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Thread: Cleaning & Sanitizing regimen

  1. #1
    Join Date
    Aug 2004
    Location
    Israel
    Posts
    51

    Cleaning & Sanitizing regimen

    I've read previous posts on this issue but I need some help with details for a meeting with the ministry of environment here. Does anybody have a cleaning & sanitizing plan that they used for local authorities to convince them that they will not be trashing the local sewage plant? We're talking about a 10 bbl micro with 3 10 bbl fermenters and a bunch of grundies (6) for conditioning tanks. All tanks are CIP. I've managed to convince them that spent grains/trub/yeast are going to the cows so it's really just the cleaning side they're concerned with.

    Some of the details they've been asking about:
    1. How often are tanks cleaned
    2. How often are the tanks sanitized
    3. How much water is used in cleaning/sanitizing process
    4. What chemicals are used in cleaning/sanitizing and in what dilutions
    5. What will be the PH of the caustic & acid solutions when sewered. I've told them I'll be reservoiring & recycling the solutions so the real question is until what PH is the caustic and the acid effective?
    6. What special equipment do I need to recycle caustic & acid solutions & is it worth it?

    Anything else you can think of that would be of interest to a sewage plant would be extremely helpful.

    Thanks.

    David

  2. #2
    Join Date
    Dec 2004
    Location
    Mukilteo, WA
    Posts
    302
    Dave,

    Please see my additions below...........


    Quote Originally Posted by Dancing Camel
    ".............I've managed to convince them that spent grains/trub/yeast are going to the cows so it's really just the cleaning side they're concerned with.
    Be careful with the grains and yeast with regards to cattle. The farmers need to use the byproducts as suppliments to a grass/hay diet or the cattle will bloat and die a somewhat horrible passing due to a ruptured stomach (from gases produced). You can do a search on Probrewer for prior discussions.


    Some of the details they've been asking about:
    1. How often are tanks cleaned
    After every use. On the day of transfer of the product from them. This is scrubbing out or caustic washing any yeast deposits that are on the surfaces.


    2. How often are the tanks sanitized
    Prior to every use. The tanks MUST be clean prior to sanitation. We use Iodifor, but Per-Acetic acid or similar is fine.

    3. How much water is used in cleaning/sanitizing process
    Cleaning: Around 20 gallons if using caustic and recirculating.
    Sanitizing: Around 8 - 10 gallons.


    4. What chemicals are used in cleaning/sanitizing and in what dilutions
    Cleaning: Caustic soda heated to around 130 - 140F. The mix will be very basic (hi pH)
    Sanitizing: Iodifor, Per-Acetic acid. Use cold. Both break down into some pretty tame solutions.
    Follow the package instructions.


    5. What will be the PH of the caustic & acid solutions when sewered. I've told them I'll be reservoiring & recycling the solutions so the real question is until what PH is the caustic and the acid effective?
    I don't have a ready answer for the pH, but you can't re-use your sanitizers. They'll go to drain. You can use your caustic as long as the pH is high enough, but you'll eventually need to change it out. You can cut it with yeast or beer to neutralize its pH (both are acidic), but your sewer district might not like you dumping yeast down the drain a whole lot.


    6. What special equipment do I need to recycle caustic & acid solutions & is it worth it?
    Basically, to re-use the caustic you need a small stainless tank somewhere in your Brewery. I don't know if you made it down to our place when you were in Everett, but we have an old yogurt flavor mix tank that looks like a mini conical fermenter without a lid. We store caustic in there. You can use all your existing process equipment (pumps, hoses). Rinse them with hot water.
    Don't forget to backfush your heat exchanger with hot caustic regularly. That system you have has the heat exchanger below the decking and it's a real pain to tear it down and clean the leaves.



    Anything else you can think of that would be of interest to a sewage plant would be extremely helpful.

    Thanks.

    David

  3. #3
    Join Date
    Oct 2002
    Location
    Stavanger Norway
    Posts
    321
    I find the less you tell them the better.
    Tell them you mainly use alkaine cleaner, get all msds and data sheets available. Use it with your new RO water at a .5% solution and have a buffer saftey tank which doubles as your CIP tank... After use you will Dilute it 10 times so that the PH is neutralized (Overkill it)....

    For sanitizing use 80C water to pasurize the tanks, Occasionally use Acid to get rid of stubborn chalk build up , again saftey buffer tank and Dilution.

    invite them to come after 1 month and do a test on you brewery drain for levels. You wont have a problem.

    As for the PH of caustic its not important its the conductivity.... you need a special Ph meter to give you that answer.

  4. #4
    Join Date
    Apr 2016
    Location
    Santa Marta, Colombia
    Posts
    2

    % of Caustic soda solution

    Hi,

    Just checking that i am doing things right. I use Caustic Soda at a 3% solution for cleaning

    and Peracetic acid at a 1% solution for steralising.

