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Dodecane thermolysis was investigated under moderate temperatures and high pressures of N2 or H2. Dodecane is stable below 600 K, whereas under severe conditions it is thermolyzed to give a series of paraffins and olefins up to C22 but with C13 missing. High reaction pressure favors the formation of saturated hydrocarbons and shifts the product distribution toward heavier components. The yield of paraffin plus olefin of the same carbon number decreases with increasing molecular weight, and the yield of the olefin is slightly higher than that of its paraffin counterpart. These observations can be satisfactorily interpreted by a free-radical-chain mechanism with certain modifications. Hydrogen participates in dodecane thermolysis through radical-capping reactions. The pseudofirst-order rate law applies to dodecane disappearance. Recently, Rebick (1981) and Mushrush and Hazlett (1984) also reported some data on hexadecane pyrolysis. Freeradical mechanisms have been shown by the authors, and first-order kinetics was obtained or adopted. Comparison between observed and predicted products by the radical-chain theory gave good agreement (Voge and Good, 1949;Rebick, 1983).The reaction conditions in our study were directed toward relatively low severity because of our interest to use dodecane as a solvent. The confounding effects of the reaction products of the solvent on other reactants were sought.

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Asselineau. K.; Busson, C.; Cha, 8.; Sandler, H. wdrocarbon Process. 1968, 47, 131. Alagy, J.; Trambouze, P.; Van Landeghem, H. Ind. Eng. Chem. Process Des. Dev. 1974. 13, 317. Furman, M. S.; Goldmen, A. M., Eds., Pro/svodstvo Ciklohexanona i Adipinovoy Kisbty O&/sleniem Ciklohexana ; Khlmija: Moscow, 1967. Grassmann, P. Chem.-Ing.-Tech. 1959, 31, 148. Heijnen, J. J.; Van't Wet, K. Chem. Eng. J. 1984, 28, 821. Kramers, J.; Westerterp, K. R. Elements of Chemical Reactor Design and Krzysztoforski, A.; SzczypiRski, Z.; Ciborowski, S. Die Chem. Prod. 1977, Leibson, 1.; Hoicomb, E. G.; Cacoso, A. G.; Jacmic, J. J. AIChE J. 1956, 2 , Pohorecki. R.; WroRski, S. Kinetyka l Termodynamika Proces6w In.?yn/er/i Pohorecki, R.; Kasperski, W.; Kruszewski, J.; Zmljewski, K. Warsaw Techni-Poluprodukty dla Sintesa follamMov; Cukerman, A. M., Ed.; Goskhimisdat: Splelman, M. AIChE o-Etttlphenol (OEP) was chosen as a representative of singking phenols In coal.derived liquids, and its thermolytic behavior, either neat or in saiutiOn with dodecane, under moderate temperatures and high pressures of N, or H, ,was studied. Side-chain cleavage Is the most important reaction, giving phenol as the main product and some cresols. Dehydroxyiation produces some arenes, and isomerization is slgniflcan~. Heavier phenols are formed as a result of radicalcoupling reactions. OEP is belived to undergo thermolytic conversion mainly by unimdecular dissociation followed by subsequent radical reactions. Corresponding mechanism and reaction networks are suggested. Mutual influences between OEP and dodecane were observed: OEP thermolysis is promoted by dodecane, while dodecane thermolysis is inhibited by OEP. Molecular hydrogen affects reactions probably by radlcal capping. Pseudo-first-order kinetics apply to OEP thermolysis, and kinetic parameters are reported.For coal-derived liquids, about 40% or more are oxygen compounds: most are phenolic, and the rest are o€ ben-zofuran or dibenzofuran types. Despite the fact that oxygen-containing compounds are much more abundant in coal-derived liquids than nitrogen-and sulfur-containing species, the organic oxygen compounds have received little attention compared to their nitrogen and sulfur counter-* To whom correspondence should be sent.