and 60: Figure 3. Minimum Steps to Explin D
Page 61 and 62: Apoaratus and Procedure Microflow R
Page 63 and 64: Model ComDound Test Figure 5 shows
Page 65 and 66:
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
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impregnating solvent. Table 3 shows
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of MoCo-TC2 at the level of 0.5 wt%
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Table 4. Effect of Temperature Prog
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In the past, chemical treatments in
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The effect of Corn20 preaatment on
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Reaction Time Figure 1 - Schematic
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DISSOLUTION OF THE ARGONNE PREMIUM
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A much more def~tive trend is seen
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EFFECT OF CHLOROBENZENE TREATMENT O
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same conditions and an extraction t
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ACKNOWLEDGEMENT The authors thank t
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THE STRUCTURAL &=RATION OF HUMINlTE
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to be originally derived from demet
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145 30 I --/---Jh I , , I I , 250 2
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THE EFFECTS OF MOISTURE AND CATIONS
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1 for the Zap lignite. These result
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content of the samples ion-exchange
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Table 1. F'yrolysis Results of Vacu
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585 I
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EFFECT OF TEMPERATURE, SAMPLE SI2E
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of some of the thermobalance runs.
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2. The mechanism of drying is a uni
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Influence of Drying and Oxidation 0
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"c gives W conversion mpared to the
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Table 1. Products dismbutions (dmmf
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- 50 45 40 E 35 2 30 E T) 25 ap 20
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Influence of Drying and Oxidation o
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FTIR . . of the L m To investigate
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CONCLUSIONS The characexizntion of
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A b S 0 r b a n C e A b s 0 r b a n
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An NMR Investigation of the Effd of
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for determining the area of the pea
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of the ronl roniponcnte nnd (2) the
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2w 180 160 9 140 120 P loo f 80 P O
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25 I 20 ' + 0 Drying lime, hours Fi
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substructure have been identified a
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Pyridine extraction showed that 60
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Figure 1. Reflected white-light pho
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Table 3. Pyridine Extraction Sample
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A bang-bang control strategy was us
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increased from 120°C to 135”C, r
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* wt% based on the amount of naphth
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Use of Biocatalysts for the Solubil
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Results Enzyme Modification with Di
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Conclusions Reducing enzymes can be
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Dynamics of the Extract Molecular-W
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where yi = (x-xi !/pi. The zero mom
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satisfactory agreement between theo
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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
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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
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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