CO2 Service

[NGbri]

Does anyone have any experience in dealing with high pressure CO2 lines? Basically I am looking for suggestions on valve manufacturers and types, and materials used for this particular service. While the CO2 will be dry for the majority of the line (<130ppm moisture), it will contain about 2.5% moisture prior to the compressors and dryers. Suggestions I have so far includ Cooper Cameron Valves, and using polyethylene lined carbon steel on any wet portions (dur to the formation of carbonic acid) and plain carbon steel on dry runs.

Also, does anyone have any sort of experience with leak detection systems for CO2?

Thanks for your help.
Brian

 

[imok2]

Maybe this company can help you:

http://www.reliablefire.com/waterdetectionfolder/waterdetsystems.html

 

[Montemayor]

NGbri:

I have had extensive experience with CO₂ – in engineering design, operation, construction, and consulting in the production of pure, food-grade CO₂ as well as in acid gas removal (sweetening) plants. I started my career with Liquid Carbonic Corp (now Praxair) where the book was written on CO₂ production and distribution and I served in the International Division designing, erecting, and operating CO₂ plants overseas. I have upgraded and modernized many units in the past as well.

If you tell me the specific service in which you are handling CO₂ I will be glad to tell you what materials to employ with success – and it won’t be Cooper Cameron Valves, polyethylene lined carbon steel, or stainless steel. Some of the CO₂ plants I designed, built, and operated overseas lasted for more than 30 years – without corrosion or maintenance problems. You mention dry CO₂, wet CO₂, compressors, and dryers but you don’t describe nor detail your process or your scope of work. For example, you don't specify whether you're dealing with the gaseous, liquid, super critical, or solid phases. I prefer not to dwell in generalities when giving out engineering advice and try to deal only in specifics. Generalities have a way of getting misinterpreted or being employed in such a way that they can do damage or harm.

Handling CO₂ can be very simple and inexpensive – within certain boundaries. But if you are going to start raising regeneration temperatures on adsorber heaters and vessels you may run into trouble. However, if you are only going to dry CO₂ to -90 oF dew point you could get by with A-516 Gr 70. It all depends on the details and what you are doing. Give us specifics and scope of work and I will make an effort to give you what you require. I’ll await your response.

 

[Cockroach]

All valve manufacturers are the same, everyone in the valve industry sleeps under the other guy's bed. There are no secrets on material usage or industrial advantage between one manufacturer to another.

Cooper-Cameron may be what you want, but you pay for the name and not necessarily enjoy the customer service or technical support when the valve develops a problem. All valves develop problems, despite the manufacturer.

I have the detail on Nuovo Pignone, carbon steel valve with electroless nickel coating on the wetted, pressure containing envelope. The ENC is baked on to HRc 55-60, it will not flake or degrade in the carbon dioxide service due to the industrial process of pickling the steel, degreasing prior to baking in the furnace, then controlling the cooling.

A lot of sales representative are going to sell you an assembly with trim you don't need. It will be important for you to research the literature, sales guys will say just about anything to bag the sale! Talk to ALL manufacturers and get input from their engineers. In this manner, you can become a little more educated about the various designs and interprete the various lies of the product line.

And by the way, it is not the steel that will give you an issue. Concentrate on the elastomers in that system. You are worried about explosive decompression and the potential for working medium (i.e. carbon dioxide) to be absorbed by the parent rubber of the o-ring. You need to be looking at durometer 90/95 along the medium valve interface.

Hope this helps.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[NGbri]

Thanks for your help guys. I just recently graduated, so a lot of this is still kind of new to me and I really appreciate all your help.

Montemayor, we are looking at capturing CO2 from flue gas (atmospheric pressure) and compressing this to a supercritical point (say 10MPa and 60C), before transporting it via pipeline for use in enhanced oil recovery projects. Depending on the process chosen, we are going to have a fair number of contaminants to remove if necessary (such as NOx, N2, CH4, SO2, Hg and PM). We also will have to dry the gas to at least 130ppm. Not sure what else you require, so let me know, and I'll see what I can do. We are still in preliminary engineering, so details are somewhat hard to come by.

Brian