[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

modelling a stirred tank reactor



Dear Sir,

i am using the Phreeqc program to model batch dissolution experiments and
speciation of aqueous equilibria. I would appreciate if you could have
either yourself or on of your students
could have a look into the following problem :


	My real interest lies in modelling  open stirred tank reactors to simulate
flow through dissolution experiments. I started with the idea to do several
iterations of a loop that would contain both a kinetic rate and a mixing
operation of the solution resulting from the dissolution and a predefined
"inlet" solution which would mix at constant volume ratios. I did not get
this to work as a mixing function (MIX) may not be part of a rate (KINETICS)
function.

	Now in theory I could do sequential steps of rate,mixing  rate,mixing
rate,mixing. Now while this does not appeal to me from a programming
viewpoint (it seems akward !) I stumbled into a larger problem. I can
recover the solution compositon by adding several PUT commands for all
necessary ions but how do I then explain PHREEQC to use these to define a
new solution that will subsequently be used in a KINETICS block.
The following schematic script showing two iterations did not
work !

> **************************************************************************
>
> TITLE
> Solution 1
> Solution 2
> MIX Solution 1   0.2
>     Solution 2   0.8
> Save Solution 3
> Use Solution 3
> KINETIC blabla
> RATE blabla
> -start
> .....
> x=MOL("Ca2+")
> PUT(x,1)
> -end
> Solution 4						THIS IS THE CRUCIAL OPERATION !!!
>    Ca   GET(1)
> MIX
>   solution 1    0.2
>   solution 4    0.8
> END
> Save Solution 5
> USER_PUNCH
> ....
> Use Solution 5
> KINETIC blabla
> RATE blabla
> -start
> .....
> x=MOL("Ca2+")
> PUT(x,1)
> -end
> Solution 6
>    Ca   GET(1)				THIS IS THE CRUCIAL OPERATION !!!
> MIX
>   solution 6    0.2
>   solution 3    0.8
> END
> Save Solution 7
> USER_PUNCH
> ....
> END
>
> **************************************************************************


Now are there more elegant ways to do it ?

How can I define a new solution from previously stored parameters OUTSIDE a
rate function ?

Can one make a DO LOOP to group a MIX and RATE function


with kind regards

Stephan Kohler

"""""""""""""""""""""""""""""""""""""""""""""""""""""
Stephan Köhler       LMTG - UMR CNRS n°5563
Observatoire Midi-Pyrénées Université Paul-Sabatier
38, rue des 36-Ponts   31400 Toulouse
TEL + 33(0) 561557611 FAX + 33(0) 561558138
"""""""""""""""""""""""""""""""""""""""""""""""""""""



Project Home Page
Complete Water Resources Division Software
USGS Home Page
Water Resources Division Home Page
NRP Home Page
Help Page
USGS Privacy Statement       

Please note that some U.S. Geological Survey (USGS) information accessed through this page may be preliminary in nature and presented prior to final review and approval by the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user.

Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. 


The URL of this page is: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/mail/msg00111.html
Email:dlpark@usgs.gov
Last modified: $Date: 2005-09-13 21:04:21 -0600 (Tue, 13 Sep 2005) $
Visitor number [an error occurred while processing this directive] since Jan 22, 1998.