430
Ind. Eng. Chem. Fundam. 1003, 22, 430-433
K for 7.5 min gave guaiacols and catechols in 8.91% yield and phenols and cresols in 0.38% yield, for a total yield of these phenolics of 9.29%. Pyrolysis for 60 rnin gave 0.58% yield of guaiacols and catechols and 1.42% of phenols and cresols, which total to 2.0%. These data show that, of the 8.3% lower yield of guaiacols and catechols observed from 60 min pyrolysis relative to 7.5 min pyrolysis, only about 1% of this, at most, went toward production of phenols and cresols. The remaining 7.3% was evidently lost to coking, polymerization and other degradation reactions. However, superposition of the observed guaiacol HDO reaction selectivity to about 40% phenol, 10% cyclohexane, and 5% benzene on the 8.91% yield of guaiacols and catechols formed from pyrolysis for 7.5 min suggests that the combination of pyrolysis and HDO could result in the formation of a 4.9% higher yield (absolute) of phenols, cresols, and naphthenes than observed from pyrolysis alone. Summary and Conclusions The catalytic hydrodeoxygenation of two lignin model compounds, anisole and guaiacol, was investigated in the temperature range of 523 to 598 K with an initial reactant concentration of 3.5 X mol/g of oil and hydrogen pressure of 34.5 bar. A 1-L batch autoclave reactor was used with a presulfided CoMo/yA1203hydroprocessing catalyst slurried in a n-hexadecane paraffinic solvent reaction medium. Anisole HDO yielded phenol, benzene, and cyclohexane as major products, and a reaction network explaining these results included primary anisole reaction to phenol and secondary decomposition of phenol to benzene and cyclohexane. Arrhenius parameters for anisole decomposition were (log A (cm3/g of cat s), E* (kcal/mol) = (11.0 f 2.8, 29.7 f 7.1). Guaiacol HDO at 523 K yielded catechol, phenol, benzene, and cyclohexane, and proceeded through reaction pathways formally akin to those for anisole HDO. The formation of catechol from guaiacol was over 30 times faster than phenol formation from anisole. These results suggest that thermochemical conversion of lignin can be controlled and modified by catalytic HDO. Relative to lignin pyrolysis, lignin HDO or HDO of lignin pyrolysis liquids should produce higher yields of less
complex phenol product spectra. Acknowledgment
The authors wish to thank Drs. B. C. Gates and D. W. B. Westerman for valuable advice and support. Registry No. COO, 1307-96-6; Moo3, 1313-27-5; lignin, 9005-53-2;guaiacol, 90-05-1;anisole, 100-66-3;cyclohexane, 11082-7; benzene, 71-43-2; catechol, 120-80-9; phenol, 108-95-2. Literature Cited Aiian, G. G.;Matllla, T. I n "Llgnlns: Occurrence, Formatbn, Structure and Reactions"; Sarkanen, K. V.; Ludwig, C. H., Ed.; Wiley-Interscience: New York, 1971. Chan, R. W.; Kreiger, B. B. J. Appl. polym. Sci. 1981, 2 6 , 1. Connors, W. J.; Johanson, L. N.; Sarkanen, K. V.; Winslow, P. Hozforschung 1960, 34, 29. Domburg. G.E.; Sergeeva, V. N.; Kaininsh, A. I . I n "Thermal Analysis", Proceedlnas, 3rd International Conference on Thermal Analvsls, Davos. 1971; Pol. 3, p 327. Freudenberg, K.; Neish, A. C. "Consitutlon and Blosynthesls of Lignin"; Spr1nger;Verlag: New York. 1966. Frledlin, L. Kh.; Baiandln. A. A.; Nazarova, N. M. Izv. Akad. Nauk S . S . S . R . , M e / Khim (Nauk) 1949, No. 1 , 102. Glasser, W. G.;Glasser, H. R. Mecronwbcules 1974, 7 , 17. Harkin, J. M. I n "Oxldative Couplng of Phenols"; Taylor, W. I.; Battersby, A. I., Ed.; MarceiDekker: New York, 1967. Hall, C. C.: Cawley, C. M. J. Soc. Chem. Ind. 1938, 5 8 , 7. Hurff. S . J. B.Ch.E. Thesis, University of Delaware, Newark, DE, 1982. Iatridls, B.; Gavalas, 0. R. Ind. Eng. Chem. Prod. Res. Dev. 1079, 18, 127. Jegers, H. E. M.Ch.E. Thesis, Unhreralty of Delaware, Newark, DE, 1982. Kalechlts, 1. V.; Lipovich, V. G.;Vykhovanets, V. V. mi.Akad. Nauk SSSR 1061, 138, 381. Kirshbaum, I. 2.; Domburg. G.E. Izv. Akad. Nauk Lafv. SSSR 1970, No. 2 , 43. Kirshbaum, I. 2.; Domburg, G.E.; Sergeeva, V. N. Khim. D e v . 