THE EFFECT OF ASPHALTENES QUANTITY ON THERMAL AND CATALYTIC CRACKING PRODUCT YIELD OF HEAVY OIL FROM KARMALSKOYE FIELD

The study investigated the composition of products resulting from thermal and catalytic cracking of mixtures of deasphaltenized oil from the Karmalskoye field with asphaltenes content of 0.0, 5.2, and 10.4wt.%. The experiments were conducted at a temperature of 450 degrees C for a duration of 100 min. The catalyst used was a mixture of tungsten carbide and nichrome powders (NiCrWC), in an amount of 0.1%wt. The presence of the NiCrWC additive during cracking of mixtures of deasphaltenized oil with different asphaltenes content has been shown to increase the yield of oils, gasoline, and diesel fractions while reducing the yield of coke and asphaltenes compared to thermal cracking. During the catalytic cracking of all the mixtures studied, the combined yield of gasoline and diesel fractions exceeds 70%wt. It is important to note that an increase in asphaltenes content during catalytic cracking results in a decrease in the yield of gasoline fractions and an increase in the yield of diesel fractions. Studies have demonstrated that the thermal cracking of heavy oil mixtures with different asphaltene contents results in a decrease in the contents of saturated and monoaromatic hydrocarbons, while the contents of biaromatic and triaromatic hydroarbons increase. Additionally, the presence of asphaltenes has been found to impact the formation of polyaromatic hydrocarbons. During catalytic cracking, the content of saturated, monoaromatic, and biaromatic hydrocarbons increases, while the content of triaromatic and polyaromatic hydrocarbons decreases. During catalytic cracking, the average structure of asphaltene molecules undergoes significant changes. The molecules become smaller, more aromatic, and monoblock, with fewer carbon atoms in the saturated moieties. This catalyst also helps reduce the amount of heteroatoms in the resulting asphaltenes.