The ethanol content in pure methanol is high
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Sometimes the ethanol content in our pure methanol is very high, reaching 3000PPM. Is there a good solution for this?
Change the location of fusel oil extraction (that is, adjust the side-stream extraction)
We tried it, but the effect was not significant. Now we are considering making adjustments in the synthesis stage to minimize side reactions, in the hope of achieving some positive results.
A high ethanol content is caused by iron ions or nickel ions from the previous stage entering the synthesis system. Check the previous section.
What process do you use? Such a high ethanol content is relatively rare. How many distillation columns are used in the process? How much water is added for extraction? How much of the fusel oils are extracted? What measures are taken to control side reactions during synthesis? Increase the amount of water used for extraction and raise the amount of fusel oils recovered
This situation usually occurs after liquid enters the methanol synthesis tower; oil and other impurities from the separator end up in the synthesis tower, causing a sudden increase in by-products. Raising the catalyst bed temperature by 5~8 degrees may alleviate the aforementioned condition after a certain period of time.
It means collecting more samples or making some changes before exporting
It is not clear what the processing technique is, nor is it known which tower top has a high ethanol content. If it is the tower top of a atmospheric pressure tower that has a high ethanol content, the cause must first be analyzed by examining the ethanol content in the crude methanol; furthermore, it is necessary to consider the location at which the fusel oils are extracted, as well as the contents of water, methanol, and ethanol in those extracted fusel oils. If the ethanol content at the top of the pressure tower is high, it is necessary to check whether the top pressure is appropriate.
Reply to 3# Qianli Yizui: What are the levels of CO and CO2 in the fresh air at your workplace? CO2 levels should be maintained around 8%; if the CO2 content is too low, the synthesis reaction dominated by CO will produce ethanol. Because CO2 has an inhibitory effect on the reaction of ethanol.
Reply to 3# Qianli Yizui: To reduce side effects in synthesis, what measures have you all taken? Could you explain it in detail to everyone?
Reply to 5# TH373637: From a process operation perspective, how can we reduce the occurrence of side reactions and avoid the formation of ethanol? Please give some advice. Thank you.