pH Adjustment Chemicals

By February 16, 2014Chemicals

A lot of time breweries will need to adjust the pH of their wastewater.  The EPA has guidelines of between pH 5-11, many states and municipalities are more strict than that.  Adding pH adjustment chemicals to your wastewater is where you literally start pouring money down the drain.  So it’s important to be efficient in your chemical choices and use.

The cheapest method to adjust the pH of your wastewater is manually.  Use a pH strip to test the pH of the water in a tank.  Then add caustic or acid by hand until the pH comes in range.  Then dump it all.  It works.  Put in a big enough tank so you only have to do it once a day or once a week and it will work just fine for the long term.

Beyond this things will get expensive- but automated.  Install a recirculation pump with a pH electrode in the loop.  A pH meter can control your chemical pumps automatically.  Dump the water when the pH gets in range.

50% sodium hydroxide is the cheapest base for your wastewater.  Storing your CIP wastewater and dumping it as needed makes it even cheaper.  But who has the tank space for that?

Of course we all know that caustic is nasty stuff to work with.  If it gets in your eyes you might go blind.  Be safe.  If you get it on your skin, wash it off with beer or spent yeast.  It works.  The biggest drawback to 50% caustic is it freezes at about 45 F.  Still, its cheaper to buy it at 50% and cut it with water in your tank to lower the freezing point.  Make sure to store caustic in tanks designed for it, 50% caustic has a very high specific gravity.  Adding water to the caustic causes an exothermic reaction, you don’t want a thin tank wall to crack.

96% sulfuric acid is usually the cheapest acid.  Again, nasty stuff to work with and make sure the tank you store it in is rated for it.  When sulfuric acid comes in to contact with water in a stainless steel pipe, corrosion of the pipe can happen.  Use an injection quill to add the chemical into the middle of the pipe.

Another alternative for acid is carbon dioxide, and breweries have a lot of that around.  I have not used this, but it does work.  Add a carbonation stone to the bottom of your tank and you’re in business.  If you could use your fermenter blow off you would have a free source.  Be careful with ventilation if going this route.

Of course there is more to it than this, but you get the idea.  And remember, I have done this many times and I know what works.  Please contact me for more specific information.  Thanks.

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