Building a flexible tool for mass balances in excel - any tips?
Building a flexible tool for mass balances in excel - any tips?
(OP)
Hi all,
I often deal with mass balances in spreadsheets. They are not terribly complex, but almost always involve a bunch of separation steps with recirculation - that translates to circular calculations.
What I do is taking one or two key values, and adjusting them by the goal seeking function till the mass balance is correct. Are there better ways?
Now, I want to build a spreadsheet as a template that allows me to easily add components. My idea is to build blocks of lines that either do a separation or mixing of streams, every output stream is indexed and the input streams take this data by vlookup or similiar.
In theory I should be able to add operations to my mass flow by copying the blocks, adjusting the parameters and selecting the correct indices.
Did anyone have a similiar idea before and run into trouble, any pointers what i should take into account from the beginning?
all help is appreciated!
I often deal with mass balances in spreadsheets. They are not terribly complex, but almost always involve a bunch of separation steps with recirculation - that translates to circular calculations.
What I do is taking one or two key values, and adjusting them by the goal seeking function till the mass balance is correct. Are there better ways?
Now, I want to build a spreadsheet as a template that allows me to easily add components. My idea is to build blocks of lines that either do a separation or mixing of streams, every output stream is indexed and the input streams take this data by vlookup or similiar.
In theory I should be able to add operations to my mass flow by copying the blocks, adjusting the parameters and selecting the correct indices.
Did anyone have a similiar idea before and run into trouble, any pointers what i should take into account from the beginning?
all help is appreciated!





RE: Building a flexible tool for mass balances in excel - any tips?
RE: Building a flexible tool for mass balances in excel - any tips?
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(2B)+(2B)' ?
RE: Building a flexible tool for mass balances in excel - any tips?
If Solver then comes up with an 'inappropriate' solution I reexamine my weightings to bias the answer in the direction I want.
Cheers
Greg Locock
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RE: Building a flexible tool for mass balances in excel - any tips?
The approach I'm trying right now is minimising a sum of squares.
Iterative solving - I want to avoid this, because the mass balance will be integrated into a larger tool where turning off automatic calculations will cause inconveniences that I want to avoid.
To explain the math: I have a reactor vessel in which I mix a fresh substrate stream and another stream that I call recirculation. Gasification happens, TS (solids) gets converted to biogas. The liquid output gets fed into a separator, with two output streams - a solid one with less water, a liquid one with less solids. Part of the latter will be pumped back into the vessel as recirculation. Now the solids content of the liquid stream depends on the input into the separation step, wich also depends on how much I recirculate. So far this is solvable by simply adjusting the solids content after the reactor vessel with the goal seek function.
Now I sometimes need to add further separation steps, and I think I want some flexibility so I can adjust my tool down the road if other process flows show up. I hope I made the problem I try to solve more clear?