Tube to Measure moisture in Recycle gas

[sansub]

Hi all
This is regarding CCRU
We have Draeger and MSA tubes to measure HCl and H2S content in our recycle gas. But we are unable to find a suitable tube to measure the moisture content in the recylce gas. Required range would be 0 - 200 ppm. Would anyone suggest a company that has tubes of desired range?

 

[BillHaddad]

I do not know of any appropriate tube, however, UOP has recommended using quartz-crystal (QCM) moisture analysis technology for continuous on-line monitoring in their liscensed processes for many years.
In fact, I believe that technology was originally developed specifically for measuring moisture in hydrogen recycle gas. The only limitation that comes to mind is that you need to isolate the analyzer during regeneration due to the spike in HCl that occurs.

 

[Samiran]

You may use a hand held dewpoint meter from Panametrics -cheap and rugged. Can be calibrated in lab.

S

 

[BillHaddad]

I would be very wary about using any aluminum oxide sensor in a H2 recycle stream. HCl attack, cal drift, temp drift, and the effects of H2 on an oxide will all work against the accuracy of that technology in this application.

The on-line (not portable) quartz crystal technology comes with a built-in moisture verification function based upon a permeation tube moisture source (you see them in calibration systems) so there is no need to uninstall the analyzer to check its function.

Also, I do not believe that UOP has ever listed aluminum oxide as a recommended technology for hydrogen recycle service.