Ageing of the mix of thermobitumen and oil (TBO) formed at low-temperature pyrolysis of kukersite in autoclaves was studied, and the effect of pyrolysis conditions on the share of fractions soluble in hexane, benzene and tetrahydrofurane was described. The results reveal a decrease in the total weight of TBO and solid residue at storage. During a month of ageing in open air the additional weight loss of the initial organic matter reaches 10-15%. At that, the yield of TBO decreases and that of the solid residue increases. The fractions of TBO soluble in hexane (maltenes + oil) and in benzene (asphaltenes) decrease, and the fraction soluble in tetrahydrofurane (pre-asphaltenes) increases.
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