Assessment of Structural Changes in Resins and Asphaltenes Depending on the Duration of Cracking Using Structural Group Analysis

Changes in the structural parameters of secondary resins and asphaltenes formed upon the cracking of asphaltenes, resins, and their mixture were assessed at different process durations. Resins and asphaltenes isolated from heavy methane oil of the Zyuzeevskoye oil field (Tatarstan) and their mixture were cracked in a batch reactor at 450°C for 60, 90, and 120 min. With increasing the duration of resin and asphaltene cracking, condensation reactions leading to an increase in the yield of coke and the formation of low-molecular-weight highly aromatic secondary resin and asphaltene molecules accelerated. It was found that the directions of thermal transformations of resin and asphaltene molecules were similar. The joint presence of resins and asphaltenes in the mixture changed the direction of their thermal transformations in the course of cracking, which was reflected in the quantitative data on the mass balance and structural parameters of secondary resins and asphaltenes formed upon the cracking of a mixture of resins with asphaltenes. Differences in the structural characteristics of resins and asphaltenes formed upon the cracking of single-component samples and their mixture were revealed.