You will need your heat of formations and your chemical reaction
Zoobie told us
CaCO3 -> CaO + CO2
first you will have to balance the equation, then you will use the heat of formations (usually refered to as DeltaF) multiplied by your stechiometric coeffs (remember reactives are negative...
I think you still need to change your composition in volume into a composition in mass so you can make the mass balance. maye you can sample your fuel and measure densities.
the TDH is a difference basically so the sign can tell you something, normally it is something like this
TDH = Against - Aid
this means that you are going to sum all the elements against your pump and substract all the elements that help your pump (height, pressure etc)
So if you are having...
I think you can get the heat of reaction out of the heat of formations, remember the hesse equation... you are going to take the heat of formation of your reactives and your products and the difference will be your heat of reaction, I dont know if it is an exothermical or endothermical reaction...
Have you tried with a tracer, perhaps you could add it on your water stream (colorant maybe) and then run your HX normally then you would have a clearer idea where the water is coming from
If your soda is being cristallized the easiest way out I see without making major changes is to dilute it, however you need to consider if you can afford a more dilluted solution (because of the increased flow, the mixing conditions etc)
if it is still crystallizing see if you can somehow heat...
