Amine Still OH Gas Incineration 2

[mcmidkiff]

Where do I look to find the minimum Btu value for sustained combustion. My amine still overhead is about 450 mscfd CO2 and 1 mscfd of H2S. I am incinerating the H2S in a flare and currently using about 100 mscfd of 1000 btu/scf gas to maintain combustion. Is ~200 btu/scf a reasonable target value?

 

[mbeychok]

mcmidkiff:

Where is this amine still located? If you are in the USA, you should really check with your local or state environmental agency ... because incinerating 1 mscfd of H2S means that your flare is emitting 1 mscfd of SO2 and I don't think they will like that.

What is the source of the feed gas to your amine absorber? That ratio of CO2 to H2S makes me think that your amine unit is not in a crude oil refinery. Is your amine unit in a natural gas treating plant? Or what?

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

 

[mcmidkiff]

1500 scf is about 2.7 moles X 64 lb of SO2/lb.mole = 170 lb SO2 per day, ~31 tpy of SO2. We are permitted at 93.5 tpy of SO2.

Yes, we are treating produced natural gas in the lower 48.

Thanks for getting me to re-check my emissions. Do you know what minimum Btu value I should maintain in order to prevent flame failure?

 

[mbeychok]

mcmidkiff:

I agree quite well with your calculation of 31 ton/year if I use the 1000 scfd of H2S given in your original post ... rather than the 1500 scfd in your second post.

40 CFR 60.18 has the EPA's minimum heating value for flared gas as 200 Btu/scf if the flare is not air or steam assisted. Here is a direct quote from 40 CFR 60.18:

"Flares shall be used only with the net heating value of the gas being combusted being 11.2 MJ/scm (300 Btu/scf) or greater if the flare is steam-assisted or air-assisted; or with the net heating value of the gas being combusted being 7.45 MJ/scm (200 Btu/scf) or greater if the flare is nonassisted." Note that the EPA's scm means standard cubic meter.

You can read 40 CFR 60.18 at this web page:

http://ecfr.gpoaccess.gov/cgi/t/tex...8&view=text&node=40:6.0.1.1.1.1.68.18&idno=40

I might point out that Guide 60 used in the province of Alberta, Canada for sour gas flares also stipulates 7.45 MJ/m3 at 15 degrees C, 1 atmosphere, and on a dry basis. You can easily find Guide 60 by using the Google search engine.

Hope this helps,

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

 

[egber]

Incinerator operation is an area which has not recieved a lot of attention and where you can achieve significant energy savings. The key point is not sustaind combustion but the residual level of H2S that is alowable in your stack gas. There are programs to optimise the h2S combustion, but most are not commercially available.
You could run an enquiry to Sulphur Experts to see what they could do. Info is available at

http://www.sulphurExperts.com.

 

[Zoobie]

I disagree with egber. mcmidkiff stated that the incineration in in a flare. Most jurisdictions (at least in North America) have regulations about flare gas heat value. Its the law.