Overcoming the difficulties encountered during the stable start-up of absorption

Charge the system with nitrogen, start the pump for a three-column cycle; introduce the heat source gradually, and ensure that the water at the bottom of the columns is thoroughly removed

Pay attention to the heat source of the reboiler at the bottom of the desorption tower to prevent the generation of large amounts of non-condensable gas.

Note: 1. Confirm the process, ensure its continuity, conduct process inspections; isolate processes related to absorption and stabilization from those related to reactions and diversion, to prevent cross-contamination. This is a matter of principle, remember that! 2. Nitrogen can be used to displace air directly. The advantage of using nitrogen compared to steam is that no condensate water is produced; the downside is that there is a risk that the air may not be completely displaced, and you know what the consequences of that are. Since starting up with stable absorption is not particularly straightforward, as a precaution, it is better to use steam to drive out air and nitrogen to drive out condensate water. 3. If steam is used to displace air, be careful: after stopping the steam supply, pay attention to the pressure in the tower. When the pressure drops to a certain level, nitrogen must be added, otherwise the tower is prone to collapsing or air may get inside. There have been lessons like this before. 4. Maintain a slight positive pressure of nitrogen; after dehydration, collect the oil. Make sure to pay close attention to the process to prevent it from flowing into other systems. . 5. Even after the oil has been collected, dehydration is still necessary. The best approach is to gradually allow the process to proceed after the oil is collected; once it reaches a certain stage, dehydration takes place. All three towers then start operating, run for a while, stop for a period of time, undergo dehydration again, and then start operating once more. If it’s cleaned thoroughly, subsequent product adjustments will be much easier. 6. When introducing a heat source at the bottom or in the middle of the tower, fractionation must be carried out properly, and everything needs to be coordinated well. If you introduce the heat source too early, you can only use a flare to maintain pressure; moreover, the lighter components get vaporized, making it difficult to detect the liquid level in the liquefied gas tank. It’s thrown in too late, and the temperature of the heat source is too high; if it’s thrown in too quickly, the reboiler will leak. 7. First, feed the bottom, then the reboiler in the middle. 8. For the heat exchanger, make sure to tighten it tightly. 9. The absorption stabilization pressure can be set a bit lower, which facilitates earlier integration of the compressor; if the pressure is too high, integration will occur later. This can now be achieved through operational adjustments, allowing operation without using a flare. 10. After saying so much, I want to emphasize that achieving stability in absorption isn’t something that requires haste; take your time. I hope this can help you.

Thank you so much! I paid more attention to a few more things!