92
Ind. Eng. Chem. Process Des. Dev. 1985, 2 4 , 92-97
T = temperature, C
f = mean
mole fraction of xylene in the collected portion of the eluted peak rim= loading capacity of adsorbent for component i, mol/g Registry No. Isopropylbenzene,98-82-8; m-xylene, 108-38-3; p-xylene, 106-42-3; ethylbenzene, 100-41-4; benzene, 71-43-2; toluene, 108-88-3. L i t e r a t u r e Cited
Carri, S.;Santacesaria, E.; Morbldelli, M.; Codignoia, F.; Di Fiore, L. U.S. Patent 4368347, Jan 11, 1983. De Vault, D. J. Am. Chem. SOC.1943, 6 5 , 532. Morbldelli, M.; Santaceseria, E.; Storti, Q.; CarrB, S. Ind. Eng. Chem. Process Des. Dev. 1885, companion paper in this issue. Santacesaria. E.; Codignola, F.; Gelosa, D.; CarrB, S. Italian Patent 21059A, 1982. Santacesaria, E.; Gelosa, D.; Danise, P.; Carri, S . Ind. Eng. Chem. Process Des. Dev. 1985, companion paper in this issue. Seko, M.; Miyake, T.; Inada. K. Ind. Eng. Chem. Prod. Res. Dev. 1979, 18, 263.
Received for review May 6, 1983 Accepted March 22, 1984
Berg, E. W. “Physical and Chemical Methods of Separatlon”; McGraw-Hill: New York, 1963.
Catalytic Hydroprocessing of SRC-I I Heavy Distillate Fractions. 4. Hydrodeoxygmation of Phenolic Compounds in the Acidic Fractions Cheng-Lle LI, ZI-ren Xu, and Bruce C. Gates’ Center for Catalytic Science and Technology, Department of Chemlcal Engineering, University of Delaware, Newark, Delaware 19716
Leonldas Petrakis’ Gulf Research and Development Company, Pittsburgh, Pennsylvania 15230
Heavy distillate obtained by hydroliquefaction of Powhatan No. 5 coal was separated into nine fractions by liquid chromatography. The very-weak-acid and weak-acid fractions were used as feeds in hydroprocessing experiments with sulfided Ni-Moly-Al,O, catalyst at 350 O C and 120 atm. Analysis by I R spectroscopy and gas chromatographylmass spectrometry wowed that the principal components of these coal liquid fractions are substituted phenols and naphthols; the principal reactions were hydrodeoxygenations. The two fractions had similar compositions and reactivities. The reactant compounds included 5,6,7,8-tetrahydro-l-naphthol,Ccyclohexylphenol, methylphenylphenol,and 2-hydroxyphenylbenzene;rate constants for the conversion of each are roughly the same, were converted an order of magnitude more rapidly than dibenzofuran about lo4 L/(g of cat. s). These in the neutrakils fraction of the coal liquid. The hydrodeoxygenatbn of the acidic compounds is rapid in comparison with other hydroprocessing reactions of coal liquids, including hydrogenation of aromatics, hydrodesulfurization, and hydrodenitrogenation.
