Discussion on catalytic devices
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This post was last edited by h*ng on 2017-9-30 23:02. The original raw material for the catalytic unit (coaxial type) is mixed wax oil; if about 20% vacuum residue is to be added to this raw material, how can the requirements for raw material processing be met? At the same time, it ensures a certain liquid yield and supports the long-term operation of the plant. I would greatly appreciate your guidance regarding various aspects such as the use of coated catalysts, the various modifications to the equipment, and the adjustment of process operations and parameters. Thank you very much.
The residue carbon content is high; when residue oil is used as a feedstock, the amount of coke formed increases, and the liquid yield decreases to varying degrees. To ensure optimal yields, it is necessary to select an appropriate preheating temperature so that the nozzles can function properly with the characteristics of this feedstock. Due to the increased amount of coke formed, the thermal load on the regenerator rises, and it is important to determine whether the heat available is sufficient to meet the production requirements
As the amount of char formation increases, increasing the main air flow could be considered; the external heat exchangers may also need to be modified.
This topic is indeed too broad; generally, such issues require a design firm to develop a plan in order to resolve them. The raw material has been changed from wax oil to residue-blended oil; although this proportion is less than 30%, it cannot be considered excessive. First, it is necessary to address the issues of raw material preheating and atomization. Second, the coking rate increases with the use of residue-blended oil, so a comprehensive assessment is required for the main fan, regenerator, as well as the regenerator centrifuge, triple centrifuge, flue gas turbine, waste heat boiler, and flue gas desulfurization and denitrification systems. If the original design provided sufficient margin, then one can consider themselves lucky. Another issue that arises when the coke formation rate increases is the thermal balance between the two units; the heat extraction load must increase. It is necessary to determine what type of reaction is taking place in order to decide by how much the heat extraction load should be increased, and a detailed calculation of heat extraction from both the interior and exterior areas is required. If the heat load is too low, the operation will be constrained by it. To ensure a certain yield of liquid product, the goals are not clear; this issue needs to be discussed with the research institute. Please provide details on the properties of the raw materials as well as the specific requirements for the product. The research institute should then design (or select) a catalyst formula and specify the reaction conditions. Generally, the research institute is only responsible for the reaction section, while the design institute is responsible for the regeneration section. The overall coordination of the two-unit system remains the responsibility of the design institute. It is crucial to ensure pressure balance between the two units, as well as to verify that the catalyst circulation rate meets the requirements of the reaction process; this aspect must not be overlooked under any circumstances. Regarding long-term operation, first, it is necessary to ensure that the design of the anti-coking system is reliable; second, the reliability of the equipment itself is important, including the quality of the linings, special valves, high-temperature equipment and moving components, as well as the steam system.
The amount of char formation increases; it is necessary to determine whether the external heat exchangers in the regenerator are sufficient, and whether the main air supply meets the requirements.