mitigate H2s content 1

[Sina]

Hello there

I work in a gas refinary. our feed gas had 1200 PPM H2s(gas flow rate=50 MMSCMD & P=80 bar).we use amine solutions to sweet gas. a new feed gas are added to refinary that has 6000 PPM H2s (gas flow rate=20 MMSCMD & P=80 bar). we want to mitigate H2s content to about 3000 PPM by an economical method and then mix these to feed gases before entering the amine plant.
about my research we can use mixing fluid technology presented by propure company which tested in statoil. I have no any data about design this device.and I am not sure that this device is suitable for us or not. (I uploaded the mixing fluid patent)

Thank you for your time.
please advice me.

 

[georgeverghese]

A couple of sharp turns in the mix gas stream should help to get good mixing without losing much on dp - install say 3 vertically cut baffle plates at 0.5-1.0m intervals, with say a 20-30% cut dia on each - that should do it.

 

[Sina]

Thank you for your time and helpful answer.
would you please give me some file about your idea, if you have?

 

[sshep]

Your patent reads to be a device to disperse a liquid into a gas stream, so it is not applicable for you. The mixing of two gas streams is not a challenge, and in any case will be mixed across the first stage of the contactor even if there is minimal piping upstream.

6000ppm will be a large load for an iron sponge bed. The most economical solution is probably to expand your amine system to handle the load from your new gas supply.

best wishes,
sshep

 

[georgeverghese]

Here is a simple sketch

 

[georgeverghese]

Baffle arrangement is similar to that for crossflow baffles in a regular shell and tube heat exchanger.

 

[Sina]

Dear georgeverghese,
Thank you for your time. amine should be injected befor or after of the tools?
Do you have any experience about that tools in your plant or elsewhere?

 

[georgeverghese]

Am assuming these 2 streams would be mixed well before the amine absorber, so these divertor mixing baffles should be some distance upstream of the absorber.

Dont see why this wouldnt work - it also avoids concerns with blockage that you would get with a conventional static mixer when mixing solids bearing streams. You could mix these streams with the mixing venturi you've proposed, but I dont see why you need to make all this extra effort for what is a simple mixing operation in gas service.

We had a similar operation in the concept design for an offshore gas field in the South China Sea in 2008-9 for diluting a sour gas stream with a sweet gas stream to keep out of NACE MR01-75 limits, and I had recommended this approach - dont remember now what the project design team finally adopted.