2 replies to this topic

[manchester]

Hi,

I'm designing sea water injection facilities in which including de-oygenation of sea water prior to inject into wells.

Recently I'm choosing De-Oxygenation Tower by using fuel gas to strip the oxygen plus addition of O2 Scavenger at Tower downstream to achieve 10 ppb O2 content.

However, I've heard that some of plant only using O2 scavenger without using De-O2 Tower.
My question: When do we can use O2 Scavenger only (without De-O2 Tower)? What is the limitation?

Thanks for ur explanation

[kkala]

I'm designing sea water injection facilities in which including de-oygenation of sea water prior to inject into wells. Recently I'm choosing De-Oxygenation Tower by using fuel gas to strip the oxygen plus addition of O2 Scavenger at Tower downstream to achieve 10 ppb O2 content.
However, I've heard that some of plant only using O2 scavenger without using De-O2 Tower.
My question: When can we use O2 Scavenger only (without De-O2 Tower)? What is the limitation?

In boiler feed water preparation, demineralized water has 7 ppm O2 content, which is reduced to 0.007 ppm (ppb) after passing from the deaerator. Then oxygen scavenger (Hydrazine, carbohydrazine) is used for further O2 reduction.
I suppose that the main reason of not using oxygen scavengers only is their high cost. Apart from it, mentioned oxygen scavengers dissociate to some extend, depending on temperature and time, so they should be added in excess. But part not having reacted can be harmfull to human health, especially hydrazine being toxic. So there are reasons to "eliminate" only the least possible amount of O2 using a scavenger.
Assumingly same reasons force to use O2 scavengers on sea water only for that part of remaining O2 that cannot be removed by other means.
If you have heard of O2 scavenger only, see if the unit has a very small capacity. Or if O2 in sea water has been seriously reduced by some organism (quite rear in my opinion).

[styx]

Hi,

I'm designing sea water injection facilities in which including de-oygenation of sea water prior to inject into wells.

Recently I'm choosing De-Oxygenation Tower by using fuel gas to strip the oxygen plus addition of O2 Scavenger at Tower downstream to achieve 10 ppb O2 content.

However, I've heard that some of plant only using O2 scavenger without using De-O2 Tower.
My question: When do we can use O2 Scavenger only (without De-O2 Tower)? What is the limitation?

Thanks for ur explanation

Hi,

You can search Nalco as the chemical supplier of oxygen scavenger chemical.