Scrubber Chemical treatment 1

[Josefog]

Hello. I need some help on the chemical adittion to the water of a wet scrubber. The pollutants are H2S, NH3, CH3NH2, (CH3)3N, C2H7N, mercaptanes and tetrahidrotiofenol. I need to determine the amount of reactants that I should add in order to control the odor. I have no experience in the subject and I don't even know which reactants to add. I've done some research but I've found many different options that are confusing. Any help?

 

[Abeyku]

I am very interested in the subject above, any help will be greatly appreciated. Thanks Josefog

 

[guerky]

Josefog,

Please, detail the flows and compositions of the streams, the equipment design, operating conditions and expected outcomes from the treatment, so i could give you a more objective answer.

I will oversimplify the problem to give you a general idea: your system has at least two main group of components with very distinct behavior: the sulfide/mercaptan/tiofenol and the amonia/amines.
The amomnia and amines are pretty water soluble (except for (CH3)3N and C2H7N) and a slightly acidic media (HCl or H2SO4, pH <5) would give you a high removal efficiency. For ammonia removal alone, only water could be used in the right operating conditions.

The sulfur containing ones are a little more tricky: they aren't very water soluble and their allowed emission limits are lower. They will need a Base/Oxydizer scrubbing system (most commomly used: NaOH/NaOCl).

As you can see, you will need at least two distinct stages for a good treatment, but three would be ideal: acid scrubbing for ammonia/amines removal, basic scrubbing for H2S and mercaptans removal and a Oxydizer (in a basic media) to finish the sulfides treatment. The basic and the oxydizer/base scrubbing could be joined in a single step/equipment, but i would not advise it if you have high amounts of mercaptans and tiofenols (you can form a lot of dissulfides, that are harder to remove).

 

[bimr]

You might search on this site:

http://www.eng-tips.com/viewthread.cfm?qid=121447

http://www.eng-tips.com/viewthread.cfm?qid=253862