Abstract
The high content of metal- and sulfur-containing compounds in the composition of heavy oil residues leads to negative impacts during their processing, the use of catalysts and equipment. To solve this problem, various methods of demetallization and deasphalting are proposed. The article provides information on various methods of demetallization, desulfurization and coking of heavy oil residues. The disadvantages of the considered methods are shown, and a thermal adsorption processing method is proposed as an effective method of demetallization and desulfurization. The results of demetallization and desulfurization of vacuum residue from the Pavlodar Petrochemical Plant (Kazakhstan) using various adsorbents: serpentine, zeolite modified with wollastonite and coke, kaolin clay with coke are presented. The maximum degree of demetallization of 81‒94% with respect to vanadium and nickel is observed when using kaolin clay modified with coke as an adsorbent and during the process at 400 °C for 4 h. The maximum degree of desulfurization 39.6% is observed during the process using zeolite modified with wollastonite and coke at 400 °C for 3 h. After demetallization and desulfurization, the vacuum residue was subjected to a coking process to produce coke with improved performance and yield. Coke with good yield (32%) and low values of ash and mass fraction of total moisture is obtained by vacuum residue coking after demetallization with kaolin clay modified with coke.