Anthracene coke formation from

According to different mechanisms of coke formation, we have observed different products of polycondensation using chromatographic, luminiscent, and UV-spectroscopic methods. For example, in the case of decomposition of benzene on different catalysts only products of the dehydrocondensation of benzene with preservation of nuclei were observed (biphenyl, biphenylbenzenes, triphenylene, products of condensation of more than four benzene nuclei, etc.) and such products as naphthalene, anthracene, and phenanthrene were not observed. In tar and coke formation from ethylene on silica gel and aluminosilicates the formation of naphthalene, chrysene, 1,2-dibenzanthracene, fluorene, its derivatives, and others, takes place and if the process is carried out on alumina at a temperature lower than 500°, mainly anthracene, phenanthrene, pyrene, and coronene are formed, but aliphatic hydrocarbons, etc., do not appear. 

Thermodynamics. Formation of coke is thermodynamically favorable even at POX conditions. Consider the formation of two compounds that approximate the structure of coke, anthracene (C14H10, a 3-ring polycyclic aromatic compound) and naphthacene (CigHi2, a 4-ring polycyclic aromatic). These compounds can be formed from n-Cie by the following two reactions ... 

Miyazawa et al. (92) related rates of decrease of aliphatic hydrogen protons during pyrolysis of ethylene tar pitch to formation of mesophase. Yokono et al, (93) used the model compound anthracene to monitor the availability of transferable hydrogen. Co-carboniza-tions of pitches with anthracene suggested that extents of formation of 9,10-dihydroanthracene could be correlated with size of optical texture. The method was then applied to the carbonization behaviour of hydrogenated ethylene tar pitch (94). This pitch, hydrogenated at 573 K, had a pronounced proton donor ability and produced, on carbonization, a coke of flow-type anisotropy compared with the coarse-grained mosaics (<10 ym dia) of coke from untreated pitch. 

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