LINDE low temperature methanol cleaning acid gas problem!
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The regeneration tower removes sulfur and recovers acidic tail gas. The hydrogen content is as high as 18% and the sulfur is 6.5%. What is the reason for the high hydrogen content? How to adjust?
I would like to ask the original poster, did you analyze whether there is hydrogen in the tail gas of the carbon dioxide desorption tower and the hydrogen sulfide concentration tower? Make a basis for judgment.
H2 cannot be desorbed in the flash tank, and CO2 is insufficiently desorbed in the cold zone. High H2 can also be considered as channel gas in the separation tank. Low acidic H2S is due to incomplete desorption of CO2 in the front, causing desorption in the hot zone to affect the acid gas concentration. There are too many reasons. It’s hard to say more without being there.
This is caused by gas cross-flow in the methanol-water separator, causing the process gas to enter the methanol-water separation tower, and then enter the thermal regeneration tower with the tower top steam. It is recommended to check the liquid level measurement and control system of the methanol-water separator. In addition, observe whether the vent valve opening of the thermal regeneration tower is much larger than normal under the same load conditions.
The reason mentioned above is relatively big, but I don’t know if the poster has analyzed it. Is there any hydrogen in the tail gas of the carbon dioxide analysis tower and the hydrogen sulfide concentration tower? If not, look for the reason as mentioned above.
Admiration, hits the nail on the head. most likely reason
What does it have to do with the opening of the vent valve of the regeneration tower? Please advise!
Due to gas blow-by, the amount of gas discharged from the top of the regeneration tower is much greater than before, so the valve opening must be increased to discharge the excess gas.
The methanol is sprayed into the low-temperature methanol-washed tube-wound heat exchanger and discharged to the liquid phase pipeline of the separation tank in front of the absorption tower. Then, the methanol water tower is removed. A slight gas leakage occurs, about 200 per hour. It is suspected that the gas phase of the methanol discharge line of the tube-wound heat exchanger is blocked.
Is your methanol equipped with a gas-liquid separation tank before it enters the methanol water tower?
After yesterday's adjustment, the analysis of CO and H2 was 11%. During the adjustment, the liquid level of the non-shifted gas methanol separation tank was only raised to 80%.
We drove the car in November last year and it will be inspected tomorrow. I would like to ask the experts whether it is necessary to open the regeneration tower and methanol water tower, and whether it is necessary to flush the reboiler. Currently, these equipments are running normally.
It should be that the height of the methanol-water separation tank from the coiled heat exchanger is not enough during the design, and the liquid seal is not good. I don't know if your pipeline has a stop valve. If not, you can consider adding a stop valve here, and control the liquid level of the methanol-water separation tank to be higher, about 80%. Our company has also encountered such a situation, and the current control is that the liquid level is relatively high. Solve the air leakage problem.