How to select the reflux ratio
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This post was last edited by visavis on 2010-6-24 at 20:50. The relationship between the reflux ratio and the number of trays for the distillation of ethanol and water has now been obtained using Aspen; it is estimated that the number of trays lies between 12 and 20, while the reflux ratio ranges from 2.6 to 4.8； Selecting the most appropriate reflux ratio and number of plates requires taking into account operating costs and equipment expenses, which have been covered in textbooks on chemical engineering principles. I would like to determine specifically the optimal reflux ratio and number of theoretical plates for the distillation of ethanol and water. I was wondering if anyone has any formulas or parameters for calculating operating costs and equipment costs, etc. PS: Packed-bed distillation column
Let’s pay attention together. It is better to use a low reflux ratio while ensuring product quality; the optimal number of theoretical plates is determined through sensitivity analysis. I’m not sure what’s wrong with my approach. Personally, I believe that cost control cannot be resolved through simple formulas; it requires continuous calculation and verification.
Now, it is planned to consider the heat load at the bottom of the tower in the same way as when selecting the feed plate
Conduct sensitivity analysis to examine energy consumption, and also determine the minimum reflux ratio; taking a value between 1.05 and 1.2 times the minimum reflux ratio is a reliable approach~
A sensitivity analysis is still necessary, taking into account the energy consumption of the condenser and reboiler as well
As long as the requirements are met, the lower the reflux ratio, the better. However, ethanol distillation actually requires a relatively high theoretical half-value, which is much higher than that in simulations; I’m not sure what purity level the original poster aims to achieve through ethanol distillation
Now it seems feasible to conduct a sensitivity analysis on the heat load at the tower bottom in Aspen, in order to select the lowest possible heat load for the tower bottom while ensuring the quality of the product at the tower top