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[rosa]

Hi,
I'm working in a gas refinary as an utility engineer.In order to avoid marine fouling in sea water pipeline, electrochlorination package produces NaOCl and it is injected to sea water. sea water electrochlorination has side products as Mg++ and Ca++ componds that deposit.
the main reactions are as below:

1) free chlorine is generated at the anode:
2Cl- --------->Cl2 + 2e–
2) hydrogen is evolved at the cathode with
the corresponding formation of OH- ions:
2H2O + 2e– ---------> 2OH– + H2

3) This overall chemical reaction can be expressed as follows:
2NaOH + Cl2 --------> NaClO + NaCl + H2O

1-Regarding to chemistry, what's the reasone of side reactions,Ph variation, electrical current,...?
2-is it possible to control the deposition rate?

I'm eagerly waiting for your answers.
razi

[Profe]

Hi Rosa

If you remember Chemical, the HClO is a weak acid and therefore their salts with NaOH (NaClO) are strong basic and the Rx:

2NaOH + Cl2 ----> NaClO + H2 it's reversible.

NaOH is strong base and with Mg ++ and Ca ++ forms precipitates that cause incrustations.

Depending on the use and application of the sea water, you will have to see a different option to avoid marine fouling.

Please send me more specific information for look in our refineries.