Introduction
Liquids derived from coal may ultimately replace petroleum, but before they are appropriate for many applications, they require expensive refining to increase hydrogen to carbon ratios and to remove heteroatoms, namely, sulfur, nitrogen and oxygen. This refining is accomplished most efficiently in catalytic reactions with hydrogen. Much is known about the removal of sulfur from fossil fuels by hydroprocessing, since hydrodesulfurization of petroleum has long been practiced on a large scale (Gates et al., 1979). Hydrodenitrogenation is also practiced industrially, but it is less well understood; it proceeds unselectively, as aromatic ring hydrogenation precedes C-N bond cleavage (Katzer and Sivasubramanian, 1979). Only little is known about hydrodeoxygenation, but the relatively high oxygen contents of many synthetic fuels point to the need for characterization of this class of reaction. Hydrodeoxygenation of some pure compounds (dibenzofuran, o-cyclohexylphenol,and l-naphthol) has been investigated (Landa et al., 1969; Krishnamurthy et al., 1981; Krishnamurthy and Shah, 1982; Vogelzang et al., 1983; Li et al., 1985). The literature demonstrates that hydrodeoxygenation of organooxygen compounds proceeds 0196-430518511124-0092$01.50/0
by direct oxygen removal as well as by pathways involving prior ring hydrogenation. The rate of the former reaction becomes much greater than the rate of the latter in 1naphthol conversion at temperatures greater than 350 “C (Li et al., 1985). Hydrodeoxygenation of dibenzofuran in heavy petroleum gas oil has been reported (Furimsky, 19781, but other data characterizing reactivities of organooxygen compounds in fossil fuels are lacking. The broad objectives of the work reported in this series of papers (Petrakis et al., 1983a,b; Katti et al., 1984) were to characterize the catalytic hydroprocessing reactions of a coal-derived liquid under conditions of potential industrial processes. A specific objective was to investigate the hydrodeoxygenation reactions. A sample of SRC-I1 liquid was separated by preparative liquid chromatography into nine fractions, each containing chemically similar compounds (Petrakis et al., 1983a). The fractions have been characterized in detail by a series of techniques, including ‘Hand 13C NMR spectracopy and high-resolution mass spectrometry (Petrakis et al., 1983b). The plan was to investigate the hydroprocessing of each of these fractions separately. The fact that each fraction is much less complex than the whole coal liquid provides the opportunity for detailed, quantitative characterization of the various 0 1984 American Chemical Society
Ind. Eng. Chem. Process Des. Dev., Vol. 24, No. 1, 1985
hydroprocessing reactions; gas chromatography/mass spectrometry even provides the opportunity for determining kinetics of the conversion of individual compounds in the coal-liquid fractions. In this paper we report on the reactions of the veryweak-acid and the weak-acid fractions. These fractions contain only low concentrations of sulfur- and nitrogencontaining compounds and high concentrations of oxygen-containing compounds (8.90 and 9.79 wt % 0, respectively) (Petrakis et al., 1983a). Characterization of these fractions by infrared and NMR spectroscopy (Grandy et al., 1984) showed that the oxygen is contained predominantly in phenolic -OH groups. Other important classes of organooxygen compounds are ethers, furans, and ketones. The neutral oxygen-containing compoundstypified by dibenzofuran-are contained in the neutral-oils fraction, the reactions of which are to be considered separately. The separation of the coal liquid into the fractions therefore makes possible a determination of the reactivities of the different classes of oxygen-containing compounds. The primary goal of the work summarized here was to determine the reactivities of the phenolic compounds in the acidic fractions. The separation of the coal liquid into fractions by preparative-scale liquid chromatography was time-consuming and expensive. One kilogram of heavy distillate of hydroliquefied coal was fractionated, yielding only 10 g of the very-weak-acid fraction and 12 g of the weak-acid fraction. The small amounts of the fractions dictated that the catalytic hydroprocessing reactions be carried out with a microreactor. Each fraction was dissolved in cyclohexane, giving a concentration of 0.25 wt 70,and then the solution was saturated with hydrogen. The reactants, maintained in the liquid phase in the high-pressure reador, flowed over a typical Ni-Mo/y-A1203 hydroprocessing catalyst, and the products were analyzed to provide a characterization of the hydroprocessing reactions.
Experimental Section Materials. The catalyst was commercial NiO-Moo3/ y-A1203(American Cyanamid HDS 9A) crushed and sieved to 150 pm average particle size and sulfided in situ as described below. Catalyst compositions and properties are given elsewhere ( H o d a et al., 1978). The acidic fractions of the coal liquid were dissolved in cyclohexane (Fisher Scientific, Certified ACS). Hydrogen was obtained from Linde as 3500 psi grade, 99.95%. Hydrogen sulfide was supplied by Linde in custom mixtures with 10 mol 90H2S in H2. Alundum “RR” (Fisher Scientific, Blue Label) (approximately 150 pm average particle size) was used as an inert reactor packing. Procedures. A high-pressure, packed-bed flow microreactor (described in detail by Eliezer et al., 1977)was used. The catalyst particles (25 to 200 mg) were mixed with alundum particles (0.4 g) to give a bed volume of about 0.3 cm3and a bed height of about 4 cm. The catalyst was presulfided in the reactor for 2 h with a flow of 0.5 to 0.7 cm3/s of 10 vol % H2Sin H2 at atmospheric pressure and 400 “C. Sulfur present in the feed maintained the catalyst in the sulfided form; the sulfur was added as carbon disulfide, which was converted rapidly into H2Sunder the reaction conditions CS2 + 4H2 2H2S + CHI (1)
-
Reactant solutions containing 0.25 wt % of one of the acidic coal-liquid fractions in cyclohexane were prepared and loaded into an autoclave serving as a saturator. The reaction mixture was purged repeatedly with hydrogen.
