THERMAL POLYCONDENSATION PROCESS AS A METHOD OF PREPARING RAW MATERIALS FOR ANISOTROPIC COKE PRODUCTION

Anisotropic coke is a highly structured carbon material with high electrical conductivity, low sulfur content and low coefficient of thermal expansion. This combination of properties determines its value when used as a raw material for the production of high-quality graphitized electrodes capable of withstanding high current loads. Recently, the use of anisotropic coke as a raw material for the production of anodes for aluminum electrolyzers and lithium-ion batteries has become widespread. The increase in demand for the considered product determines the need to develop its production technologies. High requirements are imposed on the feedstock for the production of anisotropic coke: ash content, sulfur content, asphaltenes are limited, while a high content of aromatic compounds in the feedstock is necessary to obtain a product with a developed structure. Decantoils are used as the main feedstock, heavy pyrolysis resins are also considered. In conditions of limited feedstock, in order to obtain coke with a high degree of anisotropy, it is necessary to search for technologies that increase the yield of the target product. One of the promising areas of preparation of raw material for the coking process is its thermopolycondensation. The article shows the possibility of implementation the process of thermopolycondensation of heavy gas oil of catalytic cracking at a pilot plant in order to prepare coking feedstock to increase the yield and quality of anisotropic coke. The parameters of the process corresponded to the conditions of the patented technology, which was developed at the USPTU. In addition to standardized methods, infrared spectroscopy methods were used in the analysis of feedstock and products. It was revealed that after thermopolycondensation, the residue increased in density, coking ability, and its fractional composition became heavier. The distribution of aromatic compounds by fractions of feedstock before and after thermopolycondensation has been studied. Coking of the feedstock and the residue of its preparation showed that thermopolycondensation under sufficiently mild conditions increased coke yield by 4.8 %. In addition, the structural organization of the coke produced has improved, which is promising from the point of view of selling the resulting product.