1076, No. 4, 96. Kislitsyn, A. N.; Rodionova, 2. M.; Savinykh, V. I.; Iii'ina, E. I.; Abakhumov, G. A. Sb. Tr., Tsentr. Nauch - Issled. Pro&. Inst. Lesokhim. Prom. 1971; No. 2 2 , 4. Klein, M. T. Sc.D. Thesis, M.I.T., Cambrldge. MA. 1981. Kravchenko. M. I.; Kiprianov, A. I.; Korotov, S. Ya. Nauch. Tr. Leningrad Lesofekh. Akad. 1970, 135(2), 60. Krishnamutthy, S.; Panveiker, S.; Shah, Y. T. A I C M J. 1981. 2 7 , 994. Landa, S.; Mrnkova, A.; Bartova, N. SclenHflc Papers of the Institute of Chemical Technology (Prague) 1969, D16, 159. Obolentsev, R. D. J. e n . Chem. ( U . S . S . R . )1946, 16, 1959. Rollman, L. D. J. Cafd. 1877, 48, 243. Shaposhinikov, Yu. K.; Kosyukova, L. V. Khim. Pererabofka Dev., Ref. Inform. 106$, No. 3 . 6. Weisser, 0.; Landa, S. "Sulfide Catalysts, Their Properties and Applications", Pergamon Press: New York, 1973.
Received for review August 16, 1982 Revised manuscript received April 11, 1983 Accepted July 20, 1983
Prediction of the Entropy of Vaporization at the Normal Boiling Point by the Group Contribution Method Dalsuke Hoshlno, Kunlo Nagahama, and Mitsuho Hlrata Department of Industrbi Chemistry, Faculty of Engineering, Tokyo Metropolltan Universny, 2- 1- 1 Fukasawa, Setagaya-Ku, Tokyo 158, Japan
The entropy of vaporization at the normal boiling points for 568 compounds (411 hydrocarbons and 157 nonhydrocarbons)are successfully predicted by this newly proposed group contrlbution method. This method only requires the chemical formula of the molecule. For all of the 568 compounds, direct comparisons were made between calculated results from the proposed group contribution method and Ilteratue values. The relative average error was 1.5% while the maximum error was 5.1% for sulfur chloride and l,ldifluoroethane, respectively.
Introduction
Numerous techniques for predicting the entropy of vaporization at the normal boiling point have been proposed 0196-4313/83/1022-0430$01.50/0
in the literature. The famous Trouton's rule expressed it as a constant value (Shinoda, 1978). Chen (1965), Giacalon (1951), Riedel (1954), and Vetere (Reid et al., 1977) 0 1983 American Chemical Society
Ind. Eng. Chem. Fundam., Vol. 22, No. 4, 1983
431
Table 1. Group Incrementsa increment
A S i , cal mol-'
K-'
increment,
nonring increments
9.5937 0.2320 -9.2739
--CH,
-CH*-CH-
A S i , cal mol''
oxygen increments -OH (alcohol) -OH (polyhydric alcohol)
16.1431 12.3831
-OH (phenol)
12.5903
-O-(nonring) -&(ring)
0.9091 1.2064
-c=O
1.1524
K-'
I
I
-c-
-19.1056
I
9.7455 0.3603
=CH,
=CH=C-
-9.0904
I
I
=C= =CH EC-
HC=O (aldehyde) -COOH (acid) HCOO- (formate)
0.0532 10.4266 0.9628
!I Z 2 t e )
10.0042 13.4542 12.2439 1.4042 2.7876
nitrogen increments
ring increments
20.2465 - 0.0023n -9.7467
-CH2-CH-
-NH, -NH-
(nonring)
12.4195 2.4096
-NH-
(ring)
-0.1585
(nonring)
-8.3134
I I
-c-
-19.3236
I
18.7504 + 0.3431m
=CH-
-NI
=c-
=N- (ring)
-9.3621
0.6702
I
double bond number between carbon atoms
t
0.0
(n
4)
{ -27.1977 t 9.1993n (n 2 5)
sulfur increments
halogen increments
-F
-SH
9.6777 10.0744 10.6423 10.3063
-cl -Br -1
10.7604 9.0484
-CN -NO,
-S- (nonring) -S- (ring) =S
10.5008 0,9524 0.9265 9.9953
miscellaneous
-B-
-11.9214
I
an = total number of increments in a molecule; 1 cal = 4.184 J.
