Forum Topic

Great news!- the EPA recently "approved" Coriolis mass meters on Gas streams, including Fuel Gas. The question and answer are shown below.

Subpart C General Stationary Fuel Combustion

Question: Many facilities use mass or volumetric flow meters to measure gaseous streams. Please confirm whether it is acceptable to use a mass flow meter to determine the volumetric flow rate of gaseous streams under Subpart C or the GHG Reporting Rule.

Response: Fuel flow meters that measure mass flow rates may be used, provided that the fuel density is used to convert the readings to volumetric flow rates.

Date 06/21/2010

Link is: http://www.epa.gov/climatechange/emissions/downloads09/GHG-MRR-FinalRule.pdf#page=25

Note that Fuel Density is typically either from an on-line densitometer, GC, or by use of a standard value if the gas composition is known. Remember that to derive standard volume flow (e.g. scfh), one takes mass flow (lb/min) and divided by standard density (lb/ft3). If on-line density is used, T and P must also be measured so that standard density can be calculated. The Micro Motion model 3098 and model 7812 each measure on-line gas density and could be used in this application

How does teh mirco-motion flowmeter deal with the calibration requirements found for verification of the instrument accuracy?

John- thanks for asking. We've written a document that describes a hierchy of verification and calibration- see the GHG portion of our website at www.micromotion.com for the official version.

The short story is if a) the process is critical (as many at Dupont are) that it often makese sense to upgrade the equipment to a version with on-board, in-situ meter verification. If the process doesn't warrant that, we recommend a once per 3 year wet-calibration, either via master meter or "catch and weigh".

Please let us know if there are additional questions, and how we may best be of help!

Regards,

Tom