Calorific value of gas / BtU value of gas to be burnt 2

[98769876]

What is the best way to calculate heating value of gas to be burnt? do you check composition in GC and then calculate from components - or is there a "calorific meter?"

 

[zdas04]

There is such a meter, but they tend to be pretty delicate and don't deal well with velocity effects or water.

Your gas analysis is on a dry basis (i.e., none of the labs have the ability to see water vapor in their analysis), so what your gas contract probably says is to multiply each mole percent times that component's net heating value and add up the results.

Some contracts allow the purchaser to adjust heating value for water content. You have to watch this really closely because several gathering companies are taking that to mean "theoretical saturation at STP". If your pressure is above 50 psig then that "little" difference can be really expensive. I evaluated one proposal that the water content at flowing pressure was 0.05%, and at STP it was 3.2%, financial difference was about $50k/month. When the gatherers start that crap, I always say "fine, we'll either do the calculation at flowing conditions or we'll talk to the judge about it". At that point they either back off or lose in court.

C6+ can be tricky, some labs use a typified analysis for C6+, others use C6 and ignore the heavier stuff. Most of the time it doesn't matter but occasionally there is enough C6+ that it can matter.

David

 

[ScotchWhisky]

Use ISO6976 or GPA2172 to calculate the CV/Heating value from the gas composition, those are the methods I typically see in use

 

[jmw]

There is a way to determine wobbe index via relative density measurement.
Try here for the 3098 and look at the manual.

JMW

http://www.ViscoAnalyser.com