presented correlations which were expressed by the function of critical pressure, critical temperature, and normal boiling point. McCurdy and Laidler (1963),and Hirata et al. (1979)proposed the group contribution method. McCurdy and Laidler's method (1963)was limited to a homologous series of aliphatic alcohols while that of Hirata et al. (1979)was limited to aliphatic hydrocarbons. The purpose of this investigation is to present a new and useful group contribution method of calculating the entropy of vaporization at the normal boiling points for both hydrocarbons and nonhydrocarbons.
The Proposed Group Contribution Method Among several empirical methods, the group contribution method has wide applicability for predicting the physical properties of pure compounds. By means of this method, the physical properties are easily predicted by the summation of group increments for each functional group which constitutes the compounds. The values of individual group increments can be determined by data regression using literature values. The present group contribution method is based on the following Trouton's rule (Shinoda, 1978),which indicates the entropy of vaporization at the normal boiling point. ASvb
where
=
A",b/Tb
= 21 C
d
mol-' K-'
(1)
is the entropy of vaporization at the normal
boiling point, A&, is the latent heat of vaporization at the same temperature, and Tbstands for normal boiling point. An extensive test was made by employing literature values (Miller, 1964;Procopio and Su, 1968;Wilhoit and Zwolinski, 1971) for A", coupled with T b of 568 compounds which consisted of 411 hydrocarbons (alkanes, alkenes, alkadienes, alkynes, alkylcycloalkanes, and alkylaromatics) and 157 nonhydrocarbons (oxygen-containing compounds, nitrogen-containing compounds, sulfur-containing compounds, halogen-containing compounds, and miscellaneous compounds). For 411 hydrocarbons, the value of ASvb varied from 18.643 cal mol-' K-'for propadiene to 22.239 cal mol-' K-' for 1,2-dimethylnaphthalene, and also, for 157 nonhydrocarbons, the value varied from 19.327cal mol-' K-'for chlorotrifluoromethane to 27.160 cal mol-' K-' for tert-butyl alcohol. The maximum deviations from Trouton's rule (Shinoda, 1978) reached 12.6% for hydrocarbons and 22.7% for nonhydrocarbons, respectively. As indicated by many investigators, this simple rule cannot provide the accurate ASvb predictions for a wide range of compounds. In attaining the accurate representation of A s v b , a new correlation has been proposed as follows
where ASi is the group increment. The value of -CH3 group increment was determined using the data of ethane.
