Feasibility of cooling lean methanol with propylene
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My unit uses Linde’s low-temperature methanol washing technology; the design temperature at the inlet of the lean methanol pump is 45°C, but in summer the actual temperature can reach 59–60°C, which poses a threat to the pump’s operation. I am considering using excess propylene to cool the lean methanol. I would like to ask if any colleagues have done this before, so that I can learn from their experience.
Propylene is indeed useful as a cryogenic medium, so I think yours should work…
Since it’s Lind’s technology, propylene is likely being used to provide some of the cooling capacity; a high inlet temperature of the lean methanol pump could also be due to problems with the stripping process
What is the outlet temperature of the lean methanol pump? How low can a water cooler cool the temperature? I suspect that the cooling capacity of your water cooler is insufficient, which is causing the methanol temperature in the lean methanol tank to be too high
What is the outlet temperature of the lean methanol pump? How low can a water cooler cool the temperature? I suspect that the cooling capacity of your water cooler is insufficient, which is causing the methanol temperature in the lean methanol tank to be too high
The inlet temperature of the lean methanol pump can reach 59–60°C in summer; there must be some problem somewhere. It would be best to send a screenshot of the operation.
My methanol washing process uses the Lurgi technology; my methanol-poor flow pump operates at 107 degrees without any problems. Should I consider replacing it with another such pump? Haha.
We use LURGI’s process: the inlet temperature of the methanol-poor pump is 107.2 degrees, and it is gradually cooled down to -40 degrees, also using propylene for cooling. . If you want to lower the temperature from 60 degrees to 45 degrees, using 4-degree propylene for heat exchange will be sufficient.
It’s definitely feasible, but it’s still recommended to first investigate the reasons: whether the regeneration tower is operating properly, whether the pressure is too high, and what the heat exchange efficiency is between the regeneration tower and the pump inlet. In such designs, groups of methanol-rich and methanol-poor heat exchangers are typically used, and their arrangement in a strip pattern can lead to issues like gas blockage, which affects the heat exchange efficiency
It is recommended to compare the design parameters, identify the causes, and when solving problems, cost should also be taken into account