Discussion on methanol catalysts
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Discussion on methanol catalyst issues: When a methanol catalyst reaches the end of its useful life, methanol production decreases while consumption increases. If an accident occurs at the beginning of operation of the methanol plant, causing the catalyst in the upper layer to become poisoned. In this case, one needs to consider turning the head.
“\"Tilting the head\" is a specific operation method in the petrochemical industry, representing the entire process of replacing, cleaning, or repairing a catalyst after it becomes deactivated. In the use of methanol catalysts, if catalyst poisoning or other conditions that lead to a decrease in catalyst activity occur, it is usually necessary to perform \"skimming\". The specific process of \"tilting the head\" generally includes the following steps: 1. Stop the machine: When the catalyst loses its activity and needs to be replaced, it is first necessary to stop the machine safely. 2. Discharge: The octane number booster, catalysts, and other substances inside the device are removed using nitrogen or other methods; it is necessary to ensure that the pressure inside the device is reduced and that no reactants remain inside. 3. Cleaning: Clean the reactor to remove residual catalysts and reactants. 4. Inspection: Check the physical condition and operating status inside the reactor; if there is wear or damage, repairs are necessary. 5. Load new catalyst: Load a new catalyst and adjust the appropriate loading amount and layering. 6. Startup: Reasonably control the startup conditions to prevent new catalysts from undergoing intense reactions, becoming moldy, or becoming inactive during startup. Each step in this process may involve various technical aspects and operational procedures in practice, and it requires professional technicians with a deep understanding of methanol catalysts and extensive experience to carry it out. .
There are two ways to initiate the reaction in methanol catalysts: one is to use oxidized-state catalysts, which are then reduced after being loaded. Another approach involves the use of reduced-state catalysts, with the entire process taking place under nitrogen atmosphere.
When using a reduced-state catalyst, the following issues need to be considered prior to loading: 1. The methanol plant has been properly shut down and purged; CO+H2
When using a reduced-state catalyst, the following issues need to be considered during the loading process: 1. Select a well-reduced catalyst and verify that it is in good condition. 2. All necessary safety procedures for the construction team have been completed, the construction instructions have been provided, and the site is ready for construction. 3. Complete the catalyst extraction and loading tasks under nitrogen conditions to prevent the catalyst from coming into contact with air and avoid ignition. 4. After loading is complete, conduct a check to confirm, then seal the manhole. 5. Fill with nitrogen to 0.5 MPa.
Replacing the catalyst under nitrogen conditions is now a well-established technology, and many specialized companies are capable of carrying it out. Under conditions where parking does not cause catalyst deactivation, replace some of the catalysts and ensure that all the above points are met. The temperature increase and reduction are carried out under low hydrogen conditions, as components such as H, CO, and CO2 are also released from the original catalyst
Catalysts in the oxidized state need to be reduced before use, while catalysts in the reduced state can be used directly.