Properties and structure of hard coals from a borehole Niedobczyce IG-1 in the Rybnik Coal District, Upper Silesian Coal Basin, their petrographic and group constituents 4. The structure of asphaltenes separated from tetralin extracts of coals

Abstract Asphaltenes were separated from extracts of coal from gasflame (according to Polish classification) 611-VII (according to international classification and statistical groups) to gas-coking 532-VD types obtained by chemical disintegration using tetralin as a solvent. The asphaltenes were analysed using the method of infrared spectroscopy and their structural models were determined. Comparing the derived models for structure of asphaltenes with the structure of terpenes and steroids, a hypothesis is presented of the possible formation of the basic structural skeleton of the asphaltenes during the coalification process.