I would like some advice regarding the problem of explosive polymers in dibutylene production (NMP method)
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In the process equipment for producing butadiene using the NMP method, a problem arises in that the bottom of the light-end removal tower (used to remove propyne and water) often accumulates large amounts of butadiene copolymers, and the reboiler switching cycle is also very short. In other words, it is unclear why the amount of explosive polymers produced is much higher than that in the DMF process. In terms of the process, the differences between the two types of devices are as follows: Process, Tower Pressure (MPa), Reactor Temperature (°C), Heat Source. For NMP: 0.5, 55, hot water at 98°C; for DMF: 0.4, 50, hot solvent (DMF) at 98°C. Based on these figures, it seems that there isn’t much difference between them. So I wonder whether it’s a problem with the equipment or a problem with the manufacturing process. I was wondering if there are any members here who use the same process (NMP). Could they provide some details on the specific operation of their systems, such as the replacement cycles for the column bottom filters and heat exchangers? If it’s not convenient, we can talk privately. I thank you in advance! ! !
:handshake continues to ask for help.
Pot temperature? Is MTBE the by-product in this process? Is it necessary to add a polymerization inhibitor? TBC? p-tert-Butylhydroquinone?
The byproduct is not MTBE. The polymerization inhibitor is TBC, and it is added to the reflux liquid at the top of the tower. It is a fact that the gas-phase inhibition effect of such polymerization inhibitors is generally poor, but this is not the reason. I really would like to compare the specifics of similar devices, as this helps in analyzing the true cause of the problem. Thank you for your reply!
The TBC effect in the light-end removal column for butadiene is not good; in my opinion, composite inhibitors would be better. Also, at what position on the tray do your end polymers form? Below or above the tray? Then you can determine whether the effect of the inhibitor is poor.
The NMP method is significantly better than DMF, especially for polymers; focus on managing your own operations.