3 replies to this topic

[process85]

Hi everybody!
I am working on a coal gasification project.Syngas generated from Gasifier is sent to gas sweetening processes and other downstream processes such as Sour shift and Methanation to attain the desired products.During all these processes, Process condensate is generated from different units which are routed to Sour Water stripper for stripping of H2S, NH3 and CO2.
I have the composition of various sour water streams coming to Sour water stripper.
My problem is the stripped gases from Sour water stripper are sent to SRU and I don`t know the quatity, composition and temperature of Sour gas to design the downstream SRU.
If I consider all the dissolved gases in the Sour water are stripped and sent to SRU,but I still don`t know the water content in the sour gas and the temperature.Also I dont know the stripped water composition, temperature and the flow rate.

Can anyone advise me on how to proceed and simulate the above model in Pro-II.

[Zauberberg]

For design purposes, I'd consider the following:

1. All contaminants from waste water end up in the SWS overhead stream (feeding the SRU);
2. Take this acid/waste gas composition, and saturate it with water at any temperature and pressure at which you plan to feed the SRU;
3. Temperature is selected based on the expected overhead condenser outlet temperature (e.g. 40 degC for cooling water, 50 degC if air cooling is used - but that depends on ambient conditions at your site).

Use the Sour Peng-Robinson package for modeling the system.

If you don't know the sour water material balance (i.e. how much sour water flows to the SWS Unit), then you don't have a project. How can you design anything without knowing for what quantities the unit needs to be designed?

[process85]

Thanks for your reply.

But instead of an overhead condenser, I have a Pump around circuit.Overhead gases from stripper are directly routed to SRU with temperature controlled by Pump around. With the above configuration, I have seen overhead temperatures as high as 90°C for reference projects.

Kindly advise in the above said case.

[Zauberberg]

With a pumparound loop, keep the overhead temperature above 85 degC to prevent salt deposition problems.