179. Mesophase formation in the pyrolysis of solvent-fractionated pitch

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Abstracts

Research Znstitute, Facu~fy of Enginee~ng, Hokkuido University, Sapporo, &59,Japan). Time-dependent proton NMR spectra of pitches and vacuum residues were observed at high temperatures (660-720K) and a kinetic analysis of the changes of aliphatic hydrogen fraction obtained from the spectra were made. Relations between kinetic parameters and optical textures of resultant cokes were discussed. 171. Carbonization of partially hydrogenated aromatics I. Mochida, K. Takeshita, H. Matsuoka, Y. Korai, H. Fujitsu and K. Tamaru (Research Institute of Z~dust~al Science, Kyushu University 86, Fukuoka 812, Japan). Partial hydrogenation increases the carbonization reactivity of aromatic hydrocarbons. For example no pyrene carbonize under atmospheric pressure, whereas its hydrogenated derivatives give a coke with flow texture at 25% yield. An oxidation of hydrogenated one further increases the coke yield up to 4.5%. The mechanism of carbonization of partially hydrogenated aromatics will be discussed. 172. Carbouizatktn properties of pitch oxidized by air blowing I. Mochida, T. Inaba, Y. Korai, H. Fujitsu and K. Takeshita (Research Znsfitute of Zndusf~al Science, Kyushu University 86, Fukuoka, 812, fapan). Structural change of air-oxidized extracted residue was studied by NMR, IR molecular weight measurement. Its carbonization reaction was investigated by observing the intermed~te stage of the reaction in order to reveal how the air~xidation converts the pitch to give mosaic texture. Further modification by acidic catalyst will also be reported. 173. Fourier transform IR and solid state ‘% nuclear magnetic resonance spectroscopic analysis of pyrolyzed asph&ues Victoria L. Weinberg and T. F. Yen (Uniuersity of Southern California, University Park, LA., CA 9ooo7) and Bernard C. Gerstein and P. Dubois Murphy (Iowa State University, Department of Chemistry, Ames, ZA50OIf). Asphaltenes from coal liquefaction processes were pyrolysed and their pyrolysis residues studied using Fourier transform infrared and solid state “C nuclear magnetic resonance spectroscopic analyses. Changes in structural parameters such as aromaticity and oxygen functionality were studied and their effects on mesophase formation determined. 174. R~a~~~ between bydrogeu donor abflities of pitches and coals and optical textures of cokes T. Yokono, K. Miyazawa, T. Obara, Y. Sanada (Coal Research Institute, Faculty of Engineering, Hokkaido UniversityNJ3, W-8, Sapporo WO,Japan) and H. Marsh (~o~hern Carbon Research ~borato~es, School of Chemists, Univers~y of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, England). Correlations are established of size and shape of opfical textures of cokes with the hydrogen donor abilities of parent petroleum pitches and with their pyrolysis chemistry. Hydrogen

transfer reactions are studied using model-organic compounds. Transferable hydrogen is studied in coals and hydrogenated ethylene-tar pitch. 175. Aromatie pit& production using steam cracker tar G. Dickakian (Exxon Chemical Company, Linden, N~~7~3~. Steam cracker tar which is composed of alkyl-substituted polycoused aromatic (I-5 rings) is transformed into high aromaticity pitches by physical, thermal and catalytic processes. The aromatic pitches produced by the various processes vary in their physical, chemical, thermal, molecular weight, and distillation characteristics. These characteristics are quanti~tively determined. High temperature thermal processes are found to be very efficient in preparing the high aromaticity pitch. The effect of temperature used and mechanism will be discussed. 176. C~r~~~n parry of coal based pItcItes I. Mochida, Y. Korai and K. Takeshita (Research Institute of Industrial Science, Kyushu University 86, Fukuoku 812, Japan) and K. Mukai, W. Migitaka and Y. Suetsuga (Nittetsu Chemical Industrial Company, Tokyo MI, .Zapan). Two aspects of cocarbonization process was studied to get a carbon of well~eveloped anisotropy-1. Cocar~nization of non-hydrogenative solvent treat coal (STC). By fractionation of the proper component of STC. The amount of additive required was found to be varied for the well-developed anisotropy-2. The modification activity of coal tar fractions. QI free tar obtained by an anti-solvent separation is found to show an excellent activity vs carboni~tion of a petroleum vacuum residue. 177. Kinetics of earbonIzation of anthracene Alan W. Scaroni, Philip L. Walker, Jr. and Robert G. Jenkins (~pa#ment of Materials Science & ~nginee~ng, The Pennsylvania State University, University Park, PA I6802). Liquid phase carbonization of anthracene was performed in a pressurized bomb reactor. The ap pearance of pyridine insoluble material was monitored as a function of reaction temperature and isothermal reaction time. The overall reaction was pseudo-first-order in the appearance of pyridine insolubles with rate constants of 4.3 x 109exp (-192 WfmolefRJ) s-‘. 178. The influence of qulnoline insoluble p&b constftuents on Ckecarbonisationrate and coke structure H, Tilimanns (SZGRI ELEKTRGGRAPZZZTGMBH, Werk G~esheim, Stroofstr. 27, D 6230 Frankfu~ 80, Germany). The study showed that the presence of quinoline insolubles is shifting the mesophase formation to lower temperature and increases the carbonisation rate. Furthermore can the coke structure and properties be controlled by the addition of quinoline insoluble. 179. Mesophase fo~a~n in the pyrolysis of solvent-fraetionated piteb V. L. Weinberg and J. L. White (The Ivan A. Getting Laboratories, The Aerospace Corporation, P.O. Box 92957, Los Angeles, CA 9ooo9). Petroleum pitch (Ash-