432
Ind. Eng. Chem. Fundam., Vol. 22, No. 4, 1983
Table 11. A Summary of Errors in the Calculation of Asu,, no. of compd within this range of ASub estimation error range of errors E,' % hydrocarbon nonhydrocarbon 0.0 Q E Q 1.0 200 60 1.0 < E Q 2.0 123 31 2.0 < E Q 3.0 50 25 3.0 < E Q 4.0 27 22 4.0 < E < 5.0 11 17 5.0 < E Q 6.0 2 total 411 157 average error: ZEIZNcompd = 842.71568 = 1.5% maximum error: 5.1%
% of compd studied
total
within each range
260 154 75 49 28 2 568
45.8 27.1 13.2 8.6 4.9 0.4 100.0
Table 111. Comparison of Proposed Method with Other Estimation Methods for relative average % error class of compd
no. of compd
proposed method
Chen
Giacalone
Ftiedel
Vetere
alkanes alkenes alkadienes alkynes alkyl cycloalkanes alkyl aromatics oxygen-containing compounds nitrogen-containing compounds sulfur-containing compounds halogencontaining compounds micellaneous compounds
159 159 8 7 37 41 45 13 70 27 2
1.1 1.3 2.9 1.2 1.2 1.8 2.9 2.2 1.3 2.7 3.5
1.5 3.7 5.1 5.8 2.0 2.7 5.2 4.2 2.3 1.7 4.6
2.8 2.3 4.0 4.9 1.4 1.9 5.5 3.9 2.0 1.7 3.6
1.5 3.5 5.1 5.7 1.7 2.5 6.2 4.7 3.0 1.8 5.0
1.4 3.6 5.1 6.1 1.9 2.7 5.4 4.1 2.4 1.a 4.1
overall
568
1.5
2.8
2.3
2.9
2.8
Also, the value of the -CH2- group increment was calculated by utilizing the data of 18 normal alkanes from propane to n-eicosane. In this way, a total of 43 group increments were determined from the experimental data of 568 compounds already mentioned, and the determined group increments were presented in Table I. The pattern search method of Rosenbrock (1960) was applied to correlate the data. Examples for calculations of Asvb for n-nonane, methylcyclopentane, and 1-ethylnaphthalene are presented in the Appendix.
Results and Discussions The values of entropy of vaporization a t the normal b o i i points (ASv,,) of various compounds were calculated from eq 2 with the aid of Table I. Results were compared with experimental data (Miller, 1964; Procopio and Su, 1968; &d Wilhoit and Zwolinski, 1971). A summary of errors for G v b predictions for a different class of 568 compounds (411 hydrocarbons and 157 nonhydrocarbons) is presented in Table 11. The relative average error through all the compounds is only 1.5% with a maximum error of 5.1% for sulfur chloride and 1,l-difluoromethane, respectively. For a total of 414 compounds, the error is less than f 2 % . The proposed method was compared for 568 compounds with those of Chem (1965), Giacalone (1951),Riedel(1954), and Vetere (Reid et al., 1977). These results are given in Table 111. When the critical properties were not available for those methods, Lydersen's method (Reid et al., 1977) was introduced to obtain those properties. Judging from the results of Tables I1 and 111, it can be concluded that the present group contribution method has wider applicability and is more accurate for predicting the entropy of vaporization at the normal boiling point than the previously proposed methods.
Acknowledgment The authors express their thanks to Koreyuki Mase, Hiroyuki Tanaka, and Satoru Murakami for their assistance in the computational work. Appendix The use of eq 2 with the group increment of Table I is shown by calculating the entropy of vaporization at the normal boiling points of n-nonane, methylcyclopentane, and 1-ethylnaphthalene. The experimental values of those compounds are obtained from the work of Wilhoit and Zwolinski (1971). n-Nonane (ASvb,exp= 20.8104 cal mol-' K-l) CH,(CHz),CH, = Z A S i = z(-CH3) + E(-CHZ-) = nonring incr (9.5937 X 2) + (0.2320 X 7 ) = 20.8114 cal mol-' K" 120.8104 - 20.81141 error : x 100 = 0.0% 20.8104
Methylcyclopentane (avb,exp= 20.1473 cal mol-' K-')
&Sub = Z A S i = z(-CH,-) + C(>CH-) ring incr
+ Z(-CH,)
nonring incr 4 ) t (-9.7467) + (9.5937)
= (20.2465 - 0.0023 X = 20.0843 cal mol'' K-'
error: 0.3%. 1-Ethylnaphthalene (ASvb,exp= 21.6320 cal mol-' K-l)
433
Ind. Eng. Chem. Fundam. 1983, 22, 433-436
