NaHS verses Elemental Sulfur production for H2S scrubbing 2

[metgal47]

Why do some oil refineries produce NaHS using caustic soda (NAOH) and others produce elemental sulfur when removing H2S from their stacks?

I am also trying to understand if there is a relationship between NaOH and NaHS pricing wise. I hear that NaHS is usually sold to a 3rd party in return for decent pricing of NaOH but I cannot get a confirmation of this.

Can anyone help me with these questions?
Thanks.

 

[mbeychok]

metgal47:

It is not a matter of some refineries producing spent caustic (containing NaHS and/or Na₂S) and other refineries producing elemental sulfur from the H₂S removed from their various gas streams. Most refineries do both.

Almost all refineries remove H₂S from their various byproduct gases before they subsequently burn those gases as fuel within the refinery. They then convert the H₂S to elemental sulfur. In fact, most of the 64,000,000 metric tons of sulfur produced worldwide in 2005 was produced by converting H₂S to sulfur in refineries, raw natural gas processing plants and other hydrocarbon processing plants.

Also, many (if not most) refineries use an aqueous solution of NaOH (caustic) to scrub certain liquid process streams (like kerosene, jet fuel, and LPG) to remove H₂S. The resultant spent caustic has a very, very limited market. The ultimate disposal of spent caustic is a quite a problem for many refineries.

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

 

[metgal47]

Does that mean they are happy to almost "give it away" the spent caustic (now known as NaHS)? I know that the NaHS is used in many industries (pulp & paper, mining, tanning etc) and demand in increasing.

You are right thought, my production numbers for NaHS in NA are 120,000 tonnes (.2% world S production). Does you have numbers on sulphur produced in North America by chance or know where to get them?

 

[dcasto]

I believe the NaSH market is the bleaching of paper and it is very small and controlled by the paper industry.

 

[metgal47]

Is there a way of calculating how much NaHS is produced at a refinery based on throughput or some other factor?

 

[metgal47]

Are there any instances where a refinery would decide to make more NaHS one day verses the other or is just based on how much caustic they need to scrub certain liquid streams (based on chemistry/composition of the oil to be refined)?

 

[mbeychok]

metgal47:

Regarding the last two questions of yours above, you also initiated two other separate threads asking the same questions. That is not the way to use this forum. Ask you questions only once and respond to the answers in the same thread. As matters now stand, you have initiated three threads all devoted to the same subject. You must not do that!

I have answered each of two other threads you initiated. Don't initiate any more threads on this same subject about NaHS!

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

 

[reena1957]

Dear metgal,
Try Merrichem Copany. They will be interested to answer you. Google for Merrichem.
Best wishes

 

[metgal47]

Milton,

The reason I initiated a second thread was because at other forums I have used, once people have answered the initial question, they do not continue to follow the thread. No one was responding to my other two questions so I initiated a new thread. I was not trying to be a pain. I just wanted polite answers to my questions which you did with my initial request. I do not think the way you just responded was appropriate. I don't have a chemical engineering background and I was only seeking knowledge which I thought this web-site could help me obtain.

 

[mbeychok]

metgal47:

Whenever a new posting is made to any existing thread, it is indicated as such by a green star being posted next to the listing of that thread. Therefore, people do follow threads after the initial answers. If you would just look, you will see that some of the threads have had many, many responses.

This forum frowns upon repeating questions in more than one thread. Instructing you on that point was quite appropriate. I think you will notice that I provided answers in all three of the threads you started on NaHS. If my instructing you on the proper way to use this forum was offensive to you, then so be it.

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

 

[DougW]

I am a small user of NaHS so I understand this business a little bit. NaHS in the US is made as a by-product from scrubbing H2S. TDC-home.com controls most of the NaHS produced. Akzo makes NaHS as a by-product of CS2. There are few other players. It is used by paper mills, mining and tanning. Historically there has been an excess of NaHS capacity. Uneconomical NaHS plants have been shutting down and the market was declining until mining picked up. Now the market is balanced. Most refineries make Trash Nash because it has organics, ammonia, carbonates and solids. We buyers don't want this stuff. Unless you have a high purity H2S stream void of ammonia, CO2, organics, etc. I wouldn't try to make NaHS and sell it. You will be disappointed.

 

[metgal47]

Doug,

Thanks for the information. If a company could make high purity NaHS without the ammonia, CO2 organics, do you think they could give TDC a run for their money? (i.e put them out of business?) Or do you think, there will always be a place for TDC to get cheap NaHS and sell if for a big profit? Do you know if TDC makes a large profit on selling NaHS or are their margins pretty small? I've tried talking with people at TDC but to no avail.

Thanks.