Corrosion damage to vertical steel storage tanks (VSTs) used in the oil and gas industry is one of the key factors contributing to reduced industrial and environmental safety at hydrocarbon storage facilities. The most intense corrosion processes occur in the zone where the metal comes into contact with bottom water, which is characterized by high mineralization and the presence of dissolved oxygen, carbon dioxide, and hydrogen sulfide. Under these conditions, the use of protective coatings alone does not ensure the required durability of the equipment, which necessitates the use of electrochemical protection systems. The effectiveness of cathodic protection is largely determined by the characteristics of the anode grounding electrodes, which ensure the flow of protective current in the liquid electrolyte. This article presents a systematic analysis of modern and promising anode materials used in the cathodic protection of internal surfaces of pressure vessels. The electrochemical principles of anode operation, mechanisms of anode polarization, and factors influencing the rate of anode dissolution are examined. Anodic sacrificial anodes are classified by material type and operating principle: soluble anodes based on high-silicon cast iron, magnetite and graphite electrodes, anodes made of polymer composite materials, as well as inert anodes based on noble metals with coatings of mixed oxides of platinum group metals (MMO) . A comparative analysis of operating current densities, specific dissolution rates, and operational limitations of various materials has been performed. It is shown that the selection of an anode grounding system should be based on the mineralization of the environment, the required service life of the system, and permissible current loads. Promising directions for the development of anode systems to increase their service life and energy efficiency have been identified.
CATHODIC PROTECTION, ANODE GROUNDBEDS, VERTICAL STEEL TANKS, ELECTROCHEMICAL CORROSION, FERROSILICON, MAGNETITE, MMO-COATED ANODES, VALVE METALS, ANODE CURRENT DENSITY



