Solubility

From SysCAD Documentation

Navigation: User Guide -> Solubility

Overview

The Solubility of a liquid or solid in a Solvent is the mass of that species dissolved in a fixed mass of Solvent which is in equilibrium with an excess of the species at a given temperature. The solution is said to be Saturated at these conditions.

When the user enters solubility data for a species in the Species Database, then SysCAD will calculate the saturated solubility in solution for that species throughout a project.

• If there is sufficient excess then SysCAD will dissolve sufficient mass to achieve a saturated solution.
• If there is an excess of the dissolved species, then SysCAD will automatically convert the excess to the other phase.

SysCAD will automatically calculate the Heat of Reaction (HOR) for the dissolution or precipitation reaction based on the thermodynamic data in the Species database for the two species of interest.

As an example, if the species involved is NaCl:

• If there is an excess of NaCl(s) then SysCAD will dissolve the solid form to obtain a saturated solution of NaCl(aq), with an associated drop in temperature (this is an endothermic reaction);
• If there is an excess of the aqueous species, then SysCAD will precipitate it to the solid form, NaCl(s), with an associated rise in temperature (this is an exothermic reaction).

Solubility is one of the Phase Change options available in SysCAD.

Implementation in SysCAD

• Entering Solubility Data in the Species Properties Database - A description of solubility functions that can be entered in the Species Properties Database.

• Enabling and Disabling Solubility in a Project - The automatic solubility functionality can be enabled or disabled throughout a project on the Species page in Plant Model (View - Plant Model - Species Tab).

• Selectively applying solubility in unit models - If solubility is globally disabled, it is then possible to selectively enable solubility in units with Evaluation Blocks (EB) such as ties.

• Solubility Information in Units and Pipes - The information shown in the access window of pipes, tanks, etc. is described in Material Flow Section.

• Solubility Information in a Project - The solubility information entered a project can be seen in the Species Properties Access Window (View - Species Data).

• Example Project with Solubility - This gives a description of an example project that demonstrates the use and effect of solubility data.