Dear Colleagues,

The processing of technogenic resources is becoming an increasingly relevant modern trend in the mineral and raw materials and fuel and energy sectors of the economies of industrialized states. This is primarily due to the accumulation in technogenic resources of potentially valuable components for isolation in amounts comparable in content to natural resources. The possibility of utilizing technogenic resources of fossil fuels by using them as raw materials to obtain high value-added products is especially attractive for industrial enterprises. This is especially the case for oil refining and petrochemical enterprises, gas chemical plants, coke plants and other fossil fuel processing enterprises. The processing of technogenic fossil fuel resources can be performed by physical methods (mixing, fractionation, extraction) and chemical methods (thermal, catalytic and hydrocatalytic). The chemical composition (elemental, hydrocarbon, group, SARA) and the structure of individual components (including asphaltenes) of technogenic resources determine the possibility of using a given processing method to obtain commercial products. At the same time, only high demand for the resulting products with a limited supply will determine their status as high value-added products. An example of such a product is needle coke, which in world practice is obtained from both oil-based technogenic resources (a by-product of the production of a high-octane component of motor gasoline) and coal-based technogenic resources (a by-product of the production of metallurgical coke). The main area of application for this method is in the production of graphite electrodes for steelmaking. It is the flow of the technological chain through several industries that determines this carbon material as a product with a high added value.

The purpose of this Special Issue is to consider the most relevant methods for the global industry to utilize technogenic fossil fuel resources to obtain high value-added products.

Dr. Viacheslav A. Rudko
Guest Editor

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• needle coke
• petroleum coke
• carbon fibers
• atmospheric residue
• vacuum residue
• decant oil
• ethylene tar
• coal-tar pitch
• asphaltenes
• mesophase pitch
• activated coal
• carbon black

Title: Needle Coke Structure Formation from Polymer-Modified Hydrocarbon Raw Materials During the Calcination Process
Authors: Renat R. Gabdulkhakov, Viacheslav A. Rudko *, Igor N. Pyagay, Vladimir G. Povarov
Affiliation: Scientific Center “Issues of Processing Mineral and Technogenic Resources”, Saint Petersburg Mining University, 199106 St. Petersburg, Russia; * corresponding-author
Abstract: This work is devoted to the study of the process of structure formation of needle coke, which is obtained using a polymeric modification of hydrocarbon feedstock in the process of delayed coking. The degree of structuring, quantitatively and qualitatively assessed by SEM, XRD, and Raman spectroscopy, is about 20% higher for needle coke from polymer-modified raw materials. In this work, a structural assessment of this coke, which was calcined at temperatures from 600 to 1600 °C with a step of 200 °C, was performed and characterized by the methods of physicochemical analysis in terms of composition and structure.

Title: Detailed Investigation of the Structure and the Composition of the Molecular Group of Isotropic Coke
Authors: Z.R. Ismagilov*, S.A. Sozinov, A.N. Popova, N.S. Zakharov
Affiliation: Federal Research Center of Coal and Coal Chemistry, Siberian Branch, Russian Academy of Sciences, Kemerovo, Russia
Abstract: The study of the crystal and molecular structure of isotropic coke is reported using X-ray diffraction (XRD), scanning electron microscopy (SEM), electron spin resonance (ESR) and nuclear magnetic resonance (NMR) spectroscopy experiments on two isotropic coke samples. The structural parameters (La and Lc) were determined, and the microstructure were investigated by combination of XRD and SEM methods. The difference in structural parameters of the coke samples corresponds to different morphology and textural characteristics of the coke particles: particles have amorphous sponge-like microstructure. By the combination of ESR and NMR spectroscopy methods the molecular structure of the isotropic cokes were studied. From the analysis of the profile shape of the ESR-spectra of the samples, it follows that there are differences in the series of isotropic cokes, which are the result of different degrees of coking processes. All studied specimens have two types of radical structures with different localizations of unpaired electrons. The first type of radical structures are low-molecular aromatic radicals in which the spin is localized. The second type are polyaromatic radical structures in which spin is delocalized. The degree of aromaticity and the distribution of carbon atoms into functional groups, as well as the valecin lengths of aliphatic chains calculated by NMR spectroscopy, confirm and complement the results of ESR spectroscopy. The relation established between the structural parameters, morphology, and molecular structure of the coke particles provides an additional tool for assessing coke quality. Keywords: coke, semicoke, ESR-spectroscopy, NMR-spectroscopy, XRD, scanning electron microscopy, needle coke, anisotropic coke, isotropic coke.

Title: Chemical Processing of Plastic Waste
Authors: Anton L. Maximov, Khusain M. Kadiev *, Askhab U. D Dandaev, Alexander E.Batov, Murat Y. Visaliev
Affiliation: A.V.Topchiev Institute of Petrochemical Synthesis Russian Academy of Sciences
Abstract: Chemical processing of polymer waste (PW) to produce hydrocarbons that can be used to produce valuable petroleum products is a promising way to increase the efficiency of the use of hydrocarbon raw materials. Chemical processing involves depolymerization of PW. This paper presents the results of a study on the depolymerization of polyolefins and mixtures of PW with a heavy vacuum residue (VR) by hydroconversion using suspensions of a dispersed catalyst. The influence of technological parameters of pressure (2.5 – 10.0 MPa), temperature (400-450 °C), reaction time (1.0-3.0 h), PW content in the feed mixture (5-99 wt%) and catalyst concentration in the reactor (100-3000 ppm) on the yields and properties of hydroconversion products of VR+PW mixtures was studied. With an increase in pressure up to 7.0 MPa in the reactor, an increase in the conversion of fr. > 500 °C is observed, a decrease in the content of olefins and sulfur in distillate fractions, an increase in pressure up to 10.0 MPa does not significantly improve the hydroconversion indicators. The effect of temperature and reaction time on the conversion and yield of reaction products is extreme: an increase in temperature above 400 0C and a reaction time of more than 2 hours is accompanied by a decrease in the conversion and yield of distillate fractions and an increase in the content of olefins in them, while the yield of coke sharply increases. An increase in the PW content in the raw mixture contributes to an increase in conversion, an increase in the content of paraffin-naphthenic hydrocarbons and a decrease in aromatic hydrocarbons in distillate fractions, and the involvement of rubber in the raw material leads to a certain increase in the yield of olefins, naphthenes and aromatic hydrocarbons. At a Mo concentration of 0.05-0.1 wt %, the best results are achieved for the conversion of fr. > 500 °C and the structure of the reaction products. Distillate fractions were analyzed as petroleum fractions. The results showed that the obtained liquid fractions were similar and met the quality criteria of similar oil fractions.