liquefaction pathways of bituminous subbituminous coals andtheir

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20-165 mg. Runs were typically isothermal, with temperatures selected from 20 to 80°C. The gas velocity movin9 upward past the sample was typically 80 cc/min (but ranged from 20 to 160) in the 25 mm diameter tube. The thermobalance was modified so that all of the gas flow passed around the sample, rather than partly through the weighing mechanism. The sample was placed in a quartz flat bottom bucket about 10 mm internal diameter. The samples were the -100 mesh Argonne,Premium Coal Samples: Beulah- Zap lignite and Wyodak-Anderson subbituminous (6). Samples were quickly transferred from ampoules which had been kept in constant humidity chambers with water at room temperature (2OoC or 293 K). In the thermobalance system a period of about 5 minutes was used to stabilize the system and initiate data ac- quisition. A condenser was made to replace the usual quartz en- velope and furnace that surrounds the sample. Water was circu- lated from a constant temperature bath through the condenser to maintain constant temperature during the experiments. This was more stable than the original furnace and provided uniform temperature control during the experiments. The atmosphere for the nitrogen gas runs was cylinder nitrogen (99.99%) or "house" nitrogen from the evaporation of liquid nitrogen storage containers used without further purification. Data were analyzed on a separate microcomputer as reported ear- lier (1-4). Regression analysis was used to obtain the kinetic constants in terms of mg of water lost/gm sample per 10 second time interval. Lotus 123 was used for analysis of individual run data. In some runs, approximations to a first and second deriva- tive of the rate expressions were made in Lotus 123 by averaging over a number of the 10 second time intervals before and after the point of interest. These derivatives were plotted with the rate data to aid in identifying the beginning of the transitions from an.initial phase of drying to a second, slower phase. The initial drying kinetic data from a run at a temperature different from room temperature were collected over a time in which the sample was reaching the temperature of the system. These runs indicated that the initial rate increased for about 10-30 minutes until a constant value for the first phase was reached. Figure 1 indicates typical weight changes over the duration of a run for the Beulah Zap lignite and the Wyodak-Anderson subbituminous samples. Note that the lignite has a higher initial moisture content and therefore can lose more water. Surface area measurements were carried out to complement the drying kinetic runs. The surface area was assumed to be impor- tant in that it determines the amount of exposure to the gaseous phase. The greater the surface area the greater the overall reaction rate will be, assuming a similar reactivity per unit of surface and comparable access to exterior and interior'surface. The Quantasorb Jr. instrument was used for nitrogen BET (Brunauer-Emmett-Teller) measurements of the surface. A series of values were obtained on samples which were prepared by drying in the vacuum oven at a range of temperatures as well as a set of nitrogen dried samples, prepared both in the vacuum oven' with a flow of nitrogen at atmospheric pressure, and also the products 588
of some of the thermobalance runs. The typical run gives the data from the desorption cycle. Samples of nitrogen in helium (10, 20 and 30% nitrogen) were allowed to interact with the surface of the sample. Adsorption was carried out at liquid nitrogen temperatures. The amount of adsorbed nitrogen was determined by calibration of a thermal conductivity bridge. RESULTS AND DISCUSSION A typical run indicates a rapid initial moisture loss, followed by significantly reduced rates. A plot of the logarithm of the water left as a function of time gives two straight line segments followed by a downward slope for the loss of the last 1%. See Figure 2 for typical lignite and subbituminous coal runs. The first line segment has been correlated with the loss of "freezable" water, while the latter has been associated with "non-freezableIq water as identified by Mraw and co-workers (7,s). The rate constants for the initial rate loss can be correlated with an Arrhenius plot to give an activation energy for the initial stage of water loss, but the second stage could not be correlated. A multiple regression analysis of the initial rate with the values of the absolute temperature, gas flow and sample weight was carried out with the data from 51 runs made with -100 mesh material in dry nitrogen. For an equation of the form: Log Initial Rate (mg water left/gm sample/lO second interval)= c * Temperature (K) + c3 * Gas flow (cc/min) + c3 Sample Weight (ms) f c4 The best fit was given for: C1 = C3 = -0248 -.00528 c2 =_ .00376 Cq - -3.295 - with an R2 value of .867. These values cover experiments range of 2O-8O0C, 20-160 cc/min gas flow and 20-169 mg weight. in the sample A smaller series of runs (6) made with the -100 mesh Wyodak subbituminous sample at gas flow rates of 80 cc/min were analyzed with multiple regression. The best fit over the range of 20-60°C and weight of 40-80 mg were given by: log kl (initial rate in mg water left/gm sample /10 second interval) = .0242 * Temperature (K) -.00673 * Sample weight (mg) - 9.315. The R2 value = .983. There is a similarity in the coefficients for the temperature and the weight for the two coals. The similarity in the two curves in Figure 2 would also indicate this. The surface area measurement data are given in Table 1. Table 1, Surface Area Measurements Run # Drying Temp. Su face area 5 Method OC. m /gm ND173 Nitrogen 22 1.993 589
Page 1 and 2:
LIQUEFACTION PATHWAYS OF BITUMINOUS
Page 3 and 4:
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
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
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
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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 -
Page 47 and 48:
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
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
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: EFFECT OF TEMPERATURE, SAMPLE SI2E
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 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
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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
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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
Page 179 and 180:
ZAP WIO SIDE CHAINS IN PYRIDINE EXT
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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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