n = number of group increments (use in Table I) ASi = group increment for eq 2; cal mol-’ K-’ Asvb = entropy of vaporization at the normal boiling point,
cal mol-’ K-’ Tb = normal boiling point, K Subscripts cal = calculated value lit. = literature value
+ E(-CH2-) + nonring incr Z(=C) + E(doub1e bond number between carbon atoms) ring incr
A S v b = Z A S j = E(-CH,)
E(=CH-)
=
+
(9.5937)+ (0.2320)+ (18.7504+ 0.3437 X 7) + (-9.3621 X 3) + (-27.1977 + 9.1993 X 5)= 21.6945 cal mol-’ K‘’
error: 0.3%. Nomenclature E = error, % AHvb= latent heat of vaporization at the normal boiling point, cal mol-’ Ncompd = number of compounds
Literature Cited Chen. N. H. J. Chem. Eng. Data 1085, 10, 207. Giacalone, A. Gazz. Chim. Ital. 1051, 8 1 , 180. Hoshlno, D.; Nagahama, K.; Hlrata. M. J. Jpn. Pet. Inst. 1070, 22, 32. Shinoda, K. “Principles of Solution and Solublltty”; Marcel Dekker: New Ywk, 1978; p 8. McCurdy, K. G.; Laldler, K. J. Can. J . Chem. 1063, 4 1 , 1867. Miller, D. I d . Eng. Chem. 1084, 56(3), 46. Procoplo, J. M.; Su, 0. J. Chem. Eng. 1068, 74(12). 101. ReM, R. C.; Prausnk. J. M.; Sherwood, T. K. “The Propertiis of Gases and Liquids”, 3rd ed.; McGraw-Hlll: New York, 1977; Chapter 2 and 6. Rledel, L.; Chem. Ing. Tech. 1054, 26, 679. Rosenbrock, H. H. Compuf. J . 1080. 3 , 175. Wllhok, R. C.; Zwollnskl, B. J. “Handbook of Vapor Pressure and Heats of Vaporization of Hydrocarbons and Related Compounds”, American Petroleum Institute Research Project 44, Texas A and M University, College Station, TX 1971; Sectlon 111.
Received for review August 17, 1982 Revised manuscript received May 23, 1983 Accepted July 8,1983
Aspects of Autocatalytic Reaction Kinetics Michael Frenkiach’ and David Clary Department of Chemlcal Engineering, Louisiana State Unlvers& Baton Rouge, Louisiana 70803
The kinetics of the autocatalytic system (R1)-(Rz) is investigated. A notable feature of this system appears when the dependency of the concentration of product C on the ratio r = k,/kzCAO at a given time is considered. Analysis shows that the effect of variation in r on the concentration of C depends upon the manner in which r is altered. A maximum in Cc vs. r is observed when the numerator of r is varied while the denominator is held constant; however, no maximum is observed when only the denominator is varied. Another noteworthy feature of this system is the existence of “frozen” composition at infinite reaction time.
Introduction The authors of most discussions of autocatalytic reaction kinetics (Benson, 1960; Froment and Bischoff, 1979; Hill, 1977; Houser, 1969; Levenspiel, 1972) usually concentrate on the time development of the system. This is probably due to the fact that the basic characteristic of an autocatalytic reaction is the presence of a maximum in reaction rate as a function of time or reactant concentration. However, some other fundamental aspects of the autocatalytic reaction appear to be of theoretical interest and practical importance. For example, the analysis of these aspects for the reaction sequence kl
A-B
(RU
reactant A to final product C. This or a similar sequence is a typical mechanism for a variety of natural processes for which reaction R1 (presumably a decomposition reaction) has a much greater activation energy than does reaction R2. This paper presents a detailed analysis of the reaction sequence introduced above.
Mathematical Development The kinetics of the system (Rl)-(R2) is described by the following set of differential equations dCA/dt = -k,CA - ~ & A C B (la) dC,/dt = klCA - k2CACB dC,/dt = ~ ~ C A C B
k2
A+B-C
(R2) has been successfully applied to the global kinetics of soot formation during the pyrolysis of aromatic hydrocarbons (Frenklach et al., 1983). The above sequence (Rl)-(R2) is an autocatalytic process with respect to the intermediate product B, while the overall reaction is the conversion of
with the initial conditions CAlt=O =
c&
CSl,=O = 0 C&o = 0
0196-4313/83/1022-0433$01.50/00 1983 American Chemical Society
(1b) (IC)
