CHEMICAL ENGINEERING TRANSACTIONS VOL. 57, 2017 A publication of The Italian Association of Chemical Engineering Online at www.aidic.it/cet Guest Editors: Sauro Pierucci, Jiří Jaromír Klemeš, Laura Piazza, Serafim Bakalis Copyright © 2017, AIDIC Servizi S.r.l. ISBN 978-88-95608- 48-8; ISSN 2283-9216 Analysis of Petroleum and Coal Tar Pitches as Large PAH Barbara Apicella*, Antonio Tregrossi, Fernando Stanzione, Anna Ciajolo, Carmela Russo Istituto di Ricerche sulla Combustione - C.N.R., Napoli – Italy apicella@irc.cnr.it Coal tar and petroleum pitches present quite different features, particularly in terms of structure, size and aliphatic substitution degree of the large polycyclic aromatic hydrocarbons (PAH) components. As such they are an important source of a wide range of different carbon materials mainly deriving from their thermal transformations. However, the difficulty in the controlled and modulated production of tailored carbon materials arises from the scarce compositional and structural knowledge of the parent pitches as well as that of intermediates and final products derived from their thermal treatment. The present work reports about a detailed mapping of the characteristics of solid petroleum and coal tar pitch samples kindly provided by RÜTGERS Basic Aromatics GmbH (Castrop-Rauxel, Germany). Chemical and spectroscopic techniques have been employed in order to put in evidence similarities and differences in terms of volatility, molecular weight distribution and chemical structure. In particular, conventional and advanced tools including chromatography, elemental analysis, thermogravimetry, mass spectrometry, UV-Visible absorption and fluorescence were applied the altogether from one side to offset the limits and on the other side to exploit the advantages of each technique. 1. Introduction Synthetic or fossil fuel-derived pitches are extremely complex mixtures consisting of a huge number of species mainly of aromatic nature. Synthetic pitches, customarily obtained by catalytic polymerization of polycyclic aromatic hydrocarbons, PAH, like naphthalene (Mochida et al., 2000)), have a production cost still high. Hence, they are not considered as a real alternative to coal tar pitches whose production is rapidly decreased in the last century. On the other hand, petroleum pitches appear promising as a cheap source alternative to coal tar pitches presenting quite similar physical properties in spite of a rather different chemical composition. The present work aims to analyse and compare the chemical features of quite different petroleum and coal tar pitches having also different physico-chemical properties, namely the softening point. Petroleum pitches derive from the thermal polymerization of aromatic decant oil, a by-product of the fluid catalytic cracking (fcc) of the heavy gas oil fraction of crude oil. It has been assessed that petroleum pitches generally consist of oligomers of alkylated polycyclic aromatic hydrocarbons (PAH), with the overall molecular weight (MW) ranging from approximately 200 to 2000 Da (Cristadoro et al. 2009). Coal tar pitches (CTP) constitute a valuable aromatic hydrocarbon resource and have been produced as a by-product of metallurgic cokes in large scale for centuries. Both poor utilization and mishandling may result in serious environmental and health issues, since CTP are rich in some PAHs that are carcinogenic and mutagenic (Friesen et al. 2010). After proper processing, the pitches are currently used for binders and pitch cokes, whereas, they can be transformed by sophisticated processing methods into valuable precursor of advanced carbon materials, including carbon fibers and carbon-carbon composites. High yield and quality of the resultant needle cokes carbon, stable and sufficient source and low price are important factors driving the choice of the material and treatment method. Researchers have long recognized that both the MW and structure play a role in the suitability of a given pitch for specific applications. Regardless of the source, a better understanding of pitches composition and/or structure at the molecular level is necessary for the processing technology development. Recently, a detailed characterization of a synthetic and coal tar pitch (Gargiulo et al. 2015, 2016 and DOI: 10.3303/CET1757130 Please cite this article as: Apicella B., Tregrossi A., Stazione F., Ciajolo A., Russo C., 2017, Analysis of petroleum and coal tar pitches as large pah, Chemical Engineering Transactions, 57, 775-780 DOI: 10.3303/CET1757130 775