Study of the structure of semi-coke using EPR and NMR spectroscopy methods

Abstract

The work carried out comprehensive studies of a number of industrial semi-cokes using EPR and NMR methods. Apply of EPR spectroscopy, it was shown that in all the studied semi-cokes there are two types of radical structures, the first of which are low-molecular aromatic radicals.The second type is conjugated polyaromatic structures, in which the unpaired electron is delocalized. Line shape analyzing in EPR spectra, it was found that there are differences in the presented line of isotropic cokes. In this work was shown that EPR is a highly sensitive method that makes it possible to monitor changes in the molecular structure during the production of semi-cokes. The results of the EPR studies obtained in this work are in good agreement with the results of NMR spectroscopy. The results obtained show that changing the composition of the feedstock and technological operations to obtain high-quality anisotropic cokes is impossible without assessing the molecular structure of the intermediate coking products.