The carbon steel pipeline was initially used for methanol, and it is planned to switch to MTBE later

In carbon steel pipelines, whether direct drying is feasible during the transition from using methanol in the early stages to MTBE (methyl tert-butyl ether) later on, or whether washing with water is required before drying, depends on various factors, including the specific condition of the pipeline, the properties of the medium being used, as well as safety and environmental regulations. Firstly, the direct drying method may not be able to completely remove the residual methanol in the pipeline. Methanol is a water-soluble liquid; if there are residues of methanol in the pipelines, simply drying them out may not be sufficient to remove them completely. Furthermore, methanol and MTBE have different physical properties; direct replacement may result in a mixture forming within the pipelines, affecting the purity of MTBE and its performance. Therefore, it is more recommended to use the method of washing followed by drying. Washing can effectively remove residual methanol from the pipelines, ensuring their cleanliness. At the same time, washing can also reduce the temperature and pressure inside the pipeline, creating favorable conditions for the subsequent drying process. During the water washing process, it is necessary to control the water temperature and pressure to avoid unnecessary damage to the pipelines. The drying process should be carried out after the washing is complete. When drying, use dry, oil-free, dust-free compressed air or nitrogen to ensure that the inside of the pipelines is dry with no residual moisture. During the drying process, the interior of the pipeline should be checked regularly to ensure effective drying.

Direct drying is feasible, but to ensure the cleanliness of the system and prevent possible chemical reactions, it is recommended to rinse it with water first before proceeding with drying. This allows for more effective removal of methanol residues and prevents reactions with MTBE. .

It is mainly because the weather in East China is quite cold; after being washed, it doesn’t dry easily, and when blown on, it turns into ice

Given the cold weather and the difficulty of air-drying after washing, hot air drying or the use of heating devices can be employed to help evaporate the moisture and prevent freezing. If implementation is difficult, it is recommended to use anhydrous alcohols or other suitable solvents for rinsing, followed by drying with hot air, avoiding the use of water. This can reduce freezing problems caused by low temperatures. .

Should the company consider whether hot nitrogen is available?

Given that the weather in East China is quite cold, it’s difficult for water to dry quickly; when blown on, it turns into ice. In that case, there’s no need to wash it with water. Direct material displacement distillation will do.

In carbon steel pipelines, after initially using methanol and wanting to switch to MTBE, simply drying them out is not feasible. Here are the reasons and suggestions: Reason: Residual methanol: Methanol is volatile, but direct drying may not eliminate it completely; the remaining methanol could react with MTBE or affect its performance. Safety risks: Methanol is flammable and explosive, and direct drying may increase safety hazards. Corrosion risk: Methanol is corrosive to carbon steel, and residues may accelerate pipeline corrosion. Suggested steps: Wash with water: Rinse the pipeline with water to remove as much methanol as possible. Drying: Use dry air or nitrogen to dry the pipeline to ensure no moisture remains. Testing: Test for methanol residues in the pipeline to ensure compliance with requirements. Switching: Switch to MTBE only after confirming that the pipeline is dry and free of residues. In summary, direct drying is not feasible; it is necessary to wash with water first and then dry, to ensure that the pipelines are clean and dry and to avoid problems caused by residual methanol.

Dry it directly with hot air to prevent residual methanol in the medium from affecting MTBE.