Radicals and coking behaviors during thermal cracking of two vacuum resids and their SARA fractions

Ultrasound Irradiation for Upgrading Vacuum Residue: A Comprehensive Study on Its Effects on Rheological, Structural, Thermal Behavior, and Catalytic Hydrocracking Performance

“…3 Even worse, asphaltene induces other components to form coke in the liquid phase, which then deposits on the surface of the catalyst or forms coke on the catalyst surface directly. 12 The coke on the catalyst surface covers the catalyst's active sites and blocks the pores, resulting in deactivation. This undesired coking limits the residue oil conversion rate in the upgrading process.…”

Evolution of Stable Free Radicals during Bio-Oil Pyrolysis and Its Relation to Coke Formation: An in Situ EPR Study

“…Coke formation, in turn, causes a series of problems, such as reactor blockages and catalyst deactivation, which may hamper the upgrading and utilization of bio-oil. , It has been proven that, during the thermochemical conversion of organic materials, the thermal breakage of covalent bonds produces a number of radicals. These radicals then participate in the succeeding reaction process, significantly impacting the reaction network. − As the change of radicals has been observed during the pyrolysis of bio-oil, it is believed that radicals have a significant impact on the coke formation of bio-oil . Therefore, figuring out the evolution of radicals during bio-oil polymerization is key to revealing the coke formation mechanisms.…”