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Specialty Chemistry Forums => Chemical Engineering Forum => Topic started by: TfrancisCH on December 18, 2017, 02:56:04 PM

Title: Neutralizing 15% NaOH
Post by: TfrancisCH on December 18, 2017, 02:56:04 PM
I have a client that has a 3,000 gallon tank of 15% NaOH.
I will empty the tank and need to neutralize the residual material in the tank.
What is the best method to achieve a pH range of 5 - 9?
My thought is to fill the tank with D.I. water but I'm not sure that the dilution will
have the desired effect.
Title: Re: Neutralizing 15% NaOH
Post by: Borek on December 18, 2017, 03:50:41 PM
Dilution is definitely not a way to go, unless you have around 3000×105 gallons of DI water to spare.
Title: Re: Neutralizing 15% NaOH
Post by: OrganicDan96 on December 18, 2017, 04:07:21 PM
a bit of dilute acid
Title: Re: Neutralizing 15% NaOH
Post by: wildfyr on December 18, 2017, 04:09:38 PM
Whatever the cheapest available acid is. Added slowly with mixing, cause it will get very hot if done quickly
Title: Re: Neutralizing 15% NaOH
Post by: Enthalpy on December 20, 2017, 12:58:28 PM
The OP put "empty the tank" before "achieve a PH in the tank".

Rinsing with water doesn't look hopeless to me, if done several times after emptying every time.

Reaching all the parts with water reduce the number of rinsing steps. A watering can maybe? Beware of heat the first time, and of spat every time. DI water is useful only the last time.

Then, what to do with the removed NaOH is an interesting question, if not neutralized.