BTU Analyzer

[dembous]

Hi Guys!!!

I'd like to measure the BTU value of a gas (81% Methane).
The purpose for that is to control the Air-Fuel ratio of our boilers.

I raed several papers that are about the WOBBE INDEX METER.

Does any one has experience with this kind of analyzer or any other kind that can help me?

Thanks in advance.

 

[danw2]

Cosa has a full-blown BTU analyzer. One ran in an adjoining unit at tke mill. Wobbe index.

http://www.cosa-instrument.com/Products/PDF_Files/Cosa9600Brch.pdf

There's an intriguing alternative from Cosa for commerical methane, an on-line chromatograph 'tuned' for commercially delivered methane. I'm not sure it would work at 81% methane or not, but I'm sure Cosa could tell you.

http://www.cosa-instrument.com/Products/PDF_Files/HGC303.pdf

 

[jmw]

Visit

http://www.Mobrey.com

and look for the SG analyser. This is used for Wobbe Index determination.

http://www.mobrey.com/products/density/3098.php

JMW

http://www.ViscoAnalyser.com

 

[dembous]

Thanks so much guys!!!
Enjoy your weekend.

 

[dembous]

Sorry guys!!! Can anyone tell me the ISA (or an other association) specification dealing with BTU analyzers?

 

[dcasto]

There are two types of BTU anaylzers. The first actually burns the gas with a fixed air rate and measures the flame temp to get BTU/cf. The other is a plain ol gas chromatograph (GC) that gets mole% then performs the GPA calculations to get BTU/cf.

The WOBBE number is BTU/cf / Specfic gravity^.5. If you look at the equation it is the equation of flowrate through a fixed orifice at constant differential pressure, temperature, and inlet pressure times the BTU/cf.

A wobbe index machine is either flame temp btu analyzer with a gas gravity machine or the gas chromatograph can calculate the gravity ad get the wobbe. Some machines use two calibration samples and can get extract wobbe from the flame temperature alone.

I perfer going with a GC to get all the information. Daniels makes a good one in my book.

 

[JLSeagull]

Many flare BTU applications require calculations per 40 CFR 60.18. Look into this for some guidance.

The Cosa analyzer provides heating value information such as BTU or Wobbe Index. This requires a bit of a sample system, calibration gasses, etc. For a bit more money you get the Daniel, ABB Total Flow or other simple GC that provides more information. ABB also sells a transmitter-like GC for natural gas that performs BTU calculations. The BTU analyzer is instantaneous where the GC is cyclic with 3-8 minutes per analysis. ABB, Siemens and Rosemount Analytical all sell more complex GC's if required for the specific components of your stream.

Search for an ISA paper presented at the Analytical Division in April 2006. This paper by Siemens and Lyondell pertains to the Siemens MicroSAM GC.

 

[GregLamberson]

As JLSeagull mentions, they are a little more, but have used ver ysuccessfully the Daniel Model 570 for gas composition & calculating the gas gross heating value.



Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[dcasto]

If the analyzer is a GC based, then there is the GPA standard 2261-XX, this standard is perfomanced based, not presciptive. GPA Standard 2172-XX (also API MPMS 14.5)is persciptive.