Distillation column adjustment
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There is a high proportion of light components in the feed to the distillation tower; how should operators handle this situation, in detail?
If you want others to be more detailed with you, you should first describe the problem in detail
It’s necessary to be clearer whether it’s a low-boiling tower or a high-boiling tower in order to make a judgment
The feed inlet location, bottom temperature of the tower, reflux ratio, etc., all have an impact
The adjustment approach is as follows: 1. The amount of heating steam supplied to the tower bottom can be increased appropriately, but the temperature should not be raised, as a lighter composition may lead to a decrease in the temperature at the tower bottom； 2. The backflow rate can be appropriately reduced ； 3. The pressure at the top of the tower can be appropriately reduced. The above three parameters are adjusted according to actual conditions, and the material balance is adjusted in a timely manner based on the feed composition. 4. If there are multiple feed inlets, when adjusting other parameters yields unsatisfactory results, considering raising the position of the feed inlets may be an option
An increase in the amount of light components raises the temperature at the top of the tower, and the pressure difference within the tower increases as well. Since more light components are present, more steam is needed to evaporate them; as a result, the temperature of a certain portion of the material rises compared to before. Hence, the temperature of the tower increases, and with more gas-phase components present in the tower, its pressure also rises. As for how to set up the automatic control of a distillation tower, the fundamental solution to the problem of an increasing amount of light components in the feed is to increase the amount taken out from the top of the tower; otherwise, a large amount of these light components will flow back into the tower, causing the temperature throughout the tower to drop, and this in turn will lead to a decrease in the overall tower pressure. Actually, I don’t want to change the amount of heating steam at the bottom of the tower during the distillation process, as that would disrupt the balance of the entire tower! Increasing the amount of heating steam at the bottom of the tower will raise the tower pressure as well as the tower temperature. In a distillation system, temperature, pressure, and composition generally correspond one-to-one
Pay attention to tower pressure and ensure proper material balance