Converting mg/Nm3 CH4 to PPBV

[bsteinb2]

I am looking at an engine specification that has a maximum limit on organic silicon in the gas to a combustion engine. I know the concentration of the gas in part per billion and need to know whether further treatment is required. The specification allows for "5 mg/Nm3 CH4." How do I convert this to PPB.

 

[ccfowler]

This looks very much like a request for homework help. Can you clarify the reasoning behind your posting?

Valuable advice from a professor many years ago: First, design for graceful failure. Everything we build will eventually fail, so we must strive to avoid injuries or secondary damage when that failure occurs. Only then can practicality and economics be properly considered.

 

[chicopee]

In industrial hygiene, the conversion formula is as follows:
ppm(V)=(24.45/Molecular Weight)*mg/cu.m.. The value 24.45 is @ 25 deg.C.. Divide the above answer by 1000 to get ppb(V).