93
Cycloheione
-
Product 0 1 W H S V z O I
025 0 70
I 4000
I 3600
2 3200
Wavenumber s
Figure 1. Infrared spectra indicating the O-H stretching region of the very-weak-acid fraction and products of the hydroprocessing reaction of this fraction catalyzed by sulfided Ni-Moly-Al,O,.
CS2in the cyclohexane was added to the autoclave to give a concentration of 0.1 w t %, and the reactant mixture was stirred and brought to saturation with hydrogen at 86 atm; this procedure provided a large stoichiometric excess of hydrogen over the coal-liquid fraction. Immediately after the sulfiding of the catalyst, the reactor was cooled to the desired reaction temperature (usually 350 “C), and flow of the reactant mixture was started. Because of the limited amounts of the acidic fractions, the duration of each experiment was limited to 30 to 40 h, and only one replicate experiment was done to establish the reproducibility of the results. Each run was begun with a fresh catalyst charge, and temperature, pressure, and feed flow rate were held constant during the run. Separate experiments were done to determine the effects of temperature and space velocity on conversion. Analysis of Feeds and Products for Oxygen. The oxygen contents of feeds and products were determined by neutron activation analysis by Microanalysis, Inc., Wilmington, DE. Since these concentrations were low, it was necessary to remove most of the cyclohexane solvent from the samples prior to the analysis; the distillation was carried out under helium. Alternatively, determinations of -OH group concentration in the feed and product solutions were carried out by infrared spectroscopy. The samples were placed in cells with NaCl or CaFz windows and analyzed with a Nicolet 7199 Fourier transform infrared spectrometer. The absorption of solvent (cyclohexane) in the range of 3000 to 4000 cm-’ was subtracted from the spectra. Typical results are shown in Figure 1. In a dilute solution of the coalliquid fraction in a nonpolar solvent, there is an absorption at 3590-3620 cm-’, indicative of the O-H stretching vibration of phenolic compounds (Socrates, 1980). This result was confirmed with pure compounds representative of the coal-liquid fractions (e.g., l-naphthol and 5,6,7,8tetrahydro-l-naphthol) in cyclohexane solution. Evidently, there are no significant complications indicative of hydrogen bonding of the phenolic compounds in these dilute solutions; this result is consistent with the analytical results (Petrakis et al., 1983a,b) showing the near absence of compounds with -NH groups, which would interfere in the infrared analysis. We emphasize that the O-H band characteristic of the acidic coal-liquid fractions and their products is sharp, and the data are suited to quantitative analysis (Hara et al., 1979). Solutions of 5,6,7,8-tetrahydro-l-naphthol in cy-
Ind. Eng. Chem. Process Des. Dev., Vol. 24, No. 1, 1985
94
5
07
e c
f 05
:0 2
00' 0
I
10
1
20 Time Onstreom, h
1
I
30
Figure 2. Break-in of the sulfided Ni-Mo/y-A1203 catalyst in the hydroprocessing of the very-weak-acid fraction at 350 O C and 120 atm. The space velocity was 0.64 g of very weak and fraction/(g of cat. h).
