Re-using Caustic from CIP system

Hi all, I am QA manager for a liquid manufacturing company. We had an interesting conversation with the company that installed our pasteurizer and they suggested that there are many companies that have systems to recirculate and reuse caustic from the CIP system. So rather than drop the water to the drain into the waste water they recirculate and reuse the same chemical and water from previous washes (continuing to check titration levels before each new wash). Does anyone in this forum do this? It seems like a stretch of the imagination on how this would work.  I appreciate any insight! 

In theory this could work---but would depend heavily on your ability to remove the gross debris prior to starting the CIP

Obviously is the solution becomes full of your product you would just be redistributing it as residue and not actually fully removing it, if however, your system allows for a full high pressure potable water CIP prior to running chemical, then it could work with substantial savings

It is done that way during operations in processes that use vast amounts of water-----carcasses chilling, egg washing, vegetable fluming, etc.  BUT they either follow mathematical equations for make up water and/or test the recirculated water to ensure it doesn't become a source of contamination

So---if you also implemented a testing scheme to verify the cleanliness of the solution and not just chemical concentration, you can probably manage it this way

Lots of beverage and dairy companies do this.  You can have a reuse wash tank to recover the chemical solution and also a separate recovery tank for rinses after the wash step reconvert.

The reuse wash tank must not get contaminated with the product / material you are trying to remove.  Yes, some of this will always get back to the wash tank.  If you use a blended chlorinated caustic you can monitor the chlorine level to see when it drops below your limit.  When it does you dump the wash tank and refill.  You also have to include the tanks on a regular cleaning schedule because they will buildup stuff over time.  Lots of companies that use this method utilize some type of chemical monitoring, typically conductivity, to automatically maintain the chemical level.

The recovery tank, separate tank, is something you can use to recorder rinse water after caustic step.  This recovered water can then be used as a pre-rinse for the next CIP.  Intention is to save the water overall.

there are a number of companies that build CIP skids off the shelf with integrated control systems.  You can get as simple or as fancy as you want.  Check out Sanimatic, Statco, Ecolab for more info on this.  Sanitmatic and Ecolab can help build an ROI for this type of system.