How to completely extract the side stream from a distillation column?
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In the distillation column, liquids can be extracted using side products. Now, it is desired to extract them completely for further processing before returning them to the next tray, but only the extraction volume or the extraction/feed ratio can be specified. However, since the liquid flow rate in the column is prone to change, achieving complete extraction requires manual adjustment； Especially when two side products need to be completely extracted, the manual approach can lead to interference between them, which is very inconvenient. Do anyone have any good suggestions? I know that pumparound can be completely extracted; why can’t the side product be completely extracted? However, the material extracted by pumparound can only be heat-exchanged; it cannot undergo reactions, so it does not meet my needs. I’m not sure if my description is clear enough? This post was last edited by lymountain on 2009-2-18 15:41]
Does \"complete extraction\" mean extracting all of the liquid phase? That would result in a dry plate, and Aspen will report an error. In your case, it is possible to make a connection at the point where you want the reaction to take place; this involves using two towers. After the reaction occurs in the upper tower, the liquid flows to the top of the lower tower, while the gas from the lower tower flows to the bottom of the upper tower. The upper tower does not have a reboiler, and the lower tower does not have a condenser.
The data recommends the liquid phase flow rate for the specified tray. I’m not quite clear what the poster means by “fully extracting” I’ve just encountered a software message indicating a dry plate.
What was said on the second floor is correct; it is a solution.
Do not proceed with extraction yet; first simulate the situation and then examine the liquid phase flow distribution across each tray. Determine the approximate range for the extraction volume based on the liquid phase flow rate in the layers being extracted, making sure to leave a certain margin to prevent the trays from becoming dry； Additionally, when multiple streams are recovered, it is best to provide examples of the recovery amounts LZ determined based on the process. When discussing systems in this context, we can only give a general overview of the experience with using ASPEN
You can choose total lique, to extract everything
What I mean is that, while maintaining a certain liquid level, the amount of fluid extracted is equal to the amount calculated theoretically to flow to the next stage; in other words, the flow rate of fluid to the next stage is zero. As a result, the system will not run out of fluid in actual operation, although it might appear as if the fluid level is low in the calculations. Pumparound should extract everything like this, but it doesn’t indicate that the dry plate is ready either. Simulation is carried out using two towers with circulation, and convergence is very difficult. I wonder what experience everyone has in adjusting convergence? This post was last edited by lymountain on 2009-2-19 10:39.]