clohexane were used to determine the relation between the peak height in the infrared spectrum and concentration; the plot is linear. The infrared data were therefore used for quantitative determination of -OH group concentrations. Analysis of Feeds and Products by Capillary Column Gas Chromatography. Analyses were carried out with a Perkin-Elmer 3120B gas chromatograph equipped with a capillary column (SE-54), 30 m in length and 0.2 mm in inside diameter; it was programmed at a rate of 2 "C/min from 50 to 220 "C. The gas chromatographic data provided conversions of individual compounds in the mixtures. The results were interpretable in a straightforward manner for those compounds represented by isolated peaks in the chromatograms; only a small fraction of the compounds could be characterized in this way. Combined gas chromatography/mass spectrometry was used to identify individual compounds. The chromatographic procedures were those described above; the mass spectrometer was run in one of two modes. (1)In the chemical ionization mode (with methane as the reactant gas), the mass spectra identified the parent ion, determining an estimate of the molecular weight of each compound. (2) In the electron impact mode, the fragmentation pattern of each compound was obtained, providing a fingerprint of the compound. This analysis was performed in the Mass Spectrometry Laboratory of the Department of Chemistry of The Pennsylvania State University. Selected product samples were extracted with an aqueous solution of 10% NaOH; analysis by gas chromatography indicated that there were no phenolic compounds in the hydrocarbon phase. After a sample was subjected to extraction four times (each time with the volume ratio of NaOH solution to sample being l:l), it was washed with deionized water and then stored over 4A molecular sieve to remove water. This purification allowed us to distinguish phenolic compounds from hydrocarbons in the gas chromatograms. Results Typical conversion data for the weak-acid fraction, showing oxygen removal as a function of time on stream, are presented in Figure 2. These data were determined from the infrared analysis of phenolic groups; similar data were obtained from the elemental analyses. These results indicate a break-in of the catalyst similar to that observed with 1-naphthol (Vogelzang et al., 1983);after roughly 20 h on stream, the catalyst was stable and steady-state data
00
10
05
I N V E R S E SPACE VELOCITY,
(
g
15
oP,"d,,'~y'$~ h
i
Figure 3. First-order kinetics of removal of phenolic groups in hydroprocessing of the weak-acid fraction at 350 "C and 120 atm. The concentration of phenolic groups was determined by infrared spectroscopy. Table I. Conversion of Phenolic Oxygen in Acidic Fractions of SRC-I1 Coal Liquid Catalyzed by Sulfided Ni-Mo/r-Al,Ot at 120 atm WHSV, fractional conv (g of feed fraction)/ temp, of phenolic feed fraction (g of cat. h) "C oxygen very weak acid 0.05 1.0 350 1.0 0.10 very weak acid 350 0.20 0.49 300 very weak acid 0.20 0.77 325 very weak acid 1.0 0.20 350 very weak acid 0.84 0.40 350 very weak acid 0.60 350 0.55 very weak acid weak weak weak weak weak
acid acid acid acid acid
0.20
0.40
350 300 325
0.40
350
0.60
350
0.40
1.0
0.33 0.78 0.92 0.61
were obtained. All the data reported in the following paragraphs were determined in the steady-state operating period for each experiment. Conversions of phenolic oxygen in the weak-acid fraction were determined from the infrared data as a function of space velocity at 350 "C and 120 atm; these results are summarized in Figure 3, a first-order kinetics plot. The data show that the hydrodeoxygenation process is well represented by first-order kinetics for the overall conversion of phenolics in the weak-acid fraction. The lack of sufficient feed material precluded our obtaining a similar set of detailed data for the very-weak-acid fraction. The data summarized in Table I demonstrate that the reactivity of the phenolic compounds in the very-weak-acid fraction is roughly the same as that of the compounds in the weak-acid fraction. This result is not surprising, since the two fractions are similar in composition and properties (Petrakis et al., 1983b). A few data were also determined to establish the dependence of conversion on temperature (Table I). The conversion increased markedly with temperature, as expected. The chromatograms of the weak-acid fraction and the products of its hydroprocessing (Figures 4 and 5, respectively) allowed determination of quantitative kinetics of the conversion of individual organooxygen compounds.
Ind. Eng. Chem. Process Des. Dev., Vol. 24, No. 1, 1985
95
1
Lo
t 3
> a a
c a
< c z c w
I Q i
i?
J 40
50 60 ELUTION T I M E , m i r
70
Figure 4. Chromatogram of the weak-acid fraction obtained with a capillary column programmed a t a rate of 2 "C/min from 50 to 220 "C. The designated peaks were identified by their mass spectra. 50
100
200
300
400
500
SCAN NUMBER
Figure 7. Gas chromatography/mass spectrometry traces and molecular weights of individual compounds in the very-weak-acid fraction determined by chemical ionization mass spectrometry. 10
ELdrION
'IME
m n
0.8
Figure 5. Typical chromatogram of catalytically hydrotreated products from the weak-acid fraction (the chromatographic conditions were the same as those used for the feed) (Figure 4).
n 09
+ W W
(L
z
8
07
z 3 z
0
:0 6 LL
05
\-
4-Cyclohexylphenol
\
\ .\ 0
, I
I N V E R S E SPACE V E L O C I T Y ,
IO0
200
300
400
500
SCAN NUMBER
Figure 6. Gas chromatography/mass spectrometry traces and molecular weights of individual compounds in the weak-acid fraction determined by chemical ionization mass spectrometry.
