Discussion on issues related to side-line sampling
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I currently have a distillation column; the feed contains 0.3% light components with a boiling point of 16 degrees, while the product contains 88% of such components with a boiling point of 56 degrees. The remaining components are heavy components. I would like to replace the original distillation column with a side-stream extraction column. It turns out that the feed is supplied at the bottom of the tower. The product is only ready at the top of the tower. Now I want to keep the feed position unchanged, and lower the position where the finished product is taken from the top of the tower by a few plates; the first plate will be used to collect the light components. Does anyone have any good suggestions to guide me? My simulation results are incorrect, and the final products never meet the quality standards.
Increasing the reflux ratio raises the reflux ratio and reduces the number of effective theoretical plates, but what is the purpose of doing this?
The original poster’s idea is good, but you have overlooked some defects in the specific implementation plan. I don’t know what the boiling point of the heavy component is at present, but I can offer some suggestions that you can try out. Since the content of the light component in the feed is not very high, only 0.3%, it can be extracted from the top of the tower. The feed doesn’t necessarily have to go in at the bottom of the tower; instead, a tray whose composition is similar to that of the material should be chosen for this purpose, as this is important for the stable operation of the tower. The product should be extracted from a few trays near the top of the tower, and the exact number of trays requires theoretical calculations and practical testing. The heavy component should be extracted from the bottom of the tower. The most important point is that since there isn’t much light component present, there’s no need to set up a separate tray for its extraction; a small amount can be taken out from the reflux tank, while most of the vapor from the top of the tower is condensed and returned to the tower via the reflux tank as reflux, thereby reducing unnecessary waste of material.
LZ, this simulation of yours is incorrect, right? Feeding at the bottom of the tower; you said that feeding can be done inside the tower on the second floor, but in that case the material will not meet the requirements for product separation (the tower has fixed constraints) If you need to operate under a fixed tower, then you can press 1 to increase the reflux; it’s not necessary to obtain the product on the first plate, which will meet your requirements. But as mentioned on floor 1, by doing so you increase the costs just to avoid obtaining the product at the top of the tower? Another side line? So this is impossible for you!