katchum - 15-11-2006 at 14:47
Let's say I have a scrubber with a recycle stream from the liquid out to the feed and I want to maintain a pH of 8 in the scrubber. How can I
calculate the recycle ratio R?
The gas stream is SO2 and HCl, the scrubbing liquid is NaOH (20%). Gas flow and Liquid flow rate is given. Gas concentrations y are known. V in = V
out, L in = L out.
I would say you have 4 component equations with parameters xHClin, xSO2in, xHClout, xSO2out and R.
I need one more equation, how do I find it?
Thanks
[Edited on 15-11-2006 by katchum]
Baphomet - 24-11-2006 at 05:29
Assuming SO2, HCl and NaOH flow rates are constant then the recycle rate depends exclusively on one variable. You'll need to figure out an equation
for the function R that will give the rate that keeps pH at 8 for those given parameters in a unit of time T. Then differentiate on T to get your
instantaneous rate.
Even if the flow rates are not constant but can be factored in terms of T then those just become part of the equation for R.
Grab a textbook on process engineering and with any luck you could find an example that closely matches this scenario. Good luck