Prospects for obtaining base oils from bitumen-bearing rocks of the Karasyaz-Taspas deposit

Background: With light oil reserves depleting and the demand for lubricants steadily increasing, the development of alternative sources of hydrocarbon feedstock has become a pressing issue. Despite the technological complexity of processing, natural bitumens represent a promising raw material for the production of base oils, particularly in the Republic of Kazakhstan, where domestic industrial lubricant production is currently absent. Aim: To assess the possibility of obtaining base industrial and motor oils from oil fractions derived from the fuel oil of natural bitumen at the Karasaz-Taspas deposit. Materials and methods: on the study object was fuel oil obtained by atmospheric distillation of natural bitumen. Oil fractions with boiling temperature ranges of 350–400 °C and 400–460 °C were separated using vacuum distillation. Purification was carried out using bleaching clay. The physical and chemical characteristics of the fractions were determined before and after purification according to standard ASTM and GOST methods. Results: The obtained oil fractions are characterized by a high kinematic viscosity, a viscosity index of up to 110.7, and low sulfur content (0.45 wt.%). Their physical and chemical properties meet the requirements for base oils of groups I and II according to the American Petroleum Institute classification and are comparable to industrial oils of grades I-40A and I-50A. Dewaxing and the addition of additives are necessary to improve low-temperature performance. Conclusion: Natural bitumen from the Karasyaz-Taspas deposit is a promising raw material for producing high-quality base oils. The study confirms the feasibility of comprehensive processing of natural bitumen fuel oil to produce industrial and motor oils, contributing to the replenishment of the raw material base, the sustainable development of the oil industry, and the enhancement of the country’s energy security.