Combined gas chromatography/mass spectrometry data characterizing the weak-acid and very-weak-acid fractions are shown in Figures 6 and 7, respectively;the number next to each peak represents the molecular weight of the compound determined by chemical ionization mass spectrometry. Using these data and the fragmentation patterns determined by electron impact mass spectrometry, we determined the identities of the following compounds in the weak-acid fraction: 5,6,7,8-tetrahydro-l-naphthol and 2-hydroxyphenylbenzene. The identification of each of these compounds was confirmed by the analysis of the pure compounds by gas chromatography/mass spectrometry (5,6,7,8-tetrahydro-l-naphthol, 99 % , Aldrich; 2-phenylphenol, 99+ %, Aldrich, Gold Label). Other compounds were identified by their mass spectra, but the authentic compounds were not available to confirm the identifications: 4-cyclohexylphenol, 1-hydroxy-1-dimethylindan, and an isomer of tetrahydromethylnaphthol.
1
(
2 g o f weok acld
)'
g of c o l o l y s l h
Figure 8. Reactivities of some pure compounds in the weak-acid fraction at 350 "C and 86 atm. A fourth point for 4-cyclohexylphenol is off scale.
Another compound, an isomer of methylphenylphenol, was identified tentatively by chemical ionization mass spectrometry and by its solubility in 10% NaOH. [The possibility that the compound was actually hydroxydiphenylmethane was ruled out by the retention time of the authentic compound (Aldrich, 99%) determined by gas chromatography.] The peaks of these compounds are identified in Figures 4 and 6. Identification of the remaining peaks is lacking, either because the peaks were too small or not well resolved. Most of these compounds were also shown by mass spectrometry to be present in the very-weak-acid fraction, as indicated in Figure 7 . The resolution of the peaks in this fraction was not as good as that of the peaks in the weak-acid fraction, and since there was so little of the very-weak-acid fraction available, no quantitative kinetics could be determined for the compounds present in it. Data determined for the individual compounds in the weak-acid fraction are summarized in Figure 8. These results show that the removal of each of the reactants is well represented by first-order kinetics. The pseudo-
96
Ind. Eng. Chem. Process Des. Dev., Vol. 24, No. 1, 1985
Table 11. Pseudo-First-Order Rate Constants of Oxygen-Containing Compounds in the Weak-Acid Fraction at 350 'C and 120 atm rate constant, L i k of reactant structure cat. s) 5,6,7,8-tetrahydro-1-naphthol
I
I
1
I
1
Gasoline and Kerosene
1.91 X lo4 Kerosene
2-hydroxyphenylbenzene
methylphenylphenol
4-cyclohexylphenol phenolic oxygen in weak-acid fraction dibenzothiophene in neutral oils
& d~ 8.33 x 10-5
1.52 x 10-4
moH 4.46 x 10-4
1.56 x 10-4 5.8 x 10-5
first-order rate constants are summarized in Table 11. Additional information regarding the formation of light products during catalytic hydroprocessing is provided by the gas chromatographic analyses. Since the capillary column separated the compounds according to boiling point, the chromatographic separation can be considered as a simulated distillation. Comparing the feed (Figure 4) and product (Figure 5) chromatograms, we infer that there were high yields of light products. The compounds lighter than those in the feed were lumped into two groups-those boiling in the gasoline and kerosene ranges. All the compounds having normal boiling points up to approximately 200 "C were considered to be in the gasoline range; the ones with higher boiling points were considered to be in the kerosene range. The yields are shown in Figure 9 for reaction of the weak acids at 350 "C and 120 atm at various space velocities. The lighter products formed were not acidic; they were inferred to be hydrocarbons. This inference was confirmed as follows. The feed and a few product samples were extracted with aqueous NaOH (10 wt %), dried with a molecular sieve, and injected into the gas chromatograph. The majority of the peaks in the feed chromatogram were not present in the extracted feed chromatogram [this confirms the acidic nature of the feed]. However, a similar analysis of the lighter peaks in the original and extracted product chromatograms revealed no changes. This result implies that the lighter compounds formed were not acidic. They are inferred to be hydrocarbons, consistent with the reaction networks for hydrodeoxygenation of pure compounds (Krishnamurthy et al., 1981; Li et al., 1985). Discussion The individual compounds identified in the acidic fractions of the coal liquid by gas chromatography/mass spectrometry are chiefly substituted naphthols and phenols. This conclusion points to compounds such as 1naphthol as good models for these fractions. The results are in good agreement with the previously reported characterizations of these fractions by grouptype analyses, primarily infrared and lH,'V, and 1 7 0 NMR spectroscopy (Petrakis et al., 1983b; Grandy et al., 1984). The identifications of the individual compounds also confirm the
1
I
I
I
I
1
2
3
4
5
6 I
Inverse Space Velocity,
(
,P;:+:;yes~,.h
j
Figure 9. Yields of gasoline and kerosene boiling-range products in the hydroprocessing of the very-weak-acid fraction at 350 "C and 86 atm.
