How to deal with high resistance in the synthesis tower?
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What are the reasons for the increased resistance in the synthesis tower, and how to address it?
It depends on what caused it; the air velocity can be appropriately reduced, the amount of inert gas can be decreased, and the load can be lowered. If the catalyst cokes or gets crushed, there’s nothing that can be done.
Agree with the opinion above: catalyst coking or crushing
There is a high possibility of it breaking, and it also depends on the condition of its internal components.
If it is crushed, the catalyst needs to be replaced.
1. The new catalyst presents high resistance; this may be due to the selection of a catalyst with too low a capacity, and considering a larger model might be an option. 2. The sieve at the bottom of the catalyst basket has aged and cracked, causing the catalyst to fall into the heat exchanger tubes inside the tower, which increases the resistance. 3. During catalytic reduction, if the water vapor concentration is too high and no ammonia is added to the system, water cannot be separated or removed in a timely manner, which causes the catalyst in the upper layer to become prone to pulverization. 4. Oil in the oil zone causes coking.
Based on the opinions from the upper floor, I would like to add that it might be due to an insufficient amount of the additive used to control the pressure difference.
During catalytic reduction, when the water vapor concentration is too high and no ammonia is added to the system, water cannot be separated or removed in a timely manner, which causes the catalyst in the upper layer to become prone to pulverization. I’m very interested in this sentence; have you used it in this way before? In fact, water vapor can be removed; there is a significant difference in the vapor pressure of water at 40 degrees and 200 degrees.
I guess the carbon dioxide content in the syngas is controlled at too high a level, which results in a high apparent tower pressure difference. Take a look at the analysis data when the tower pressure difference is lower and compare it; by adjusting the hydrogen-to-carbon ratio of the fresh gas to a slightly higher value, the problem should be resolved after a few hours of operation.
The guy above might be involved in ammonia synthesis; it sounds to me like that’s the name of some equipment, something like a three-tube ammonia synthesis system. Or is it a three-tube type cold-shock methanol synthesis tower?
This post was last edited by LJH1911 on 2012-2-21 at 17:35. I work in ammonia synthesis, specifically with IIIJ towers. It seems now that you are referring to the methanol tower. Our methanol tower, in combination with the hydrocarbonation tower, is used to replace copper washing. The methanol tower operates at 13 Mpa and contains zinc oxide desulfurization agents; there were also instances of extremely high pressure differences. This was because a high-pressure water washing tower was installed before the synthesis tower, and the operators failed to prevent water from entering the methanol tower, causing the zinc oxide to become powdered and stick together in clumps, which increased the resistance. In the end, it was necessary to replace the catalyst.