CO2 Compressor System - "Expert" Second Guessing Design 5

[JavaMoose]

Just need some help from some experts on the board. We have a CO2 compressor system that was designed for us by an outside engineering firm (choice from on high) that is now being questioned by an outside Engineer that was brought on as a consultant (again, decision from on high). His concern is that the compressor itself will be destroyed by the water (and carbonic acid created) from the wet CO2. He is also concerned since this Sullair compressor is designed for Air and not CO2.

Upon looking at the system and components, he advised our management that it was incorrectly designed and will, at most, last a year...likely less. I don't have a personal stake in this, but a team member does. I'm hoping y'all can give me some feeling or information to either back up our consultant or confirm the system is solid. I'll try to be liberal with the information, but if I am missing a parameter that could help, please let me know.

CO2 is provided to us from an industrial partner, they can provide 100X our required capacity. The industrial CO2 is very wet, I was told 100%. The CO2 leaves the industrial connection at .5 bar (regulated by a valve system, will not drop below .5 bar) and 150*F. It then travels through 2" steel pipe for approx. 75ft uncovered, then another 75ft under 3ft of earth (underground pipe is wrapped to prevent corrosion). It then is stubbed up above ground with a double valve, after the valve it runs 140ft above ground through 2" ABS pipe. From there, it enters an ABS water trap, then into the system. System is as below.

System design:
Saturated CO2 will first be cooled in an aluminum after-cooler which has a design rating of 200 CFM @ 100 PSI.
Supersaturated CO2 will pass through a filter to remove gross condensate, then enter intake of compressor.
Saturated CO2 will be compressed to 100 PSI in oil flooded rotary screw compressor which uses 100% silicone lubricant.
Compressed CO2 passes through a coalescing particulate filter then enters a refrigerated air dryer. The dryer reduces the temperature of the compressed CO2 and removes water to a pressure dew point of 35-37 º F.
Compressed, dry CO2 passes through a fine coalescer filter and a carbon filter to remove any remaining traces of lubricant.
Clean, dry CO2 is stored in the 80 gallon receiver @ 100 PSI, and regulated to 50 PSI as it is discharged for use.

Components:
1ea. 200 CFM @100 PSI Air cooled aftercooler, 115 V. 1 HP motor
1ea SCF 235N water trap/primary filter w/ auto drain.
1ea. Air compressor, ES-6-10H-24KT, 10 HP, 208V, 24KT Silicone fluid, 36 CFM @ 125 PSI
1ea. Refrigerated air dryer, SRS 50, 115V, rated at 50 CFM @ 100 PSI
1ea. SCF 65N Dryer after filter
1ea. SCH 65N Final filter
1ea. SCC Carbon polishing filter
1ea. 80 gallon Vertical ASME Air receiver (tank)

 

[jbattershell]

wish i would have bumped into this thread earlier. as the thread has gone silent since september, I am believing that all has been solved.

in any case, listening to those that have experience with CO2 and water compression systems would be wise. the carbonic acid will develop and it will try to eat and disolve all of your carbon steel internals in the compressor. while an air compressor will compressor wet CO2 gas, it will do it effectively for very long service.

if the compressor is for a test purpose and for only limited time, then take your chances and see how long the system lasts. if however, you are not wanting to take chances and need better risk mitigation, then follow the advice of the experts and change out some of the components so that they will stand up to the carbonic acid formed in the gas stream.