Lesson 2 - Water
In this lesson we take a closer look at water from a utilities perspective. We will consider different forms of water treatment and look at the equipment required and operation thereof. The focus will be on treatment required for process and service water. Water chemistry will not be covered in any detail, as this is covered in Diploma Brewing Module 1.
Serial Ion-exchange Systems
By putting different ion-exchange units in series, you can remove a variety of ions from the water to achieve various levels of de-mineralisation. If you were to put all of the ion exchangers in series, you would end up with completely demineralised water.
This is shown in the figure below.
Figure: Ion exchangers in series
Mixed bed reactor
Instead of having two exchange systems in series, we can use a reactor that contains both a SAC (H+ type) and SBA (OH-) resin type within one ion exchanger. The mixed bed reactor should ensure that it releases only hydrogen and hydroxyl ions, thus forming water.
General considerations
Ion exchangers have two key disadvantages: they require chemicals for regeneration, and the resins need to be disposed of once they are no longer usable.