Issue of methanol washing consumption during the commissioning of MTBE plants
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Dear fellow sailors, how is the amount of methanol used for washing calculated during the startup of an MTBE plant? Is there a certain swelling ratio related to the catalyst? Please provide a solution.
Why does it seem like it wasn’t explained clearly? Am I just not familiar with this process?
After washing the catalyst before starting up, methanol is used to replace the water in the catalyst. How should the amount of methanol be estimated?
Based on personal opinion: 1) Should methanol be added after catalyst filtration? Let me ask one more question: if there is water in the catalyst, can you replace that water with methanol? They are mutually soluble. I’m not very familiar with this process you mentioned, but in our process, methanol serves two functions: a) it acts as a catalyst and is washed back into the reactor after filtration ； b. As a solvent for the reaction system ； If it’s just Type A of effect, based on experience, an addition of 200-300L is appropriate (about 100L for the filter) ； If it’s type B action, it depends on your process.
Alcohol washing of the catalyst is primarily intended to remove the water contained within it. If the catalyst has a moisture content of 50% on a wet basis, it is required that the moisture content in the methanol after alcohol washing be 15%. The calculation formula is as follows: (Catalyst volume filled in the reactor on a wet basis × 50%) / (Catalyst volume filled in the reactor on a wet basis × 50% + Amount of methanol used for washing) = 15%, with all values expressed in tons. The amount of methanol calculated using this formula represents a basic figure; whether the alcohol washing process will be effective depends also on factors such as the reaction time in the reactor and the number of times alcohol washing is performed. It is recommended to keep the reaction time as long as possible, and to use methanol for the initial washing step before proceeding to the subsequent washing steps, as this can help save methanol. Additionally, when loading the catalyst into the container, a certain amount of headroom is reserved, so there is no need to consider the swelling ratio.
Issues regarding the amount of methanol used for washing in MTBE plants during operation http://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1522438
If it is a newly replaced catalyst, soak it in methanol for 24 hours; a sample analysis showing an moisture content of less than 20% is sufficient.
Fill it with methanol and carry out cyclic washing; there is no need to consider how much methanol to use in the first pass – the actual water content in the methanol after cyclic soaking should be taken as the guide. Generally, the water content in the reactor should be less than 12%, and that in the catalytic distillation tower less than 10%