earlier conclusion that they are relatively small one- and two-ring compounds with few substituents, typically methyl (Petrakis et al., 1983b). All the data reported here are indicative of hydrodeoxygenation as the principal reaction characteristic of the catalytic hydroprocessing of the acidic fractions. These results are consistent with those of Li et al. (1985), who investigated the reaction network involving 1-naphthol and hydrogen in the presence of sulfided Ni-Mo/yAl,O,; Li's results show that hydrogenation of the aromatic rings takes place in parallel with hydrodeoxygenation. We infer from these pure-compound data that hydrogenation was also important in the conversion of the acidic fractions, but there is no basis for a quantitative determination of the extent of the hydrogenation reactions. The data reported here demonstrate that the reactions leading to the conversion of the individual organooxygen compounds (and the overall hydrodeoxygenation) are fast in comparison with other catalytic hydroprocessing reactions occurring in the presence of the same catalyst at the same temperature and pressure. For example, the individual rate constants for conversion of 5,6,7,8-tetrahydro-1-naphthol and 4-cyclohexylphenol at 350 "C and and 4.5 X lob4L/(g of cat. s), re120 atm are 1.9 X spectively. In contrast, the pseudo-first-order rate constant for conversion of dibenzothiophene in the neutral-oils fraction of the coal liquid under the same reaction conditions is 5.8 X 10-5L/(g of cat. s) (Katti et al., 1984). Data obtained for hydroprocessing of the neutral oils under somewhat different conditions (a batch reactor at 350 "C and 35 atm, with the same Ni-Mo/y-A1203 catalyst) show that conversion of dibenzofuran is an order of magnitude slower than conversion of dfbemthiophene; hydrogenation of aromatic hydrocarbons (namely, pyrene and phenanthrene) was also observed to be about an order of magnitude slower than the conversion of dibenzothiophene (Katti, 1984). To sum up, the data demonstrate that the hydrodeoxygenation of the phenolic compounds appears to be a fast hydroprocessing reaction under practical reaction conditions. The data are not sufficient, however, to provide a demonstration of the competitive inhibition effects in these hydroprocessing reactions. There are pure compound data, however, indicating that the hydro-
Ind. Eng. Chem. Process Des. Dev. 1085, 2 4 , 97-107
07
in the laboratory. The work was supported by the U.S. Department of Energy.
deoxygenation of dibenzofuran is strongly inhibited by 7,8-benzoquinoline (Krishnamurthy and Shah, 1982), and we expect that basic nitrogen-containing compounds inhibit conversion of phenolic compounds as well. The reactivities of the individual organooxygen compounds in the acidic fractions are all roughly the same (Table 11, Figure 8), the greatest difference being a ratio of 5.4 for 4-cyclohexylphenol and 2-hydroxyphenylbenzene. These results are in good agreement with the pure compound data of Krishnamurthy et al. (1981) (obtained at about 350 OC and 104 atm with an Ni-Mo/y-A120, catalyst). We suggest that the small differences in the observed reactivities reflect subtle steric and electronic effects. For process modeling, it may be a good approximation to use one rate constant to represent all the substituted phenols and partially hydrogenated naphthols. The relative rapidity of the conversions of these oxygen-containing compounds implies that they may be largely converted in hydroprocessing of coal liquids (and other fossil fuels), with relatively high hydrogen consumptions being expected. Water is a product of the hydrodeoxygenation reactions, and we might expect it to have an effect on the catalyst structure and activity. The data of Figure 3 indicate that-at least in the presence of excess H2S and hydrogen-the effect is small, being reflected only in the break-in period. These results are in agreement with those observed in experiments with 1-naphthol (Vogelzang et al., 1983). Acknowledgment We thank S. S. Starry and S. K. Banerjee for assistance
Registry No. Ni, 7440-02-0;M o , 7439-98-7;5,6,7,8-tetrahydro-1-naphthol,529-35-1;4-cyclohexylphenol,1131-60-8;3(3-methylphenyl)phenol,9325486-5;2-hydroxyphenylbenzene, 90-43-7.
