SOUR WATER STRIPPING: ONE OR TWO STAGES (COLUMNS)

[roker]

Hello all,

What are the parameters dictating installing a SWS with one or two columns in series? Are the required feed conditions different (temp, press., ph) for maximum stripping H2S and NH3 so it can not be achieved in the same column?

Regards,
roker

 

[mbeychok]

Roker:

The primary motivation for a two-column sour water stripper is to remove and recover the hydrogen sulfide and ammonia as separate streams.

Sending the removed hydrogen sulfide (without any ammonia) to the subsequent sulfur recovery unit has many desirable benefits.

The removed ammonia (without any hydrogen sulfide) can be converted into a fertilizer such as ammonium sulfate.

Read this article about Chevron Oil's two-column sour water stripping called the "WWT (Waste Water Treating) process":

http://www.chevron.com/products/prodserv/refiningtechnology/waste_wtr_treat_6a.shtm

Milton Beychok
(Visit me at www.air-dispersion.com)
.

 

[25362]

It appears to be easier to control the pH for efficient SWS, while at the same time separating H₂S from NH₃, in a two-step process.