O2 Removal from Exhaust Gas 1

[ggordonstewart]

Does anyone know how to economically remove O2 from the exhaust of gas engine drivers? I want to remove 6.54% O2 from a 4 MMSCFD exhaust gas stream (the other components are 6.54% CO@, 13.09% H2O and 73.83% N2). The scrubbed gas must contain less than 0.5% O2. The gas will be compressed from atmospheric pressure to its injection pressure of 175 PSIG. You can process the gas at the compressor suction or discharge. I have looked at membranes, but they seem to have trouble achieving the required O2 content. G. Gordon Stewart, P.Eng.
Gas & Oil Process Engineering Consultant

http://www.ggordonstewart.com/

ggstewar@telusplanet.net

 

[jonralph]

I guess you are looking at producing inert gas for gas lift (pressure seems low?) underbalanced drilling or purging? I don't know the answer but I do know there are companies in the AB area using exhaust gas for underbalanced drilling, it killed the market for nitrogen membrane units. You might want ty searching through the underbalanced drilling companies. I seem to remember somebody at the U of A had done some r&d on the subject, especially on the scrubbing of the exhaust gas to prefent the formation of carbonic?? acid. The other line of enquiry you might want to try is the use of inert/exhaust gas for blanketing in holds of supertankers but I think the O2 content might be too high.

Hope this helps

jralph@pslg.com

 

[dcasto]

A catalytic converter of some sort will work. The system will combine the O2 with methane at temperatures around 700 deg F. Your analsys indicates you must be doing something like this already because there is no CO or NOx. The biggest problem you'll encouter is corrsion from the CO2. You'll need to dry this this stuff immeadiately or use a lot of SS.
We use a patented DeOX system from OPD to remove O2 from our natural gas streams for sale into pipelines.

25610 Clay Rd
Katy, TX 77493
(281) 371-2499

Good luck

 

[ggordonstewart]

dcasto:
Please send me your email address so I can get more info from you. Mine is ggstewar@telusplanet.net. G. Gordon Stewart, P.Eng.
Gas & Oil Process Engineering Consultant

http://www.ggordonstewart.com/

ggstewar@telusplanet.net

 

Gordon

This can be done with technology that is already in the large demonstration stage for power generation plants with CO2 sequestration. Basics are as follows which could be adapted to what you need:

1. A HP combustion tube is used where methane is fired with the gas mixture at pressure. Combustion tube has water injectors (use quality BFW that is generated in the process) to reduce combustion temperature. Has internal ceramic lining. The current demonstration units are firing 100 % oxygen with methane. Latest projects down in the USA have received major funding from DOE.
2. Can run at stoichiometric or sub stoichiometric conditions.
3. Exhaust gas normally goes through 1st stage (HP) steam turbine in conventional power generation configuration. This could be used for powering your compressor which you will need.
4. Reheat combustion tube with secondary firing is used on power generation plants - you will not need this.
5. Combustion temperature is fixed by the mechanical limitations of steam turbine blades at the coincident inlet pressure to the steam turbine. The water injection flow rate is used to control the exit temperature.
6. You will have to reject energy at the backend. Condensed water is used for injection on the combustor tube and also exits the process as a byproduct - you can sell this as distilled water.
7. You will have to check the flammability of the gas mixture with the stoichiometric amount of natural gas addition - use the Le Chatelier calculation method for the flammability envelope.
8. A detailed analysis of the pseudo power cycle will fix the pressure that you need to compress to in order to achieve the required power output to drive the compressor and to also meet the 175 psig Inside Battery Limit pressure.

If you want to pursue this, contact me at courtneydehn@canada.com.

I will be back in Canada mid December.

Courtney Dehn
Process Manager
TG Engineering Inc,
Calgary