Literature Cited Ellezer. K. F.; Bhlnde, M.; Houalla, M.; Broderlck, D. H.; Gates, B. C.; Katzer, J. R.; Olson, J. H. Ind. En Chem. Fundem. 1977, 16, 380. Furimsky, E. Fuel 1978,57, 194. Gates, B. C.; Katzer. J. R.; Schult. G. C. A. "Chemistry of Catalytic Processes"; McGraw-HIII: New York, 1979. G r a m , D. W.; Petrakls, L.; Young, D. C.; Gates, B. C. Netwe (London) 1884, 308, 175. Hara, T.; Tewarl, K. C.; Li, N. C.; Fu, Y. C. Prep., Dlv. Fuel Chem., Am. Chem. Soc. 1979,24(3), 215. Houalla, M.; Nag, N. K.; Sapre. A. V.; Broderick, D. H.; Gates, B. C. A I C E J . 1978,2 4 , 1015. Kattl, S. S. Ph.D. thesis, University of Delaware, Newark, DE, 1984. Kattl, S. S.; Westerman, D. W. 8.; Gates, B. C.; Youngless, T.; Petrakis, L., Ind. Eng. Chsm. Proc. Des. Dev. 1884,2 3 . 773. Katzer. J. R.; Slvasubramanlan, R. Catel. Rev.-Scl. Eng. 1878, 2 0 , 155. Krishnamwthy, S.; Panvelker. S.; Shah, Y. T. A I C E J . 1881,2 7 . 994. Krishnamurthy, S.; Shah, Y. T. Chem. Eng. Commun. 1862. 16, 109. Landa, S.; Mmkova, A.; Bartova. N. Sci. Pap. Inst. Chem. Tech. Prague 1868,D 16, 159. Li, C.4.; Xu, 2.43.; Cao, L A . ; Gates, B. C.; Petrakis, L. AIChEJ. 1885,in press. Petrakls, L.; Ruberto, R. G.; Young, D. C.; Gates, B. C. Ind. Eng. Chem. Process. Des. D e v . 1983a,2 2 , 292. Petrakis, L.; Young, D. C.; Ruberto, R. G.; Gates, B. C. Ind. Eng. Chem. Process D e s . D e v . 1983b,22, 298. Socrates, 0."Infrared Characteristlc Group Frequencies"; Wlley-InterscC ence: New York. 1480. Vogelzang, M. W.; Ll, C.-L.; Schult, G. C. A.; Gates, B. C.; Petrakls, L. J . Catel. 1983,84,170.
.
Received for review M a y 13, 1983 Accepted April 9,1984
Thermophysical Properties of Coal Liquids. 3. Vapor Pressure and Heat of Vaporization of Narrow Boiling Coal Liquid Fractions James A. Gray' Gulf Research and Development Company, Pittsburgh, Pennsylvania 15230
Gerald D. Holder University of Pittsburgh, Pittsburgh, Pennsylvania
1526 1
C. Jeff Brady, John R. Cunningham, John R. Freeman, and Grant M. Wllson Wlttec Research Company, Provo, Utah 8460 1
Coal liquids produced from SRC-I1 processing of Pittsburgh Seam bituminous coal from Powhatan No. 6 Mine were distilled into a number of narrow boiling cuts. Vapor pressure measurements were performed on 6 heart cuts at temperatures from 267 to 788 K and pressures to 3.6 MPa with both batch still and flow apparatuses. Heats of vaporization were measured in a flow calorimeter on these same fractions at temperatures from 366 to 755 K. After a number of correlation methods were reviewed, it was found that the modified BWR equatbn-of-state developed by Brul6 and co-workers specifically for coal fluids gave the best representationof vapor pressure data. An empirical method InvoMng a simple boiling point relatlonship combined with the Watson equation gave the best predictions of the latent heat data.
Introduction In the design of coal processing plants, in many instances one must accurately estimate thermodynamic properties such as vapor pressures and heats of vaporization of coal 0196-4305/85/ 1124-0097$01.50/0
liquid fractions. Although a number of generalized methods have been published (Reid et al., 1977; MI, 1976) and are widely used for paraffinic petroleum-derived fractions, there has been some concern (Newman, 1981, 0 1984 American Chemical Society