Abstracts land A2401,at two stages of pyrolysis, has been solventfractionated by successive Soxhlet extractions with solvents such as hexane, cyclohexane, toluene, tetrahydrofuran, and pyridine. The fractions have been coked at room pressure and at 5OOOpsiand evaluated in terms of their mesophase microstructures. 180. Mesophase transformatfon ia a solventsxtracted Pf@b J. E. Zimmer (Acurex Coloration, Mountuin View, CA 94042). The mesophase transformation has been observed micrographically in a solvent-extracted petroleum pitch. The toluene extraction produced an insoluble, asphaltene fraction, with a high carbon yield and a narrow molecular weight distribution that transformed readily at 320-340°C. This rapid transformation is similar to that for conventional nematic liquid crystals. 181. Quantftatfvedeterminatfon of mesopbase content in pitch S. Chwastiak, R. T. Lewis and J. D. Ruggiero (Union barge Coloration, Carbon Products ~vision~ Parma Box 6116, Cleveland, Technical Center, P.U. OH 44IO1). A quantitative microscopy method has been

developed for measuring the mesophase content in pitch. The general technique utilizes area measurements on photomicro~aphs of polished specimens to determine volume percent mesophase. Typical data will be presented and the limitations of the method will be discussed. 182. Tbe growth and coalescenceof mesophase H. Marsh and M. Forrest (Northent Carbon Research Laboratories, School of Chemistry, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 ?RU, Bng~and). me mechanism of bonding between individual

anisotropic units in cokes, in particular fine-grained mosaics, is investigated by optical and scanning electron microscopy. Carbon black is added to pitch carbonizations to simulate Q.I. content. The effects of carbon black additives on mesophase growth and coalescence for high and low viscosity pitches are monitored by optical microscopy and SEM. 183. The co-carhmizatfon of pitch with K&CO3to prevent formation of anisotropfccarbon H. Lopez and H. Marsh (Noshes Carbon Research ~aborato~es, Sehoo~ of Chemists, university of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, England). Certain inorganic additives to pitch prevent

the formation of anisotropic carbon during carbonization. Potassium carbonate was carbonized with A240 petroleum pitch and it was observed that extent of formation of isotropic carbon is a function of final HIT, heating rate, % of added KzC03, the addition of I&O and soak time at the final HTT. 184. Co.u&mization of petroleum pitch and model organic compounds L. Pacheco and J. Rincon (~pa~ment of Chemists, Uniuersidad National, Bogotd, Columbia, S.A.). Ashland petroleum pitch A-240, A-170, organic model com-

145

pounds containing tellurium and nickel formiate were co-carbonized and the resultant cokes examined for optical texture. Compounds having tellurium in their structure do not affect the optical texture of the petroleum coke while nickel formiate causes a change of the flow-tube texture towards isotropic areas surrounding the deposits of metallic nickel. 185. Rela~~~ps between metals and natural earbonaceousmaterials (kerogensand crude 0%) S. Bonnamy, A. Oberlin and M. Oberlin (Z.aborutoire Marcel Mathieu, ER 131 du CNRS, EUR Sciences, 45046-Orleans, Cedex, France). Uranium is commonly

associated to kerogens in ore deposits. In hydrogen rich materials, the organometallic compounds which form repeatedly are quickly destroyed into IJOz microcrystals by coalification and by thermal treatment. Oxygen rich chars release uranium at earlier stages which eventually react with uraniferous clays and form UTi206. Similarly vanadium contained in asphalts is transformed into V203 whereas nickel forms metal crystals. 186, Ability of asphalts to grapbitize: structure and microstructure M. Monthioux, M. Oberlin and A. Oberlin (Laboratoire Marcel Mathieu, ER 131 du CNRS, EUR Sciences, 45046-Orleans, Cedex, France) and R. Boulet (Znstitut Francais du P&role, 1-4, Avenue de Bois Prkau, B.P. 31 I, 945~2-Rueil-Malmaison, Cedex, France). Asphalts

were extracted from crude oils of various elemental compositions with n alcanes. They were then heattreated to 2900°C. The mutual association of aromatic molecules was studied by high resolution electron microscopy, the ability to graphitize by X-ray diffraction. Graphitizability is inversely proportional to (0 + N t &)/C atomic ratio. 187. The plastic bebaviour of pbenolic resin tbermosets immediately prior to carbonization G. M. Jenkins and M. Leaves (~pa~ment of Metaflurgy and Mate~als Technology, university College of Swanseu, Wales). It is demonstrated that large torsional

creep strains can be induced in rods of “thermoset” phenolic resin between 200 and 4OO’Cprior to its transformation to a glassy carbon. The effect of thermal history, gaseous environment and the addition of plasticizers and “stiffeners” on this plastic behaviour is described. Possible improvements in the formulation of glassy carbon precursors and thermally stable phenolics are discussed. 188. DffIerential scamdug calorimetry of pitches and Ifquidcrystalhe materfats J. B. Barr and I. C. Lewis (Union Carbide Corporation, Carbon Products Hivision, Parma Technical Center, P.O. Box 6116, Cleaveland, OH 44101).

Differential scanning calorimetry was used to characterize the thermal transitions in conventional pitches, mesophase pitches, and liquid crystal forming compounds. Glass transition temperatures were determined for both isotropic and mesophase pitches. Heats and