    Does that sound right?

  5. #5
    Join Date
    Feb 2016
    Location
    Atlanta, Georgia
    Posts
    7
    Divide those numbers by 10. Use a 0.3% caustic and 0.1% concentration of Peracetic Acid.
    Loeffler Chemical Corporation
    (404) 629-0999
    800-769-5020 (US & Canada only)
    www.loefflerchemical.com

  6. #6
    Join Date
    Apr 2016
    Location
    Santa Marta, Colombia
    Posts
    2

    i've been wasting chemical

    Quote Originally Posted by Brian@Loeffler View Post
    Divide those numbers by 10. Use a 0.3% caustic and 0.1% concentration of Peracetic Acid.

    Wow really?!? Thanks. I have been wasting a lot of chemical then. Are you sure that 0.1% of peracetic acid will sterilise well enough?

    cheers

  7. #7
    Join Date
    Feb 2016
    Location
    Atlanta, Georgia
    Posts
    7
    Not necessarily, Surf Monkey. Different manufacturers of Peracetic Acid make different strengths. The most common I see in the field are 5.1%, 5.6%, 15%, and 22%. Ultimately the final use concentration is most important. I recommend a concentration of 150-250ppm, provided EPA registrations do not differ in your state, since Pediococcus in Texas may require a different concentration of Peracetic Acid than Pediococcus in California. Always check the label on the product for the appropriate use concentration, and then adjust said usage concentrations to achieve 150-250ppm.

    For a 15% Peracetic Acid, a 150-250ppm solution is made by using 0.1 - 0.166% by volume, or 0.128 - 0.213 fluid ounces per gallon. For a 5.1% Peracetic Acid, the usage rates would be about three times higher.

    Caustic is an entirely different story. Sodium Hydroxide is very dependent on the additives in the caustic. Simple caustic alone will typically require 2-4% by caustic to achieve modest results. Most commodity Sodium Hydroxide is sold as a saturated 50% solution, so usage concentrations are 4-8% by volume (or higher for commodity caustic sold at less than 50% concentration). As performance chemistry is added to the caustic, the concentration of Sodium Hydroxide must decrease, but the overall use concentration may also still decrease. This is why trials with caustic are so important--the comparison cannot be made on paper like with Peracetic Acid or other products where sole importance is the concentration of chemical. Most top-tier caustics contain 25 - 35% Sodium Hydroxide and are used at 0.5 - 3% by volume.

    Do not forget that tanks will require regular descaling with an acid--most often a Nitric-Phosphoric blend. A concentration of 1-2% by volume, or 0.5 - 1.0% total Nitric and Phosphoric acids is normal, but your mileage may vary. This will need to be performed regularly on your bright tanks (and fermenters if you unitank) to remove Calcium Oxalate (beerstone). You should also descale your HLT and kettle as you develop hard water scale. Nitric Acid is most often used for passivation of stainless steel at about 4-6% Nitric Acid.

    Getting back on topic with the OP--Most municipal water treatment facilities are concerned primarily with pH, BOD/COD, TSS/TDS, and Phosphates/Nitrates (in that order). Your cleaning solutions will have the largest impact on pH--especially your caustic and acid CIP cleaners, as these are used in the largest volumes and have the strongest pH swings. A neutral to slightly alkaline pH of 7 - 9 is optimal for your discharge. Some customers are restricted by their municipalities to ranges as wide as 5 - 12. Some sewer lines are steel, and strong acids will quickly destroy these pipes. Also, most treatment facilities must add caustic to the incoming effluent to raise the pH. This is why caustic is more environmentally friendly than non-caustic cleaners. A pH neutralization is all that is required to render caustic into essentially salt water. A buffer tank for your effluent will help even out the high and low pH swings from your CIP solutions. A cheap poly tank is sufficient for this purpose. This can be batch-discharged to the drain after a pH adjustment or it can simply overflow-to-drain. The larger this tank, the better as it will require less treatment on your behalf.

    The oxygen demand of your effluent is mostly from the brewing process itself. Yeast is terribly high in BOD, and breweries with excessive restrictions on BOD/COD discharges can usually thank their nearby colleagues for dumping yeast down the drain. You should also avoid sending kettle trub and spent grain down the drain if possible.

    Michael is right, it is the conductivity that is important, not the pH of your caustic. (Also, I second the idea that the less you tell them, the better.) A very, very small change in pH will correlate with a huge change in caustic concentration. If you do not have conductivity controls in the brewery, use a field titration kit or perform a P&M titration. As for caustic storage, anything that is resistant to caustic will work. Some breweries even use cast iron tanks for caustic.
    Loeffler Chemical Corporation
    (404) 629-0999
    800-769-5020 (US & Canada only)
    www.loefflerchemical.com

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