8 replies to this topic

[sukariawan]

Dear all...

 

Currently iam facing some problem to select the sour water treament.

the main issue is the h2S content.

The produce water contain H2S approximately 117 mg/L..

the water treatment shall be able to reduce the H2S content to 0.5 mg/L.

The capacity of water treatment is about 1200 BPD

To be honnest this my first time to design sour water treatment, so I start from many reference and very confusing.

pls advise...

 

[RockDock]

This is a routine operation that exists at most refineries and large number of gas plants.

 

When I design these systems I pretty much always start from a template and adjust the process according to my needs. I normally use one of my previous designs as a starting point. Since you don't have any previous designs, you should start from one of the ProMax templates.

 

The major decision you will need to make is the stripping medium. Do you use a thermosyphon, kettle reboiler, fuel gas or steam? Evaluate all those options with your ProMax model.

 

In the column, you can set your H2S specification for your treated water. ProMax will then determine the duty required to meet that specification.

 

A google search led me to these videos:

 

 

(this one is a step by step instruction for your design)

 

I hope this helps you.

[eonecaem]

@RockDock

 

 Thanks for your information, is there any common applicable method than water stripper for this purpose?

 cost for stripper is very high. 

[RockDock]

If all you have is H2S, you may be able to use a heat exchanger and separator, leaving out the column. It also depends on your pressure. This of course would not be possible if you have a base in the feed like NH3 or if you have phenol. Just model all your options and compare the costs.

[gegio1960]

I don't think 0.5 mg/l H2S can be obtained by heating and flashing only.

[suyogchemical2002]

I completely agree with gegio1960. Just by heating & flashing it is extremly difficult to obtain such a low level value. One have to have a acid/caustic injection to sour water stream. Ammonia present in the water also makes H2S stripping difficult.

[P.K.Rao]

What is the minimum H2S that can be obtained in your present method? What is the pH of water after maximun possible H2S is removed?

[Erwin APRIANDI]

There are several ways to remove H2S from water

1. Stripping (Removal of the H2S gas in the water by introducing gas and may be some heat, in order to reduce the solubility of the H2S gas in higher temperature

2. Absorption or Adsorption, there are several ways, whether it is using a resin or a bed that can trap the H2S component but not the water.

3. Chemical treatment, to add a H2S Scavenger chemical which will react with the H2S and reduce the H2S concentration, but to remember that the S (Sulphur) is still in the water but in a different form, not ass H2S.

 

To apply any of the application you have to consider the flow of the sour water to be treat, concentration of H2S in the sour water and also what is the final spec of the treated sour water.

 

I can only help with this general info hope this can help 

[P.K.Rao]

Bring the sour water pH to around 6.5 after removing maximum H2S by the present method and chlorinate. Keep 0.5 ppm residual chlorine. All H2S will be removed in a fraction of second. You can chlorinate even if H2S is high but chlorine consumption would be high and there would be turbidity in the water due to free sulfur.