【CO2 Stripping Method】Problems of temperature rise and passivation due to air + steam
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In our plant, air and steam are used for heating and passivation; the air is introduced at the CO2 pipeline, while water is added at the inlet of the high-pressure ammonium methanate condenser. After vaporization inside the ammonium methanate condenser, steam is generated. May I ask: 1. In your plant, where are air and steam introduced for heating and passivation, as well as water? 2. Do you think there are any issues with our factory’s approach? In my opinion, this approach used in our plant may not be effective for passivating the stripping tower, as steam does not reach it easily; I would appreciate some discussion on this matter. This post was last edited by cthlj2007 on 2009-4-2 22:46]
For temperature-induced passivation, the rate of temperature increase should be the main control factor; strict control over the amount of steam and air is not required. However, during the temperature increase process, it is necessary to adjust the flow rates and ratios of these two substances in a timely manner to ensure the desired rate of temperature increase and the effectiveness of passivation. The amount of steam and air required for the temperature-raising passivation in the CO2 stripping method has not been specifically defined. In practice, the heating rate should be below 30°C; below 100°C, it should be at least 8°C per unit time, and above 100°C, it should be at least 12°C per unit time. Once the temperature reaches 125°C, the process must remain at that temperature for 4–6 hours to be considered successful.
Is the high-pressure ammonium acetate condenser mentioned by the poster a pool-type condenser? . . Can the temperature be reached? Our plant introduces both steam and air into the CO2 pipeline of the stripping tower, and it is necessary to flush the stripping tower at regular intervals. With this method, the temperature at the upper part of the synthesis tower (below the flared section) often fails to meet the required standards; after the heating and passivation process is complete, the temperature is only 110 degrees.
Steam also needs to be introduced into the overflow pipe of the synthesis tower to raise its temperature from top to bottom; care should be taken to drain the condensate from the lower part
We use the traditional CO2 stripping method and dream of having a pond-type condenser. Using the method I suggested, there is no issue with the temperature rise of the high-voltage coil, and it can meet the specified requirements. Depending on the method you are using, have you paid attention to sealing the overflow pipe and suction pipe? If they are not sealed, steam may take a shortcut via \"stripper tower → overflow pipe → top of the synthesis tower → high-pressure washer\", or via \"stripper tower → high-pressure ammonium methoxide condenser → synthesis tower → suction pipe → high-pressure washer\", or perhaps through part of these paths? And what about the amount of water or steam added? System pressure? What is the temperature difference at the top of the synthesis tower? For example, is the temperature 110 degrees at the top, while it is 140 degrees at the bottom and middle? Is there any issue with the temperature sensor at the top? (This can be detected even during normal production.) Also: What is the steam pressure applied to your CO2 pipelines? How to flush the stripping tower at regular intervals? Where to aim? Are there any requirements regarding the temperature of the flushing fluid? This post was last edited by cthlj2007 on 2009-4-2 12:44]
Steam is introduced into the synthesis tower; does the steam not go directly into the high-pressure scrubber 3203-C and escape from there? This post was last edited by 1025199692 on 2009-4-5 02:16]
Air and steam can be introduced simultaneously into the high-pressure flushing water pipeline of the synthesis tower outlet pipe.
1. Where in your plant is the heating and passivation of air + steam, along with the addition of air, steam (or water)? Adding steam to the overflow pipe of the synthesis tower to raise the temperature for passivation is beneficial for the synthesis tower. Steam can be directed to pool condensers, stripping towers, and high-pressure washers, where it effectively raises the temperature for passivation. The air in the container is sufficient; no additional air needs to be added. 2. Do you think there are any issues with our factory’s approach? Temperature-induced passivation doesn’t require adding water, right?
In my opinion, as long as the system pressure reaches the required level and the medium reaches the area where the temperature is to be increased, there should be no major problems. I am considering the passivation issue of the stripping tower. It should also be noted that the purpose of adding water in our factory is to vaporize it and produce steam; no steam is added directly to the system. Additionally: In plants that use pool condensers, the high-pressure circuit should also be the same as in traditional systems. How can it be ensured that steam can flow to the pool condenser, stripping tower, and high-pressure washer? Also, “using the air in the container” means using only the air that enters through the open parts of the equipment, without the need to add air to the system separately? It is said that factories using new materials are like this; I’m not sure if that’s true.