3 replies to this topic

I am currently designing a reboiled stripper for my final year project. This is a stripper that uses reboiled feed as its stripping agent. I will need to determine the number of stages, vapur and bottoms flowrates as well as doing plate to plate equilibribrium calculations.

The stripper resembles a distillation column but with no reflux. Therefore Fenske, Underwood and Gilliard methods are not appropriate to determine the number of equilbrium stages.

I have done some reading on the Kremser group methods which detail calculations for conventional absorbers and strippers. Is this same approach that should be used for designing a reboiled stripper?


Thanks
Chima

Edited by enybclu, 12 February 2011 - 01:03 PM.

[Art Montemayor]

Chima:

Don’t starve us of basic data, but rather give us specific information.

What is “reboiled feed” and how is the “stripping agent” being used and applied? The best way to respond to these type of continuing queries involving general statements is to furnish a detailed sketch of the proposed operation, as well as the fluid identifications, compositions, temperatures, pressures, etc. If you have done any work at all on this project, it would be polite, courteous, and save a lot of time if you submitted it in an Excel workbook format.

We can help you; you will find our Forum members very receptive and helpful – but we can only help you to the same degree with which you help us help you.

Await your reply.

Hello

Apologies for the vagueness of my process description. The process fluid is a hydrocarbon stream containing C₁- C₁₀ compunds with H₂S impurities. The vessel is a reboiled stripper that removes the methane, ethane, ethylene and H₂S from the hydrocarbon liquid stream. Unlike conventional strippers, there is no external stripping gas used. The stripping vapour is generated by reboiling the bottom product.

With the Kremser equation I hope to determine the number of stages in the stripper and also do a material balance at each stage. I have set up a spreadsheet with key flowrates and process parameters.

The process has been simulated in Hysys and I am using the process parameters like temperature, pressure and flowrates from the simulation

I need to calculate the k-values for the key components. I can do this by henry's law, K = H/P. However, I need to get the regression co-efficients of each component and then use a suitable correlation that relates H to temperature.

 Reboiled Stripper Data.xlsx   137.1KB   78 downloads

[Zauberberg]

Kremser-Brown equation is more suitable for isothermal, highly diluted systems, which is not the case here and it could produce inaccurate results. I remember using Kremser-Brown for stripping H2O from hydrocarbon condensate by using dry natural gas. And the results were quite good.

You said that you have used simulator to obtain flows and other process parameters. You can use it for getting the K-values as well. This option is provided in the Column window, "Performance" tab. Go to the "Plots" option and pick a table or graph view, which will list K-values for the selected components for each tray.