How is the nitrogen amount stripped in low-temperature methanol washing determined?

The nitrogen amount lifted by air stripping is primarily adjusted proportionally according to changes in system load! For example, the full-load gas flow rate is 200,000 units per hour, while the nitrogen gas flow rate for air lifting is 100 million units per hour! When operating at half load, the nitrogen stripping rate can be adjusted to just over 50 million per hour! Basically proportional adjustment!

If the flow meter is in good condition, it’s no problem to use proportional control; however, the current flow meter isn’t that reliable. If you’re not sure at first, focus on the following aspects: First, check the valve positions – specifically, the vent valve of the stripping tower and the nitrogen valve used for stripping. If your load is at half capacity but your vent valve is already open to around 50%, it indicates that there is too much nitrogen (unless there are other reasons). Second: Check the pressure in the regeneration tower. If the feed to the regeneration tower is relatively stable, but the pressure in the tower fluctuates significantly and the vent volume is high, it means that the nitrogen used for air lift is insufficient. If necessary, an analysis of acidic gases should be conducted. If these gases are not concentrated, the approximate proportions are: about 6% to 7% hydrogen sulfide, around 90% carbon dioxide, and about 1% to 2% nitrogen. It should be noted, however, that the amount of acidic gas vented at this time is relatively large (you can figure this out by comparing it with the value specified in the design). Third: Check the temperature, specifically the temperature of the methanol-rich stream in the stripping tower. If there is not much variation in this temperature compared to that of the methanol-rich stream entering the tower, or if it differs significantly from the design value, you should consider the amount of nitrogen used in the stripping process. Everyone is welcome to continue the discussion.